fix: Pin nesbot/carbon to ^2.72 for PHP 8.2 compatibility

The num-num/ubl-invoice package allows Carbon 2.x or 3.x, but Carbon 3.x
pulls in Symfony 8.x components that require PHP 8.4+. Pinning Carbon to
2.x ensures compatibility with OSPOS's PHP 8.2 requirement.

app/Database/Migrations/20260304000000_AddUBLConfig.php

@@ -0,0 +1,24 @@
+<?php
+
+namespace App\Database\Migrations;
+
+use CodeIgniter\Database\Migration;
+
+class AddUBLConfig extends Migration
+{
+    public function up(): void
+    {
+        log_message('info', 'Adding UBL configuration.');
+
+        $config_values = [
+            ['key' => 'invoice_format', 'value' => 'pdf_only'],
+        ];
+
+        $this->db->table('app_config')->ignore(true)->insertBatch($config_values);
+    }
+
+    public function down(): void
+    {
+        $this->db->table('app_config')->whereIn('key', ['invoice_format'])->delete();
+    }
+}

app/Helpers/country_helper.php

@@ -0,0 +1,229 @@
+<?php
+
+use Config\OSPOS;
+
+/**
+ * Country code helper for mapping country names to ISO 3166-1 alpha-2 codes
+ */
+if (!function_exists('getCountryCode')) {
+    /**
+     * Convert country name to ISO 3166-1 alpha-2 code
+     * 
+     * @param string $countryName Country name (full name in English)
+     * @return string ISO 3166-1 alpha-2 code, or 'BE' as default for Belgium
+     */
+    function getCountryCode(string $countryName): string
+    {
+        if (empty($countryName)) {
+            return 'BE'; // Default to Belgium
+        }
+
+        $countryMap = [
+            // Major countries
+            'Belgium' => 'BE',
+            'Belgique' => 'BE',
+            'België' => 'BE',
+            'United States' => 'US',
+            'USA' => 'US',
+            'United States of America' => 'US',
+            'United Kingdom' => 'GB',
+            'UK' => 'GB',
+            'Great Britain' => 'GB',
+            'France' => 'FR',
+            'Germany' => 'DE',
+            'Deutschland' => 'DE',
+            'Netherlands' => 'NL',
+            'The Netherlands' => 'NL',
+            'Nederland' => 'NL',
+            'Italy' => 'IT',
+            'Italia' => 'IT',
+            'Spain' => 'ES',
+            'España' => 'ES',
+            'Poland' => 'PL',
+            'Polska' => 'PL',
+            'Portugal' => 'PT',
+            'Sweden' => 'SE',
+            'Sverige' => 'SE',
+            'Norway' => 'NO',
+            'Norge' => 'NO',
+            'Denmark' => 'DK',
+            'Danmark' => 'DK',
+            'Finland' => 'FI',
+            'Suomi' => 'FI',
+            'Switzerland' => 'CH',
+            'Suisse' => 'CH',
+            'Schweiz' => 'CH',
+            'Austria' => 'AT',
+            'Österreich' => 'AT',
+            'Ireland' => 'IE',
+            'Luxembourg' => 'LU',
+            'Greece' => 'GR',
+            'Czech Republic' => 'CZ',
+            'Czechia' => 'CZ',
+            'Hungary' => 'HU',
+            'Romania' => 'RO',
+            'Bulgaria' => 'BG',
+            'Slovakia' => 'SK',
+            'Slovenia' => 'SI',
+            'Estonia' => 'EE',
+            'Latvia' => 'LV',
+            'Lithuania' => 'LT',
+            'Croatia' => 'HR',
+            'Serbia' => 'RS',
+            'Montenegro' => 'ME',
+            'Bosnia and Herzegovina' => 'BA',
+            'North Macedonia' => 'MK',
+            'Albania' => 'AL',
+            'Kosovo' => 'XK',
+            'Turkey' => 'TR',
+            'Türkiye' => 'TR',
+            'Russia' => 'RU',
+            'Russian Federation' => 'RU',
+            'Ukraine' => 'UA',
+            'Belarus' => 'BY',
+            'Moldova' => 'MD',
+            'Georgia' => 'GE',
+            'Armenia' => 'AM',
+            'Azerbaijan' => 'AZ',
+            'Kazakhstan' => 'KZ',
+            'Uzbekistan' => 'UZ',
+            
+            // Other major economies
+            'China' => 'CN',
+            'Japan' => 'JP',
+            'South Korea' => 'KR',
+            'Korea' => 'KR',
+            'India' => 'IN',
+            'Australia' => 'AU',
+            'New Zealand' => 'NZ',
+            'Canada' => 'CA',
+            'Mexico' => 'MX',
+            'Brazil' => 'BR',
+            'Argentina' => 'AR',
+            'Chile' => 'CL',
+            'Colombia' => 'CO',
+            'Peru' => 'PE',
+            'South Africa' => 'ZA',
+            'Egypt' => 'EG',
+            'Nigeria' => 'NG',
+            'Kenya' => 'KE',
+            'Morocco' => 'MA',
+            
+            // If already ISO code, return as-is
+            'BE' => 'BE',
+            'US' => 'US',
+            'GB' => 'GB',
+            'FR' => 'FR',
+            'DE' => 'DE',
+            'NL' => 'NL',
+            'IT' => 'IT',
+            'ES' => 'ES',
+            'PT' => 'PT',
+            'SE' => 'SE',
+            'NO' => 'NO',
+            'DK' => 'DK',
+            'FI' => 'FI',
+            'CH' => 'CH',
+            'AT' => 'AT',
+            'IE' => 'IE',
+            'LU' => 'LU',
+            'GR' => 'GR',
+            'CZ' => 'CZ',
+            'HU' => 'HU',
+            'RO' => 'RO',
+            'BG' => 'BG',
+            'SK' => 'SK',
+            'SI' => 'SI',
+            'EE' => 'EE',
+            'LV' => 'LV',
+            'LT' => 'LT',
+            'HR' => 'HR',
+            'RS' => 'RS',
+            'ME' => 'ME',
+            'BA' => 'BA',
+            'MK' => 'MK',
+            'AL' => 'AL',
+            'TR' => 'TR',
+            'RU' => 'RU',
+            'UA' => 'UA',
+        ];
+
+        // Try exact match first
+        $normalized = trim($countryName);
+        if (isset($countryMap[$normalized])) {
+            return $countryMap[$normalized];
+        }
+
+        // Try case-insensitive match
+        $normalizedLower = strtolower($normalized);
+        foreach ($countryMap as $key => $code) {
+            if (strtolower($key) === $normalizedLower) {
+                return $code;
+            }
+        }
+
+        // Try partial match (e.g., "United States" → "US")
+        foreach ($countryMap as $key => $code) {
+            if (stripos($key, $normalized) !== false || stripos($normalized, $key) !== false) {
+                return $code;
+            }
+        }
+
+        // Try matching ISO code directly
+        if (preg_match('/^[A-Z]{2}$/i', $normalized)) {
+            return strtoupper($normalized);
+        }
+
+        // Check if the country_codes config has a default
+        $config = config(OSPOS::class)->settings;
+        if (isset($config['country_codes']) && !empty($config['country_codes'])) {
+            $countries = explode(',', $config['country_codes']);
+            if (!empty($countries)) {
+                return strtoupper(trim($countries[0]));
+            }
+        }
+
+        // Default to Belgium (for Peppol compliance in Belgium)
+        return 'BE';
+    }
+}
+
+if (!function_exists('getCurrencyCode')) {
+    /**
+     * Get ISO 4217 currency code for a country
+     * 
+     * @param string $countryCode ISO 3166-1 alpha-2 country code
+     * @return string ISO 4217 currency code
+     */
+    function getCurrencyCode(string $countryCode): string
+    {
+        $currencyMap = [
+            'BE' => 'EUR',
+            'FR' => 'EUR',
+            'DE' => 'EUR',
+            'NL' => 'EUR',
+            'IT' => 'EUR',
+            'ES' => 'EUR',
+            'PT' => 'EUR',
+            'IE' => 'EUR',
+            'AT' => 'EUR',
+            'LU' => 'EUR',
+            'FI' => 'EUR',
+            'GR' => 'EUR',
+            'US' => 'USD',
+            'GB' => 'GBP',
+            'CH' => 'CHF',
+            'JP' => 'JPY',
+            'CN' => 'CNY',
+            'CA' => 'CAD',
+            'AU' => 'AUD',
+            'NZ' => 'NZD',
+            'IN' => 'INR',
+            'BR' => 'BRL',
+            'MX' => 'MXN',
+            'ZA' => 'ZAR',
+        ];
+
+        return $currencyMap[$countryCode] ?? 'EUR'; // Default to EUR
+    }
+}

app/Helpers/tabular_helper.php

@@ -85,6 +85,7 @@ function get_sales_manage_table_headers(): string
     if ($config['invoice_enable']) {
         $headers[] = ['invoice_number' => lang('Sales.invoice_number')];
         $headers[] = ['invoice' => '', 'sortable' => false, 'escape' => false];
+        $headers[] = ['ubl' => '', 'sortable' => false, 'escape' => false];
     }
 
     $headers[] = ['receipt' => '', 'sortable' => false, 'escape' => false];
@@ -121,6 +122,13 @@ function get_sale_data_row(object $sale): array
                 '<span class="glyphicon glyphicon-list-alt"></span>',
                 ['title' => lang('Sales.show_invoice')]
             );
+        $row['ubl'] = empty($sale->invoice_number)
+            ? '-'
+            : anchor(
+                "$controller/ublInvoice/$sale->sale_id",
+                '<span class="glyphicon glyphicon-download"></span>',
+                ['title' => lang('Sales.download_ubl'), 'target' => '_blank']
+            );
     }
 
     $row['receipt'] = anchor(

app/Language/en/Sales.php

@@ -1,234 +1,237 @@
 <?php
 
 return [
-    "customers_available_points"       => "Points Available",
-    "rewards_package"                  => "Rewards",
-    "rewards_remaining_balance"        => "Reward Points remaining value is ",
-    "account_number"                   => "Account #",
-    "add_payment"                      => "Add Payment",
-    "amount_due"                       => "Amount Due",
-    "amount_tendered"                  => "Amount Tendered",
-    "authorized_signature"             => "Authorized Signature",
-    "bank_transfer"                    => "Bank Transfer",
-    "cancel_sale"                      => "Cancel",
-    "cash"                             => "Cash",
-    "cash_1"                           => "",
-    "cash_2"                           => "",
-    "cash_3"                           => "",
-    "cash_4"                           => "",
-    "cash_adjustment"                  => "Cash Adjustment",
-    "cash_deposit"                     => "Cash Deposit",
-    "cash_filter"                      => "Cash",
-    "change_due"                       => "Change Due",
-    "change_price"                     => "Change Selling Price",
-    "check"                            => "Check",
-    "check_balance"                    => "Check remainder",
-    "check_filter"                     => "Check",
-    "close"                            => "",
-    "comment"                          => "Comment",
-    "comments"                         => "Comments",
-    "company_name"                     => "",
-    "complete"                         => "",
-    "complete_sale"                    => "Complete",
-    "confirm_cancel_sale"              => "Are you sure you want to clear this sale? All items will be cleared.",
-    "confirm_delete"                   => "Are you sure you want to delete the selected Sale(s)?",
-    "confirm_restore"                  => "Are you sure you want to restore the selected Sale(s)?",
-    "credit"                           => "Credit Card",
-    "credit_deposit"                   => "Credit Deposit",
-    "credit_filter"                    => "Credit Card",
-    "current_table"                    => "",
-    "customer"                         => "Customer",
-    "customer_address"                 => "Address",
-    "customer_discount"                => "Discount",
-    "customer_email"                   => "Email",
-    "customer_location"                => "Location",
-    "customer_mailchimp_status"        => "MailChimp Status",
-    "customer_optional"                => "(Required for Due Payments)",
-    "customer_required"                => "(Required)",
-    "customer_total"                   => "Total",
-    "customer_total_spent"             => "",
-    "daily_sales"                      => "",
-    "date"                             => "Sale Date",
-    "date_range"                       => "Date Range",
-    "date_required"                    => "A correct date must be entered.",
-    "date_type"                        => "Date is a required field.",
-    "debit"                            => "Debit Card",
-    "debit_filter"                     => "",
-    "delete"                           => "Allow Delete",
-    "delete_confirmation"              => "Are you sure you want to delete this sale? This action cannot be undone.",
-    "delete_entire_sale"               => "Delete Entire Sale",
-    "delete_successful"                => "Sale delete successful.",
-    "delete_unsuccessful"              => "Sale delete failed.",
-    "description_abbrv"                => "Desc.",
-    "discard"                          => "Discard",
-    "discard_quote"                    => "",
-    "discount"                         => "Disc",
-    "discount_included"                => "% Discount",
-    "discount_short"                   => "%",
-    "due"                              => "Due",
-    "due_filter"                       => "Due",
-    "edit"                             => "Edit",
-    "edit_item"                        => "Edit Item",
-    "edit_sale"                        => "Edit Sale",
-    "email_receipt"                    => "Email Receipt",
-    "employee"                         => "Employee",
-    "entry"                            => "Entry",
-    "error_editing_item"               => "Error editing item",
-    "negative_price_invalid"           => "Price cannot be negative.",
-    "negative_quantity_invalid"        => "Quantity cannot be negative.",
-    "negative_discount_invalid"        => "Discount cannot be negative.",
-    "discount_percent_exceeds_100"     => "Percentage discount cannot exceed 100%.",
-    "discount_exceeds_item_total"      => "Discount cannot exceed the item total.",
-    "negative_total_invalid"           => "Sale total cannot be negative. Check item discounts and quantities.",
-    "find_or_scan_item"                => "Find or Scan Item",
-    "find_or_scan_item_or_receipt"     => "Find or Scan Item or Receipt",
-    "giftcard"                         => "Gift Card",
-    "giftcard_balance"                 => "Gift Card Balance",
-    "giftcard_filter"                  => "",
-    "giftcard_number"                  => "Gift Card Number",
-    "group_by_category"                => "Group by Category",
-    "group_by_type"                    => "Group by Type",
-    "hsn"                              => "HSN",
-    "id"                               => "Sale ID",
-    "include_prices"                   => "Include Prices?",
-    "invoice"                          => "Invoice",
-    "invoice_confirm"                  => "This invoice will be sent to",
-    "invoice_enable"                   => "Invoice Number",
-    "invoice_filter"                   => "Invoices",
-    "invoice_no_email"                 => "This customer does not have a valid email address.",
-    "invoice_number"                   => "Invoice #",
-    "invoice_number_duplicate"         => "Invoice Number {0} must be unique.",
-    "invoice_sent"                     => "Invoice sent to",
-    "invoice_total"                    => "Invoice Total",
-    "invoice_type_custom_invoice"      => "Custom Invoice (custom_invoice.php)",
-    "invoice_type_custom_tax_invoice"  => "Custom Tax Invoice (custom_tax_invoice.php)",
-    "invoice_type_invoice"             => "Invoice (invoice.php)",
-    "invoice_type_tax_invoice"         => "Tax Invoice (tax_invoice.php)",
-    "invoice_unsent"                   => "Invoice failed to be sent to",
-    "invoice_update"                   => "Recount",
-    "item_insufficient_of_stock"       => "Item has insufficient stock.",
-    "item_name"                        => "Item Name",
-    "item_number"                      => "Item #",
-    "item_out_of_stock"                => "Item is out of stock.",
-    "key_browser"                      => "Helpful Shortcuts",
-    "key_cancel"                       => "Cancels Current Quote/Invoice/Sale",
-    "key_customer_search"              => "Customer Search",
-    "key_finish_quote"                 => "Finish Quote/Invoice without payment",
-    "key_finish_sale"                  => "Add Payment and Complete Invoice/Sale",
-    "key_full"                         => "Open in Full Screen Mode",
-    "key_function"                     => "Function",
-    "key_help"                         => "Shortcuts",
-    "key_help_modal"                   => "Open Shortcuts Window",
-    "key_in"                           => "Zoom in",
-    "key_item_search"                  => "Item Search",
-    "key_out"                          => "Zoom Out",
-    "key_payment"                      => "Add Payment",
-    "key_print"                        => "Print Current Page",
-    "key_restore"                      => "Restore Original Display/Zoom",
-    "key_search"                       => "Search Reports Tables",
-    "key_suspend"                      => "Suspend Current Sale",
-    "key_suspended"                    => "Show Suspended Sales",
-    "key_system"                       => "System Shortcuts",
-    "key_tendered"                     => "Edit Amount Tendered",
-    "key_title"                        => "Sales Keyboard Shortcuts",
-    "mc"                               => "",
-    "mode"                             => "Register Mode",
-    "must_enter_numeric"               => "Amount Tendered must be a number.",
-    "must_enter_numeric_giftcard"      => "Gift Card Number must be a number.",
-    "new_customer"                     => "New Customer",
-    "new_item"                         => "New Item",
-    "no_description"                   => "No description",
-    "no_filter"                        => "All",
-    "no_items_in_cart"                 => "There are no Items in the cart.",
-    "no_sales_to_display"              => "No Sales to display.",
-    "none_selected"                    => "You have not selected any Sale(s) to delete.",
-    "nontaxed_ind"                     => " ",
-    "not_authorized"                   => "This action is not authorized.",
-    "one_or_multiple"                  => "Sale(s)",
-    "payment"                          => "Payment Type",
-    "payment_amount"                   => "Amount",
-    "payment_not_cover_total"          => "Payment Amount must be greater than or equal to Total.",
-    "payment_type"                     => "Type",
-    "payments"                         => "",
-    "payments_total"                   => "Payments Total",
-    "price"                            => "Price",
-    "print_after_sale"                 => "Print after Sale",
-    "quantity"                         => "Quantity",
-    "quantity_less_than_reorder_level" => "Warning: Desired Quantity is below Reorder Level for that Item.",
-    "quantity_less_than_zero"          => "Warning: Desired Quantity is insufficient. You can still process the sale, but audit your inventory.",
-    "quantity_of_items"                => "Quantity of {0} Items",
-    "quote"                            => "Quote",
-    "quote_number"                     => "Quote Number",
-    "quote_number_duplicate"           => "Quote Number must be unique.",
-    "quote_sent"                       => "Quote sent to",
-    "quote_unsent"                     => "Quote failed to be sent to",
-    "receipt"                          => "Sales Receipt",
-    "receipt_no_email"                 => "This customer does not have a valid email address.",
-    "receipt_number"                   => "Sale #",
-    "receipt_sent"                     => "Receipt sent to",
-    "receipt_unsent"                   => "Receipt failed to be sent to",
-    "refund"                           => "Refund Type",
-    "register"                         => "Sales Register",
-    "remove_customer"                  => "Remove Customer",
-    "remove_discount"                  => "",
-    "return"                           => "Return",
-    "rewards"                          => "Reward Points",
-    "rewards_balance"                  => "Reward Points Balance",
-    "sale"                             => "Sale",
-    "sale_by_invoice"                  => "Sale by Invoice",
-    "sale_for_customer"                => "Customer:",
-    "sale_time"                        => "Time",
-    "sales_tax"                        => "Sales Tax",
-    "sales_total"                      => "",
-    "select_customer"                  => "Select Customer",
-    "selected_customer"                => "Selected Customer",
-    "send_invoice"                     => "Send Invoice",
-    "send_quote"                       => "Send Quote",
-    "send_receipt"                     => "Send Receipt",
-    "send_work_order"                  => "Send Work Order",
-    "serial"                           => "Serial",
-    "service_charge"                   => "",
-    "show_due"                         => "",
-    "show_invoice"                     => "Show Invoice",
-    "show_receipt"                     => "Show Receipt",
-    "start_typing_customer_name"       => "Start typing customer details...",
-    "start_typing_item_name"           => "Start typing Item Name or scan Barcode...",
-    "stock"                            => "Stock",
-    "stock_location"                   => "Stock Location",
-    "sub_total"                        => "Subtotal",
-    "successfully_deleted"             => "You have successfully deleted",
-    "successfully_restored"            => "You have successfully restored",
-    "successfully_suspended_sale"      => "Sale suspend successful.",
-    "successfully_updated"             => "Sale update successful.",
-    "suspend_sale"                     => "Suspend",
-    "suspended_doc_id"                 => "Document",
-    "suspended_sale_id"                => "ID",
-    "suspended_sales"                  => "Suspended",
-    "table"                            => "Table",
-    "takings"                          => "Daily Sales",
-    "tax"                              => "Tax",
-    "tax_id"                           => "Tax Id",
-    "tax_invoice"                      => "Tax Invoice",
-    "tax_percent"                      => "Tax %",
-    "taxed_ind"                        => "T",
-    "total"                            => "Total",
-    "total_tax_exclusive"              => "Tax excluded",
-    "transaction_failed"               => "Sales Transaction failed.",
-    "unable_to_add_item"               => "Item add to Sale failed",
-    "unsuccessfully_deleted"           => "Sale(s) delete failed.",
-    "unsuccessfully_restored"          => "Sale(s) restore failed.",
-    "unsuccessfully_suspended_sale"    => "Sale suspend failed.",
-    "unsuccessfully_updated"           => "Sale update failed.",
-    "unsuspend"                        => "Unsuspend",
-    "unsuspend_and_delete"             => "Action",
-    "update"                           => "Update",
-    "upi"                              => "UPI",
-    "visa"                             => "",
-    "wallet"                           => "Wallet",
-    "wholesale"                        => "",
-    "work_order"                       => "Work Order",
-    "work_order_number"                => "Work Order Number",
-    "work_order_number_duplicate"      => "Work Order Number must be unique.",
-    "work_order_sent"                  => "Work Order sent to",
-    "work_order_unsent"                => "Work Order failed to be sent to",
+    'customers_available_points'       => 'Points Available',
+    'rewards_package'                  => 'Rewards',
+    'rewards_remaining_balance'        => 'Reward Points remaining value is ',
+    'account_number'                   => 'Account #',
+    'add_payment'                      => 'Add Payment',
+    'amount_due'                       => 'Amount Due',
+    'amount_tendered'                  => 'Amount Tendered',
+    'authorized_signature'             => 'Authorized Signature',
+    'bank_transfer'                    => 'Bank Transfer',
+    'cancel_sale'                      => 'Cancel',
+    'cash'                             => 'Cash',
+    'cash_1'                           => '',
+    'cash_2'                           => '',
+    'cash_3'                           => '',
+    'cash_4'                           => '',
+    'cash_adjustment'                  => 'Cash Adjustment',
+    'cash_deposit'                     => 'Cash Deposit',
+    'cash_filter'                      => 'Cash',
+    'change_due'                       => 'Change Due',
+    'change_price'                     => 'Change Selling Price',
+    'check'                            => 'Check',
+    'check_balance'                    => 'Check remainder',
+    'check_filter'                     => 'Check',
+    'close'                            => '',
+    'comment'                          => 'Comment',
+    'comments'                         => 'Comments',
+    'company_name'                     => '',
+    'complete'                         => '',
+    'complete_sale'                    => 'Complete',
+    'confirm_cancel_sale'              => 'Are you sure you want to clear this sale? All items will be cleared.',
+    'confirm_delete'                   => 'Are you sure you want to delete the selected Sale(s)?',
+    'confirm_restore'                  => 'Are you sure you want to restore the selected Sale(s)?',
+    'credit'                           => 'Credit Card',
+    'credit_deposit'                   => 'Credit Deposit',
+    'credit_filter'                    => 'Credit Card',
+    'current_table'                    => '',
+    'customer'                         => 'Customer',
+    'customer_address'                 => 'Address',
+    'customer_discount'                => 'Discount',
+    'customer_email'                   => 'Email',
+    'customer_location'                => 'Location',
+    'customer_mailchimp_status'        => 'MailChimp Status',
+    'customer_optional'                => '(Required for Due Payments)',
+    'customer_required'                => '(Required)',
+    'customer_total'                   => 'Total',
+    'customer_total_spent'             => '',
+    'daily_sales'                      => '',
+    'date'                             => 'Sale Date',
+    'date_range'                       => 'Date Range',
+    'date_required'                    => 'A correct date must be entered.',
+    'date_type'                        => 'Date is a required field.',
+    'debit'                            => 'Debit Card',
+    'debit_filter'                     => '',
+    'delete'                           => 'Allow Delete',
+    'delete_confirmation'              => 'Are you sure you want to delete this sale? This action cannot be undone.',
+    'delete_entire_sale'               => 'Delete Entire Sale',
+    'delete_successful'                => 'Sale delete successful.',
+    'delete_unsuccessful'              => 'Sale delete failed.',
+    'description_abbrv'                => 'Desc.',
+    'discard'                          => 'Discard',
+    'discard_quote'                    => '',
+    'discount'                         => 'Disc',
+    'discount_included'                => '% Discount',
+    'discount_short'                   => '%',
+    'due'                              => 'Due',
+    'due_filter'                       => 'Due',
+    'edit'                             => 'Edit',
+    'edit_item'                        => 'Edit Item',
+    'edit_sale'                        => 'Edit Sale',
+    'email_receipt'                    => 'Email Receipt',
+    'employee'                         => 'Employee',
+    'entry'                            => 'Entry',
+    'error_editing_item'               => 'Error editing item',
+    'negative_price_invalid'           => 'Price cannot be negative.',
+    'negative_quantity_invalid'        => 'Quantity cannot be negative.',
+    'negative_discount_invalid'        => 'Discount cannot be negative.',
+    'discount_percent_exceeds_100'     => 'Percentage discount cannot exceed 100%.',
+    'discount_exceeds_item_total'      => 'Discount cannot exceed the item total.',
+    'negative_total_invalid'           => 'Sale total cannot be negative. Check item discounts and quantities.',
+    'find_or_scan_item'                => 'Find or Scan Item',
+    'find_or_scan_item_or_receipt'     => 'Find or Scan Item or Receipt',
+    'giftcard'                         => 'Gift Card',
+    'giftcard_balance'                 => 'Gift Card Balance',
+    'giftcard_filter'                  => '',
+    'giftcard_number'                  => 'Gift Card Number',
+    'group_by_category'                => 'Group by Category',
+    'group_by_type'                    => 'Group by Type',
+    'hsn'                              => 'HSN',
+    'id'                               => 'Sale ID',
+    'include_prices'                   => 'Include Prices?',
+    'invoice'                          => 'Invoice',
+    'invoice_confirm'                  => 'This invoice will be sent to',
+    'invoice_enable'                   => 'Invoice Number',
+    'invoice_filter'                   => 'Invoices',
+    'invoice_no_email'                 => 'This customer does not have a valid email address.',
+    'invoice_number'                   => 'Invoice #',
+    'invoice_number_duplicate'         => 'Invoice Number {0} must be unique.',
+    'invoice_sent'                     => 'Invoice sent to',
+    'invoice_total'                    => 'Invoice Total',
+    'invoice_type_custom_invoice'      => 'Custom Invoice (custom_invoice.php)',
+    'invoice_type_custom_tax_invoice'  => 'Custom Tax Invoice (custom_tax_invoice.php)',
+    'invoice_type_invoice'             => 'Invoice (invoice.php)',
+    'invoice_type_tax_invoice'         => 'Tax Invoice (tax_invoice.php)',
+    'invoice_unsent'                   => 'Invoice failed to be sent to',
+    'invoice_update'                   => 'Recount',
+    'item_insufficient_of_stock'       => 'Item has insufficient stock.',
+    'item_name'                        => 'Item Name',
+    'item_number'                      => 'Item #',
+    'item_out_of_stock'                => 'Item is out of stock.',
+    'key_browser'                      => 'Helpful Shortcuts',
+    'key_cancel'                       => 'Cancels Current Quote/Invoice/Sale',
+    'key_customer_search'              => 'Customer Search',
+    'key_finish_quote'                 => 'Finish Quote/Invoice without payment',
+    'key_finish_sale'                  => 'Add Payment and Complete Invoice/Sale',
+    'key_full'                         => 'Open in Full Screen Mode',
+    'key_function'                     => 'Function',
+    'key_help'                         => 'Shortcuts',
+    'key_help_modal'                   => 'Open Shortcuts Window',
+    'key_in'                           => 'Zoom in',
+    'key_item_search'                  => 'Item Search',
+    'key_out'                          => 'Zoom Out',
+    'key_payment'                      => 'Add Payment',
+    'key_print'                        => 'Print Current Page',
+    'key_restore'                      => 'Restore Original Display/Zoom',
+    'key_search'                       => 'Search Reports Tables',
+    'key_suspend'                      => 'Suspend Current Sale',
+    'key_suspended'                    => 'Show Suspended Sales',
+    'key_system'                       => 'System Shortcuts',
+    'key_tendered'                     => 'Edit Amount Tendered',
+    'key_title'                        => 'Sales Keyboard Shortcuts',
+    'mc'                               => '',
+    'mode'                             => 'Register Mode',
+    'must_enter_numeric'               => 'Amount Tendered must be a number.',
+    'must_enter_numeric_giftcard'      => 'Gift Card Number must be a number.',
+    'new_customer'                     => 'New Customer',
+    'new_item'                         => 'New Item',
+    'no_description'                   => 'No description',
+    'no_filter'                        => 'All',
+    'no_items_in_cart'                 => 'There are no Items in the cart.',
+    'no_sales_to_display'              => 'No Sales to display.',
+    'none_selected'                    => 'You have not selected any Sale(s) to delete.',
+    'nontaxed_ind'                     => ' ',
+    'not_authorized'                   => 'This action is not authorized.',
+    'one_or_multiple'                  => 'Sale(s)',
+    'payment'                          => 'Payment Type',
+    'payment_amount'                   => 'Amount',
+    'payment_not_cover_total'          => 'Payment Amount must be greater than or equal to Total.',
+    'payment_type'                     => 'Type',
+    'payments'                         => '',
+    'payments_total'                   => 'Payments Total',
+    'price'                            => 'Price',
+    'print_after_sale'                 => 'Print after Sale',
+    'quantity'                         => 'Quantity',
+    'quantity_less_than_reorder_level' => 'Warning: Desired Quantity is below Reorder Level for that Item.',
+    'quantity_less_than_zero'          => 'Warning: Desired Quantity is insufficient. You can still process the sale, but audit your inventory.',
+    'quantity_of_items'                => 'Quantity of {0} Items',
+    'quote'                            => 'Quote',
+    'quote_number'                     => 'Quote Number',
+    'quote_number_duplicate'           => 'Quote Number must be unique.',
+    'quote_sent'                       => 'Quote sent to',
+    'quote_unsent'                     => 'Quote failed to be sent to',
+    'receipt'                          => 'Sales Receipt',
+    'receipt_no_email'                 => 'This customer does not have a valid email address.',
+    'receipt_number'                   => 'Sale #',
+    'receipt_sent'                     => 'Receipt sent to',
+    'receipt_unsent'                   => 'Receipt failed to be sent to',
+    'refund'                           => 'Refund Type',
+    'register'                         => 'Sales Register',
+    'remove_customer'                  => 'Remove Customer',
+    'remove_discount'                  => '',
+    'return'                           => 'Return',
+    'rewards'                          => 'Reward Points',
+    'rewards_balance'                  => 'Reward Points Balance',
+    'sale'                             => 'Sale',
+    'sale_by_invoice'                  => 'Sale by Invoice',
+    'sale_for_customer'                => 'Customer:',
+    'sale_time'                        => 'Time',
+    'sales_tax'                        => 'Sales Tax',
+    'sales_total'                      => '',
+    'select_customer'                  => 'Select Customer',
+    'selected_customer'                => 'Selected Customer',
+    'send_invoice'                     => 'Send Invoice',
+    'send_quote'                       => 'Send Quote',
+    'send_receipt'                     => 'Send Receipt',
+    'send_work_order'                  => 'Send Work Order',
+    'serial'                           => 'Serial',
+    'service_charge'                   => '',
+    'show_due'                         => '',
+    'show_invoice'                     => 'Show Invoice',
+    'show_receipt'                     => 'Show Receipt',
+    'start_typing_customer_name'       => 'Start typing customer details...',
+    'start_typing_item_name'           => 'Start typing Item Name or scan Barcode...',
+    'stock'                            => 'Stock',
+    'stock_location'                   => 'Stock Location',
+    'sub_total'                        => 'Subtotal',
+    'successfully_deleted'             => 'You have successfully deleted',
+    'successfully_restored'            => 'You have successfully restored',
+    'successfully_suspended_sale'      => 'Sale suspend successful.',
+    'successfully_updated'             => 'Sale update successful.',
+    'suspend_sale'                     => 'Suspend',
+    'suspended_doc_id'                 => 'Document',
+    'suspended_sale_id'                => 'ID',
+    'suspended_sales'                  => 'Suspended',
+    'table'                            => 'Table',
+    'takings'                          => 'Daily Sales',
+    'tax'                              => 'Tax',
+    'tax_id'                           => 'Tax Id',
+    'tax_invoice'                      => 'Tax Invoice',
+    'tax_percent'                      => 'Tax %',
+    'taxed_ind'                        => 'T',
+    'total'                            => 'Total',
+    'total_tax_exclusive'              => 'Tax excluded',
+    'transaction_failed'               => 'Sales Transaction failed.',
+    'unable_to_add_item'               => 'Item add to Sale failed',
+    'unsuccessfully_deleted'           => 'Sale(s) delete failed.',
+    'unsuccessfully_restored'          => 'Sale(s) restore failed.',
+    'unsuccessfully_suspended_sale'    => 'Sale suspend failed.',
+    'unsuccessfully_updated'           => 'Sale update failed.',
+    'unsuspend'                        => 'Unsuspend',
+    'unsuspend_and_delete'             => 'Action',
+    'update'                           => 'Update',
+    'upi'                              => 'UPI',
+    'visa'                             => '',
+    'wallet'                           => 'Wallet',
+    'wholesale'                        => '',
+    'work_order'                       => 'Work Order',
+    'work_order_number'                => 'Work Order Number',
+    'work_order_number_duplicate'      => 'Work Order Number must be unique.',
+    'work_order_sent'                  => 'Work Order sent to',
+    'work_order_unsent'                => 'Work Order failed to be sent to',
+    'download_ubl'                     => 'Download UBL Invoice',
+    'ubl_generation_failed'            => 'UBL invoice generation failed',
+    'sale_not_found'                   => 'Sale not found',
 ];

app/Libraries/Email_lib.php

@@ -118,4 +118,38 @@ class Email_lib
 
         return '<img id="image" src="data:' . $mimeType . ';base64,' . $logo_data . '" alt="company_logo">';
     }
+    
+    /**
+     * Send email with multiple attachments
+     *
+     * @param string $to
+     * @param string $subject
+     * @param string $message
+     * @param array $attachments
+     * @return bool
+     */
+    public function sendMultipleAttachments(string $to, string $subject, string $message, array $attachments): bool
+    {
+        $email = $this->email;
+
+        $email->setFrom($this->config['email'], $this->config['company']);
+        $email->setTo($to);
+        $email->setSubject($subject);
+        $email->setMessage($message);
+
+        foreach ($attachments as $attachment) {
+            if (!empty($attachment) && file_exists($attachment)) {
+                $email->attach($attachment);
+            }
+        }
+
+        $result = $email->send();
+
+        if (!$result) {
+            log_message('error', $email->printDebugger());
+        }
+
+        return $result;
+    }
+
 }

app/Libraries/InvoiceAttachment/InvoiceAttachment.php

@@ -0,0 +1,40 @@
+<?php
+
+namespace App\Libraries\InvoiceAttachment;
+
+interface InvoiceAttachment
+{
+    /**
+     * Generate the attachment content and write to a temp file.
+     *
+     * @param array $saleData The sale data from _load_sale_data()
+     * @param string $type The document type (invoice, tax_invoice, quote, work_order, receipt)
+     * @return string|null Absolute path to generated file, or null on failure
+     */
+    public function generate(array $saleData, string $type): ?string;
+
+    /**
+     * Check if this attachment type is applicable for the document type.
+     * E.g., UBL only works for invoice/tax_invoice
+     *
+     * @param string $type The document type
+     * @param array $saleData The sale data (to check invoice_number existence)
+     * @return bool
+     */
+    public function isApplicableForType(string $type, array $saleData): bool;
+
+    /**
+     * Get the file extension for this attachment.
+     *
+     * @return string E.g., 'pdf', 'xml'
+     */
+    public function getFileExtension(): string;
+
+    /**
+     * Get the config values that enable this attachment.
+     * Returns array of config values that should generate this attachment.
+     *
+     * @return array E.g., ['pdf_only', 'both'] for PDF
+     */
+    public function getEnabledConfigValues(): array;
+}

app/Libraries/InvoiceAttachment/InvoiceAttachmentGenerator.php

@@ -0,0 +1,75 @@
+<?php
+
+namespace App\Libraries\InvoiceAttachment;
+
+class InvoiceAttachmentGenerator
+{
+    /** @var InvoiceAttachment[] */
+    private array $attachments = [];
+
+    /**
+     * Register an attachment generator.
+     */
+    public function register(InvoiceAttachment $attachment): self
+    {
+        $this->attachments[] = $attachment;
+        return $this;
+    }
+
+    /**
+     * Create generator with attachments based on config.
+     * Factory method that instantiates the right attachments.
+     *
+     * @param string $invoiceFormat Config value: 'pdf_only', 'ubl_only', or 'both'
+     * @return self
+     */
+    public static function createFromConfig(string $invoiceFormat): self
+    {
+        $generator = new self();
+
+        if (in_array($invoiceFormat, ['pdf_only', 'both'], true)) {
+            $generator->register(new PdfAttachment());
+        }
+
+        if (in_array($invoiceFormat, ['ubl_only', 'both'], true)) {
+            $generator->register(new UblAttachment());
+        }
+
+        return $generator;
+    }
+
+    /**
+     * Generate all applicable attachments for a sale.
+     *
+     * @param array $saleData The sale data
+     * @param string $type The document type
+     * @return string[] Array of file paths to generated attachments
+     */
+    public function generateAttachments(array $saleData, string $type): array
+    {
+        $files = [];
+
+        foreach ($this->attachments as $attachment) {
+            if ($attachment->isApplicableForType($type, $saleData)) {
+                $filepath = $attachment->generate($saleData, $type);
+                if ($filepath !== null) {
+                    $files[] = $filepath;
+                }
+            }
+        }
+
+        return $files;
+    }
+
+    /**
+     * Clean up temporary attachment files.
+     *
+     * @param string[] $files
+     */
+    public static function cleanup(array $files): void
+    {
+        foreach ($files as $file) {
+            @unlink($file);
+        }
+    }
+}

app/Libraries/InvoiceAttachment/PdfAttachment.php

@@ -0,0 +1,61 @@
+<?php
+
+namespace App\Libraries\InvoiceAttachment;
+
+use CodeIgniter\Config\Services;
+
+class PdfAttachment implements InvoiceAttachment
+{
+    /**
+     * @inheritDoc
+     */
+    public function generate(array $saleData, string $type): ?string
+    {
+        $view = Services::renderer();
+        $html = $view->setData($saleData)->render("sales/{$type}_email");
+
+        helper(['dompdf', 'file']);
+
+        $tempPath = tempnam(sys_get_temp_dir(), 'ospos_pdf_');
+        if ($tempPath === false) {
+            log_message('error', 'PDF attachment: failed to create temp file');
+            return null;
+        }
+
+        $filename = $tempPath . '.pdf';
+        rename($tempPath, $filename);
+
+        $pdfContent = create_pdf($html);
+        if (file_put_contents($filename, $pdfContent) === false) {
+            log_message('error', 'PDF attachment: failed to write content');
+            @unlink($filename);
+            return null;
+        }
+
+        return $filename;
+    }
+
+    /**
+     * @inheritDoc
+     */
+    public function isApplicableForType(string $type, array $saleData): bool
+    {
+        return true;
+    }
+
+    /**
+     * @inheritDoc
+     */
+    public function getFileExtension(): string
+    {
+        return 'pdf';
+    }
+
+    /**
+     * @inheritDoc
+     */
+    public function getEnabledConfigValues(): array
+    {
+        return ['pdf_only', 'both'];
+    }
+}

app/Libraries/InvoiceAttachment/UblAttachment.php

@@ -0,0 +1,69 @@
+<?php
+
+namespace App\Libraries\InvoiceAttachment;
+
+use App\Libraries\UBLGenerator;
+
+class UblAttachment implements InvoiceAttachment
+{
+    public function __construct()
+    {
+        require_once ROOTPATH . 'vendor/autoload.php';
+    }
+
+    /**
+     * @inheritDoc
+     */
+    public function generate(array $saleData, string $type): ?string
+    {
+        try {
+            $generator = new UBLGenerator();
+            $xml = $generator->generateUblInvoice($saleData);
+
+            $tempPath = tempnam(sys_get_temp_dir(), 'ospos_ubl_');
+            if ($tempPath === false) {
+                log_message('error', 'UBL attachment: failed to create temp file');
+                return null;
+            }
+
+            $filename = $tempPath . '.xml';
+            rename($tempPath, $filename);
+
+            if (file_put_contents($filename, $xml) === false) {
+                log_message('error', 'UBL attachment: failed to write content');
+                @unlink($filename);
+                return null;
+            }
+
+            return $filename;
+        } catch (\Exception $e) {
+            log_message('error', 'UBL attachment generation failed: ' . $e->getMessage());
+            return null;
+        }
+    }
+
+    /**
+     * @inheritDoc
+     */
+    public function isApplicableForType(string $type, array $saleData): bool
+    {
+        return in_array($type, ['invoice', 'tax_invoice'], true)
+            && !empty($saleData['invoice_number']);
+    }
+
+    /**
+     * @inheritDoc
+     */
+    public function getFileExtension(): string
+    {
+        return 'xml';
+    }
+
+    /**
+     * @inheritDoc
+     */
+    public function getEnabledConfigValues(): array
+    {
+        return ['ubl_only', 'both'];
+    }
+}

app/Libraries/UBLGenerator.php

@@ -0,0 +1,369 @@
+<?php
+
+namespace App\Libraries;
+
+use DateTime;
+use NumNum\UBL\AccountingParty;
+use NumNum\UBL\Address;
+use NumNum\UBL\AllowanceCharge;
+use NumNum\UBL\Contact;
+use NumNum\UBL\Country;
+use NumNum\UBL\Generator;
+use NumNum\UBL\Invoice;
+use NumNum\UBL\InvoiceLine;
+use NumNum\UBL\Item;
+use NumNum\UBL\LegalMonetaryTotal;
+use NumNum\UBL\Party;
+use NumNum\UBL\PartyTaxScheme;
+use NumNum\UBL\Price;
+use NumNum\UBL\TaxCategory;
+use NumNum\UBL\TaxScheme;
+use NumNum\UBL\TaxSubTotal;
+use NumNum\UBL\TaxTotal;
+use NumNum\UBL\UnitCode;
+
+helper(['country']);
+
+class UBLGenerator
+{
+    /**
+     * Generate UBL invoice XML from sale data
+     *
+     * @param array $saleData Sale data from _load_sale_data()
+     *
+     * @return string UBL XML string
+     */
+    public function generateUblInvoice(array $saleData): string
+    {
+        $taxScheme     = (new TaxScheme())->setId('VAT');
+        $isTaxIncluded = ! empty($saleData['tax_included']);
+
+        $supplierParty = $this->buildSupplierParty($saleData, $taxScheme);
+        $customerParty = $this->buildCustomerParty($saleData['customer_object'] ?? null, $taxScheme);
+        $invoiceLines  = $this->buildInvoiceLines($saleData, $taxScheme, $isTaxIncluded);
+        $taxTotal      = $this->buildTaxTotal($saleData['taxes'] ?? [], $taxScheme);
+        $monetaryTotal = $this->buildMonetaryTotal($saleData);
+
+        $invoice = (new Invoice())
+            ->setUBLVersionId('2.1')
+            ->setCustomizationId('urn:cen.eu:en16931:2017')
+            ->setProfileId('urn:fdc:peppol.eu:2017:poacc:billing:01:1.0')
+            ->setId($saleData['invoice_number'] ?? '')
+            ->setIssueDate(new DateTime($saleData['transaction_date'] ?? 'now'))
+            ->setInvoiceTypeCode(380)
+            ->setAccountingSupplierParty($supplierParty)
+            ->setAccountingCustomerParty($customerParty)
+            ->setInvoiceLines($invoiceLines)
+            ->setTaxTotal($taxTotal)
+            ->setLegalMonetaryTotal($monetaryTotal);
+
+        // Set currency if available
+        if (! empty($saleData['currency_code'])) {
+            Generator::$currencyID = $saleData['currency_code'];
+        }
+
+        $generator = new Generator();
+
+        return $generator->invoice($invoice);
+    }
+
+    /**
+     * Build supplier (seller) party
+     */
+    protected function buildSupplierParty(array $saleData, TaxScheme $taxScheme): AccountingParty
+    {
+        $config = $saleData['config'] ?? [];
+
+        $addressParts = $this->parseAddress($config['address'] ?? '');
+        $countryCode  = getCountryCode($config['country'] ?? '');
+
+        $country = (new Country())->setIdentificationCode($countryCode);
+        $address = (new Address())
+            ->setStreetName($addressParts['street'] ?? '')
+            ->setBuildingNumber($addressParts['number'] ?? '')
+            ->setCityName($addressParts['city'] ?? '')
+            ->setPostalZone($addressParts['zip'] ?? '')
+            ->setCountrySubentity($config['state'] ?? '')
+            ->setCountry($country);
+
+        $party = (new Party())
+            ->setName($config['company'] ?? '')
+            ->setPostalAddress($address);
+
+        $partyTaxScheme = null;
+        if (! empty($config['account_number'])) {
+            $partyTaxScheme = (new PartyTaxScheme())
+                ->setCompanyId($config['account_number'])
+                ->setTaxScheme($taxScheme);
+            $party->setPartyTaxScheme($partyTaxScheme);
+        } elseif (! empty($config['tax_id'])) {
+            // Use tax_id if account_number is not set
+            $partyTaxScheme = (new PartyTaxScheme())
+                ->setCompanyId($config['tax_id'])
+                ->setTaxScheme($taxScheme);
+            $party->setPartyTaxScheme($partyTaxScheme);
+        }
+
+        return (new AccountingParty())->setParty($party);
+    }
+
+    /**
+     * Build customer (buyer) party
+     */
+    protected function buildCustomerParty(?object $customerInfo, TaxScheme $taxScheme): AccountingParty
+    {
+        if ($customerInfo === null) {
+            return (new AccountingParty())->setParty(new Party());
+        }
+
+        $countryCode = getCountryCode($customerInfo->country ?? '');
+
+        $country = (new Country())->setIdentificationCode($countryCode);
+        $address = (new Address())
+            ->setStreetName($customerInfo->address_1 ?? '')
+            ->setAddressLine([$customerInfo->address_2 ?? ''])
+            ->setCityName($customerInfo->city ?? '')
+            ->setPostalZone($customerInfo->zip ?? '')
+            ->setCountrySubentity($customerInfo->state ?? '')
+            ->setCountry($country);
+
+        $partyName = ! empty($customerInfo->company_name)
+            ? $customerInfo->company_name
+            : trim(($customerInfo->first_name ?? '') . ' ' . ($customerInfo->last_name ?? ''));
+
+        $party = (new Party())
+            ->setName($partyName)
+            ->setPostalAddress($address);
+
+        if (! empty($customerInfo->email)) {
+            $contact = (new Contact())
+                ->setElectronicMail($customerInfo->email)
+                ->setTelephone($customerInfo->phone_number ?? '');
+            $party->setContact($contact);
+        }
+
+        $accountingParty = (new AccountingParty())->setParty($party);
+
+        if (! empty($customerInfo->account_number)) {
+            $accountingParty->setSupplierAssignedAccountId($customerInfo->account_number);
+        }
+
+        if (! empty($customerInfo->tax_id)) {
+            $partyTaxScheme = (new PartyTaxScheme())
+                ->setCompanyId($customerInfo->tax_id)
+                ->setTaxScheme($taxScheme);
+            $party->setPartyTaxScheme($partyTaxScheme);
+        }
+
+        return $accountingParty;
+    }
+
+    /**
+     * Build invoice lines
+     */
+    protected function buildInvoiceLines(array $saleData, TaxScheme $taxScheme, bool $isTaxIncluded): array
+    {
+        $lines     = [];
+        $itemTaxes = $saleData['item_taxes'] ?? [];
+        $cart      = $saleData['cart'] ?? [];
+
+        foreach ($cart as $item) {
+            $itemId       = $item['item_id'] ?? 0;
+            $quantity     = (float) ($item['quantity'] ?? 0);
+            $unitPrice    = (float) ($item['price'] ?? 0);
+            $discount     = (float) ($item['discount'] ?? 0);
+            $discountType = (int) ($item['discount_type'] ?? 0);
+
+            // Calculate discount amount per unit
+            if ($discountType === PERCENT && $discount > 0) {
+                // Percentage discount
+                $discountAmountPerUnit = round($unitPrice * $discount / 100, 4);
+            } else {
+                // Fixed discount (discount is total for the line, divide by quantity)
+                $discountAmountPerUnit = $quantity > 0 ? round($discount / $quantity, 4) : 0;
+            }
+
+            // Net price per unit (after discount)
+            $netPricePerUnit = round($unitPrice - $discountAmountPerUnit, 4);
+            if ($netPricePerUnit < 0) {
+                $netPricePerUnit = 0;
+            }
+
+            // Get tax rate for this item
+            $taxRate     = 0.0;
+            $taxCategory = (new TaxCategory())
+                ->setId('S')
+                ->setPercent(0)
+                ->setTaxScheme($taxScheme);
+
+            if (isset($itemTaxes[$itemId]) && ! empty($itemTaxes[$itemId])) {
+                // Use the first (primary) tax for this item
+                $itemTax = $itemTaxes[$itemId][0];
+                $taxRate = (float) ($itemTax['percent'] ?? 0);
+
+                if (abs($taxRate) < 0.001) {
+                    $taxCategory->setId('Z'); // Zero rated
+                } elseif ($taxRate < 0) {
+                    $taxCategory->setId('E'); // Exempt
+                } else {
+                    $taxCategory->setId('S'); // Standard
+                }
+                $taxCategory->setPercent(round($taxRate, 2));
+            }
+
+            // Calculate line extension amount (net line total)
+            $lineExtensionAmount = round($netPricePerUnit * $quantity, 2);
+
+            // Build Price - PriceAmount MUST be the net price excluding VAT per Peppol EN16931 (BR-27)
+            // "The price of an item, exclusive of VAT, after subtracting discount"
+            $price = (new Price())
+                ->setBaseQuantity(1.0)
+                ->setUnitCode(UnitCode::UNIT);
+
+            if ($isTaxIncluded && $taxRate > 0) {
+                // Tax-inclusive: cart price includes VAT, so extract the net price
+                // net_price = gross_price / (1 + tax_rate/100)
+                $taxExclusivePricePerUnit = round($netPricePerUnit / (1 + $taxRate / 100), 4);
+                $price->setPriceAmount($taxExclusivePricePerUnit);
+
+                // Recalculate line extension amount with tax-exclusive price
+                $lineExtensionAmount = round($taxExclusivePricePerUnit * $quantity, 2);
+            } else {
+                // Tax-exclusive: cart price is already the net price
+                $price->setPriceAmount(round($netPricePerUnit, 4));
+            }
+
+            // Add AllowanceCharge if there's a discount (gross-to-net price reduction)
+            if ($discountAmountPerUnit > 0) {
+                $allowanceCharge = (new AllowanceCharge())
+                    ->setChargeIndicator(false) // false = allowance/discount
+                    ->setAllowanceChargeReason('Discount')
+                    ->setAmount(round($discountAmountPerUnit, 4))
+                    ->setBaseAmount(round((float) ($item['price'] ?? 0), 4));
+
+                $price->setAllowanceCharge($allowanceCharge);
+            }
+
+            // Build Item
+            $itemObj = (new Item())
+                ->setName($item['name'] ?? '')
+                ->setDescription($item['description'] ?? '')
+                ->setClassifiedTaxCategory($taxCategory);
+
+            // Add SellersItemIdentification if item_number exists (BR-25)
+            if (! empty($item['item_number'])) {
+                $itemObj->setSellersItemIdentification((string) $item['item_number']);
+            }
+
+            // Build InvoiceLine
+            $line = (new InvoiceLine())
+                ->setId(isset($item['line']) ? (string) $item['line'] : '1')
+                ->setInvoicedQuantity($quantity)
+                ->setLineExtensionAmount($lineExtensionAmount)
+                ->setItem($itemObj)
+                ->setPrice($price);
+
+            $lines[] = $line;
+        }
+
+        return $lines;
+    }
+
+    /**
+     * Build tax total from sales_taxes table data
+     */
+    protected function buildTaxTotal(array $taxes, TaxScheme $taxScheme): TaxTotal
+    {
+        $totalTax     = '0';
+        $taxSubTotals = [];
+
+        foreach ($taxes as $tax) {
+            if (isset($tax['tax_rate'])) {
+                $taxRate   = (string) $tax['tax_rate'];
+                $taxAmount = (string) ($tax['sale_tax_amount'] ?? '0');
+
+                // Use sale_tax_basis directly from DB instead of reverse-computing
+                $taxableAmount = (string) ($tax['sale_tax_basis'] ?? '0');
+
+                // Determine category ID based on tax rate
+                $categoryId = 'S'; // Standard
+                $floatRate  = (float) $taxRate;
+                if (abs($floatRate) < 0.001) {
+                    $categoryId = 'Z'; // Zero rated
+                } elseif ($floatRate < 0) {
+                    $categoryId = 'E'; // Exempt
+                }
+
+                $taxCategory = (new TaxCategory())
+                    ->setId($categoryId)
+                    ->setPercent(round($floatRate, 2))
+                    ->setTaxScheme($taxScheme);
+
+                $taxSubTotal = (new TaxSubTotal())
+                    ->setTaxableAmount(round((float) $taxableAmount, 2))
+                    ->setTaxAmount(round((float) $taxAmount, 2))
+                    ->setTaxCategory($taxCategory);
+
+                $taxSubTotals[] = $taxSubTotal;
+                $totalTax       = bcadd($totalTax, $taxAmount);
+            }
+        }
+
+        $taxTotal = new TaxTotal();
+        $taxTotal->setTaxAmount(round((float) $totalTax, 2));
+
+        foreach ($taxSubTotals as $subTotal) {
+            $taxTotal->addTaxSubTotal($subTotal);
+        }
+
+        return $taxTotal;
+    }
+
+    /**
+     * Build monetary total
+     */
+    protected function buildMonetaryTotal(array $saleData): LegalMonetaryTotal
+    {
+        // In OSPOS, after get_totals(): subtotal is ALWAYS tax-exclusive (net)
+        // total is ALWAYS tax-inclusive (gross)
+        $subtotal  = (float) ($saleData['subtotal'] ?? 0);
+        $total     = (float) ($saleData['total'] ?? 0);
+        $amountDue = (float) ($saleData['amount_due'] ?? 0);
+
+        return (new LegalMonetaryTotal())
+            ->setLineExtensionAmount(round($subtotal, 2))
+            ->setTaxExclusiveAmount(round($subtotal, 2))
+            ->setTaxInclusiveAmount(round($total, 2))
+            ->setPayableAmount(round($amountDue, 2));
+    }
+
+    /**
+     * Parse address string into components
+     */
+    protected function parseAddress(string $address): array
+    {
+        $parts = array_filter(array_map('trim', explode("\n", $address)));
+
+        $result = [
+            'street' => '',
+            'number' => '',
+            'city'   => '',
+            'zip'    => '',
+        ];
+
+        if (! empty($parts)) {
+            $result['street'] = $parts[0];
+            if (isset($parts[1])) {
+                // Match 4-5 digit postal codes (e.g., 1234, 12345) followed by city name
+                if (preg_match('/(\d{4,5})\s*(.+)/', $parts[1], $matches)) {
+                    $result['zip']  = $matches[1];
+                    $result['city'] = $matches[2];
+                } else {
+                    $result['city'] = $parts[1];
+                }
+            }
+        }
+
+        return $result;
+    }
+}

app/Models/Sale.php

@@ -2,10 +2,10 @@
 
 namespace App\Models;
 
+use App\Libraries\Sale_lib;
 use CodeIgniter\Database\BaseBuilder;
 use CodeIgniter\Database\ResultInterface;
 use CodeIgniter\Model;
-use App\Libraries\Sale_lib;
 use Config\OSPOS;
 use ReflectionException;
 
@@ -14,11 +14,11 @@ use ReflectionException;
  */
 class Sale extends Model
 {
-    protected $table = 'sales';
-    protected $primaryKey = 'sale_id';
+    protected $table            = 'sales';
+    protected $primaryKey       = 'sale_id';
     protected $useAutoIncrement = true;
-    protected $useSoftDeletes = false;
-    protected $allowedFields = [
+    protected $useSoftDeletes   = false;
+    protected $allowedFields    = [
         'sale_time',
         'customer_id',
         'employee_id',
@@ -28,7 +28,7 @@ class Sale extends Model
         'invoice_number',
         'dinner_table_id',
         'work_order_number',
-        'sale_type'
+        'sale_type',
     ];
 
     public function __construct()
@@ -45,16 +45,16 @@ class Sale extends Model
         $config = config(OSPOS::class)->settings;
         $this->create_temp_table(['sale_id' => $sale_id]);
 
-        $decimals = totals_decimals();
-        $sales_tax = 'IFNULL(SUM(sales_items_taxes.sales_tax), 0)';
+        $decimals        = totals_decimals();
+        $sales_tax       = 'IFNULL(SUM(sales_items_taxes.sales_tax), 0)';
         $cash_adjustment = 'IFNULL(SUM(payments.sale_cash_adjustment), 0)';
-        $sale_price = 'CASE WHEN sales_items.discount_type = ' . PERCENT
-            . " THEN sales_items.quantity_purchased * sales_items.item_unit_price - ROUND(sales_items.quantity_purchased * sales_items.item_unit_price * sales_items.discount / 100, $decimals) "
+        $sale_price      = 'CASE WHEN sales_items.discount_type = ' . PERCENT
+            . " THEN sales_items.quantity_purchased * sales_items.item_unit_price - ROUND(sales_items.quantity_purchased * sales_items.item_unit_price * sales_items.discount / 100, {$decimals}) "
             . 'ELSE sales_items.quantity_purchased * (sales_items.item_unit_price - sales_items.discount) END';
 
         $sale_total = $config['tax_included']
-            ? "ROUND(SUM($sale_price), $decimals) + $cash_adjustment"
-            : "ROUND(SUM($sale_price), $decimals) + $sales_tax + $cash_adjustment";
+            ? "ROUND(SUM({$sale_price}), {$decimals}) + {$cash_adjustment}"
+            : "ROUND(SUM({$sale_price}), {$decimals}) + {$sales_tax} + {$cash_adjustment}";
 
         $sql = 'sales.sale_id AS sale_id,
                 MAX(DATE(sales.sale_time)) AS sale_date,
@@ -73,9 +73,9 @@ class Sale extends Model
                 MAX(IFnull(payments.sale_cash_adjustment, 0)) AS cash_adjustment,
                 MAX(IFnull(payments.sale_cash_refund, 0)) AS cash_refund,
                 ' . "
-                $sale_total AS amount_due,
+                {$sale_total} AS amount_due,
                 MAX(IFnull(payments.sale_payment_amount, 0)) AS amount_tendered,
-                (MAX(payments.sale_payment_amount)) - ($sale_total) AS change_due,
+                (MAX(payments.sale_payment_amount)) - ({$sale_total}) AS change_due,
                 " . '
                 MAX(payments.payment_type) AS payment_type';
 
@@ -89,7 +89,7 @@ class Sale extends Model
         $builder->join(
             'sales_items_taxes_temp AS sales_items_taxes',
             'sales_items.sale_id = sales_items_taxes.sale_id AND sales_items.item_id = sales_items_taxes.item_id AND sales_items.line = sales_items_taxes.line',
-            'LEFT OUTER'
+            'LEFT OUTER',
         );
 
         $builder->where('sales.sale_id', $sale_id);
@@ -114,15 +114,25 @@ class Sale extends Model
     public function search(?string $search, array $filters, ?int $rows = 0, ?int $limit_from = 0, ?string $sort = 'sales.sale_time', ?string $order = 'desc', ?bool $count_only = false)
     {
         // Set default values
-        if ($rows == null) $rows = 0;
-        if ($limit_from == null) $limit_from = 0;
-        if ($sort == null) $sort = 'sales.sale_time';
-        if ($order == null) $order = 'desc';
-        if ($count_only == null) $count_only = false;
+        if ($rows === null) {
+            $rows = 0;
+        }
+        if ($limit_from === null) {
+            $limit_from = 0;
+        }
+        if ($sort === null) {
+            $sort = 'sales.sale_time';
+        }
+        if ($order === null) {
+            $order = 'desc';
+        }
+        if ($count_only === null) {
+            $count_only = false;
+        }
 
-        $config = config(OSPOS::class)->settings;
+        $config    = config(OSPOS::class)->settings;
         $db_prefix = $this->db->getPrefix();
-        $decimals = totals_decimals();
+        $decimals  = totals_decimals();
 
         // Only non-suspended records
         $where = 'sales.sale_status = 0 AND ';
@@ -133,18 +143,18 @@ class Sale extends Model
         $this->create_temp_table_sales_payments_data($where);
 
         $sale_price = 'CASE WHEN `sales_items`.`discount_type` = ' . PERCENT
-            . " THEN `sales_items`.`quantity_purchased` * `sales_items`.`item_unit_price` - ROUND(`sales_items`.`quantity_purchased` * `sales_items`.`item_unit_price` * `sales_items`.`discount` / 100, $decimals) "
+            . " THEN `sales_items`.`quantity_purchased` * `sales_items`.`item_unit_price` - ROUND(`sales_items`.`quantity_purchased` * `sales_items`.`item_unit_price` * `sales_items`.`discount` / 100, {$decimals}) "
             . 'ELSE `sales_items`.`quantity_purchased` * (`sales_items`.`item_unit_price` - `sales_items`.`discount`) END';
 
         $sale_cost = 'SUM(`sales_items`.`item_cost_price` * `sales_items`.`quantity_purchased`)';
 
-        $tax = 'IFNULL(SUM(`sales_items_taxes`.`tax`), 0)';
-        $sales_tax = 'IFNULL(SUM(`sales_items_taxes`.`sales_tax`), 0)';
-        $internal_tax = 'IFNULL(SUM(`sales_items_taxes`.`internal_tax`), 0)';
+        $tax             = 'IFNULL(SUM(`sales_items_taxes`.`tax`), 0)';
+        $sales_tax       = 'IFNULL(SUM(`sales_items_taxes`.`sales_tax`), 0)';
+        $internal_tax    = 'IFNULL(SUM(`sales_items_taxes`.`internal_tax`), 0)';
         $cash_adjustment = 'IFNULL(SUM(`payments`.`sale_cash_adjustment`), 0)';
 
-        $sale_subtotal = "ROUND(SUM($sale_price), $decimals) - $internal_tax";
-        $sale_total = "ROUND(SUM($sale_price), $decimals) + $sales_tax + $cash_adjustment";
+        $sale_subtotal = "ROUND(SUM({$sale_price}), {$decimals}) - {$internal_tax}";
+        $sale_total    = "ROUND(SUM({$sale_price}), {$decimals}) + {$sales_tax} + {$cash_adjustment}";
 
         $this->create_temp_table_sales_items_taxes_data($where);
 
@@ -171,7 +181,7 @@ class Sale extends Model
                 $sale_total . ' AS amount_due',
                 'MAX(`payments`.`sale_payment_amount`) AS amount_tendered',
                 '(MAX(`payments`.`sale_payment_amount`)) - (' . $sale_total . ') AS change_due',
-                'MAX(`payments`.`payment_type`) AS payment_type'
+                'MAX(`payments`.`payment_type`) AS payment_type',
             ], false);
         }
 
@@ -182,7 +192,7 @@ class Sale extends Model
         $builder->join(
             'sales_items_taxes_temp AS sales_items_taxes',
             'sales_items.sale_id = sales_items_taxes.sale_id AND sales_items.item_id = sales_items_taxes.item_id AND sales_items.line = sales_items_taxes.line',
-            'LEFT OUTER'
+            'LEFT OUTER',
         );
 
         $builder->where($where);
@@ -227,7 +237,7 @@ class Sale extends Model
             $builder->where('sales.sale_time BETWEEN ' . $this->db->escape(rawurldecode($filters['start_date'])) . ' AND ' . $this->db->escape(rawurldecode($filters['end_date'])));
         }
 
-        if (!empty($search)) {    // TODO: duplicated code.  We should think about refactoring out a method.
+        if (! empty($search)) {    // TODO: duplicated code.  We should think about refactoring out a method.
             if ($filters['is_valid_receipt']) {
                 $pieces = explode(' ', $search);
                 $builder->where('sales.sale_id', $pieces[1]);
@@ -242,13 +252,13 @@ class Sale extends Model
         }
 
         // TODO: This needs to be converted to a switch statement
-        if ($filters['sale_type'] == 'sales') {    // TODO: we need to think about refactoring this block to a switch statement.
+        if ($filters['sale_type'] === 'sales') {    // TODO: we need to think about refactoring this block to a switch statement.
             $builder->where('sales.sale_status = ' . COMPLETED . ' AND payment_amount > 0');
-        } elseif ($filters['sale_type'] == 'quotes') {
+        } elseif ($filters['sale_type'] === 'quotes') {
             $builder->where('sales.sale_status = ' . SUSPENDED . ' AND sales.quote_number IS NOT NULL');
-        } elseif ($filters['sale_type'] == 'returns') {
+        } elseif ($filters['sale_type'] === 'returns') {
             $builder->where('sales.sale_status = ' . COMPLETED . ' AND payment_amount < 0');
-        } elseif ($filters['sale_type'] == 'all') {
+        } elseif ($filters['sale_type'] === 'all') {
             $builder->where('sales.sale_status = ' . COMPLETED);
         }
 
@@ -290,12 +300,12 @@ class Sale extends Model
         $payments = $builder->get()->getResultArray();
 
         // Consider Gift Card as only one type of payment and do not show "Gift Card: 1, Gift Card: 2, etc." in the total
-        $gift_card_count = 0;
+        $gift_card_count  = 0;
         $gift_card_amount = 0;
 
         foreach ($payments as $key => $payment) {
             if (strstr($payment['payment_type'], lang('Sales.giftcard'))) {
-                $gift_card_count  += $payment['count'];
+                $gift_card_count += $payment['count'];
                 $gift_card_amount += $payment['payment_amount'];
 
                 // Remove the "Gift Card: 1", "Gift Card: 2", etc. payment string
@@ -327,7 +337,7 @@ class Sale extends Model
     {
         $suggestions = [];
 
-        if (!$this->is_valid_receipt($search)) {
+        if (! $this->is_valid_receipt($search)) {
             $builder = $this->db->table('sales');
             $builder->distinct()->select('first_name, last_name');
             $builder->join('people', 'people.person_id = sales.customer_id');
@@ -369,21 +379,11 @@ class Sale extends Model
         return $builder->get();
     }
 
-    /**
-     * @param string $year
-     * @param int $start_from
-     * @return int
-     */
     public function get_invoice_number_for_year(string $year = '', int $start_from = 0): int
     {
         return $this->get_number_for_year('invoice_number', $year, $start_from);
     }
 
-    /**
-     * @param string $year
-     * @param int $start_from
-     * @return int
-     */
     public function get_quote_number_for_year(string $year = '', int $start_from = 0): int
     {
         return $this->get_number_for_year('quote_number', $year, $start_from);
@@ -394,31 +394,32 @@ class Sale extends Model
      */
     private function get_number_for_year(string $field, string $year = '', int $start_from = 0): int
     {
-        $year = $year == '' ? date('Y') : $year;
+        $year = $year === '' ? date('Y') : $year;
 
         $builder = $this->db->table('sales');
         $builder->select('COUNT( 1 ) AS number_year');
         $builder->where('DATE_FORMAT(sale_time, "%Y" ) = ', $year);
-        $builder->where("$field IS NOT NULL");
+        $builder->where("{$field} IS NOT NULL");
         $result = $builder->get()->getRowArray();
 
-        return ($start_from + $result['number_year']);
+        return $start_from + $result['number_year'];
     }
 
     /**
      * Checks if valid receipt
      */
-    public function is_valid_receipt(string|null &$receipt_sale_id): bool    // TODO: like the others, maybe this should be an array rather than a delimited string... either that or the parameter name needs to be changed. $receipt_sale_id implies that it's an int.
+    public function is_valid_receipt(?string &$receipt_sale_id): bool    // TODO: like the others, maybe this should be an array rather than a delimited string... either that or the parameter name needs to be changed. $receipt_sale_id implies that it's an int.
     {
         $config = config(OSPOS::class)->settings;
 
-        if (!empty($receipt_sale_id)) {
+        if (! empty($receipt_sale_id)) {
             // POS #
             $pieces = explode(' ', $receipt_sale_id);
 
-            if (count($pieces) == 2 && preg_match('/(POS)/i', $pieces[0])) {
+            if (count($pieces) === 2 && preg_match('/(POS)/i', $pieces[0])) {
                 return $this->exists($pieces[1]);
-            } elseif ($config['invoice_enable']) {
+            }
+            if ($config['invoice_enable']) {
                 $sale_info = $this->get_sale_by_invoice_number($receipt_sale_id);
 
                 if ($sale_info->getNumRows() > 0) {
@@ -440,11 +441,14 @@ class Sale extends Model
         $builder = $this->db->table('sales');
         $builder->where('sale_id', $sale_id);
 
-        return ($builder->get()->getNumRows() == 1);    // TODO: ===
+        return $builder->get()->getNumRows() === 1;    // TODO: ===
     }
 
     /**
      * Update sale
+     *
+     * @param mixed|null $sale_id
+     * @param mixed|null $sale_data
      */
     public function update($sale_id = null, $sale_data = null): bool
     {
@@ -455,7 +459,7 @@ class Sale extends Model
         $success = $builder->update($update_data);
 
         // Touch payment only if update sale is successful and there is a payments object otherwise the result would be to delete all the payments associated to the sale
-        if ($success && !empty($sale_data['payments'])) {
+        if ($success && ! empty($sale_data['payments'])) {
             // Run these queries as a transaction, we want to make sure we do all or nothing
             $this->db->transStart();
 
@@ -463,14 +467,14 @@ class Sale extends Model
 
             // Add new payments
             foreach ($sale_data['payments'] as $payment) {
-                $payment_id = $payment['payment_id'];
-                $payment_type = $payment['payment_type'];
-                $payment_amount = $payment['payment_amount'];
-                $cash_refund = $payment['cash_refund'];
+                $payment_id      = $payment['payment_id'];
+                $payment_type    = $payment['payment_type'];
+                $payment_amount  = $payment['payment_amount'];
+                $cash_refund     = $payment['cash_refund'];
                 $cash_adjustment = $payment['cash_adjustment'];
-                $employee_id = $payment['employee_id'];
+                $employee_id     = $payment['employee_id'];
 
-                if ($payment_id == NEW_ENTRY && $payment_amount != 0) {
+                if ($payment_id === NEW_ENTRY && $payment_amount !== 0) {
                     // Add a new payment transaction
                     $sales_payments_data = [
                         'sale_id'         => $sale_id,
@@ -478,17 +482,17 @@ class Sale extends Model
                         'payment_amount'  => $payment_amount,
                         'cash_refund'     => $cash_refund,
                         'cash_adjustment' => $cash_adjustment,
-                        'employee_id'     => $employee_id
+                        'employee_id'     => $employee_id,
                     ];
                     $success = $builder->insert($sales_payments_data);
-                } elseif ($payment_id != NEW_ENTRY) {
-                    if ($payment_amount != 0) {
+                } elseif ($payment_id !== NEW_ENTRY) {
+                    if ($payment_amount !== 0) {
                         // Update existing payment transactions (payment_type only)
                         $sales_payments_data = [
                             'payment_type'    => $payment_type,
                             'payment_amount'  => $payment_amount,
                             'cash_refund'     => $cash_refund,
-                            'cash_adjustment' => $cash_adjustment
+                            'cash_adjustment' => $cash_adjustment,
                         ];
 
                         $builder->where('payment_id', $payment_id);
@@ -510,6 +514,7 @@ class Sale extends Model
     /**
      * Save the sale information after the sales is complete but before the final document is printed
      * The sales_taxes variable needs to be initialized to an empty array before calling
+     *
      * @throws ReflectionException
      */
     public function save_value(
@@ -525,22 +530,22 @@ class Sale extends Model
         int $sale_type,
         ?array $payments,
         ?int $dinner_table_id,
-        ?array &$sales_taxes
+        ?array &$sales_taxes,
     ): int {    // TODO: this method returns the sale_id but the override is expecting it to return a bool. The signature needs to be reworked.  Generally when there are more than 3 maybe 4 parameters, there's a good chance that an object needs to be passed rather than so many params.
-        $config = config(OSPOS::class)->settings;
+        $config    = config(OSPOS::class)->settings;
         $attribute = model(Attribute::class);
-        $customer = model(Customer::class);
-        $giftcard = model(Giftcard::class);
+        $customer  = model(Customer::class);
+        $giftcard  = model(Giftcard::class);
         $inventory = model('Inventory');
-        $item = model(Item::class);
+        $item      = model(Item::class);
 
         $item_quantity = model(Item_quantity::class);
 
-        if ($sale_id != NEW_ENTRY) {
+        if ($sale_id !== NEW_ENTRY) {
             $this->clear_suspended_sale_detail($sale_id);
         }
 
-        if (count($items) == 0) {    // TODO: ===
+        if (count($items) === 0) {    // TODO: ===
             return -1;    // TODO: Replace -1 with a constant
         }
 
@@ -554,13 +559,13 @@ class Sale extends Model
             'quote_number'      => $quote_number,
             'work_order_number' => $work_order_number,
             'dinner_table_id'   => $dinner_table_id,
-            'sale_type'         => $sale_type
+            'sale_type'         => $sale_type,
         ];
 
         // Run these queries as a transaction, we want to make sure we do all or nothing
         $this->db->transStart();
 
-        if ($sale_id == NEW_ENTRY) {
+        if ($sale_id === NEW_ENTRY) {
             $builder = $this->db->table('sales');
             $builder->insert($sales_data);
             $sale_id = $this->db->insertID();
@@ -570,19 +575,19 @@ class Sale extends Model
             $builder->update($sales_data);
         }
 
-        $total_amount = 0;
+        $total_amount      = 0;
         $total_amount_used = 0;
 
         foreach ($payments as $payment_id => $payment) {
-            if (!empty(strstr($payment['payment_type'], lang('Sales.giftcard')))) {
+            if (! empty(strstr($payment['payment_type'], lang('Sales.giftcard')))) {
                 // We have a gift card, and we have to deduct the used value from the total value of the card.
-                $splitpayment = explode(':', $payment['payment_type']);    // TODO: this variable doesn't follow our naming conventions.  Probably should be refactored to split_payment.
+                $splitpayment       = explode(':', $payment['payment_type']);    // TODO: this variable doesn't follow our naming conventions.  Probably should be refactored to split_payment.
                 $cur_giftcard_value = $giftcard->get_giftcard_value($splitpayment[1]);    // TODO: this should be refactored to $current_giftcard_value
                 $giftcard->update_giftcard_value($splitpayment[1], $cur_giftcard_value - $payment['payment_amount']);
-            } elseif (!empty(strstr($payment['payment_type'], lang('Sales.rewards')))) {
+            } elseif (! empty(strstr($payment['payment_type'], lang('Sales.rewards')))) {
                 $cur_rewards_value = $customer->get_info($customer_id)->points;
                 $customer->update_reward_points_value($customer_id, $cur_rewards_value - $payment['payment_amount']);
-                $total_amount_used = floatval($total_amount_used) + floatval($payment['payment_amount']);
+                $total_amount_used = (float) $total_amount_used + (float) ($payment['payment_amount']);
             }
 
             $sales_payments_data = [
@@ -591,13 +596,13 @@ class Sale extends Model
                 'payment_amount'  => $payment['payment_amount'],
                 'cash_refund'     => $payment['cash_refund'],
                 'cash_adjustment' => $payment['cash_adjustment'],
-                'employee_id'     => $employee_id
+                'employee_id'     => $employee_id,
             ];
 
             $builder = $this->db->table('sales_payments');
             $builder->insert($sales_payments_data);
 
-            $total_amount = floatval($total_amount) + floatval($payment['payment_amount']) - floatval($payment['cash_refund']);
+            $total_amount = (float) $total_amount + (float) ($payment['payment_amount']) - (float) ($payment['cash_refund']);
         }
 
         $this->save_customer_rewards($customer_id, $sale_id, $total_amount, $total_amount_used);
@@ -607,7 +612,7 @@ class Sale extends Model
         foreach ($items as $line => $item_data) {
             $cur_item_info = $item->get_info($item_data['item_id']);
 
-            if ($item_data['price'] == 0.00) {
+            if ($item_data['price'] === 0.00) {
                 $item_data['discount'] = 0.00;
             }
 
@@ -623,13 +628,13 @@ class Sale extends Model
                 'item_cost_price'    => $item_data['cost_price'],
                 'item_unit_price'    => $item_data['price'],
                 'item_location'      => $item_data['item_location'],
-                'print_option'       => $item_data['print_option']
+                'print_option'       => $item_data['print_option'],
             ];
 
             $builder = $this->db->table('sales_items');
             $builder->insert($sales_items_data);
 
-            if ($cur_item_info->stock_type == HAS_STOCK && $sale_status == COMPLETED) {    // TODO: === ?
+            if ($cur_item_info->stock_type === HAS_STOCK && $sale_status === COMPLETED) {    // TODO: === ?
                 // Update stock quantity if item type is a standard stock item and the sale is a standard sale
                 $item_quantity_data = $item_quantity->get_item_quantity($item_data['item_id'], $item_data['item_location']);
 
@@ -637,10 +642,10 @@ class Sale extends Model
                     [
                         'quantity'    => $item_quantity_data->quantity - $item_data['quantity'],
                         'item_id'     => $item_data['item_id'],
-                        'location_id' => $item_data['item_location']
+                        'location_id' => $item_data['item_location'],
                     ],
                     $item_data['item_id'],
-                    $item_data['item_location']
+                    $item_data['item_location'],
                 );
 
                 // If an items was deleted but later returned it's restored with this rule
@@ -650,13 +655,13 @@ class Sale extends Model
 
                 // Inventory Count Details
                 $sale_remarks = 'POS ' . $sale_id;    // TODO: Use string interpolation here.
-                $inv_data = [
+                $inv_data     = [
                     'trans_date'      => date('Y-m-d H:i:s'),
                     'trans_items'     => $item_data['item_id'],
                     'trans_user'      => $employee_id,
                     'trans_location'  => $item_data['item_location'],
                     'trans_comment'   => $sale_remarks,
-                    'trans_inventory' => -$item_data['quantity']
+                    'trans_inventory' => -$item_data['quantity'],
                 ];
 
                 $inventory->insert($inv_data, false);
@@ -665,14 +670,14 @@ class Sale extends Model
             $attribute->copy_attribute_links($item_data['item_id'], 'sale_id', $sale_id);
         }
 
-        if ($customer_id == NEW_ENTRY || $customer->taxable) {
+        if ($customer_id === NEW_ENTRY || $customer->taxable) {
             $this->save_sales_tax($sale_id, $sales_taxes[0]);
             $this->save_sales_items_taxes($sale_id, $sales_taxes[1]);
         }
 
         if ($config['dinner_table_enable']) {
             $dinner_table = model(Dinner_table::class);
-            if ($sale_status == COMPLETED) {    // TODO: === ?
+            if ($sale_status === COMPLETED) {    // TODO: === ?
                 $dinner_table->release($dinner_table_id);
             } else {
                 $dinner_table->occupy($dinner_table_id);
@@ -721,7 +726,7 @@ class Sale extends Model
                 'item_tax_amount'   => $tax_item['item_tax_amount'],
                 'sales_tax_code_id' => $tax_item['sales_tax_code_id'],
                 'tax_category_id'   => $tax_item['tax_category_id'],
-                'jurisdiction_id'   => $tax_item['jurisdiction_id']
+                'jurisdiction_id'   => $tax_item['jurisdiction_id'],
             ];
 
             $builder->insert($sales_items_taxes);
@@ -756,8 +761,36 @@ class Sale extends Model
         return $builder->get()->getResultArray();
     }
 
+    /**
+     * Return all item taxes for a sale (for UBL invoice generation)
+     * Returns array keyed by item_id, each containing array of tax info
+     */
+    public function get_sale_item_taxes_by_sale(int $sale_id): array
+    {
+        $builder = $this->db->table('sales_items_taxes');
+        $builder->select('item_id, line, name, percent, tax_type, item_tax_amount');
+        $builder->where('sale_id', $sale_id);
+        $builder->orderBy('line', 'asc');
+
+        $results = $builder->get()->getResultArray();
+
+        // Group by item_id
+        $itemTaxes = [];
+
+        foreach ($results as $row) {
+            $itemId = $row['item_id'];
+            if (! isset($itemTaxes[$itemId])) {
+                $itemTaxes[$itemId] = [];
+            }
+            $itemTaxes[$itemId][] = $row;
+        }
+
+        return $itemTaxes;
+    }
+
     /**
      * Deletes list of sales
+     *
      * @throws ReflectionException
      */
     public function delete_list(array $sale_ids, int $employee_id, bool $update_inventory = true): bool
@@ -787,6 +820,10 @@ class Sale extends Model
      * Delete sale.  Hard deletes are not supported for sales transactions.
      * When a sale is "deleted" it is simply changed to a status of canceled.
      * However, if applicable the inventory still needs to be updated
+     *
+     * @param mixed|null $sale_id
+     * @param mixed|null $employee_id
+     *
      * @throws ReflectionException
      */
     public function delete($sale_id = null, bool $purge = false, bool $update_inventory = true, $employee_id = null): bool
@@ -796,11 +833,11 @@ class Sale extends Model
 
         $sale_status = $this->get_sale_status($sale_id);
 
-        if ($update_inventory && $sale_status == COMPLETED) {
+        if ($update_inventory && $sale_status === COMPLETED) {
             // Defect, not all item deletions will be undone?
             // Get array with all the items involved in the sale to update the inventory tracking
-            $inventory = model('Inventory');
-            $item = model(Item::class);
+            $inventory     = model('Inventory');
+            $item          = model(Item::class);
             $item_quantity = model(Item_quantity::class);
 
             $items = $this->get_sale_items($sale_id)->getResultArray();
@@ -808,7 +845,7 @@ class Sale extends Model
             foreach ($items as $item_data) {
                 $cur_item_info = $item->get_info($item_data['item_id']);
 
-                if ($cur_item_info->stock_type == HAS_STOCK) {
+                if ($cur_item_info->stock_type === HAS_STOCK) {
                     // Create query to update inventory tracking
                     $inv_data = [
                         'trans_date'      => date('Y-m-d H:i:s'),
@@ -816,7 +853,7 @@ class Sale extends Model
                         'trans_user'      => $employee_id,
                         'trans_comment'   => 'Deleting sale ' . $sale_id,
                         'trans_location'  => $item_data['item_location'],
-                        'trans_inventory' => $item_data['quantity_purchased']
+                        'trans_inventory' => $item_data['quantity_purchased'],
                     ];
                     // Update inventory
                     $inventory->insert($inv_data, false);
@@ -852,7 +889,7 @@ class Sale extends Model
     public function get_sale_items_ordered(int $sale_id): ResultInterface
     {
         $config = config(OSPOS::class)->settings;
-        $item = model(Item::class);
+        $item   = model(Item::class);
 
         $builder = $this->db->table('sales_items AS sales_items');
         $builder->select('
@@ -876,18 +913,18 @@ class Sale extends Model
         $builder->where('sales_items.sale_id', $sale_id);
 
         // Entry sequence (this will render kits in the expected sequence)
-        if ($config['line_sequence'] == '0') {    // TODO: Replace these with constants and this should be converted to a switch.
+        if ($config['line_sequence'] === '0') {    // TODO: Replace these with constants and this should be converted to a switch.
             $builder->orderBy('line', 'asc');
         }
         // Group by Stock Type (nonstock first - type 1, stock next - type 0)
-        elseif ($config['line_sequence'] == '1') {
+        elseif ($config['line_sequence'] === '1') {
             $builder->orderBy('stock_type', 'desc');
             $builder->orderBy('sales_items.description', 'asc');
             $builder->orderBy('items.name', 'asc');
             $builder->orderBy('items.qty_per_pack', 'asc');
         }
         // Group by Item Category
-        elseif ($config['line_sequence'] == '2') {
+        elseif ($config['line_sequence'] === '2') {
             $builder->orderBy('category', 'asc');
             $builder->orderBy('sales_items.description', 'asc');
             $builder->orderBy('items.name', 'asc');
@@ -927,8 +964,8 @@ class Sale extends Model
             $payments[lang('Sales.rewards')] = lang('Sales.rewards');
         }
         $sale_lib = new Sale_lib();
-        if ($sale_lib->get_mode() == 'sale_work_order') {
-            $payments[lang('Sales.cash_deposit')] = lang('Sales.cash_deposit');
+        if ($sale_lib->get_mode() === 'sale_work_order') {
+            $payments[lang('Sales.cash_deposit')]   = lang('Sales.cash_deposit');
             $payments[lang('Sales.credit_deposit')] = lang('Sales.credit_deposit');
         }
 
@@ -969,11 +1006,11 @@ class Sale extends Model
         $builder = $this->db->table('sales');
         $builder->where('quote_number', $quote_number);
 
-        if (!empty($sale_id)) {
+        if (! empty($sale_id)) {
             $builder->where('sale_id !=', $sale_id);
         }
 
-        return ($builder->get()->getNumRows() == 1);    // TODO: ===
+        return $builder->get()->getNumRows() === 1;    // TODO: ===
     }
 
     /**
@@ -984,11 +1021,11 @@ class Sale extends Model
         $builder = $this->db->table('sales');
         $builder->where('invoice_number', $invoice_number);
 
-        if (!empty($sale_id)) {
+        if (! empty($sale_id)) {
             $builder->where('sale_id !=', $sale_id);
         }
 
-        return ($builder->get()->getNumRows() == 1);    // TODO: ===
+        return $builder->get()->getNumRows() === 1;    // TODO: ===
     }
 
     /**
@@ -998,11 +1035,11 @@ class Sale extends Model
     {
         $builder = $this->db->table('sales');
         $builder->where('invoice_number', $work_order_number);
-        if (!empty($sale_id)) {
+        if (! empty($sale_id)) {
             $builder->where('sale_id !=', $sale_id);
         }
 
-        return ($builder->get()->getNumRows() == 1);    // TODO: ===
+        return $builder->get()->getNumRows() === 1;    // TODO: ===
     }
 
     /**
@@ -1012,7 +1049,7 @@ class Sale extends Model
     {
         $giftcard = model(Giftcard::class);
 
-        if (!$giftcard->exists($giftcard->get_giftcard_id($giftcardNumber))) {    // TODO: camelCase is used here for the variable name but we are using _ everywhere else. CI4 moved to camelCase... we should pick one and do that.
+        if (! $giftcard->exists($giftcard->get_giftcard_id($giftcardNumber))) {    // TODO: camelCase is used here for the variable name but we are using _ everywhere else. CI4 moved to camelCase... we should pick one and do that.
             return 0;
         }
 
@@ -1043,22 +1080,22 @@ class Sale extends Model
         $decimals = totals_decimals();
 
         $sale_price = 'CASE WHEN sales_items.discount_type = ' . PERCENT
-            . " THEN sales_items.quantity_purchased * sales_items.item_unit_price - ROUND(sales_items.quantity_purchased * sales_items.item_unit_price * sales_items.discount / 100, $decimals) "
+            . " THEN sales_items.quantity_purchased * sales_items.item_unit_price - ROUND(sales_items.quantity_purchased * sales_items.item_unit_price * sales_items.discount / 100, {$decimals}) "
             . 'ELSE sales_items.quantity_purchased * (sales_items.item_unit_price - sales_items.discount) END';
 
         $sale_cost = 'SUM(sales_items.item_cost_price * sales_items.quantity_purchased)';
 
-        $tax = 'IFNULL(SUM(sales_items_taxes.tax), 0)';
-        $sales_tax = 'IFNULL(SUM(sales_items_taxes.sales_tax), 0)';
-        $internal_tax = 'IFNULL(SUM(sales_items_taxes.internal_tax), 0)';
+        $tax             = 'IFNULL(SUM(sales_items_taxes.tax), 0)';
+        $sales_tax       = 'IFNULL(SUM(sales_items_taxes.sales_tax), 0)';
+        $internal_tax    = 'IFNULL(SUM(sales_items_taxes.internal_tax), 0)';
         $cash_adjustment = 'IFNULL(SUM(payments.sale_cash_adjustment), 0)';
 
         if ($config['tax_included']) {
-            $sale_total = "ROUND(SUM($sale_price), $decimals) + $cash_adjustment";
-            $sale_subtotal = "$sale_total - $internal_tax";
+            $sale_total    = "ROUND(SUM({$sale_price}), {$decimals}) + {$cash_adjustment}";
+            $sale_subtotal = "{$sale_total} - {$internal_tax}";
         } else {
-            $sale_subtotal = "ROUND(SUM($sale_price), $decimals) - $internal_tax + $cash_adjustment";
-            $sale_total = "ROUND(SUM($sale_price), $decimals) + $sales_tax + $cash_adjustment";
+            $sale_subtotal = "ROUND(SUM({$sale_price}), {$decimals}) - {$internal_tax} + {$cash_adjustment}";
+            $sale_total    = "ROUND(SUM({$sale_price}), {$decimals}) + {$sales_tax} + {$cash_adjustment}";
         }
 
         // Create a temporary table to contain all the sum of taxes per sale item
@@ -1100,7 +1137,7 @@ class Sale extends Model
 
         $this->db->query($sql);
         $item = model(Item::class);
-        $sql = 'CREATE TEMPORARY TABLE IF NOT EXISTS ' . $this->db->prefixTable('sales_items_temp') .
+        $sql  = 'CREATE TEMPORARY TABLE IF NOT EXISTS ' . $this->db->prefixTable('sales_items_temp') .
             ' (INDEX(sale_date), INDEX(sale_time), INDEX(sale_id))
             (
                 SELECT
@@ -1122,7 +1159,7 @@ class Sale extends Model
                     MAX(sales.employee_id) AS employee_id,
                     MAX(CONCAT(employee.first_name, " ", employee.last_name)) AS employee_name,
                     items.item_id AS item_id,
-                    MAX(' . $item->get_item_name() . ') AS name,
+                    MAX(' . $item->get_item_name() . ") AS name,
                     MAX(items.item_number) AS item_number,
                     MAX(items.category) AS category,
                     MAX(items.supplier_id) AS supplier_id,
@@ -1137,12 +1174,12 @@ class Sale extends Model
                     MAX(sales_items.description) AS description,
                     MAX(payments.payment_type) AS payment_type,
                     MAX(payments.sale_payment_amount) AS sale_payment_amount,
-                    ' . "
-                    $sale_subtotal AS subtotal,
-                    $tax AS tax,
-                    $sale_total AS total,
-                    $sale_cost AS cost,
-                    ($sale_subtotal - $sale_cost) AS profit
+
+                    {$sale_subtotal} AS subtotal,
+                    {$tax} AS tax,
+                    {$sale_total} AS total,
+                    {$sale_cost} AS cost,
+                    ({$sale_subtotal} - {$sale_cost}) AS profit
                     " . '
                 FROM ' . $this->db->prefixTable('sales_items') . ' AS sales_items
                 INNER JOIN ' . $this->db->prefixTable('sales') . ' AS sales
@@ -1173,7 +1210,7 @@ class Sale extends Model
      */
     public function get_all_suspended(?int $customer_id = null): array
     {
-        if ($customer_id == NEW_ENTRY) {
+        if ($customer_id === NEW_ENTRY) {
             $query = $this->db->query("SELECT sale_id, case when sale_type = '" . SALE_TYPE_QUOTE . "' THEN quote_number WHEN sale_type = '" . SALE_TYPE_WORK_ORDER . "' THEN work_order_number else sale_id end as doc_id, sale_id as suspended_sale_id, sale_status, sale_time, dinner_table_id, customer_id, employee_id, comment FROM "
                 . $this->db->prefixTable('sales') . ' where sale_status = ' . SUSPENDED);
         } else {
@@ -1189,7 +1226,7 @@ class Sale extends Model
      */
     public function get_dinner_table(int $sale_id)    // TODO: this is returning null or the table_id.  We can keep it this way but multiple return types can't be declared until PHP 8.x
     {
-        if ($sale_id == NEW_ENTRY) {
+        if ($sale_id === NEW_ENTRY) {
             return null;
         }
 
@@ -1221,11 +1258,6 @@ class Sale extends Model
         return $builder->get()->getRow()->sale_status;
     }
 
-    /**
-     * @param int $sale_id
-     * @param int $sale_status
-     * @return void
-     */
     public function update_sale_status(int $sale_id, int $sale_status): void
     {
         $builder = $this->db->table('sales');
@@ -1244,7 +1276,7 @@ class Sale extends Model
 
         $row = $builder->get()->getRow();
 
-        if ($row != null) {
+        if ($row !== null) {
             return $row->quote_number;
         }
 
@@ -1261,7 +1293,7 @@ class Sale extends Model
 
         $row = $builder->get()->getRow();
 
-        if ($row != null) {    // TODO: === ?
+        if ($row !== null) {    // TODO: === ?
             return $row->work_order_number;
         }
 
@@ -1278,7 +1310,7 @@ class Sale extends Model
 
         $row = $builder->get()->getRow();
 
-        if ($row != null) {    // TODO: === ?
+        if ($row !== null) {    // TODO: === ?
             return $row->comment;
         }
 
@@ -1308,7 +1340,7 @@ class Sale extends Model
         $config = config(OSPOS::class)->settings;
 
         if ($config['dinner_table_enable']) {
-            $dinner_table = model(Dinner_table::class);
+            $dinner_table    = model(Dinner_table::class);
             $dinner_table_id = $this->get_dinner_table($sale_id);
             $dinner_table->release($dinner_table_id);
         }
@@ -1330,7 +1362,7 @@ class Sale extends Model
         $config = config(OSPOS::class)->settings;
 
         if ($config['dinner_table_enable']) {
-            $dinner_table = model(Dinner_table::class);
+            $dinner_table    = model(Dinner_table::class);
             $dinner_table_id = $this->get_dinner_table($sale_id);
             $dinner_table->release($dinner_table_id);
         }
@@ -1365,30 +1397,24 @@ class Sale extends Model
         return $builder->get();
     }
 
-    /**
-     * @param int $customer_id
-     * @param int $sale_id
-     * @param float $total_amount
-     * @param float $total_amount_used
-     */
     private function save_customer_rewards(int $customer_id, int $sale_id, float $total_amount, float $total_amount_used): void
     {
         $config = config(OSPOS::class)->settings;
 
-        if (!empty($customer_id) && $config['customer_reward_enable']) {
-            $customer = model(Customer::class);
+        if (! empty($customer_id) && $config['customer_reward_enable']) {
+            $customer         = model(Customer::class);
             $customer_rewards = model(Customer_rewards::class);
-            $rewards = model(Rewards::class);
+            $rewards          = model(Rewards::class);
 
             $package_id = $customer->get_info($customer_id)->package_id;
 
-            if (!empty($package_id)) {
-                $points_percent = $customer_rewards->get_points_percent($package_id);
-                $points = $customer->get_info($customer_id)->points;
-                $points = ($points == null ? 0 : $points);
-                $points_percent = ($points_percent == null ? 0 : $points_percent);
+            if (! empty($package_id)) {
+                $points_percent      = $customer_rewards->get_points_percent($package_id);
+                $points              = $customer->get_info($customer_id)->points;
+                $points              = ($points === null ? 0 : $points);
+                $points_percent      = ($points_percent === null ? 0 : $points_percent);
                 $total_amount_earned = ($total_amount * $points_percent / 100);
-                $points = $points + $total_amount_earned;
+                $points += $total_amount_earned;
 
                 $customer->update_reward_points_value($customer_id, $points);
 
@@ -1402,7 +1428,6 @@ class Sale extends Model
     /**
      * Creates a temporary table to store the sales_payments data
      *
-     * @param string $where
      * @return array
      */
     private function create_temp_table_sales_payments_data(string $where): void
@@ -1412,7 +1437,7 @@ class Sale extends Model
             'payments.sale_id',
             'SUM(CASE WHEN `payments`.`cash_adjustment` = 0 THEN `payments`.`payment_amount` ELSE 0 END) AS sale_payment_amount',
             'SUM(CASE WHEN `payments`.`cash_adjustment` = 1 THEN `payments`.`payment_amount` ELSE 0 END) AS sale_cash_adjustment',
-            'GROUP_CONCAT(CONCAT(`payments`.`payment_type`, " ", (`payments`.`payment_amount` - `payments`.`cash_refund`)) SEPARATOR ", ") AS payment_type'
+            'GROUP_CONCAT(CONCAT(`payments`.`payment_type`, " ", (`payments`.`payment_amount` - `payments`.`cash_refund`)) SEPARATOR ", ") AS payment_type',
         ]);
         $builder->join('sales', 'sales.sale_id = payments.sale_id', 'inner');
         $builder->where($where);
@@ -1429,12 +1454,10 @@ class Sale extends Model
     /**
      * Temporary table to store the sales_items_taxes data
      *
-     * @param string $where
-     * @return \CodeIgniter\Database\BaseBuilder
+     * @return BaseBuilder
      */
     private function create_temp_table_sales_items_taxes_data(string $where): void
     {
-
         $builder = $this->db->table('sales_items_taxes AS sales_items_taxes');
         $builder->select([
             'sales_items_taxes.sale_id AS sale_id',
@@ -1442,7 +1465,7 @@ class Sale extends Model
             'sales_items_taxes.line AS line',
             'SUM(sales_items_taxes.item_tax_amount) AS tax',
             'SUM(CASE WHEN sales_items_taxes.tax_type = 0 THEN sales_items_taxes.item_tax_amount ELSE 0 END) AS internal_tax',
-            'SUM(CASE WHEN sales_items_taxes.tax_type = 1 THEN sales_items_taxes.item_tax_amount ELSE 0 END) AS sales_tax'
+            'SUM(CASE WHEN sales_items_taxes.tax_type = 1 THEN sales_items_taxes.item_tax_amount ELSE 0 END) AS sales_tax',
         ]);
         $builder->join('sales', 'sales.sale_id = sales_items_taxes.sale_id', 'inner');
         $builder->join('sales_items', 'sales_items.sale_id = sales_items_taxes.sale_id AND sales_items.line = sales_items_taxes.line', 'inner');
@@ -1455,15 +1478,9 @@ class Sale extends Model
             . ' (INDEX(sale_id), INDEX(item_id)) ENGINE=MEMORY AS (' . $sub_query . ')');
     }
 
-    /**
-     * @param string $search
-     * @param array $filters
-     * @param BaseBuilder $builder
-     * @return void
-     */
     private function add_filters_to_query(?string $search, array $filters, BaseBuilder $builder): void
     {
-        if (!empty($search)) {    // TODO: this is duplicated code.  We should think about refactoring out a method
+        if (! empty($search)) {    // TODO: this is duplicated code.  We should think about refactoring out a method
             if ($filters['is_valid_receipt']) {
                 $pieces = explode(' ', $search);
                 $builder->where('sales.sale_id', $pieces[1]);
@@ -1481,16 +1498,15 @@ class Sale extends Model
             }
         }
 
-        if ($filters['location_id'] != 'all') {
+        if ($filters['location_id'] !== 'all') {
             $builder->where('sales_items.item_location', $filters['location_id']);
         }
 
-        if ($filters['selected_customer'] != false) {
+        if ($filters['selected_customer'] !== false) {
             $sale_lib = new Sale_lib();
             $builder->where('sales.customer_id', $sale_lib->get_customer());
         }
 
-
         if ($filters['only_invoices']) {
             $builder->where('sales.invoice_number IS NOT NULL');
         }

app/Views/sales/invoice.php

@@ -69,6 +69,7 @@ if (isset($error_message)) {
             <div class="btn btn-info btn-sm" id="show_email_button"><?= '<span class="glyphicon glyphicon-envelope">&nbsp;</span>' . lang('Sales.send_invoice') ?></div>
         </a>
     <?php endif; ?>
+    <?= anchor("sales/ublInvoice/$sale_id_num", '<span class="glyphicon glyphicon-download">&nbsp;</span>' . lang('Sales.download_ubl'), ['class' => 'btn btn-info btn-sm']) ?>
     <?= anchor("sales", '<span class="glyphicon glyphicon-shopping-cart">&nbsp;</span>' . lang('Sales.register'), ['class' => 'btn btn-info btn-sm', 'id' => 'show_sales_button']) ?>
     <?= anchor("sales/manage", '<span class="glyphicon glyphicon-list-alt">&nbsp;</span>' . lang('Sales.takings'), ['class' => 'btn btn-info btn-sm', 'id' => 'show_takings_button']) ?>
 </div>

composer.json

@@ -31,6 +31,8 @@
         "dompdf/dompdf": "^2.0.3",
         "ezyang/htmlpurifier": "^4.17",
         "laminas/laminas-escaper": "2.18.0",
+        "nesbot/carbon": "^2.72",
+        "num-num/ubl-invoice": "^2.4",
         "paragonie/random_compat": "^2.0.21",
         "picqer/php-barcode-generator": "^2.4.0",
         "tamtamchik/namecase": "^3.0.0"

tests/Libraries/InvoiceAttachment/InvoiceAttachmentGeneratorTest.php

@@ -0,0 +1,121 @@
+<?php
+
+namespace Tests\Libraries\InvoiceAttachment;
+
+use CodeIgniter\Test\CIUnitTestCase;
+use App\Libraries\InvoiceAttachment\InvoiceAttachmentGenerator;
+use App\Libraries\InvoiceAttachment\InvoiceAttachment;
+use App\Libraries\InvoiceAttachment\PdfAttachment;
+use App\Libraries\InvoiceAttachment\UblAttachment;
+
+class InvoiceAttachmentGeneratorTest extends CIUnitTestCase
+{
+    public function testCreateFromConfigPdfOnly(): void
+    {
+        $generator = InvoiceAttachmentGenerator::createFromConfig('pdf_only');
+        $this->assertInstanceOf(InvoiceAttachmentGenerator::class, $generator);
+    }
+
+    public function testCreateFromConfigUblOnly(): void
+    {
+        $generator = InvoiceAttachmentGenerator::createFromConfig('ubl_only');
+        $this->assertInstanceOf(InvoiceAttachmentGenerator::class, $generator);
+    }
+
+    public function testCreateFromConfigBoth(): void
+    {
+        $generator = InvoiceAttachmentGenerator::createFromConfig('both');
+        $this->assertInstanceOf(InvoiceAttachmentGenerator::class, $generator);
+    }
+
+    public function testCreateFromConfigPdfOnlyRegistersPdfAttachment(): void
+    {
+        $generator = InvoiceAttachmentGenerator::createFromConfig('pdf_only');
+        $attachments = $this->getPrivateProperty($generator, 'attachments');
+        
+        $this->assertCount(1, $attachments);
+        $this->assertInstanceOf(PdfAttachment::class, $attachments[0]);
+    }
+
+    public function testCreateFromConfigUblOnlyRegistersUblAttachment(): void
+    {
+        $generator = InvoiceAttachmentGenerator::createFromConfig('ubl_only');
+        $attachments = $this->getPrivateProperty($generator, 'attachments');
+        
+        $this->assertCount(1, $attachments);
+        $this->assertInstanceOf(UblAttachment::class, $attachments[0]);
+    }
+
+    public function testCreateFromConfigBothRegistersBothAttachments(): void
+    {
+        $generator = InvoiceAttachmentGenerator::createFromConfig('both');
+        $attachments = $this->getPrivateProperty($generator, 'attachments');
+        
+        $this->assertCount(2, $attachments);
+        $this->assertInstanceOf(PdfAttachment::class, $attachments[0]);
+        $this->assertInstanceOf(UblAttachment::class, $attachments[1]);
+    }
+
+    public function testRegisterAddsAttachment(): void
+    {
+        $generator = new InvoiceAttachmentGenerator();
+        $mockAttachment = new class implements InvoiceAttachment {
+            public function generate(array $saleData, string $type): ?string { return null; }
+            public function isApplicableForType(string $type, array $saleData): bool { return true; }
+            public function getFileExtension(): string { return 'test'; }
+            public function getEnabledConfigValues(): array { return ['test']; }
+        };
+        
+        $result = $generator->register($mockAttachment);
+        
+        $this->assertSame($generator, $result);
+        $attachments = $this->getPrivateProperty($generator, 'attachments');
+        $this->assertCount(1, $attachments);
+    }
+
+    public function testRegisterIsChainable(): void
+    {
+        $generator = new InvoiceAttachmentGenerator();
+        $mockAttachment = new class implements InvoiceAttachment {
+            public function generate(array $saleData, string $type): ?string { return null; }
+            public function isApplicableForType(string $type, array $saleData): bool { return true; }
+            public function getFileExtension(): string { return 'test'; }
+            public function getEnabledConfigValues(): array { return ['test']; }
+        };
+        
+        $result = $generator->register($mockAttachment)->register($mockAttachment);
+        
+        $attachments = $this->getPrivateProperty($result, 'attachments');
+        $this->assertCount(2, $attachments);
+    }
+
+    public function testGenerateAttachmentsReturnsEmptyArrayWhenNoAttachmentsRegistered(): void
+    {
+        $generator = new InvoiceAttachmentGenerator();
+        $result = $generator->generateAttachments([], 'invoice');
+        
+        $this->assertIsArray($result);
+        $this->assertEmpty($result);
+    }
+
+    public function testCleanupRemovesFiles(): void
+    {
+        $tempFile1 = tempnam(sys_get_temp_dir(), 'test_');
+        $tempFile2 = tempnam(sys_get_temp_dir(), 'test_');
+        
+        $this->assertFileExists($tempFile1);
+        $this->assertFileExists($tempFile2);
+        
+        InvoiceAttachmentGenerator::cleanup([$tempFile1, $tempFile2]);
+        
+        $this->assertFileDoesNotExist($tempFile1);
+        $this->assertFileDoesNotExist($tempFile2);
+    }
+
+    public function testCleanupHandlesNonExistentFiles(): void
+    {
+        // Should not throw an exception
+        InvoiceAttachmentGenerator::cleanup(['/non/existent/file1', '/non/existent/file2']);
+        $this->assertTrue(true);
+    }
+}

tests/Libraries/InvoiceAttachment/PdfAttachmentTest.php

@@ -0,0 +1,70 @@
+<?php
+
+namespace Tests\Libraries\InvoiceAttachment;
+
+use CodeIgniter\Test\CIUnitTestCase;
+use App\Libraries\InvoiceAttachment\PdfAttachment;
+
+class PdfAttachmentTest extends CIUnitTestCase
+{
+    private PdfAttachment $attachment;
+
+    protected function setUp(): void
+    {
+        parent::setUp();
+        $this->attachment = new PdfAttachment();
+    }
+
+    public function testGetFileExtensionReturnsPdf(): void
+    {
+        $this->assertEquals('pdf', $this->attachment->getFileExtension());
+    }
+
+    public function testGetEnabledConfigValuesReturnsCorrectArray(): void
+    {
+        $values = $this->attachment->getEnabledConfigValues();
+        
+        $this->assertIsArray($values);
+        $this->assertContains('pdf_only', $values);
+        $this->assertContains('both', $values);
+        $this->assertCount(2, $values);
+    }
+
+    public function testIsApplicableForTypeReturnsTrueForInvoice(): void
+    {
+        $this->assertTrue($this->attachment->isApplicableForType('invoice', []));
+    }
+
+    public function testIsApplicableForTypeReturnsTrueForTaxInvoice(): void
+    {
+        $this->assertTrue($this->attachment->isApplicableForType('tax_invoice', []));
+    }
+
+    public function testIsApplicableForTypeReturnsTrueForQuote(): void
+    {
+        $this->assertTrue($this->attachment->isApplicableForType('quote', []));
+    }
+
+    public function testIsApplicableForTypeReturnsTrueForWorkOrder(): void
+    {
+        $this->assertTrue($this->attachment->isApplicableForType('work_order', []));
+    }
+
+    public function testIsApplicableForTypeReturnsTrueForReceipt(): void
+    {
+        $this->assertTrue($this->attachment->isApplicableForType('receipt', []));
+    }
+
+    public function testIsApplicableForTypeReturnsTrueForAnyType(): void
+    {
+        // PDF should work for any document type
+        $this->assertTrue($this->attachment->isApplicableForType('random_type', []));
+    }
+
+    public function testIsApplicableForTypeIgnoresSaleData(): void
+    {
+        // PDF attachment doesn't depend on invoice_number
+        $this->assertTrue($this->attachment->isApplicableForType('invoice', ['invoice_number' => null]));
+        $this->assertTrue($this->attachment->isApplicableForType('invoice', ['invoice_number' => 'INV-001']));
+    }
+}

tests/Libraries/InvoiceAttachment/UblAttachmentTest.php

@@ -0,0 +1,103 @@
+<?php
+
+namespace Tests\Libraries\InvoiceAttachment;
+
+use CodeIgniter\Test\CIUnitTestCase;
+use App\Libraries\InvoiceAttachment\UblAttachment;
+
+class UblAttachmentTest extends CIUnitTestCase
+{
+    private UblAttachment $attachment;
+
+    protected function setUp(): void
+    {
+        parent::setUp();
+        $this->attachment = new UblAttachment();
+    }
+
+    public function testGetFileExtensionReturnsXml(): void
+    {
+        $this->assertEquals('xml', $this->attachment->getFileExtension());
+    }
+
+    public function testGetEnabledConfigValuesReturnsCorrectArray(): void
+    {
+        $values = $this->attachment->getEnabledConfigValues();
+        
+        $this->assertIsArray($values);
+        $this->assertContains('ubl_only', $values);
+        $this->assertContains('both', $values);
+        $this->assertCount(2, $values);
+    }
+
+    public function testIsApplicableForTypeReturnsTrueForInvoiceWithInvoiceNumber(): void
+    {
+        $saleData = ['invoice_number' => 'INV-001'];
+        
+        $this->assertTrue($this->attachment->isApplicableForType('invoice', $saleData));
+    }
+
+    public function testIsApplicableForTypeReturnsTrueForTaxInvoiceWithInvoiceNumber(): void
+    {
+        $saleData = ['invoice_number' => 'INV-001'];
+        
+        $this->assertTrue($this->attachment->isApplicableForType('tax_invoice', $saleData));
+    }
+
+    public function testIsApplicableForTypeReturnsFalseForInvoiceWithoutInvoiceNumber(): void
+    {
+        $saleData = ['invoice_number' => null];
+        
+        $this->assertFalse($this->attachment->isApplicableForType('invoice', $saleData));
+    }
+
+    public function testIsApplicableForTypeReturnsFalseForInvoiceWithEmptyInvoiceNumber(): void
+    {
+        $saleData = ['invoice_number' => ''];
+        
+        $this->assertFalse($this->attachment->isApplicableForType('invoice', $saleData));
+    }
+
+    public function testIsApplicableForTypeReturnsFalseForInvoiceWithoutInvoiceNumberKey(): void
+    {
+        $saleData = [];
+        
+        $this->assertFalse($this->attachment->isApplicableForType('invoice', $saleData));
+    }
+
+    public function testIsApplicableForTypeReturnsFalseForQuoteEvenWithInvoiceNumber(): void
+    {
+        $saleData = ['invoice_number' => 'INV-001'];
+        
+        $this->assertFalse($this->attachment->isApplicableForType('quote', $saleData));
+    }
+
+    public function testIsApplicableForTypeReturnsFalseForWorkOrderEvenWithInvoiceNumber(): void
+    {
+        $saleData = ['invoice_number' => 'INV-001'];
+        
+        $this->assertFalse($this->attachment->isApplicableForType('work_order', $saleData));
+    }
+
+    public function testIsApplicableForTypeReturnsFalseForReceiptEvenWithInvoiceNumber(): void
+    {
+        $saleData = ['invoice_number' => 'INV-001'];
+        
+        $this->assertFalse($this->attachment->isApplicableForType('receipt', $saleData));
+    }
+
+    public function testIsApplicableForTypeReturnsFalseForUnknownType(): void
+    {
+        $saleData = ['invoice_number' => 'INV-001'];
+        
+        $this->assertFalse($this->attachment->isApplicableForType('unknown_type', $saleData));
+    }
+
+    public function testGenerateReturnsNullForMissingConfig(): void
+    {
+        // Without proper sale_data, generate should fail gracefully
+        $result = $this->attachment->generate([], 'invoice');
+        
+        $this->assertNull($result);
+    }
+}