From eccf08cf8f4a7242a3d1817d418a94a55bce5be2 Mon Sep 17 00:00:00 2001
From: Steve Ireland <stevei@ruledomain.com>
Date: Sat, 15 Jul 2017 16:42:27 -0400
Subject: [PATCH] Improve tax category maintenance.

---
 application/controllers/Config.php           | 25 ++++++++++++++++++--
 application/language/en/config_lang.php      |  1 +
 application/models/Item.php                  |  8 +++++++
 application/models/Tax.php                   |  8 +++++++
 application/views/partial/tax_categories.php |  8 ++++++-
 5 files changed, 47 insertions(+), 3 deletions(-)

diff --git a/application/controllers/Config.php b/application/controllers/Config.php
index db2bc40e8..794a803e0 100644
--- a/application/controllers/Config.php
+++ b/application/controllers/Config.php
@@ -637,6 +637,7 @@ class Config extends Secure_Controller
 		);
 
 		$success = $this->Appconfig->batch_save($batch_save_data) ? TRUE : FALSE;
+		$delete_rejected = FALSE;
 
 		if($customer_sales_tax_support)
 		{
@@ -674,7 +675,16 @@ class Config extends Secure_Controller
 			{
 				if(!in_array($category['tax_category_id'], $not_to_delete))
 				{
-					$this->Tax->delete_tax_category($category['tax_category_id']);
+					$usg1 = $this->Tax->get_tax_category_usage($category['tax_category_id']);
+					$usg2 = $this->Item->get_tax_category_usage($category['tax_category_id']);
+					if(($usg1 + $usg2) == 0)
+					{
+						$this->Tax->delete_tax_category($category['tax_category_id']);
+					}
+					else
+					{
+						$delete_rejected = TRUE;
+					}
 				}
 			}
 		}
@@ -683,9 +693,20 @@ class Config extends Secure_Controller
 
 		$success &= $this->db->trans_status();
 
+		$message = "";
+		if($success && $delete_rejected)
+		{
+			$message = $this->lang->line('config_tax_category_used');
+			$success = false;
+		}
+		else
+		{
+			$message = $this->lang->line('config_saved_' . ($success ? '' : 'un') . 'successfully');
+		}
+
 		echo json_encode(array(
 			'success' => $success,
-			'message' => $this->lang->line('config_saved_' . ($success ? '' : 'un') . 'successfully')
+			'message' => $message
 		));
 	}
 
diff --git a/application/language/en/config_lang.php b/application/language/en/config_lang.php
index 2735698c6..528d704bf 100644
--- a/application/language/en/config_lang.php
+++ b/application/language/en/config_lang.php
@@ -225,6 +225,7 @@ $lang["config_table_configuration"] = "Table Configuration";
 $lang["config_takings_printer"] = "Takings Printer";
 $lang["config_tax"] = "Tax";
 $lang["config_tax_category"] = "Tax Category";
+$lang["config_tax_category_used"] = "Tax category cannot be deleted because it is being used.";
 $lang["config_tax_configuration"] = "Tax Configuration";
 $lang["config_tax_decimals"] = "Tax Decimals";
 $lang["config_tax_included"] = "Tax Included";
diff --git a/application/models/Item.php b/application/models/Item.php
index f3aedc25a..28bdb740d 100644
--- a/application/models/Item.php
+++ b/application/models/Item.php
@@ -52,6 +52,14 @@ class Item extends CI_Model
 		return $this->db->count_all_results();
 	}
 
+	public function get_tax_category_usage($tax_category_id)
+	{
+		$this->db->from('items');
+		$this->db->where('tax_category_id', $tax_category_id);
+
+		return $this->db->count_all_results();
+	}
+
 	/*
 	Get number of rows
 	*/
diff --git a/application/models/Tax.php b/application/models/Tax.php
index 9df461acd..0386d8f17 100644
--- a/application/models/Tax.php
+++ b/application/models/Tax.php
@@ -44,6 +44,14 @@ class Tax extends CI_Model
 		return $this->db->count_all_results();
 	}
 
+	public function get_tax_category_usage($tax_category_id)
+	{
+		$this->db->from('tax_code_rates');
+		$this->db->where('rate_tax_category_id', $tax_category_id);
+
+		return $this->db->count_all_results();
+	}
+
 	/**
 	Gets information about a particular tax_code
 	*/
diff --git a/application/views/partial/tax_categories.php b/application/views/partial/tax_categories.php
index 38b47c6ba..dbb3129df 100644
--- a/application/views/partial/tax_categories.php
+++ b/application/views/partial/tax_categories.php
@@ -32,7 +32,13 @@ foreach($tax_categories as $tax_category => $category)
         </div>
 		<span class="add_tax_category glyphicon glyphicon-plus" style="padding-top: 0.5em;"></span>
 		<span>&nbsp;&nbsp;</span>
-		<span class="remove_tax_category glyphicon glyphicon-minus" style="padding-top: 0.5em;"></span>
+        <?php
+        if($tax_category_id > 0) {
+        ?>
+		    <span class="remove_tax_category glyphicon glyphicon-minus" style="padding-top: 0.5em;"></span>
+        <?php
+		}
+        ?>
 	</div>
 <?php
 }