Bugfixes to get Migration working on MySQL and MariaDB (#4551)

* Bugfixes to get Migration working on MySQL

Signed-off-by: objec <objecttothis@gmail.com>

* MariaDB compatibility fixes

- Drop foreign key constraints before making charset changes
- Fix dropAllForeignKeyConstraints helper function.
- Added `IF EXISTS` to DROP statements
- Do not try to readd FK constraints for tables which were dropped.
- MariaDB 11.8.x changes the default implicit collation to uca1400 which breaks the IndiaGST migration, et. al. Explicitly declare utf8_general_ci in affected migrations.

Signed-off-by: objec <objecttothis@gmail.com>

* Fix changes which break MySQL migrations

- MySQL does not support IF EXISTS in foreign key constraints. Since the PHP is now handling dropping those constraints, these lines are redundant. Remove them.

Signed-off-by: objec <objecttothis@gmail.com>

* Resolve code review recommendations

- Add try/catch around DB connect statement
- Heed result of execute_script function and throw an exception on failure.

Signed-off-by: objec <objecttothis@gmail.com>

* Refactor out duplicate code

Signed-off-by: objec <objecttothis@gmail.com>

* Initialize array variable causing potential issues

Signed-off-by: objec <objecttothis@gmail.com>

---------

Signed-off-by: objec <objecttothis@gmail.com>

app/Config/OSPOS.php

@@ -5,6 +5,7 @@ namespace Config;
 use App\Models\Appconfig;
 use CodeIgniter\Cache\CacheInterface;
 use CodeIgniter\Config\BaseConfig;
+use Config\Database;
 
 /**
  * This class holds the configuration options stored from the database so that on launch those settings can be cached
@@ -13,7 +14,7 @@ use CodeIgniter\Config\BaseConfig;
  */
 class OSPOS extends BaseConfig
 {
-    public array $settings;
+    public array $settings = [];
     public string $commit_sha1 = 'dev';    // TODO: Travis scripts need to be updated to replace this with the commit hash on build
     private CacheInterface $cache;
 
@@ -33,26 +34,35 @@ class OSPOS extends BaseConfig
 
         if ($cache) {
             $this->settings = decode_array($cache);
-        } else {
-            try {
-                $appconfig = model(Appconfig::class);
-                foreach ($appconfig->get_all()->getResult() as $app_config) {
-                    $this->settings[$app_config->key] = $app_config->value;
-                }
-                $this->cache->save('settings', encode_array($this->settings));
-            } catch (\Exception $e) {
-                // Database table doesn't exist yet (migrations haven't run)
-                // or database connection failed. Return empty settings to
-                // allow migration page to display. Catches mysqli_sql_exception
-                // which is not a subclass of DatabaseException.
-                $this->settings = [
-                    'language' => 'english',
-                    'language_code' => 'en',
-                    'company' => 'Home',
-                    'barcode_type' => 'Code39'
-                ];
-            }
+            return;
         }
+
+        try {
+            $db = Database::connect();
+
+            if (!$db->tableExists('app_config')) {
+                $this->settings = $this->getDefaultSettings();
+                return;
+            }
+
+            $appconfig = model(Appconfig::class);
+            foreach ($appconfig->get_all()->getResult() as $app_config) {
+                $this->settings[$app_config->key] = $app_config->value;
+            }
+            $this->cache->save('settings', encode_array($this->settings));
+        } catch (\Exception $e) {
+            $this->settings = $this->getDefaultSettings();
+        }
+    }
+
+    private function getDefaultSettings(): array
+    {
+        return [
+            'language'      => 'english',
+            'language_code' => 'en',
+            'company'       => 'Home',
+            'barcode_type'  => 'Code39'
+        ];
     }
 
     /**
@@ -63,4 +73,4 @@ class OSPOS extends BaseConfig
         $this->cache->delete('settings');
         $this->set_settings();
     }
-}
+}