FEATURE #1373: add history of content

This commit contains only core funcionality of displaying history. Module settings must be implemented in each module.

app/Models/ContentHistory.php

@@ -2,6 +2,10 @@
 
 namespace App\Models;
 
+use App\Handlers\Contracts\AppHandler;
+use App\Handlers\Contracts\HistoryHandler;
+use App\Handlers\Handler;
+use App\Helpers\Differ;
 use Illuminate\Database\Eloquent\Model;
 
 /**
@@ -10,10 +14,8 @@ use Illuminate\Database\Eloquent\Model;
 class ContentHistory extends Model
 {
     protected $table = 'content_history';
-
     // this table does not have created_at and updated_at fields
     public $timestamps = false;
-
     protected $fillable = [
         'user_id',
         'content_id',
@@ -22,8 +24,81 @@ class ContentHistory extends Model
         'new_value',
         'old_value'
     ];
-
     protected $guarded = [];
 
-        
+    /**
+     * Returns history grouped by revisions (edit_batches)
+     *
+     * @param Content $content
+     *
+     * @return array
+     */
+    public function getStructuredHistoryOf(Content $content)
+    {
+        $data = $content->history()
+                        ->select('content_history.*', 'contents.module_handler', 'users.email AS user_email', 'users.name AS user_name')
+                        ->join('users', 'users.id', '=', 'content_history.user_id')
+                        ->join('contents', 'contents.id', '=', 'content_history.content_id')
+                        ->orderBy('changed_at', 'DESC')
+                        ->get();
+
+        $info = [];
+        $history = [];
+        foreach ($data as $change) {
+            $info[$change->edit_batch] = [
+                'changed_at' => $change->changed_at,
+                'user'       => [
+                    'id'    => $change->user_id,
+                    'name'  => $change->user_name,
+                    'email' => $change->user_email
+                ]
+            ];
+
+            $change = $this->handleChangeset($change);
+
+            $history[$change->edit_batch][] = $change;
+        }
+
+        return [
+            'changesets' => $history,
+            'info'       => $info
+        ];
+    }
+
+    /**
+     * @param $change
+     *
+     * @return HistoryHandler
+     */
+    protected function getHistoryHandler($change)
+    {
+        /**
+         * @var $handler        AppHandler
+         * @var $historyHandler HistoryHandler
+         */
+
+        // get handler of given content page
+        if ($change->column == 'module_settings') {
+            $handler = $handler = $change->module_handler;
+        } else {
+            $handler = Handler::class;
+        }
+
+        return $handler::getHistoryHandler();
+    }
+
+    public function handleChangeset($change)
+    {
+        $historyHandler = $this->getHistoryHandler($change);
+
+        $change->column_trans = $historyHandler::parseColumnName($change->column);
+        $change->diff = $historyHandler::parseChangedValue($change);
+
+        return $change;
+    }
+
+    public function getDiff($change)
+    {
+        return Differ::htmlDiff($change->old_value, $change->new_value);
+    }
 }