Prepared website with even cleaner file structure and layout

lib/php/management/insert.php

@@ -0,0 +1,39 @@
+<?php
+    if ( ! isset ( $_SESSION [ 'user_id' ] ) ) {
+        header ( 'Content-Type: application/json' );
+        http_response_code ( 401 );
+        $response = [
+            'status' => 401,
+            'error_message' => 'You either are not logged in or you do not have permissions to insert new URLs.'
+        ];
+        echo ( json_encode ( $response ) );
+        exit;
+    }
+    if ( ! isset ( $_POST [ 'url' ] ) ) {
+        header ( 'Content-Type: application/json' );
+        http_response_code ( 400 );
+        $response = [
+            'status' => 400,
+            'error_message' => 'You either did not provide a URL or you provided an invalid one.'
+        ];
+        echo ( json_encode ( $response ) );
+        exit;
+    }
+    $database = new Database ( $GLOBALS [ 'config' ] [ 'db' ] );
+    $database->connect ( );
+    $url = $_POST [ 'url' ];
+    $database->prepare ( "INSERT INTO `links` ( `URL`, `created_by` ) VALUES ( :url, " . $_SESSION [ 'user_id' ] . " );" );
+    $database->bind ( [ ':url' => $url ] );
+    $database->execute ( );
+    $database->prepare ( "SELECT MAX( links.ID ) as `last` FROM links;");
+    $database->execute ( );
+    $result = $database->get_result ( );
+    $row = $result->fetchAll ( ) [ 0 ];
+    header ( 'Content-Type: application/json' );
+    $response = [
+        'status' => 200,
+        'message' => 'URL inserted correctly.',
+        'last_insert' => $row [ 'last' ],
+    ];
+    echo ( json_encode ( $response ) );
+    exit;

lib/php/management/logout.php

@@ -0,0 +1,3 @@
+<?php
+    $_SESSION [ 'user_id' ] = NULL;
+    header ( "Location: " . substr ( $_SERVER [ 'SCRIPT_NAME' ], 0, -10 ) . "/" );