edit lesson: putting all together; media with privile level

17 files changed, 873 insertions, 155 deletions

diff --git a/core/classes/Render.php b/core/classes/Render.php
index 75f46d5..3b68c26 100644
--- a/core/classes/Render.php
+++ b/core/classes/Render.php
@@ -344,5 +344,15 @@
     }
 
 
+    /** render file
+     * 
+     */
+    public static function file($path, $madia_type)
+    {
+        $content = file_get_contents($path);
+        header("Content-Type: {$media_type}");
+        echo $content;
+    }
+
 
 }
\ No newline at end of file
diff --git a/public/app/controllers/Auth.php b/public/app/controllers/Auth.php
index d7b0c3b..b00843c 100644
--- a/public/app/controllers/Auth.php
+++ b/public/app/controllers/Auth.php
@@ -322,6 +322,13 @@ class Auth {
     }
 
 
+    public static function is_admin()
+    {
+        $manager = new Classroom_manager();
+        return ($manager->isGranted([1,2,3]));
+    }
+
+
     
 }
 
diff --git a/public/app/controllers/admin/Course_admin.php b/public/app/controllers/admin/Course_admin.php
index ef9ef0e..d1048b7 100644
--- a/public/app/controllers/admin/Course_admin.php
+++ b/public/app/controllers/admin/Course_admin.php
@@ -98,6 +98,167 @@ class Course_admin {
     }
 
 
+    ## -------------------------------------------------------------------------
+    ##
+    ## LESSON METHODS
+    ##
+    ## -------------------------------------------------------------------------
+
+
+    /** get_lesson
+     * 
+     * @param $id (int) : lesson's id
+     */
+    public static function get_lesson($id)
+    {
+        // get (first) lesson with id = $id; render as json
+        Render::json(Registry::use('database')->query(
+            "SELECT lesson.*, 
+            ( SELECT
+                CONCAT('[', GROUP_CONCAT(JSON_OBJECT(
+                    'id', media.id,
+                    'label', media.label,
+                    'type', media.type,
+                    'path', media.path )),
+                ']')
+                FROM media
+                LEFT JOIN lesson_media ON lesson_media.media_id = media.id
+                WHERE lesson_media.lesson_id = :id
+            ) AS medias_json,
+            lesson_privilege.privilege_id
+            FROM lesson
+            LEFT JOIN lesson_privilege ON lesson_privilege.lesson_id = lesson.id
+            WHERE lesson.id = :id",
+            [ ':id' => $id]
+        )->getFirst());
+    }
+
+
+    /** add_lesson
+     * insert a new lesson
+     * 
+     * all parametres are passed via $_POST array
+     * 
+     * POST @param title
+     * POST @param course_id
+     * POST @param intro
+     * POST @param body
+     * POST @param published
+     */
+    public static function add_lesson()
+    {
+        $post = Registry::get('REQUEST')->POST;
+
+        // insert lesson content into daabase
+        $id = Registry::use('database')->query(
+            "INSERT INTO lesson (title, course_id, intro, `body`, `status`)
+            VALUES (:title, :courseid, :intro, :body, :status)",
+            [
+                ':title' => $post['title'],
+                ':courseid' => $post['course_id'],
+                ':intro' => $post['intro'],
+                ':body' => $post['body'],
+                'status' => $post['status']
+            ]
+        )->lastInsertID();
+
+        // set lesson privileges to database
+        Registry::use('database')->runQuery(
+            "INSERT INTO lesson_privilege (lesson_id, privilege_id)
+            VALUES (:lesson_id, :privilege_id)",
+            [
+                ':lesson_id' => $id,
+                ':privilege_id' => $post['privilege_id']
+            ]
+        );
+
+        // update media's privileges
+        self::update_medias_privileges($post['media'], $post['privilege_id']);
+
+        // set lesson's media files
+        self::create_medias_for_lesson($post['media'], $id, $post['privilege_id']);
+
+        return true;
+    }
+
+
+    public static function update_lesson()
+    {
+        $post = Registry::get('REQUEST')->POST;
+
+        // print_r($post); die();
+
+        // update lesson's content
+        Registry::use('database')->query(
+            "UPDATE lesson
+            SET title = :title,
+                course_id = :courseid,
+                intro = :intro, `body` = :body,
+                `status` = :status
+            WHERE id = :id",
+            [
+                ':id' => $post['id'],
+                ':title' => $post['title'],
+                ':courseid' => $post['course_id'],
+                ':intro' => $post['intro'],
+                ':body' => $post['body'],
+                ':status' => $post['status']
+            ]
+        );
+
+        // update lesson's privileges
+        Registry::use('database')->runQuery(
+            "UPDATE lesson_privilege SET privilege_id = :privilege_id
+            WHERE lesson_id = :lesson_id",
+            [
+                ':lesson_id' => $post['id'],
+                ':privilege_id' => $post['privilege_id']
+            ]
+        );
+
+        // update media's privileges
+        self::update_medias_privileges($post['media'], $post['privilege_id']);
+
+        // remove all old lesson's links to media files
+        Registry::use('database')->runQuery(
+            "DELETE from lesson_media WHERE lesson_id = :lesson",
+            [ ':lesson' => $post['id'] ]
+        );
+
+        // update lesson's media files
+        self::create_medias_for_lesson($post['media'], $post['id'], $post['privilege_id']);
+
+        return true;
+    }
+
+    /** update medias privileges
+     * 
+     * @param $medias (array) : array of media id(s)
+     * @param $privilege (int) : privilege id
+     * @return true (always)
+     */
+    private static function update_medias_privileges($medias, $privilege)
+    {
+        // create WHERE IN (LIST) holders and params for prepare statement
+        $params = [ ':privilege' => $privilege];
+        $holders = [];
+        foreach($medias as $key => $media) {
+            $params[':id'.$key] = $media;
+            $holders[] = ':id'.$key;
+        }
+        $list = '('. implode(',', $holders) .')';
+
+        // print_r(['params' => $params, 'list' => $list]); die();
+
+        Registry::use('database')->runQuery(
+            "UPDATE media SET privilege_id = :privilege
+            WHERE id IN {$list}",
+            $params
+        );
+
+        return true;
+    }
+
 
 
     ## -------------------------------------------------------------------------
@@ -107,18 +268,66 @@ class Course_admin {
     ## -------------------------------------------------------------------------
 
 
+    /** files
+     * echo all files
+     * @return (array)
+     */
+    public static function files()
+    {
+        return  proxy(                  // cache-get files
+            [\app\models\cms\Course_model::class, 'files'],
+            [], CACHE_ROOT_TTL
+        );
+    }
+
+
     /** upload_file
      * upload the file to the file system
      * 
      * the method reads the POST and FILES array
      * to retrieve all needed parametres
      *
-     * + $_FILES[file]
-     * + $_POST[folder] : lesson's ID
-     * + $_POST[reference] : reference type
+     * FILES @param file
+     * POST @param folder : lesson's ID or somthing random
+     * POST @param reference : reference type
+     * POST @param 
      */
     public static function upload_file()
     {
+        $request = Registry::get('REQUEST');
+
+        $uploaded = self::upload_to_fs();    // upload file to file-system
+
+        if ($uploaded['success']) {
+
+            $media_id = self::define_media([    // define media in database; get id
+                'title' => $request->POST['title'],
+                'type' => $uploaded['type'],
+                'path' => $uploaded['path']
+            ]);
+
+            Render::json([      // render results as json
+                'success' => true,
+                'id' => $media_id,
+                'title' => $request->POST['title'],
+                'path' => $uploaded['path'],
+                'type' => $uploaded['type']
+            ]);
+
+        } else {
+            Render::json(['success' => false ]);
+        }
+    }
+
+
+    /** upload to fs
+     * upload file to File-System
+     * 
+     * POST @param folder
+     * FILES @param file
+     */
+    private static function upload_to_fs()
+    {
         $post = Registry::get('REQUEST')->POST;
         $files = Registry::get('REQUEST')->FILES;
 
@@ -181,7 +390,7 @@ class Course_admin {
         if (move_uploaded_file($files["file"]["tmp_name"], $store_filename)) {
             return [
                 'success' => true,
-                'path' => $store_filename,
+                'path' => $relative_filename,
                 'type' => $mime_type
             ];
 
@@ -207,22 +416,61 @@ class Course_admin {
      * 
      * create a record in media table
      * 
-     * @param $data 
+     * @param $data (array): [title => , path => , type => mime-type]
      * @return id (int): id of created media record
      */
-    public static function define_media($data)
+    private static function define_media($data)
     {
-        $sql = "INSERT INTO wiki_media (`title`, `type`, `path`)
-            VALUES (:title, :mimetype, :filepath)";
-		$stmt = $this->pdo->prepare($sql);
-		$stmt->execute([
-            'title' => $data['title'],
-            'mimetype' => $data['type'],
-            'filepath' => $data['path']
-        ]);
-        $inserted_id = $this->pdo->lastInsertId();
-
-		return $inserted_id;
+        $request = Registry::get('REQUEST');
+
+        $media_id = Registry::use('database')->query(
+            "INSERT INTO media (label, `type`, `path`)
+            VALUES (:label, :mimetype, :filepath)",
+            [
+                'label' => $data['title'],
+                'mimetype' => $data['type'],
+                'filepath' => $data['path']
+            ]
+        )->lastInsertID();
+		return $media_id;
+    }
+
+
+    /** create media for post
+     * 
+     * links post to each media-file of the media `id`s array
+     * @param $media (array): a list of media-file `id`s
+     * @param $post_id (int)
+     */
+    private static function create_medias_for_lesson($medias, $lesson_id)
+    {
+        foreach($medias as $key => $medi) {
+            self::link_media_to_lesson($medi, $lesson_id);   // link to lesson
+        }
+        return true;
+    }
+
+
+    /** link one media-file to a specific post
+     *
+     * NOTE:
+     * the method does not check if media is linked already
+     * so be sure that the pair of (media_id,post_id) not exist
+     * 
+     * @param $media_id (int)
+     * @param $lesson_id (int)
+     */
+    private static function link_media_to_lesson( $media_id, $lesson_id )
+    {
+        Registry::use('database')->runQuery(
+            "INSERT INTO lesson_media (lesson_id, media_id)
+            VALUES (:lesson, :media)",
+            [
+                'lesson' => $lesson_id,
+                'media' => $media_id,
+            ]
+        );
+        return true;
     }
 
 
diff --git a/public/app/controllers/cms/Course.php b/public/app/controllers/cms/Course.php
new file mode 100644
index 0000000..b671a5f
--- /dev/null
+++ b/public/app/controllers/cms/Course.php
@@ -0,0 +1,36 @@
+<?php 
+
+namespace app\controllers\cms;
+
+use Registry;
+use Render;
+use app\controllers\Auth;
+use app\models\cms\Course_model;
+
+class Course {
+
+    /** serve file by file_path
+     * (request is valid only for admin users)
+     * 
+     * @param $file_path (string): relative file path
+     * GET @param type (string) : media-type of file
+     */
+    public static function serve_file($file_path)
+    {
+        // check privileges
+        if (Auth::is_admin()) {     // TODO: -OR- has prvivilege
+
+            $media_type = Registry::get('REQUEST')->GET['type'];    // get media-type
+            $real_path = MEDIA_STORAGE_ROOT . $file_path;           // construct real path
+
+            if (!file_exists($real_path)) {
+                Render::view('error/404');
+
+            } else {
+                Render::file($real_path, $media_type);
+            }
+
+        }
+    }
+
+}
\ No newline at end of file
diff --git a/public/app/models/cms/Course_model.php b/public/app/models/cms/Course_model.php
index 4740a4f..3d0ac1c 100644
--- a/public/app/models/cms/Course_model.php
+++ b/public/app/models/cms/Course_model.php
@@ -216,5 +216,16 @@ class Course_model {
     }
 
 
+    /** files
+     * return all files
+     * @param void
+     * @return array
+     */
+    public static function files()
+    {
+        return Registry::use('database')->runQuery("SELECT * from media", []);
+    }
+
+
 
 }
diff --git a/public/app/routes/backend.php b/public/app/routes/backend.php
index 704d161..7f4717d 100644
--- a/public/app/routes/backend.php
+++ b/public/app/routes/backend.php
@@ -4,6 +4,25 @@ use app\controllers\Auth;
 use app\controllers\admin\Course_admin;
 use app\models\admin\Privilege_model;
 
+
+// admin panel
+// ---
+Route::add('/admin', function () {
+    Auth::allowRoles([1, 2, 3]);        // allow few admin-panel roles
+    Render::view('admin/skeleton', [
+        'title' => 'Διαχείριση Classroom',
+        'action' => 'panel',
+    ]);
+});
+Route::add('/admin/panel', function () {
+    Auth::allowRoles([1, 2, 3]);        // allow few admin-panel roles
+    Render::view('admin/skeleton', [
+        'title' => 'Διαχείριση Classroom',
+        'action' => 'panel',
+    ]);
+});
+
+
 // admin lessons
 // ---
 Route::add('/admin/lessons', function () {
@@ -15,7 +34,7 @@ Route::add('/admin/lessons', function () {
 });
 
 
-// admin categories (=courses)
+// admin categories (=courses) /////////////////////////////////////////////////
 // -----------------------------------------------------------------------------
 
 // manage categories page
@@ -54,7 +73,7 @@ Route::add('/admin/api/categories/update', function () {
 );
 
 
-// admin privileges
+// admin privileges ////////////////////////////////////////////////////////////
 // -----------------------------------------------------------------------------
 
 // manage privileges page
@@ -84,8 +103,12 @@ Route::add('/admin/api/privileges', function () {
 
 
 
-// new lesson
+// admin lesson ////////////////////////////////////////////////////////////////
 // -----------------------------------------------------------------------------
+
+
+// new lesson
+// ---
 Route::add('/admin/edit_lesson', function () {
     Auth::allowRoles([1, 2, 3]);    // allow few admin-panel roles
     Render::view('admin/skeleton', [
@@ -94,18 +117,55 @@ Route::add('/admin/edit_lesson', function () {
     ]);
 });
 
-// new lesson
-// -----------------------------------------------------------------------------
+// edit lesson (give lesson-id)
+// ---
 Route::add('/admin/edit_lesson/([0-9]*)', function ($id) {
     Auth::allowRoles([1, 2, 3]);    // allow few admin-panel roles
     Render::view('admin/skeleton', [
-        'title' => 'Νέο Μάθημα',
+        'title' => 'Επεξεργασία Μαθήματος',
         'action' => 'edit_lesson',
         'id' => intval($id)
     ]);
 });
 
+// ajax: get lesson
+// ---
+Route::add('/admin/api/lesson/([0-9]*)', function ($id) {
+    Auth::allowRoles([1, 2, 3]);    // allow few admin-panel roles
+    Course_admin::get_lesson($id);
+});
+
+
+Route::add('/admin/api/lesson/add', function () {
+    Auth::allowRoles([1, 2, 3]);    // allow few admin-panel roles
+    Course_admin::add_lesson();
+}, 'post');
+
+
+Route::add('/admin/api/lesson/update', function () {
+    Auth::allowRoles([1, 2, 3]);    // allow few admin-panel roles
+    Course_admin::update_lesson();
+}, 'post');
+
+
+
+// admin files /////////////////////////////////////////////////////////////////
+////////////////////////////////////////////////////////////////////////////////
+
+Route::add('/admin/files', function () {
+    Auth::allowRoles([1, 2, 3]);
+    Render::view('admin/skeleton', [
+        'title' => 'Διαχείριση Μέσων (media)',
+        'action' => 'files',
+    ]);
+});
 
+// ajax: get lesson
+// ---
+Route::add('/admin/api/files', function () {
+    Auth::allowRoles([1, 2, 3]);    // allow few admin-panel roles
+    Render::json(Course_admin::files());
+});
 
 // ajax: file-upload
 // ---
@@ -113,3 +173,8 @@ Route::add('/admin/api/file_upload', function () {
     Auth::allowRoles([1, 2, 3]);    // allow few admin-panel roles
     Render::json(Course_admin::upload_file());
 }, 'post');
+
+
+
+
+
diff --git a/public/app/routes/frontend.php b/public/app/routes/frontend.php
index dde0fcd..898b23a 100644
--- a/public/app/routes/frontend.php
+++ b/public/app/routes/frontend.php
@@ -2,6 +2,7 @@
 
 use app\controllers\Auth;
 use app\controllers\Classroom_user;
+use app\controllers\cms\Course;
 use app\models\cms\Course_model;
 
 // Home/Welcome
@@ -65,6 +66,13 @@ Route::add('/about/([0-9a-zA-Z-_]*)/([0-9a-zA-Z-_]*)/([0-9a-zA-Z-_]*)',
 );
 
 
+// serve file
+// ---
+Route::add('/serve/file/([0-9a-zA-Z-_\.\/]*)', function ($path) {
+    Course::serve_file($path);
+});
+
+
 /** URL-format Proposal:
  * -----------------------------------------------------------------------------
  * 
diff --git a/public/app/views/admin/admin-menu.php b/public/app/views/admin/admin-menu.php
index 92c2f54..b783b39 100644
--- a/public/app/views/admin/admin-menu.php
+++ b/public/app/views/admin/admin-menu.php
@@ -17,10 +17,12 @@
  */
 
 $admin_options = [
+    'panel' => 'Διαχείριση',
     'edit_lesson' => 'Νέο Μάθημα',
     'lessons' => 'Μαθήματα',
     'categories' => 'Κεφάλαια',
-    'pages' => 'Σελίδες',
+    // 'pages' => 'Σελίδες',
+    'files' => 'Αρχεία',
     'privileges' => 'Πρόσβαση',
     'users' => 'Χρήστες'
 ];
@@ -28,8 +30,6 @@ $admin_options = [
 
 <div class="top-bar">
 
-    <span class="btn btn-warning">Admin</span>
-
     <?php foreach($admin_options as $opt => $label) : ?>
 
         <?php if (($opt == $action) & (!$id)) : ?> 
diff --git a/public/app/views/admin/edit_lesson.php b/public/app/views/admin/edit_lesson.php
index 7d74c38..ef875b4 100644
--- a/public/app/views/admin/edit_lesson.php
+++ b/public/app/views/admin/edit_lesson.php
@@ -16,7 +16,7 @@
     <div><h5><?=$action_title?></h5></div>
     <div>
         <button type="button" class="btn pull-right"
-            data-toggle="modal" data-target="#editorModal" data-action="preview">
+            data-bs-toggle="modal" data-bs-target="#editorModal" data-action="preview">
             <i class="fas fa-search"></i> &nbsp; Προεπισκόπηση
         </button>
     </div>
diff --git a/public/app/views/admin/files.php b/public/app/views/admin/files.php
new file mode 100644
index 0000000..c6d2771
--- /dev/null
+++ b/public/app/views/admin/files.php
@@ -0,0 +1,96 @@
+ <!-- title bar -->
+ <div class="title-bar">
+    <div><h5>Διαχείριση Επιπέδων Πρόσβασης</h5></div>
+    <div>
+        <!-- Button trigger modal 
+          <button type="button" class="btn pull-right"
+              data-bs-toggle="modal" data-bs-target="#managePrivileges" data-id="0">
+              <i class="fas fa-plus"></i> &nbsp; Νέο Επίπεδο
+          </button>
+        -->
+    </div>
+</div>
+
+<div class="manage">
+    <div class="row">
+        <div class="col-md-12">
+
+            <div id="files">
+
+                <table id="dt-files" class="table table-responsive dt-table" style="width:100%">
+                    <thead>
+                        <th class="dt-id">α/α</th>
+                        <th class="dt-label">Περιγραφή</th>
+                        <th class="dt-path">Διαδρομή</th>
+                        <th class="dt-type">Media-Type</th>
+                        <th class="dt-privilege">Πρόσβαση</th>
+                        <th class="dt-actions"></th>
+                    </thead>
+                </table>
+
+            </div>
+
+
+        </div>
+    </div>
+</div><!-- /manage -->
+
+
+
+<!-- MODAL for new/edit category -->
+<!-- NOTE: tabindex="-1" removed, ref:https://github.com/select2/select2-bootstrap-theme/issues/41 -->
+<div class="modal fade" id="manageFiles" aria-labelledby="myModalLabel" aria-hidden="true">
+    <div class="modal-dialog modal-lg" role="document">
+        <div class="modal-content">
+        
+        <form method="post" action="">
+
+            <div class="modal-header">
+                <h4 class="modal-title" id="myModalLabel">Πρόσβαση αρχείου</h4>
+                <button type="button" class="btn-close" data-bs-dismiss="modal" aria-label="Close"></button>
+            </div><!-- /modal-header -->
+
+            <!-- modal-body -->
+            <div class="modal-body">
+
+                <!-- form fields -->
+                    
+                <div class="row form-group">
+                    <label class="control-label col-sm-12" for="label">Κατηγορία Επιπέδου Πρόσβασης</label>
+                    <div class="col-sm-12">
+                        <input class="form-control form-control-sm" type="text" name="label" value="" required="">
+                    </div>
+                </div>
+
+                <div class="row form-group">
+                    <label class="control-label col-sm-12" for="included_id">Κατηγορία Επιπέδου Πρόσβασης</label>
+                    <div class="col-sm-12">
+                        <select class="form-control form-control-sm form-select form-select-sm" id="privilege_id" name="privilege_id" required></select>
+                    </div>
+                </div>
+
+                <div class="row form-group">
+                    <input type="hidden" name="id" value="0"><!-- action = (0) ? 'new' : 'edit' -->
+                </div>
+                        
+
+            </div><!-- /modal body -->
+
+            <div class="modal-footer">
+                <div class="row form-actions">
+
+                    <div class="col">
+                        <button type="button" class="btn btn-default js-modal-close col-sm-12" data-bs-dismiss="modal">Κλείσιμο</button>
+                    </div>
+                    <div class="col">
+                        <button class="btn btn-success col-sm-12" type="submit">Καταχώριση</button>
+                    </div>
+
+                </div>
+            </div><!-- /modal-footer -->
+
+        </form><!-- /form -->
+
+        </div>
+    </div>
+</div>
diff --git a/public/app/views/admin/panel.php b/public/app/views/admin/panel.php
new file mode 100644
index 0000000..59b8cba
--- /dev/null
+++ b/public/app/views/admin/panel.php
@@ -0,0 +1,4 @@
+<br/>
+<br/>
+<br/>
+<h4>Admin panel</h4>
\ No newline at end of file
diff --git a/public/app/views/components/header_includes.php b/public/app/views/components/header_includes.php
index e5e51cd..62dc616 100644
--- a/public/app/views/components/header_includes.php
+++ b/public/app/views/components/header_includes.php
@@ -49,7 +49,10 @@
     <script src="https://cdn.datatables.net/v/bs5/jszip-2.5.0/dt-1.13.4/b-2.3.6/b-colvis-2.3.6/b-html5-2.3.6/b-print-2.3.6/cr-1.6.2/date-1.4.0/fc-4.2.2/fh-3.3.2/kt-2.8.2/r-2.4.1/rr-1.3.3/sc-2.1.1/sl-1.6.2/sr-1.2.2/datatables.min.js"></script>
 
     <!-- select2 js -->
-    <script src="https://cdn.jsdelivr.net/npm/select2@4.1.0-rc.0/dist/js/select2.min.js"></script>    
+    <script src="https://cdn.jsdelivr.net/npm/select2@4.1.0-rc.0/dist/js/select2.min.js"></script>   
+    
+    <!-- marked -->
+    <script src="/assets/js/marked/marked.min.js"></script>
 <?php endif ?>
 
 
diff --git a/public/assets/css/class.css b/public/assets/css/class.css
index 598f441..e87861a 100644
--- a/public/assets/css/class.css
+++ b/public/assets/css/class.css
@@ -345,6 +345,7 @@
     color: var(--class-btn-blue);
     border-bottom: 3px solid var(--class-blue);
     padding: 0 8px;
+    text-align: revert-layer;
 }
 .classroom .article-body table tbody td {
     padding: 6px 8px;
diff --git a/public/assets/css/overides.css b/public/assets/css/overides.css
index 568164b..e3d5e1b 100644
--- a/public/assets/css/overides.css
+++ b/public/assets/css/overides.css
@@ -109,3 +109,23 @@ ul.select2-results__options li { font-size: 14px; padding: 4px 8px; }
 .admin-container .edit-post textarea[name=intro] { height: 94px ;} /* almost 3 (half-)lines */
 
 
+.admin-container .edit-post .post-media button.over-bar { margin: -26px 0 0 0; float: right; }
+.admin-container .edit-post .post-media ul {
+   border: 1px solid #ccc;
+   border-radius: 4px;
+   padding: 6px;
+}
+
+.admin-container .edit-post .post-media ul li {
+   border-bottom: 1px solid #ddd;
+   list-style-type: none;
+   padding: 3px 6px;
+
+   display: flex;
+   justify-content: space-between;
+   align-items: center;
+}
+.admin-container .edit-post .post-media ul li:last-child { border-bottom: none ;}
+.admin-container .edit-post .post-media ul li:hover { background: #eee; }
+
+.edit-post .post-media li .btn-xs { font-size: 14px; width: 24px; height: 24px; padding:0; }
\ No newline at end of file
diff --git a/public/assets/js/admin/edit_lesson.js b/public/assets/js/admin/edit_lesson.js
index ba31470..c5b0501 100644
--- a/public/assets/js/admin/edit_lesson.js
+++ b/public/assets/js/admin/edit_lesson.js
@@ -25,7 +25,6 @@ var files = [];     // array of { id:.., title:.., type:.., path:.. } records
 
 const files_root = '/media/';    // files root firectory
 
-var pageUrl = new URL(window.location.href);
 
 // an alternative--id when a lesson_id not exists (needed for file-upload)
 // ... consist of a 6-digit date string + random number up to 999
@@ -89,22 +88,9 @@ const upload_file_form = () => {
                     '<input type="text" class="form-control " value="" name="title" id="title" placeholder="Τίτλος για το Αρχείο" required="">',
                 '</div>',
 
-                '<div class="row">',
-
-                    '<div class="col-7"><div class="form-group">',
-                        '<label class="control-label" for="file">Εισαγωγή Αρχείου</label>',
-                        '<input class="form-control" type="file" id="file" name="file" required="">',
-                    '</div></div>',
-
-                    '<div class="col-5"><div class="form-group">',
-                        '<label class="control-label" for="category_id">Είδος</label>',
-                        '<select class="form-control form-select" id="reference" name="reference" required="">',
-                            '<option"></option>',
-                            '<option value="1">Παραπομπή (εμφανίζεται)</option>',
-                            '<option value="0">Βοηθητικό αρχείο (κρυφό)</option>',
-                        '</select>',
-                    '</div></div>',
-
+                '<div class="form-group">',
+                    '<label class="control-label" for="file">Εισαγωγή Αρχείου</label>',
+                    '<input class="form-control" type="file" id="file" name="file" required="">',
                 '</div>',
 
             '</div>',
@@ -172,6 +158,13 @@ $(document).ready(function() {
         width: '100%'
     });
 
+    // inti category (select2)
+    // ...
+    $("#privilege_id").select2({
+        placeholder: 'Επίπεδο Πρόσβασης',
+        width: '100%'
+    });
+
 
     // // init tags (select2)
     // // ...
@@ -200,33 +193,25 @@ $(document).ready(function() {
      */
     if (id) {   // if an `id` is given, load post .. then init_form
 
-        $.getJSON( "/admin/api/", { action: "get_post", id: id } )
+        $.getJSON( "/admin/api/lesson/" + id )
         .done( function (data) {
-            post = data;            // keep post
+            lesson = data;            // keep post
 
             // update fields' values
-            $('input[name=id]').val(post.id);           // id
-            $('input[name=title]').val(post.title);     // title
-            $('textarea[name=intro]').val(post.intro);  // intro
-            $('textarea[name=body]').val(post.body);    // body         
+            $('input[name=id]').val(lesson.id);           // id
+            $('input[name=title]').val(lesson.title);     // title
+            $('textarea[name=intro]').val(lesson.intro);  // intro
+            $('textarea[name=body]').val(lesson.body);    // body         
             $('input[name=status]').prop(               // status
                 'checked',
-                ((post.status==1)? true : false))
+                ((lesson.status==1)? true : false))
             .trigger('change');
 
-            $('#post-info').html('Δημιουργία: '+post.creation_date+'<br>Τελευταία Ενημέρωση: '+ post.update_date);
-
-            $('#delete').prop( "disabled", false );     // enable delete button
-
-            // if intro exist, show intro (optinal) field
-            if ((post.intro != null) && (post.intro != '')) {
-                $('.optional label[for=intro]').addClass('show');   // unhide section
-            }
+            // $('#post-info').html('Δημιουργία: '+post.creation_date+'<br>Τελευταία Ενημέρωση: '+ post.update_date);
 
             // parse media files; then draw
-            if (post.medias_json != null) {
-                files = JSON.parse(post.medias_json);
-                $('.optional label[for=media]').addClass('show');   // unhide section
+            if (lesson.medias_json != null) {
+                files = JSON.parse(lesson.medias_json);
             }
             draw_files_list();      // then draw the files list
             
@@ -234,7 +219,6 @@ $(document).ready(function() {
         });
 
     } else {    // else ... just init_form
-        $('#delete').prop( "disabled", true );     // disable delete button for new post attempt
         init_form_values();
     }
 
@@ -265,15 +249,15 @@ $(document).ready(function() {
             });
             categories.sort( compare_label );  // sort categories by breadcrumb
 
-            // // construct tags data
-            // // ---
-            // Object.keys(tags_response[0]).forEach( key => {
-            //     tag = tags_response[0][key];
-            //     tags.push({
-            //         id: tag.id,
-            //         label: tag.name
-            //     });
-            // });
+            // construct tags data
+            // ---
+            /// Object.keys(tags_response[0]).forEach( key => {
+            ///     tag = tags_response[0][key];
+            ///     tags.push({
+            ///         id: tag.id,
+            ///         label: tag.name
+            ///     });
+            /// });
 
             // construct provileges data
             // ---
@@ -294,20 +278,20 @@ $(document).ready(function() {
 
             } else {
                 // setup category_id options; select post's chosen category-id
-                set_parent_options( $('#category_id'), categories, post.category_id );
+                set_parent_options( $('#course_id'), categories, lesson.course_id );
 
                 // parse selected tags
                 // ---
-                var selected_tag_ids = [];
-                if (post.tags_json != null) {
-                    var selected_tags = JSON.parse(post.tags_json);
-                    selected_tags.forEach( itag => { selected_tag_ids.push(itag.id); })
-                }
+                /// var selected_tag_ids = [];
+                /// if (post.tags_json != null) {
+                ///     var selected_tags = JSON.parse(post.tags_json);
+                ///     selected_tags.forEach( itag => { selected_tag_ids.push(itag.id); })
+                /// }
                 // setup tags options; select post's chosen tags
-                set_parent_options( $('#tags'), tags, selected_tag_ids );
+                set_parent_options( $('#privilege_id'), privileges, lesson.privilege_id );
 
                 // ALSO: if tags selectd, show tags field
-                if (selected_tag_ids.length != 0) { $('.optional label[for=tags]').addClass('show'); }
+                // if (selected_tag_ids.length != 0) { $('.optional label[for=tags]').addClass('show'); }
             }
 
         });
@@ -347,28 +331,15 @@ $(document).ready(function() {
         var ref_icon, ref_class;
 
         files.forEach( item => {
-            // preapre [show|hide]-file as reference
-            if (item.reference == 1) {
-                ref_icon = '<i class="fas fa-eye"></i>';
-                ref_class = 'btn-default';
-    
-            } else {
-                ref_icon = '<i class="fas fa-eye-slash"></i>';
-                ref_class = 'btn-disabled';
-            }
-
             var copy = [    // copy button
                 '<button type="button" class="btn btn-xs btn-default js-copy"',
-                    'data-url="' + item.path + '">',
+                    ' data-url="' + item.path +'"',
+                    ' data-type="' + item.type + '"',
+                    '>',
                     '<i class="far fa-clone"></i>',
                 '</button>'
             ].join('');
-            var ref = [   // show|hide (is_reference)
-                '<button type="button" class="btn btn-xs '+ ref_class +' js-reference"',
-                    'data-id="' + item.id + '">',
-                    ref_icon,
-                '</button>'
-            ].join('');
+
             var del = [    // delete button
                 '<button type="button" class="btn btn-xs btn-danger js-delete"',
                     'data-id="' + item.id + '">',
@@ -377,9 +348,9 @@ $(document).ready(function() {
             ].join('');
             var option = [  // li html
                 '<li>',
-                    '<div class="text">' + item.title + '</div>',
+                    '<div class="text">' + item.label + '</div>',
                     '<div class="actions">',
-                        ref, ' ', copy, ' ',  del,
+                        copy, ' ',  del,
                     '</div>',
                 '</li>'
             ].join('');
@@ -400,20 +371,20 @@ $(document).ready(function() {
     $('.edit-post form').submit( event => {
         event.preventDefault();
 
-        // rearrange tags to old and new ones
-        // ---
-        var old_tags = [];
-        var new_tags = [];
-        var tags = $('#tags').select2('data');      
-        tags.forEach( t => {
-            if (!parseInt(t.id)) {
-                 new_tags.push(t.text);
-            } else {    old_tags.push(t.id); }
-        })
+        // // rearrange tags to old and new ones
+        // // ---
+        // var old_tags = [];
+        // var new_tags = [];
+        // var tags = $('#tags').select2('data');      
+        // tags.forEach( t => {
+        //     if (!parseInt(t.id)) {
+        //          new_tags.push(t.text);
+        //     } else {    old_tags.push(t.id); }
+        // })
 
         var attachments = [];
         // attachments (array) of "`media_id`;`reference`" strings
-        files.forEach( f => { attachments.push( f.id +';'+ f.reference ) });
+        files.forEach( f => { attachments.push( f.id ) });
 
         // prepare data to POST
         // ---
@@ -423,7 +394,7 @@ $(document).ready(function() {
             course_id: parseInt($('#course_id').select2('data')[0].id),
             intro: $('.edit-post form textarea[name=intro]').val(),
             body: $('.edit-post form textarea[name=body]').val(),
-            status: (($('input[name=status]').is(":checked")) ? 1 : 0),
+            status: ( ($('select[name=status]').val() == "0") ? 0 : 1 ),
             privilege_id: parseInt($('#privilege_id').select2('data')[0].id),
             // tags: old_tags,
             // new_tags: new_tags,
@@ -432,65 +403,38 @@ $(document).ready(function() {
 
         // select action url (add or update)
         // ---
-        var request = '/wiki/ajax?action=' + ((data.id == 0) ? 'add_post' : 'update_post');
+        var request = '/admin/api/lesson/' + ((data.id == 0) ? 'add' : 'update');
 
         // send POST (ajax) request
         $.post(request, data)
         .done(function( data ) {
-            window.location.href = '/wiki/admin?action=posts';      // seems ok; bach to articles
+            console.log(data);
+            //window.location.href = '/admin/lessons';      // seems ok; bach to articles
         });       
 
     });
 
 
-    // go-back (to posts)
+    // go-back (to lessons)
     // --- -- -- - - -
     $('#go-back').click( event => {
-        window.location.href = '/wiki/admin?action=posts';
-    });
-
-
-    // delete
-    // --- -- -- - - -
-    $('#delete').click( event => {
-        // ask before deletion
-        swal({
-            title: 'Είστε βέβαιος;',
-            html: "Ζητήσατε να διαγραφεί το άρθρο.<br>Παρακαλώ επιβεβαιώστε την διαγραφή.<br>ΠΡΟΣΟΧΗ: Δεν θα έχετε την δυνατότητα αναίρεσης!",
-            type: 'warning',
-            showCancelButton: true,
-            confirmButtonColor: '#3085d6',
-            cancelButtonColor: '#d33',
-            cancelButtonText: 'Ακύρωση',
-            confirmButtonText: 'Ναι, να διαγραφεί',
-            showLoaderOnConfirm: true,
-            preConfirm: function() {
-                return new Promise(function(resolve) {
-                    $.getJSON( "/wiki/ajax", { action: "delete_post", id: id } )
-                    .done( function (data) {
-                        // return to posts-administration
-                        window.location.href = '/wiki/admin?action=posts';
-                    });
-                });
-            }, 
-            allowOutsideClick: false
-        }).catch(swal.noop);
-
+        if (confirm('Θέλετε να ακυρώσετε τις όποιες αλλαγές και να φύγτε από τη σελίδα;')) {
+            window.location.href = '/admin/lessons';
+        }
     });
 
 
-
     // copy url button
     // --- -- -- - - -
-    $('.wiki').on('click', 'button.js-copy', function (e) {
+    $('.admin-container').on('click', 'button.js-copy', function (e) {
         var copytext = '';   // default: copy nothing
 
         if ($(this).data('id') !== undefined) {
-            copytext = pageUrl.origin +'/wiki/post?id=' + $(this).data('id');
+            copytext = window.location.origin +'/lesson/' + $(this).data('id');
         }
 
         if ($(this).data('url') !== undefined) {
-            copytext = files_root + $(this).data('url');
+            copytext = window.location.origin + '/serve/file/' + $(this).data('url') + '?type=' + $(this).data('type');
         }
         
         navigator.clipboard
@@ -498,6 +442,7 @@ $(document).ready(function() {
         .then(() => {   // notify the copy event
             $(this).addClass('copied');
             setTimeout( () => { $(this).removeClass('copied'); }, 700);
+            console.log(copytext, ' copied!');
         })
         .catch(() => {
             console.log("error on coping text");
@@ -508,7 +453,8 @@ $(document).ready(function() {
 
     // delete (remove) file button
     // --- -- -- - - -
-    $('.wiki').on('click', 'button.js-delete', function (e) {
+    $('.admin-container').on('click', 'button.js-delete', function (e) {
+        console.log('delete!');
         var media_id = $(this).data('id');
 
         // remove from files array the one with id == media_id
@@ -521,12 +467,11 @@ $(document).ready(function() {
     });
 
 
-
-    
+   
 
     // show|hide file as referece button
     // --- -- -- - - -
-    $('.wiki').on('click', 'button.js-reference', function (e) {
+    $('.admin-container').on('click', 'button.js-reference', function (e) {
         var id = $(this).data('id');
         
         // toggle reference attribute of item with `id` = id
@@ -608,8 +553,7 @@ $(document).ready(function() {
                         id: response.id,
                         title: response.title,
                         path: response.path,
-                        type: response.type,
-                        reference: $('#reference').val()
+                        type: response.type
                     });
                     draw_files_list();                   
 
diff --git a/public/assets/js/admin/files.js b/public/assets/js/admin/files.js
new file mode 100644
index 0000000..bfb0c73
--- /dev/null
+++ b/public/assets/js/admin/files.js
@@ -0,0 +1,264 @@
+// Globals
+// -----------------------------------------------------------------------------
+var privileges = [];
+var files = [];
+var table;
+
+
+
+// Supplamentary functions
+// -----------------------------------------------------------------------------
+
+// array.indexOf polyfill
+// --- -- -- - - -
+if (!Array.prototype.indexOf)
+{
+  Array.prototype.indexOf = function(elt /*, from*/)
+  {
+    var len = this.length >>> 0;
+
+    var from = Number(arguments[1]) || 0;
+    from = (from < 0)
+         ? Math.ceil(from)
+         : Math.floor(from);
+    if (from < 0)
+      from += len;
+
+    for (; from < len; from++)
+    {
+      if (from in this &&
+          this[from] === elt)
+        return from;
+    }
+    return -1;
+  };
+}
+
+// return file record by file-id
+// --- -- -- - - -
+function privilege_record(id) {
+    var record = 0;
+    files.forEach(el => { if (el.id == id) record = el; });
+   
+    return record;
+}
+
+
+// create actions html (edit and delete buttons)
+// --- -- -- - - -
+function create_actions_html(id) {
+
+    var del, edit;
+
+    del = "";
+
+    edit = [
+        '<button type="button" class="btn btn-sm btn-warning"',
+            'data-bs-toggle="modal" data-bs-target="#manageFiles"',
+            'data-id="'+ id +'">',
+            '<i class="fas fa-pencil-alt"></i>',
+        '</button>'
+    ].join('\n');
+
+    return edit +' '+ del;
+}
+
+
+
+$(document).ready(function() {
+
+    // When document is ready
+    // -------------------------------------------------------------------------
+
+    
+    /** init selec2 element (used to specify parent-category)
+     * --- -- -- - - -
+     */
+    $("#privilege_id").select2({
+        placeholder: 'Επίπεδο πρόσβασης',
+        dropdownParent: $('#manageFiles'),
+        width: '100%',
+    });
+
+    
+    /** init_table
+     * --- -- -- - - -
+     * get categories
+     * constuct categories array
+     * render dataTable 
+     */
+    function init_table() {
+
+        // get all categories from server (ajax)
+        $.getJSON( "/admin/api/files")
+        .done(function( json ) {
+            // then ...
+
+            // reset categories
+            files.length = 0;
+
+            // construct (new) categories data
+            Object.keys(json).forEach( key => {
+                el = json[key];
+                files.push({
+                    id: el.id,
+                    label: el.label,
+                    path: el.path,
+                    type: el.type,
+                    privilege_id: ((el.privilege_id == null) ? 0 : el.privilege_id),
+                    actions: create_actions_html(el.id)
+                });
+            });
+
+            // sort by breadcrumb
+            // categories.sort( compare_breadcrumb );
+
+            // destroy previous datatable table instances
+            $('#dt-files').dataTable().fnClearTable();
+            $('#dt-files').dataTable().fnDestroy();
+
+            // (re-)create categories datatable
+            table = $('#dt-files').DataTable({
+                language: { url: '/libs/DataTables/localization/Greek.json' },           
+                data: files,
+                ordering: false,
+                columns: [
+                    { data: 'id' },
+                    { data: 'label' },
+                    { data: 'path' },
+                    { data: 'type' },
+                    { data: 'privilege_id' },
+                    { data: 'actions' }
+                ]
+            });
+
+        })
+        .fail(function( jqxhr, textStatus, error ) {
+            console.log( "Request Failed (" + error +")" );
+        });
+
+    }
+    init_table();   // init table on first run
+
+
+
+    /** When modal show-up
+     * -------------------------------------------------------------------------
+     * ... prepare the manage-category form 
+     * ... update select2 with possible parents
+     */
+    $('#managePrivileges').on('show.bs.modal', event => {
+        var button = $(event.relatedTarget);        // Button that triggered the modal
+        var id = parseInt( button.data('id') );     // category_id from data-id
+        // var modal = $(this);    // modal object     
+        
+        // update modal literature
+        // ---
+        $('#managePrivileges .modal-title').html(             // modal title
+            (id) ? 'Ενημέρωση Επιπέδου Πρόσβασης' : 'Δημιουργία Επιπέδου Πρόσβασης'
+        );
+        $('#managePrivileges form input[name=id]').val( id );     // category id (hidden)
+        $('#managePrivileges form input[name=label]').val(    // category label
+            (id) ? privilege_record(id).label : ""
+        );
+        prepare_included_element(id);        // prepare <select> for parents
+    })
+
+    /** prepare_included_element()
+     * ---
+     * @param id (int) : id of selected privilege
+     * -> Get all posible included privileges
+     * -> call set_included_options() to render the options
+     */
+    function prepare_included_element(id) {
+        var may_included = [];
+
+        if (id) {   // get all possible parents
+
+            // TODO: 
+            // specify forbiden privilege IDs for being included
+
+            // filter privileges adn prepare possible included privileges
+            privileges.forEach( el => {
+                if (id != el.id)  {
+                    may_included.push({
+                        id: el.id,
+                        label: el.label
+                    });
+                }
+            });
+            console.log(may_included);
+            set_included_options(may_included, privilege_record(id).included_id);
+
+
+        } else {    // new record; all categories are possible parrents
+            privileges.forEach( el => {
+                may_included.push({
+                    id: el.id,
+                    label: el.label,
+                });
+            })
+            set_included_options(may_included, -1);
+        }
+    }
+
+    /** set_included_options()
+     * -> create options for parents <select>
+     * -> choose selected parent
+     * @param may_included (array): array of possible included privileges
+     * @param selected (int): selected included privilege
+     */
+    function set_included_options(may_included, selected) {
+        // sort parents by breadcrumb
+        // parents.sort( compare_breadcrumb );
+
+        // remove any olded options from select2
+        $('#included_id option').each(function() { $(this).remove(); });
+
+        // first option is the root category
+        $('#included_id').append('<option value="0">— κανένα —</option>')
+
+        // add all other parent options
+        may_included.forEach( i => {
+            $('#included_id').append(`<option value="${i.id}">${i.label}</option>`);
+        });
+
+        if (selected == -1) {   // new category; remove any parent pre-selection
+            $('#included_id').val(0).trigger('change');
+
+        } else {    // category exists; choose selected parent
+            $('#included_id').val(selected).trigger('change');
+        }
+    }
+
+
+
+
+    // When form is submited
+    // -------------------------------------------------------------------------
+
+    $('#manageCategory form').submit( event => {
+        event.preventDefault();
+
+        // prepare data to POST
+        var data = {
+            id: parseInt($('#manageCategory form input[name=id]').val()),
+            label: $('#manageCategory form input[name=label]').val(),
+            parent_id: parseInt($('#parent_id').select2('data')[0].id)
+        };
+
+        // select action url (add or update)
+        var request = '/admin/api/category/' + ((data.id == 0)  ? 'add' : 'update');
+
+        // send POST request
+        $.post(request, data)
+        .done(function( data ) {
+
+            $('#manageCategory').modal('hide');     // when done, close modal
+
+            init_table();       // reload table of categories
+        });       
+
+    });
+
+});
diff --git a/public/assets/js/admin/panel.js b/public/assets/js/admin/panel.js
new file mode 100644
index 0000000..24b465e
--- /dev/null
+++ b/public/assets/js/admin/panel.js
@@ -0,0 +1 @@
+console.log('Admin Panel!');
\ No newline at end of file