skeleton commit; based on an anom project

14 files changed, 1778 insertions, 0 deletions

diff --git a/public/app/models/.gitkeep b/public/app/models/.gitkeep
new file mode 100644
index 0000000..e69de29
--- /dev/null
+++ b/public/app/models/.gitkeep
diff --git a/public/app/models/Jorge.php b/public/app/models/Jorge.php
new file mode 100644
index 0000000..5d79007
--- /dev/null
+++ b/public/app/models/Jorge.php
@@ -0,0 +1,172 @@
+<?php
+
+namespace app\models;
+
+use \Registry;
+
+/** Jorge
+ * a database reference and adminitration toolkit
+ * ---
+ * The name Jorge comes from Uberto Eco's book: 'il nome della rosa',
+ * (Jorge is the blind monk who supervises the monastery's library ;)
+ */
+class Jorge
+{
+
+    /** tables
+     * array to keep all database-tables' critical information.
+     * @key create (array) includes all 'CREATE TABLE' statements
+     * @key relate (array) includes relations between tables
+     * @key fields (array) includes all important fields (when no select*)
+     * @key filter (array) includes all fields used to filter results
+     */
+    private $tables = [
+        'create' => [],
+        'relate' => [],
+        'fields' => []
+    ];
+
+    public function __construct()
+    {
+        $db = Registry::use('database');
+
+        // get all tables
+        $tableList = $db->runQuery("SHOW TABLES", []);
+        
+        // get all CREATE TABLE statements
+        foreach($tableList as $tableArray) {
+            $table = array_shift($tableArray);
+            $create = $db->runQuery("SHOW CREATE TABLE {$table}", []);
+            $this->tables['create'][$table] = $create[0]['Create Table'];
+        }
+
+        // define relations
+        $this->tables['relate'] = [
+
+            'lesson' => [
+                'course' => 'course.id = lesson.course_id',
+                'lesson_media' => 'lesson_media.lesson_id = lesson.id',
+                'lesson_privilege' => 'lesson_privilege.lesson_id = lesson.id'
+            ],
+
+            'page' => [
+                'page_media' => 'page_media.page_id = page.id'
+            ],
+
+            'user' => [
+                'user_privilege' => 'user_privilege.user_id = user.id'
+            ],
+
+            'privilege' => [
+                'user_privilege' => 'user_privilege.privilege_id = privilege.id'
+            ],
+
+        ];
+
+        $this->extractTableFields();
+
+        // return true;
+    }
+
+
+    /** Create...
+     * one or more database tables
+     * ---
+     * @param $datasource (string|void) : table name or none
+     * if none then all tables will be created
+     * @return (boolean)
+     * 
+     * NOTE:
+     * for safety reasons this method is not executing SQL;
+     * it just echoes the SQL that needs to be executed in 
+     * order to crate all database tables.
+     */
+    public function create($datasource = '')
+    {
+        // if no datasource passed then datasource is all tables
+        if ($datasource == '') {
+            $datasource = array_keys(self::$tables['create']);
+        
+        } else {
+            // if datasource exist, make it an array
+            if (array_key_exists($datasource, self::$tables['create'])) {
+                $datasource = [ $datasource ];
+
+            } else {
+                // table does not exist
+                return fasle;
+            }
+        }
+
+        $sql = "";
+        foreach( $datasource as $table ) {          
+            $sql .= "-- CREATE ". $table .";\n". self::$tables['create'][$table] . "\n\n";
+        }
+
+        return ['sql' => $sql];
+    }
+
+
+    /** Calculate fields of every table
+     * ---
+     * Parse every CREATE SQL statement and extract list of fields;
+     * Algorithm implements linear-parsing (faster than a recursive one)
+     */
+    private function extractTableFields()
+    {
+        // words used by SQL that can not be field names
+        $nonFields = ['PRIMARY', 'KEY', '(', ')', 'CONSTRAINT', 'UNIQUE'];    // reduced list (used on CREATE)
+
+        foreach( $this->tables['create'] as $table => $sqlCreate ) {
+
+            $fields = [];   // variable to hold the extracted fields
+
+            // get text between first open-parentesis and last close-parentesis
+            // this is waht lies between 'CREATE TABLE table(' and ') [ENGINE whatever]'
+            // (including the patenteses)
+            preg_match_all(
+                "/\((((?>[^()]+)|(?R))*)\)/",
+                str_replace("\n", '', $sqlCreate),
+                $match
+            );
+            // remove 1st+last parentesis
+            $mainDefinitions = substr($match[0][0], 1, -1);
+
+            // replace comma (,) on sub-parenthesis
+            // ex: 'decimal(18, 2)' turns to 'decimal(18: 2)'
+            // or: 'PRIMARY KEY (id1, id2)' turns to 'PRIMARY KEY (id1: id2)'
+            $sentences = preg_replace(
+                '/\\(([0-9a-zA-Z_`]*)[ ,]([0-9a-zA-Z_` ]*)\\)/',
+                '($1:$2)',
+                $mainDefinitions,
+                -1
+            );
+
+            // devide the banth of sentences to field definitions
+            $defines = explode(',', $sentences);
+
+            // now each denine holds a full field definition
+            // like: `ID` int(11) NOT NULL AUTO_INCREMENT
+
+            foreach($defines as $def) {
+                // check the first term of each sentence
+                $terms = explode(' ', trim($def,));
+                $term = array_shift($terms);
+                
+                if (!in_array($term, $nonFields)) {
+                    $fields[ str_replace('`', '', $term) ] = implode(' ', $terms);
+                }
+            }
+
+            $this->tables['fields'][$table] = $fields;
+        }
+
+        return;
+    }
+
+    public function databaseDocumentation()
+    {
+        return $this->tables['fields'];
+    }
+    
+}
\ No newline at end of file
diff --git a/public/app/models/_info.md b/public/app/models/_info.md
new file mode 100644
index 0000000..5504523
--- /dev/null
+++ b/public/app/models/_info.md
@@ -0,0 +1,150 @@
+
+# info about the structrure of the models
+
+According to the former impementation (atcom) the project will need to handle 200+ tables.
+The former project includes 209 tables with 5 or more rows (and 325 tables totaly)
+
+
+
+## Database schema
+
+Main tables and recomended constraints:
+
+```
+SET NAMES utf8;
+SET time_zone = '+00:00';
+SET foreign_key_checks = 0;
+SET sql_mode = 'NO_AUTO_VALUE_ON_ZERO';
+
+SET NAMES utf8mb4;
+
+DROP TABLE IF EXISTS `course`;
+CREATE TABLE `course` (
+  `id` int(11) NOT NULL AUTO_INCREMENT,
+  `parent_id` int(11) NOT NULL COMMENT 'if 0 then this is a root course',
+  `label` varchar(140) COLLATE utf8mb4_unicode_ci NOT NULL,
+  PRIMARY KEY (`id`)
+) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci;
+
+
+DROP TABLE IF EXISTS `lesson`;
+CREATE TABLE `lesson` (
+  `id` int(11) NOT NULL AUTO_INCREMENT,
+  `course_id` int(11) NOT NULL,
+  `title` varchar(140) COLLATE utf8mb4_unicode_ci NOT NULL,
+  `body` text COLLATE utf8mb4_unicode_ci NOT NULL,
+  `published` tinyint(4) NOT NULL DEFAULT '0' COMMENT '0 = unpublished, 1 = published',
+  PRIMARY KEY (`id`),
+  KEY `course_id` (`course_id`),
+  CONSTRAINT `lesson_ibfk_1` FOREIGN KEY (`course_id`) REFERENCES `course` (`id`),
+  CONSTRAINT `lesson_ibfk_2` FOREIGN KEY (`course_id`) REFERENCES `course` (`id`)
+) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci;
+
+
+DROP TABLE IF EXISTS `lesson_media`;
+CREATE TABLE `lesson_media` (
+  `lesson_id` int(11) NOT NULL,
+  `media_id` int(11) NOT NULL,
+  PRIMARY KEY (`lesson_id`,`media_id`),
+  KEY `media_id` (`media_id`),
+  CONSTRAINT `lesson_media_ibfk_1` FOREIGN KEY (`lesson_id`) REFERENCES `lesson` (`id`),
+  CONSTRAINT `lesson_media_ibfk_2` FOREIGN KEY (`lesson_id`) REFERENCES `lesson` (`id`),
+  CONSTRAINT `lesson_media_ibfk_3` FOREIGN KEY (`lesson_id`) REFERENCES `lesson` (`id`),
+  CONSTRAINT `lesson_media_ibfk_4` FOREIGN KEY (`media_id`) REFERENCES `media` (`id`),
+  CONSTRAINT `lesson_media_ibfk_5` FOREIGN KEY (`lesson_id`) REFERENCES `lesson` (`id`) ON DELETE NO ACTION,
+  CONSTRAINT `lesson_media_ibfk_6` FOREIGN KEY (`media_id`) REFERENCES `media` (`id`) ON DELETE NO ACTION,
+  CONSTRAINT `lesson_media_ibfk_7` FOREIGN KEY (`lesson_id`) REFERENCES `lesson` (`id`) ON DELETE NO ACTION,
+  CONSTRAINT `lesson_media_ibfk_8` FOREIGN KEY (`media_id`) REFERENCES `media` (`id`) ON DELETE NO ACTION
+) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci;
+
+
+DROP TABLE IF EXISTS `lesson_privilege`;
+CREATE TABLE `lesson_privilege` (
+  `lesson_id` int(11) NOT NULL,
+  `privilege_id` int(11) NOT NULL COMMENT 'minimum privilege required to access the lesson',
+  KEY `lesson_id` (`lesson_id`),
+  KEY `privilege_id` (`privilege_id`),
+  CONSTRAINT `lesson_privilege_ibfk_1` FOREIGN KEY (`lesson_id`) REFERENCES `lesson` (`id`),
+  CONSTRAINT `lesson_privilege_ibfk_2` FOREIGN KEY (`privilege_id`) REFERENCES `privilege` (`id`)
+) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci;
+
+
+DROP TABLE IF EXISTS `media`;
+CREATE TABLE `media` (
+  `id` int(11) NOT NULL AUTO_INCREMENT,
+  `label` varchar(140) COLLATE utf8mb4_unicode_ci NOT NULL,
+  `type` varchar(64) COLLATE utf8mb4_unicode_ci NOT NULL,
+  `path` varchar(320) COLLATE utf8mb4_unicode_ci NOT NULL,
+  `referable` tinyint(4) NOT NULL DEFAULT '1' COMMENT '0 = hidden, 1 = referable',
+  PRIMARY KEY (`id`)
+) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci;
+
+
+DROP TABLE IF EXISTS `page`;
+CREATE TABLE `page` (
+  `id` int(11) NOT NULL AUTO_INCREMENT,
+  `title` varchar(140) COLLATE utf8mb4_unicode_ci NOT NULL,
+  `body` text COLLATE utf8mb4_unicode_ci NOT NULL,
+  `published` tinyint(4) NOT NULL DEFAULT '0' COMMENT '0 = unpublished; 1 = published',
+  PRIMARY KEY (`id`)
+) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci;
+
+
+DROP TABLE IF EXISTS `page_media`;
+CREATE TABLE `page_media` (
+  `page_id` int(11) NOT NULL,
+  `media_id` int(11) NOT NULL,
+  KEY `page_id` (`page_id`),
+  KEY `media_id` (`media_id`),
+  CONSTRAINT `page_media_ibfk_1` FOREIGN KEY (`page_id`) REFERENCES `page` (`id`) ON DELETE NO ACTION,
+  CONSTRAINT `page_media_ibfk_2` FOREIGN KEY (`media_id`) REFERENCES `media` (`id`) ON DELETE NO ACTION
+) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci;
+
+
+DROP TABLE IF EXISTS `privilege`;
+CREATE TABLE `privilege` (
+  `id` int(11) NOT NULL AUTO_INCREMENT,
+  `alias` varchar(8) COLLATE utf8mb4_unicode_ci NOT NULL COMMENT 'keep it simple; use latin',
+  `label` varchar(140) COLLATE utf8mb4_unicode_ci NOT NULL,
+  PRIMARY KEY (`id`),
+  UNIQUE KEY `alias` (`alias`)
+) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci;
+
+
+DROP TABLE IF EXISTS `privilege_inherit`;
+CREATE TABLE `privilege_inherit` (
+  `higher_id` int(11) NOT NULL COMMENT 'higher priviledges inherit (include) lower ones',
+  `lower_id` int(11) NOT NULL,
+  PRIMARY KEY (`higher_id`,`lower_id`)
+) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci;
+
+
+DROP TABLE IF EXISTS `user`;
+CREATE TABLE `user` (
+  `id` int(11) NOT NULL AUTO_INCREMENT,
+  `first_name` int(11) NOT NULL,
+  `last_name` int(11) NOT NULL,
+  `email` int(11) NOT NULL,
+  `expiration` int(11) NOT NULL COMMENT 'account expiration date; 0 = never',
+  `password` int(11) NOT NULL,
+  `salt` int(11) NOT NULL,
+  `otp` int(11) NOT NULL COMMENT 'one time password for reset password',
+  `otp_expiration` int(11) NOT NULL,
+  `active` int(11) NOT NULL COMMENT 'account flag; 1=active, 0=inactive',
+  PRIMARY KEY (`id`)
+) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci;
+
+
+DROP TABLE IF EXISTS `user_privilege`;
+CREATE TABLE `user_privilege` (
+  `user_id` int(11) NOT NULL,
+  `privilege_id` int(11) NOT NULL,
+  PRIMARY KEY (`user_id`,`privilege_id`),
+  KEY `privilege_id` (`privilege_id`),
+  CONSTRAINT `user_privilege_ibfk_1` FOREIGN KEY (`user_id`) REFERENCES `user` (`id`),
+  CONSTRAINT `user_privilege_ibfk_2` FOREIGN KEY (`privilege_id`) REFERENCES `privilege` (`id`)
+) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci;
+
+```
+
+
diff --git a/public/app/models/admin/History_model.php b/public/app/models/admin/History_model.php
new file mode 100644
index 0000000..04ce630
--- /dev/null
+++ b/public/app/models/admin/History_model.php
@@ -0,0 +1,34 @@
+<?php
+namespace app\models\admin;
+
+use \Registry;
+
+
+class History_model
+{
+
+    /** track user access
+     * 
+     */
+    public static function trackUserAccess($user_id, $type, $message, $note='_')
+    {
+
+        Registry::use('database')->query(
+            "INSERT INTO history
+                (user_id, `type`, `message`, `note`, `ip`)
+            VALUES
+                (:uid, :type, :msg, :note, :ip)",
+            [
+                ':uid' => $user_id,
+                ':type' => $type,
+                ':msg' => $message,
+                ':note' => $note,
+                ':ip' => Registry::get('REQUEST')->IP
+            ]
+        )->lastInsertID();
+        
+    }
+
+
+
+}
\ No newline at end of file
diff --git a/public/app/models/admin/Privilege_model.php b/public/app/models/admin/Privilege_model.php
new file mode 100644
index 0000000..c385484
--- /dev/null
+++ b/public/app/models/admin/Privilege_model.php
@@ -0,0 +1,42 @@
+<?php
+
+namespace app\models\admin;
+
+use Registry;
+use Render;
+
+
+class Privilege_model {
+
+    /** privileges
+     * ---
+     * get all privileges
+     * 
+     * @param void
+     * @return privileges (array)
+     */
+    public static function privileges()
+    {
+        return Registry::use('database')->runQuery(
+                "SELECT * FROM privilege",[]
+        );
+    }
+
+    /** edit privileges
+     * ---
+     */
+    public static function edit_privileges()
+    {
+        // TODO: ...
+    }
+
+
+    /** update course
+     * ---
+     */
+    public static function update_course()
+    {
+        // TODO: ...
+    }
+
+}
\ No newline at end of file
diff --git a/public/app/models/admin/User_model.php b/public/app/models/admin/User_model.php
new file mode 100644
index 0000000..2885dc1
--- /dev/null
+++ b/public/app/models/admin/User_model.php
@@ -0,0 +1,299 @@
+<?php
+
+namespace app\models\admin;
+
+use \Registry;
+use app\models\admin\History_model as History;
+
+class User_model
+{
+
+    /** check user (by index key)
+     * 
+     * @param $indexKey (string) : key for user identification
+     * @param $value (string)
+     * 
+     * @param $email (string): user's email
+     */
+    public static function checkUser($email)
+    {
+        $user = Registry::use('database')->query(
+            "SELECT * FROM user WHERE email = :email AND active = 1",
+            [ ':email' => $email ]
+        )->getFirst();
+       
+        // if no user, return false
+        if ($user === false)     return false;
+       
+        return $user;
+    }
+
+
+    /** get user (by index key)
+     * 
+     * user detailed array
+     * includes all user properties + granted roles + privileges
+     * 
+     * @param $id (int) : user id
+     * @param $value (string)
+     */
+    public static function getUser($id)
+    {
+        $user = Registry::use('database')->query(
+            "SELECT user.*,
+            (   -- construct array (json) of roles granted to user
+                SELECT CONCAT(
+                    '[',
+                    GROUP_CONCAT(role.id),
+                    ']'
+                )
+                FROM `role`
+                WHERE role.id IN (
+                    SELECT user_role.role_id
+                    FROM user_role
+                    WHERE user_role.user_id = :id
+                )
+            ) AS Roles_json,
+            (   -- construct array of (root-)privileges granted to user
+                SELECT CONCAT(
+                    '[',
+                    GROUP_CONCAT(privilege.id),
+                    ']'
+                )
+                FROM privilege
+                WHERE privilege.id IN (
+                    SELECT user_privilege.privilege_id
+                    FROM user_privilege
+                    WHERE user_privilege.user_id = :id
+                )
+            ) AS RootPrivileges_json,
+            (   -- construct array of (root-)privileges granted to user
+                SELECT CONCAT(
+                    '[',
+                    GROUP_CONCAT(privilege.includes),
+                    ']'
+                )
+                FROM privilege
+                WHERE privilege.id IN (
+                    SELECT user_privilege.privilege_id
+                    FROM user_privilege
+                    WHERE user_privilege.user_id = :id
+                )
+            ) AS SubPrivileges_json
+            FROM user
+            WHERE id = :id",
+            [ ':id' => $id ]
+        )->getFirst();
+
+        
+        // if no user, return false
+        if ($user === false)     return false;
+
+
+        // TODO:
+        // * merge root+sub privilede lists
+        // * convert json strings to php arrays
+
+
+        // TODO:
+        // cache user super array
+      
+        return $user;
+    }
+
+
+    /** create user
+     * 
+     * creates user record;
+     * assigns privileged (usualy defaults);
+     * creates activation_code
+     * 
+     * @param $data (array): Request->POST array
+     * @param $password (string): secure hashed password
+     * 
+     * @return $activation_code
+     * 
+     */
+    public static function registerUser($data, $password, $privileges = DEFAULT_PRIVILEGES)
+    {
+        $required_fields = [
+            'name',
+            'surname',
+            'email',
+            'password'
+        ];
+
+        // check required fields
+        $isOK = true;
+        foreach($required_fields as $fi) {
+            if (empty($data[$fi]))    $isOK = false;
+        }
+        // if empty required fields exists ... return false
+        if (!$isOK) {
+            return [ "success" => false, 'error' => EMPTY_REQUIRED_FIELDS ];
+        }
+
+
+        // TODO:
+        // check if email exists
+        // ...
+
+        // create an activation code
+        $activation_code = md5($data['email'].time().rand(0, 10000));
+
+        // if isOK go on and...
+        // create user record
+        $new_user_id = Registry::use('database')->query(
+            "INSERT INTO user
+                (`first_name`, `last_name`, `email`, `password`, `active`, `activation`)
+            VALUES
+                (:nam, :surname, :email, :pass, :act, :actcode)",
+            [ 
+                ':nam' => $data['name'],
+                ':surname' => $data['surname'],
+                ':email' => $data['email'],
+                ':pass' => $password,
+                ':act' => 0,      // needs email confirmation to be activated ...
+                ':actcode' => $activation_code    // ... with the activation code
+            ]
+        )->lastInsertID();
+
+        // set default privileges
+        self::set_user_privileges($new_user_id, $privileges);
+
+        // set reader role
+        self::set_user_role($new_user_id, 5);
+
+        // update history
+        History::trackUserAccess($new_user_id, TRACK_ACCOUNT, 'Create User Account');
+
+        // return success and user id
+		return [
+            "success" => true,
+            'id' => $new_user_id ,
+            'activation' => $activation_code
+        ];
+    }
+
+
+    /** set_user_privileges
+     * 
+     * @param $privileges (array)
+     */
+    public static function set_user_privileges($user, $privileges)
+    {
+        $db = Registry::use('database');    // database connection
+        foreach($privileges as $pri) {      // pri = privilege id
+            $db->runQuery(
+                "INSERT INTO user_privilege (user_id, privilege_id) VALUES (:user, :pri)",
+                [ ':user' => $user, ":pri" => $pri ]
+            );
+        }
+        return true;
+    }
+
+
+    /** set_user_role
+     * 
+     * user, role are (int) IDs
+     */
+    public static function set_user_role($user, $role)
+    {
+
+        Registry::use('database')->runQuery(
+            "INSERT INTO user_role (user_id, role_id) VALUES (:user, :role)",
+            [ ':user' => $user, ":role" => $role ]
+        );
+
+        return true;
+    }
+
+
+    /** activate
+     * 
+     * check if activation code is valid;
+     * if valid, set account active;
+     * 
+     * @param $ticket (hex/MD5): activation code;
+     * 
+     */
+    public static function activate($ticket)
+    {
+        $user = Registry::use('database')->query(
+            "SELECT * FROM user WHERE activation = :ticket",
+            [ 'ticket' => $ticket ]
+        )->getFirst();
+
+        // if no user with this activation code, return false
+        if ($user === false)     return false;
+
+        // remove activation code from user record
+        Registry::use('database')->runQuery(
+            "UPDATE user
+                SET active = 1, `activation` = NULL
+            WHERE activation = :ticket",
+            [ 'ticket' => $ticket ]
+        );
+
+        // update history
+        History::trackUserAccess($user['id'], TRACK_ACCOUNT, 'User Account Activated');
+
+        return true;
+
+    }
+
+
+}
+
+/* example query getUser (super-array)
+--- -- -- - - -
+
+SELECT user.*,
+(   -- array (json) of roles granted to user
+    SELECT CONCAT('[', GROUP_CONCAT(role.id), ']')
+    FROM `role`
+    WHERE role.id IN (
+        SELECT user_role.role_id
+        FROM user_role
+        WHERE user_role.user_id = 1
+    )
+) AS Roles_json,
+(
+    SELECT CONCAT(
+        '[',
+        GROUP_CONCAT(privilege.id),
+        ']'
+    )
+    FROM privilege
+    WHERE privilege.id IN (
+        SELECT user_privilege.privilege_id
+        FROM user_privilege
+        WHERE user_privilege.user_id = 1
+    )
+) AS RootPrivileges_json,
+(
+    SELECT CONCAT(  -- array of array of sub-privileges
+        '[',
+        GROUP_CONCAT(   -- array (json) of subprivileges
+            (
+                SELECT CONCAT(
+                    '[',
+                    GROUP_CONCAT(included_id),
+                    ']'
+                )
+                FROM privilege_includes
+                WHERE privilege_id = privilege.id
+            )
+        ),
+        ']'
+    )
+    FROM privilege
+    WHERE privilege.id IN (
+        SELECT user_privilege.privilege_id
+        FROM user_privilege
+        WHERE user_id = 1
+    )
+) AS SubPrivileges_json
+FROM user
+WHERE id = 1
+--- */
\ No newline at end of file
diff --git a/public/app/models/cms/Course_model.php b/public/app/models/cms/Course_model.php
new file mode 100644
index 0000000..6614993
--- /dev/null
+++ b/public/app/models/cms/Course_model.php
@@ -0,0 +1,314 @@
+<?php 
+namespace app\models\cms;
+
+use \Registry;
+
+
+class Course_model {
+    
+    /** COURSES
+     * -------------------------------------------------------------------------
+     */
+
+	/** get all categories
+     * 
+     * raw table data (simplest SELECT)
+     * 
+     */ 
+	public static function get_categories()
+	{
+        return Registry::use('database')->runQuery(
+		    "SELECT * FROM course ORDER BY label",
+            []
+        );
+	}
+
+    /** courses struct
+     * 
+     * a super array with almost any info needed about courses
+     * 
+     * @return (array) ['tree' => ..., 'breadcrumbs' => ... ]
+     */
+    public static function courses_struct()
+    {
+        $tree = self::category_tree();
+        return [
+            'tree' => $tree,
+            'breadcrumbs' => self::breadcrumbs($tree)
+        ];
+    }
+
+
+    /** constuct a category_tree
+     * 
+     * returns a tree representation of the categories
+     * 
+     * NOTE:
+     * category_tree() is an expensive method;
+     * it calls 2 other methods implementing recursive algorithms
+     * thus it uses many sources to run (particularly RAM).
+     * Caching the result is strogly recommended.
+     * 
+     */
+    public static function category_tree()
+    {
+        $categories = self::get_categories();          // get all categories
+
+        $tree = self::to_tree($categories);            // format to a tree
+
+        $tree_wParents = self::tree_parents($tree);    // add parents section for each tree-node
+
+        return $tree_wParents;
+    }
+
+
+    /** to_tree
+     * 
+     * constructs a tree from raw-table data;
+     * this is a private method and uses a recursive algorithm
+     * 
+     * @param $dataset (array): flar array of records with id/parent-id pairs
+     * @return $root (array): id of root category
+     * 
+     * (**) each node has 2 parts:
+     * .... .. rec    : all record attributes/data as passed into $dataset
+     * .... .. childs : array of (children) nodes
+     */
+    private static function to_tree($dataset, $root = 0)
+    {
+        $return = [];
+
+        // loop data ; search for direct children of root
+        foreach($dataset as $key => $rec) {
+
+            $child = $rec['id'];
+            $parent = $rec['parent_id'];
+
+            if ($parent == $root) {     // a direct child is found
+
+                unset($dataset[$key]);     // remove item (no need to traverse again)
+
+                // Append the child into result array ; parse its children
+                $return[] = [
+                    'rec' => [          
+                        'id' => $rec['id'],
+                        'label' => $rec['label'],
+                        'order' => $rec['order'],
+                        'parent' => $rec['parent_id']
+                    ],
+                    'childs' => self::to_tree($dataset, $child)     // recursively
+                ];
+            }
+        }
+        return empty($return) ? [] : $return;
+    }
+
+    
+    /** tree_parents
+     * 
+     * adds a section to each tree node with all parents of each node
+     * 
+     * @param $tree (array) : nodes array (each node has `rec` and `childs` sections )
+     * @param $parents (array); DO NOT SET IT (takes values automaticaly)
+     * @return array of nodes with an extra node[parents] section
+     * 
+     */
+    private static function tree_parents($tree, $parents = [])
+    {
+        $tree_with_parents = [];
+
+        foreach($tree as $key => $node) {
+            // parents to be pushed for node's children
+            $push_parents = $parents;           // parents so far
+            $push_parents[] = $node['rec'];     // this record will be a new parent
+
+            $tree_with_parents[$key] = [
+                'rec' => $node['rec'],
+                'parents' => $parents,
+                'childs' => ($node['childs'] == [])
+                    ? []
+                    : self::tree_parents($node['childs'], $push_parents)
+            ];
+        }
+
+        return $tree_with_parents;
+    }
+
+
+    /** all_breadcrumbs
+     * -------------------------------------------------------------------------
+     * 
+     * returns an array of all breadcrumbs
+     * where array-key of each record is category[id]
+     * 
+     * NOTE:
+     * ---
+     * Course_model::all_breadcrumbs returns an indexed super-array;
+     * each array item includes a banch of information: [
+     *    breadcrumb,
+     *    rec: [ id , title ],
+     *    parents: [ [id, title] , ... ]
+     *    childs: [ [id, title] , ... ],
+     *    level
+     * ]
+     * 
+     * Use Cases:
+     * ---
+     * as a super-array, the output can be used in many cases
+     * for example...
+     * into <select-option> form elements
+     * .. while selecting category for a post
+     * .. or editing a category
+     * or directry referring to category's parents/childs
+     * 
+     * Arguments:
+     * ---
+     * @param $tree (array) : category tree (with childs and parents parts)
+     * @param $detimiter (string, optional) : string to split breadcrumb's path-nodes
+     * @param $exception (int, optional) : id of category to exclude (subcategories shall be excluded too)
+     * @param $l (int, not-pass) : depth level of the node; DO NOT SET (takes values automaticaly)
+     * @return array of breadcrumbs
+     * -------------------------------------------------------------------------
+     */
+    static public function breadcrumbs($tree, $delimiter = " / ", $exception = 0, $l = 0)
+    {
+        $all = [];      // results array
+
+        foreach($tree as $node) {       // loop through all nodes
+
+            if (intval($node['rec']['id']) != $exception) {     // if node is not exception
+
+                // construct breadcrumb html of node
+                // --- -- -- - - -
+                $breadcrumb = "";
+                foreach($node['parents'] as $par) {     // first: join path titles
+                    $breadcrumb .= $par['label'] . $delimiter;
+                }
+                $breadcrumb .= $node['rec']['label'];   // last: append title
+
+                // make a new super record
+                // --- -- -- - - -
+                $all[$node['rec']['id']] = [        // set record is as key
+                    'breadcrumb' => $breadcrumb,        // add breadcrump to results
+                    'rec' => $node['rec'],              // + node info 
+                    'parents' => $node['parents'],      // + parents array
+                    'childs' => self::first_level_childs($node),    // + direct childs
+                    'level' => $l                       // + level
+                ];
+
+                // recursively traverse children nodes
+                // --- -- -- - - -
+                if (isset($node['childs']) && $node['childs'] != []) {
+                    $child_breadcrumbs = self::breadcrumbs(
+                        $node['childs'],
+                        $delimiter,
+                        $exception,
+                        $l+1
+                    );
+
+                    $all = $all + $child_breadcrumbs;   // concatenate arrays (keep array-keys)
+                } 
+            }
+
+        }
+        return $all;
+        
+    }
+
+    /** first_level_childs
+     * --- -- -- - - -
+     * used by all_breadcrumbs()
+     */
+    static private function first_level_childs($node)
+    {
+        $childs = [];
+        if ($node['childs'] == []) {
+            return [];
+        }
+        foreach($node['childs'] as $key => $kid) {
+            $childs[] = [
+                'id' => $kid['rec']['id'],
+                'label' => $kid['rec']['label']
+            ];
+        }
+        return $childs;
+    }
+
+
+
+
+    /** LESSONS
+     * -------------------------------------------------------------------------
+     */
+    
+
+    /** lessons of course
+     * 
+     * @param $id (int) : course_id
+     */
+    public static function lessons_of_course($id)
+    {
+        // TODO: order results in some way
+
+        return Registry::use('database')->runQuery(
+            "SELECT lesson.*, lesson_privilege.privilege_id FROM lesson
+            LEFT JOIN lesson_privilege ON lesson_privilege.lesson_id = lesson.id
+            WHERE lesson.status = 1 AND lesson.course_id = :id
+            ORDER BY lesson_privilege.privilege_id ASC",
+            [':id' => $id]
+        );
+    }
+
+    /** lesson
+     * 
+     * @param $id (int) : lesson id
+     */
+    public static function lesson($id)
+    {
+        // TODO: order results in some way
+
+        return Registry::use('database')->query(
+            "SELECT lesson.*, lesson_privilege.privilege_id FROM lesson
+            LEFT JOIN lesson_privilege ON lesson_privilege.lesson_id = lesson.id
+            WHERE lesson.status = 1 AND lesson.id = :id",
+            [':id' => $id]
+        )->getFirst();
+    }
+
+
+
+    /** files
+     * return all files
+     * @param void
+     * @return array
+     */
+    public static function files()
+    {
+        return Registry::use('database')->runQuery("SELECT * from media", []);
+    }
+
+
+    /** pages
+     * 
+     * return all pages as array;
+     * array key of each item shall be the page-id
+     * 
+     * @param void
+     * @return array
+     */
+    public static function pages()
+    {
+        $result = [];
+        $pages =  Registry::use('database')->runQuery("SELECT * FROM page", []);
+        foreach($pages as $key => $page) {
+            $result[ $page['id'] ] = [
+                'title' => $page['title'],
+                'body' => $page['body'],
+                'status' => $page['status']
+            ];
+        }
+        // print_r($result); die();
+        return $result;
+    }
+
+}
diff --git a/public/app/models/cms/Media_model.php b/public/app/models/cms/Media_model.php
new file mode 100644
index 0000000..6a4a681
--- /dev/null
+++ b/public/app/models/cms/Media_model.php
@@ -0,0 +1,36 @@
+<?php
+
+namespace app\models\cms;
+
+use \Registry;
+
+
+class Media_model
+{
+    public static function serve($type, $id, $ticket)
+    {
+
+        // get media data
+        // [ type =>, rights =>, path =>  ]
+
+        // validate ticket
+        // ValidateAccess::for($ticket)
+
+        // serve
+        // header("Content-type: type");
+        // passthru('cat $media_path');
+
+
+        return Registry::use('database')->query(
+            "SELECT * FROM pages
+                WHERE FullFriendlyUrl = :url AND IsActive = 1",
+            [ ':url' => $url ]
+        )->getFirst();
+    }
+
+}
+
+
+
+// check:
+// https://stackoverflow.com/questions/1353850/serve-image-with-php-script-vs-direct-loading-an-image
\ No newline at end of file
diff --git a/public/app/models/cms/Page_model.php b/public/app/models/cms/Page_model.php
new file mode 100644
index 0000000..fda5fb1
--- /dev/null
+++ b/public/app/models/cms/Page_model.php
@@ -0,0 +1,18 @@
+<?php
+
+namespace app\models\cms;
+
+use \Registry;
+
+class Page_model
+{
+    public static function fromUrl($url)
+    {
+        return Registry::use('database')->query(
+            "SELECT * FROM pages
+                WHERE FullFriendlyUrl = :url AND IsActive = 1",
+            [ ':url' => $url ]
+        )->getFirst();
+    }
+
+}
\ No newline at end of file
diff --git a/public/app/models/market/Market_repository.php b/public/app/models/market/Market_repository.php
new file mode 100644
index 0000000..1338426
--- /dev/null
+++ b/public/app/models/market/Market_repository.php
@@ -0,0 +1,235 @@
+<?php 
+
+namespace app\models\market;
+
+use \Repository;
+
+/** Market_repository
+ * (thematic-entity repository)
+ * ---
+ * SQL entity templates for Market
+ * 
+ * Every '_base' is a repository of common 'prepare' SQL-queries;
+ * They usually include holders for attaching/binding data safely;
+ * These queries are expensive in syntax but fast on run time and
+ * are used to collect multi-joined amounts ot data.
+ * 
+ * Organize yous repositories in logical/thematic groups (partitioning).
+ * This way your repository is managable and uses very few sources.
+ * 
+ * This class acts like a namespaced repository for geting your code readable
+ * Avoid pushing very simple queries into repository classes. A record like...
+ *     'CARS_by:Age' => "SELECT * FROM cars WHERE age = :Age"
+ * ... won't make your code sexier nor easier to read; it will just increase
+ * your label's entropy and make trickier to pick your next sensable label;
+ * 
+ * repository classes include two methods (inherited by the abstract, so
+ * you do not need to implement something more than just construct
+ * the $repository array)
+ * ** pull: for pulling a query by a friendly name
+ * ** echo: optional method used by some devolopment tools
+ * 
+ * TODO: development tool using echo is still in progress
+ */
+class Market_repository extends Repository
+{
+    //// use Repository;     // repository trait includes
+    ////     // a method to pull an entity of the gathering
+    ////     // and method to (TODO:) ...
+
+    /** repository is an array of Prepare SWL queries;
+     * each query is attached to the array via a friendly label;
+     * 
+     * NOTE: (PROPOSAL)
+     * ---
+     * about the label:
+     * 1. keep names short descriptive but not too long
+     * 2. main entity/entities shall be UPPERCASED
+     * 3. determinands/adjectives shall be Cappitalized
+     * 4. words are connected with underscore (_)
+     * 5. if SQL inludes bind-holderd, label shall be suffixed with '_by:'
+     * followed by holder names connected with undercores (case-sensitively)
+     * 
+     * about the data-bind holders (if present):
+     * 1. all holders are prefixed with ':'
+     * 2. holder name shall begin with a letter and contain one word.
+     * 
+     * example:
+     * 'Active_EMPLOYEES_by:Age_CityID' => "SELECT Em.*, c.*
+     * FROM employee Em LEFT JOIN city c ON c.id = Em.city_id
+     * WHERE c.id = :CityID AND Em.age = :Age"
+     * 
+     * It is recommended to leave a descriptive comment befor each declaration
+     * and you may also include sql-comments inside the query.
+     */
+    public static $repository = [
+
+        // PRODUCTS by: storeID, ProductUrl
+        // picks all product properties
+        // + default image + price for certain store
+        'Active_PRODUCT_by:storeID_ProductUrl' =>
+            "SELECT p.*,
+                pc.ID AS ProductCategory,
+                pc.Hierarchy,
+                pc.FullFriendlyUrl AS `Path`,
+                prices.ProductPrice_OriginalPrice AS Price,
+                prices.ProductPrice_DiscountedPrice AS DiscountPrice,
+                prices.UnitMeasurePrice_OriginalPrice AS PerUnitPrice,
+                prices.UnitMeasurePrice_DiscountedPrice AS PerUnitDiscountPrice,
+                b.Title BrandName
+            FROM products p
+            LEFT JOIN products_to_product_categories p2pc ON p.ID = p2pc.SimpleProductID
+            LEFT JOIN product_categories pc ON p2pc.ProductCategoryID = pc.ID
+            LEFT JOIN prices ON p.SKU = prices.SKU
+            LEFT JOIN products_to_images p2i ON p2i.SimpleProductID = p.ID
+            LEFT JOIN assets ON assets.ID = p2i.ImageID
+            LEFT JOIN brands b ON b.ID = p.BrandID
+            WHERE pc.IsActive = 1 AND pc.IsCurrentlyActive = 1
+                AND p2i.Order = 1
+                AND p.IsActive = 1
+                AND p.Published = 1
+                AND prices.PriceListID = :storeID
+            AND p.FriendlyUrl = :ProductUrl"
+        ,
+
+        // PRODUCTS by: storeID, ProductID
+        // picks all product properties
+        // + default image + price for certain store
+        'Active_PRODUCT_by:storeID_ProductID' =>
+            "SELECT p.*,
+                pc.ID AS ProductCategory,
+                pc.Hierarchy,
+                pc.FullFriendlyUrl AS `Path`,
+                prices.ProductPrice_OriginalPrice AS Price,
+                prices.ProductPrice_DiscountedPrice AS DiscountPrice,
+                prices.UnitMeasurePrice_OriginalPrice AS PerUnitPrice,
+                prices.UnitMeasurePrice_DiscountedPrice AS PerUnitDiscountPrice,
+                b.Title BrandName
+            FROM products p
+            LEFT JOIN products_to_product_categories p2pc ON p.ID = p2pc.SimpleProductID
+            LEFT JOIN product_categories pc ON p2pc.ProductCategoryID = pc.ID
+            LEFT JOIN prices ON p.SKU = prices.SKU
+            LEFT JOIN products_to_images p2i ON p2i.SimpleProductID = p.ID
+            LEFT JOIN assets ON assets.ID = p2i.ImageID
+            LEFT JOIN brands b ON b.ID = p.BrandID
+            WHERE pc.IsActive = 1 AND pc.IsCurrentlyActive = 1
+                AND p2i.Order = 1
+                AND p.IsActive = 1
+                AND p.Published = 1
+                AND prices.PriceListID = :storeID
+            AND p.ID = :ProductID"
+        ,
+
+        // CATEGORY-PRODUCTS by: storeID, likeHierarchy
+        // traverses all products from category and subcategories
+        // picke price and default image
+        'CATEGORY-PRODUCTS_by:storeID_likeHierarchy' =>
+            "SELECT p.*,
+                assets.Url AS ImageUrl,
+                pc.FullFriendlyUrl AS `Path`,
+                prices.ProductPrice_OriginalPrice AS Price,
+                prices.ProductPrice_DiscountedPrice AS DiscountPrice,
+                prices.UnitMeasurePrice_OriginalPrice AS PerUnitPrice,
+                prices.UnitMeasurePrice_DiscountedPrice AS PerUnitDiscountPrice
+            FROM products p
+            LEFT JOIN prices ON p.SKU = prices.SKU
+            LEFT JOIN products_to_product_categories p2pc ON p2pc.SimpleProductID = p.ID
+            LEFT JOIN product_categories pc ON pc.ID = p2pc.ProductCategoryID
+            LEFT JOIN products_to_images p2i ON p2i.SimpleProductID = p.ID
+            LEFT JOIN assets ON assets.ID = p2i.ImageID
+            WHERE p2pc.ProductCategoryID IN (
+                SELECT `ID` FROM product_categories
+                WHERE Hierarchy LIKE :likeHierarchy
+            )
+            AND p2i.Order = 1
+            AND p.IsActive = 1
+            AND p.Published = 1
+            AND prices.PriceListID = :storeID"
+        ,
+
+        // Count Products
+        // of all last-lever Product categories
+        // by StoreID
+        // ---
+        // used on creating product_categories tree
+        // ProductCategories_model::tree()
+        'Count_Last_Level_PRODUCTS_by:storeID' =>
+            "SELECT pc.ID, COUNT(p.ID) as `Counter`
+            FROM product_categories pc
+            LEFT JOIN products_to_product_categories p2pc ON pc.ID = p2pc.ProductCategoryID
+            LEFT JOIN products p ON p2pc.SimpleProductID = p.ID
+            LEFT JOIN prices ON p.SKU = prices.SKU
+            LEFT JOIN products_to_images p2i ON p2i.SimpleProductID = p.ID
+            LEFT JOIN assets ON assets.ID = p2i.ImageID
+            WHERE pc.IsActive = 1 AND pc.IsCurrentlyActive = 1
+                AND p2i.Order = 1
+                AND pc.Level = 2
+                AND p.IsActive = 1
+                AND p.Published = 1
+                AND prices.PriceListID = :storeID
+            GROUP BY pc.ID"
+        ,
+
+        // PRODUCT by: ProductID
+        // Join images array (json string)
+        // Join prices for all stores (json string)
+        'Active_PRODUCT_complete_by:ProductID' =>
+            "SELECT p.*, pc.ID AS ProductCategory,
+            pc.Hierarchy, pc.FullFriendlyUrl AS `Path`,
+            (  -- get all store prices as Json
+                SELECT JSON_ARRAYAGG(JSON_OBJECT(
+                    'Store', prices.PriceListID,
+                    'Price', prices.ProductPrice_OriginalPrice,
+                    'DiscountPrice', prices.ProductPrice_DiscountedPrice,
+                    'PerUnitPrice', prices.UnitMeasurePrice_OriginalPrice,
+                    'PerUnitDiscountPrice', prices.UnitMeasurePrice_DiscountedPrice
+                ))
+                FROM prices
+                WHERE prices.SKU = p.SKU
+            ) as pricesJson,
+            (   -- get all images as Json
+                SELECT JSON_ARRAYAGG(JSON_OBJECT(
+                    'Order', p2i.Order,
+                    'Url', assets.Url,
+                    'Title', assets.Title,
+                    'Description', assets.Description
+                ))
+                FROM products_to_images p2i
+                LEFT JOIN assets ON assets.ID = p2i.ImageID
+                WHERE p2i.SimpleProductID = p.ID
+            ) AS imagesJson,
+            b.Title BrandName
+            FROM products p
+            LEFT JOIN products_to_product_categories p2pc ON p.ID = p2pc.SimpleProductID
+            LEFT JOIN product_categories pc ON p2pc.ProductCategoryID = pc.ID
+            LEFT JOIN products_to_images p2i ON p2i.SimpleProductID = p.ID
+            LEFT JOIN assets ON assets.ID = p2i.ImageID
+            LEFT JOIN brands b ON b.ID = p.BrandID
+            WHERE pc.IsActive = 1 AND pc.IsCurrentlyActive = 1
+                AND p2i.Order = 1
+                AND p.IsActive = 1
+                AND p.Published = 1
+            AND p.ID = :ProductID"
+        ,
+
+        // Product images by: ProductID
+        // (sorted by 'order' field)
+        'PRODUCT_IMAGES_by:productID' =>
+            "SELECT a.Url, a.Title, a.Description
+            FROM products p
+            LEFT JOIN products_to_images p2i ON p2i.SimpleProductID = p.ID
+            LEFT JOIN assets a ON a.ID = p2i.ImageID
+            WHERE p.IsActive = 1
+                AND p.Published = 1
+                AND p.ID = :productID
+            ORDER BY p2i.Order"
+
+    ];
+
+    /* no need to impement anything else;
+     * you can overide if needed the default methods:
+     * + public static function pull($entity){ }
+     * + public static function echo($content =false){ }
+     */
+
+}
diff --git a/public/app/models/market/Payment_template.txt b/public/app/models/market/Payment_template.txt
new file mode 100644
index 0000000..4a66a1a
--- /dev/null
+++ b/public/app/models/market/Payment_template.txt
@@ -0,0 +1,98 @@
+class WC_Piraeusbank_Gateway extends WC_Payment_Gateway {
+
+	public function __construct()
+		    
+	function pb_get_pages($title = false, $indent = true)
+
+	function pb_get_installments($title = false, $indent = true)
+
+	function generate_piraeusbank_form($order_id)
+
+	function process_payment($order_id)
+
+	function receipt_page($order)
+
+	function check_piraeusbank_response()
+
+	function piraeusbank_message()
+
+	function woocommerce_add_piraeusbank_gateway($methods)
+	
+	function piraeusbank_plugin_action_links($links, $file)
+
+}
+
+
+
+class WC_NBG_Gateway extends WC_Payment_Gateway {
+
+	public function __construct()
+
+	public function admin_options()
+
+	function init_form_fields()
+
+	function nbg_get_pages($title = false, $indent = true)
+
+	function nbg_get_installments($title = false, $indent = true)
+
+	function generate_nbg_form($order_id)
+
+	function process_payment($order_id)
+
+	function receipt_page($order) {
+
+	function check_nbg_response()
+
+	function nbg_message()
+
+	function woocommerce_add_nbg_gateway($methods)
+
+	function nbg_plugin_action_links($links, $file)
+
+}
+
+
+
+global $wc;
+
+            $this->id = 'nbg_gateway';
+            $this->icon = apply_filters('nbg_icon', plugins_url('assets/nbg.png', __FILE__));
+            $this->has_fields = false;
+            $this->notify_url = WC()->api_request_url('WC_NBG_Gateway');
+			$this->method_description = __('National Bank Greece Payment Gateway allows you to accept payment through various channels such as Maestro, Mastercard  and Visa cards On your Woocommerce Powered Site.', 'woocommerce-nbg-payment-gateway');
+            $this->redirect_page_id = $this->get_option('redirect_page_id');
+			$this->method_title = 'National Bank of Greece Gateway';
+			
+			// Load the form fields.
+			$this->init_form_fields();
+		    
+            //dhmioyrgia vashs
+
+            global $wpdb;
+
+            if ($wpdb->get_var("SHOW TABLES LIKE '" . $wpdb->prefix . "nbg_transactions'") === $wpdb->prefix . 'nbg_transactions') {
+                // The database table exist
+            } else {
+                // Table does not exist
+                $query = 'CREATE TABLE IF NOT EXISTS ' . $wpdb->prefix . 'nbg_transactions (id int(11) unsigned NOT NULL AUTO_INCREMENT,merchantreference varchar(30) not null, reference varchar(100) not null, orderid varchar(100) not null , timestamp datetime default null, PRIMARY KEY (id))';
+                $wpdb->query($query);
+            }
+			
+
+            // Load the settings.
+            $this->init_settings();
+
+
+            // Define user set variables
+            $this->title = $this->get_option('title');
+            $this->description = $this->get_option('description');
+			$this->nbg_Username = $this->get_option('nbg_Username');
+            $this->nbg_Password = $this->get_option('nbg_Password');
+			
+		    $this->nbg_description= $this->get_option('nbg_description');
+            $this->mode = $this->get_option('mode');			
+            $this->nbg_installments= $this->get_option('nbg_installments');
+            //Actions
+            add_action('woocommerce_receipt_nbg_gateway', array($this, 'receipt_page'));
+            add_action('woocommerce_update_options_payment_gateways_' . $this->id, array($this
diff --git a/public/app/models/market/ProductCategories_model.php b/public/app/models/market/ProductCategories_model.php
new file mode 100644
index 0000000..d8c274e
--- /dev/null
+++ b/public/app/models/market/ProductCategories_model.php
@@ -0,0 +1,199 @@
+<?php
+
+namespace app\models\market;
+
+use \Registry;
+use app\models\market\Market_repository;
+
+
+/** ProductCategories_model
+ * --- 
+ * undertakes to collect any product_categories data
+ * from the database and prepare needed data structures.
+ *
+ */
+class ProductCategories_model
+{
+
+    /** Get (product_) category from (full-friendly_) URL
+     * --- (self explanatory)
+     * @param $url (string): Full-Friendly-URL
+     * @return $category (array); also includes all category products
+     */
+    public static function categoryFromUrl($url)
+    {
+        $db = Registry::use('database');
+        $category = $db->query( "SELECT * FROM product_categories
+            WHERE FullFriendlyUrl = :url AND IsActive = 1",
+            [ ':url' => $url ]
+        )->getFirst();
+
+        if ($category === false) { return false; }  // no category? -> false
+
+        // GET PRODUCTS of category
+        $category['products'] = self::categoryProductsByHierarchy($category['Hierarchy']);
+        return $category;
+    }
+
+
+    /** Get (product_) category from ID
+     * --- (self explanatory)
+     * @param $id (int): Catgory ID (usualy from products)
+     * @return $category (array); also includes all category products
+     */
+    public static function categoryFromID($id)
+    {
+        return Registry::use('database')->query( "SELECT * FROM product_categories
+            WHERE `ID` = :url AND IsActive = 1",
+            [':id' => $id]
+        )->getFirst();
+
+    }
+
+   
+    /** categoryProductsByHierarchy
+     * ---
+     * This method returns the products belonging to a certain
+     * category (and all it's the children/sub-categories);
+     * It uses category.Hierarchy in a WHERE LIKE condition to
+     * make it fast.
+     * 
+     * The method is category.Level agnostic
+     * 
+     * @param $category (array)
+     * @return $products (array)
+     */
+    public static function categoryProductsByHierarchy($hierarchy, $store = 904)
+    {
+        // GET PRODUCTS of category
+        // NOTE:
+        // category.Hierarchy is used 
+       
+        return Registry::use('database')->runQuery(
+            Market_repository::pull('CATEGORY-PRODUCTS_by:storeID_likeHierarchy'),
+            [
+                ':likeHierarchy' => $hierarchy.'%',
+                ':storeID'    => 904
+            ]
+        );
+    }
+
+
+    # depricated:
+    # now Proxy has the responsibility to cache whatever
+    # ---
+    # /** GET tree of product_categories
+    #  * ---
+    #  * get from cache or cache it after creation
+    #  */
+    # public static function tree($store = 904)
+    # {
+    #     $cacheKey = get_called_class() . $store .'/tree';
+    # 
+    #     // IF category CACHED
+    #     $cache = Registry::use('cache');
+    #     $tree = $cache->get($cacheKey);
+    #     if ($tree !== false) {
+    #         return $tree;
+    #     }
+    # 
+    #     // (not cached) Create and Cache it
+    #     $tree = self::createCategoriesTree();
+    #     $cache->set($cacheKey, $tree, CACHE_ROOT_TTL);
+    # 
+    #     return $tree;
+    # }
+
+
+    /** CREATE product_categories tree
+     * NOTE: includes active categories only;
+     * 
+     * Algorith uses 'Hierarchy' for category path-positioning,
+     * implementing a linear conctruction of the requested tree;
+     * (faster and less source-consuming than a recursive algo)
+     */
+    public static function tree($store = 904)
+    {
+        $tree = [];     // variable to hold results
+
+        $db = Registry::use('database');
+
+        // get raw categories data ---------------------------------------------
+
+        $raw = $db->runQuery( "SELECT `ID`, Title, `Level`, Hierarchy,
+            ParentID, `Order`, FullFriendlyUrl
+            FROM product_categories pc
+            WHERE IsActive = 1 AND IsCurrentlyActive = 1
+            ORDER BY pc.Level asc, pc.Order asc, pc.Hierarchy asc",
+            []
+        );
+
+        // count products per 3rd level category -------------------------------
+
+        $countProducts = $db->runQuery(
+            Market_repository::pull('Count_Last_Level_PRODUCTS_by:storeID'),
+            [ ':storeID' => $store ]
+        );
+        // map categoryID -> Counter
+        $mapCounter = [];
+        foreach($countProducts as $rec) $mapCounter[$rec['ID']] = $rec['Counter'];
+
+        // parse raw data to hierarchical tree (2 pass) ------------------------
+
+        // 1st pass: parse raw data, construct and fill the $tree array ........
+        foreach($raw as $rec) {
+
+            // create category path from Hierarchy (format: .10.10100. )
+            // so remove 1st and last dots (.) from Hierarchy string
+            // then explode via dot-character (.)
+            $categoryPath = explode('.', substr($rec['Hierarchy'], 1, -1));
+
+            switch ($rec['Level']) {
+                case 0:
+                    $tree[$categoryPath[0]] = [
+                        'info' => $rec,
+                        'childs' => []
+                    ]; break;
+
+                case 1:
+                    $tree[$categoryPath[0]]['childs'][$categoryPath[1]] = [
+                        'info' => $rec,
+                        'childs' => []
+                    ]; break;
+
+                case 2:
+                    $tree[$categoryPath[0]]['childs'][$categoryPath[1]]['childs'][$categoryPath[2]] = [
+                        'info' => $rec,
+                        'count' => isset($mapCounter[$categoryPath[2]]) ? $mapCounter[$categoryPath[2]] : 0
+                    ]; break;
+                
+                default:
+                    // nothing...
+            }
+            
+        }
+
+        // 2nd pass: remove categories with no products ........................
+        foreach($tree as $id0 => $rec0) {
+            $count0 = 0;
+
+            foreach($rec0['childs'] as $id1 => $rec1) {
+                $count1 = 0;
+
+                foreach($rec1['childs'] as $id2 => $rec2) {
+                    if ($rec2['count']>0)     $count1++;
+                    else    unset($tree[$id0]['childs'][$id1]['childs'][$id2]);
+                }
+
+                if ($count1 > 0)    $count0++;
+                else        unset($tree[$id0]['childs'][$id1]);
+            }
+
+            if (!$count0)   unset($tree[$id0]);
+        }
+
+        return $tree;
+    }
+
+
+}
\ No newline at end of file
diff --git a/public/app/models/market/Product_model.php b/public/app/models/market/Product_model.php
new file mode 100644
index 0000000..aa554a1
--- /dev/null
+++ b/public/app/models/market/Product_model.php
@@ -0,0 +1,49 @@
+<?php
+
+namespace app\models\market;
+
+use \Registry;
+use app\models\market\Market_repository as Market;
+
+class Product_model
+{
+    public static function fromUrl($url, $store = 904)
+    {
+        $product = Registry::use('database')->query(
+            Market::pull('Active_PRODUCT_by:storeID_ProductUrl'),
+            [
+                ':storeID' => $store,
+                ':ProductUrl' => $url
+            ]
+        )->getFirst();
+       
+        // if no product, return false
+        if ($product === false)     return false;
+       
+        // inject product's images
+        $product['Images'] = self::getProductImages($product['ID']);
+
+        return $product;
+    }
+
+
+    public static function getProductImages($id)
+    {
+        ## return Registry::use('database')->runQuery(
+        ##     "SELECT a.Url, a.Title, a.Description
+        ##     FROM products p
+        ##     LEFT JOIN products_to_images p2i ON p2i.SimpleProductID = p.ID
+        ##     LEFT JOIN assets a ON a.ID = p2i.ImageID
+        ##     WHERE p.IsActive = 1 AND p.Published = 1
+        ##     AND p.ID = :id
+        ##     ORDER BY p2i.Order",
+        ##     [ ':id' => $id ]
+        ## );
+
+        return Registry::use('database')->runQuery(
+            Market::pull('PRODUCT_IMAGES_by:productID'),
+            ['productID' => $id ]
+        );
+    }
+
+}
\ No newline at end of file
diff --git a/public/app/models/todo.md b/public/app/models/todo.md
new file mode 100644
index 0000000..defd21e
--- /dev/null
+++ b/public/app/models/todo.md
@@ -0,0 +1,132 @@
+
+
+Privilege
+---
+
+Privilege::list_of_privileges( privilege_id )
+
+Privilege::privileges_tree()
+
+
+
+
+
+User
+---
+
+User::get_privileges
+
+
+User::has_privilege( privilege_id )
+
+
+User::reset_password()
+    -> create otp
+    -> send email
+
+
+User::set_privilege( privilege_id )
+
+
+User::track_action()
+    -> user_id
+    -> action : Contoller::method(args)
+    -> timestamp
+
+
+
+Lesson:
+---
+
+Lesson::create_lesson( POST )
+
+Lesson::get_lesson( lesson_id )
+
+
+
+Course
+---
+
+Course::create_course( POST )
+
+Course::courses_tree()
+
+
+
+Upgrades (??)
+---
+
+
+A1
+
+A2 : includes A1
+
+A3 : includes A1, A2
+
+A4 : includes A1, A2, A3
+
+
+A1  100
+A2  200
+A3  350
+A4  500
+
+B1  100
+B2  200
+B3  400
+B4  800
+
+
+:1 -> 0%
+:2 -> 15%
+:3 -> 20%
+
+
+
+
+A1 -> A2
+A1 -> A3
+A1 -> A4
+
+A2 -> A3
+A2 -> A4
+
+A3 -> A4
+
+A1 < A2 < A3 < A4
+
+
+
+B1 -> B2
+B1 -> B3
+B1 -> B4
+
+B2 -> B3
+B2 -> B4
+
+B3 -> B4
+
+
+A1+B1
+
+A2+B2
+
+A3+B3
+
+
+A1+B1 -> A2+B2
+A1+B1 -> A3+B3
+A1+B1 -> A4+B4
+
+A2+B2 -> A3+B3
+A2+B2 -> A4+B4
+
+A3+B3 -> A4+B4
+
+
+
+UPGRADE PRICE = upper_priv_price - own_priv_price
+
+buy 1 item : -0%
+buy 2 items : -10%
+buy 3 items : -15%