<?php
defined('BASEPATH') or exit('No direct script access allowed');

class User extends CI_Controller
{
    public function __construct()
    {
        parent::__construct();

        $this->load->database();
        $this->load->library('session');
        /*cache control*/
        $this->output->set_header('Cache-Control: no-store, no-cache, must-revalidate, post-check=0, pre-check=0');
        $this->output->set_header('Pragma: no-cache');

        // THIS FUNCTION DECIDES WHTHER THE ROUTE IS REQUIRES PUBLIC INSTRUCTOR.
        //$this->get_protected_routes($this->router->method);

        // THIS MIDDLEWARE FUNCTION CHECKS WHETHER THE USER IS TRYING TO ACCESS INSTRUCTOR STUFFS.
        $this->instructor_authorization($this->router->method);

        $this->instructor_approval();

        // CHECK CUSTOM SESSION DATA
        $this->user_model->check_session_data('user');


    }

    function instructor_approval(){
        $user_id = $this->session->userdata('user_id');
        $query = $this->db->get_where('users', array('id' => $user_id));

        if ($query->num_rows() > 0) {
            $this->session->set_userdata('is_instructor', $query->row('is_instructor'));
        }
    }


    public function get_protected_routes($method)
    {
        // IF ANY FUNCTION DOES NOT REQUIRE PUBLIC INSTRUCTOR, PUT THE NAME HERE.
        $unprotected_routes = ['save_course_progress','start_quiz', 'retake_quiz','finish_quize_submission','submit_quiz_answer'];

        if (!in_array($method, $unprotected_routes)) {
            if (get_settings('allow_instructor') != 1) {
                redirect(site_url('home'), 'refresh');
            }
        }
    }

    public function instructor_authorization($method)
    {
        // IF THE USER IS NOT AN INSTRUCTOR HE/SHE CAN NEVER ACCESS THE OTHER FUNCTIONS EXCEPT FOR BELOW FUNCTIONS.
        if ($this->session->userdata('is_instructor') != 1) {
            $unprotected_routes = ['become_an_instructor', 'manage_profile', 'save_course_progress', 'start_quiz', 'retake_quiz', 'submit_quiz_answer', 'finish_quize_submission'];

            if (!in_array($method, $unprotected_routes)) {
                redirect(site_url('user/become_an_instructor'), 'refresh');
            }
        }
    }

    public function index()
    {
        if ($this->session->userdata('user_login') == true) {
            $this->dashboard();
        } else {
            redirect(site_url('login'), 'refresh');
        }
    }

    public function dashboard()
    {
        if ($this->session->userdata('user_login') != true) {
            redirect(site_url('login'), 'refresh');
        }

        $page_data['page_name'] = 'dashboard';
        $page_data['page_title'] = get_phrase('dashboard');
        $this->load->view('backend/index.php', $page_data);
    }

    public function courses()
    {
        if ($this->session->userdata('user_login') != true) {
            redirect(site_url('login'), 'refresh');
        }
        $page_data['selected_category_id']   = isset($_GET['category_id']) ? $_GET['category_id'] : "all";
        $page_data['selected_instructor_id'] = $this->session->userdata('user_id');
        $page_data['selected_price']         = isset($_GET['price']) ? $_GET['price'] : "all";
        $page_data['selected_status']        = isset($_GET['status']) ? $_GET['status'] : "all";
        $page_data['courses']                = $this->crud_model->filter_course_for_backend($page_data['selected_category_id'], $page_data['selected_instructor_id'], $page_data['selected_price'], $page_data['selected_status']);
        $page_data['page_name']              = 'courses-server-side';
        $page_data['categories']             = $this->crud_model->get_categories();
        $page_data['page_title']             = get_phrase('active_courses');
        $this->load->view('backend/index', $page_data);
    }

    // This function is responsible for loading the course data from server side for datatable SILENTLY
    public function get_courses()
    {
        if ($this->session->userdata('user_login') != true) {
            redirect(site_url('login'), 'refresh');
        }
        $courses = array();
        // Filter portion
        $filter_data['selected_category_id']   = $this->input->post('selected_category_id');
        $filter_data['selected_instructor_id'] = $this->input->post('selected_instructor_id');
        $filter_data['selected_price']         = $this->input->post('selected_price');
        $filter_data['selected_status']        = $this->input->post('selected_status');

        // Server side processing portion
        $columns = array(
            0 => '#',
            1 => 'title',
            2 => 'category',
            3 => 'lesson_and_section',
            4 => 'enrolled_student',
            5 => 'status',
            6 => 'price',
            7 => 'actions',
            8 => 'course_id'
        );

        // Coming from databale itself. Limit is the visible number of data
        $limit = html_escape($this->input->post('length'));
        $start = html_escape($this->input->post('start'));
        $order = "";
        $dir   = $this->input->post('order')[0]['dir'];

        $totalData = $this->lazyload->count_all_courses($filter_data);
        $totalFiltered = $totalData;

        // This block of code is handling the search event of datatable
        if (empty($this->input->post('search')['value'])) {
            $courses = $this->lazyload->courses($limit, $start, $order, $dir, $filter_data);
        } else {
            $search = $this->input->post('search')['value'];
            $courses =  $this->lazyload->course_search($limit, $start, $search, $order, $dir, $filter_data);
            $totalFiltered = $this->lazyload->course_search_count($search);
        }

        // Fetch the data and make it as JSON format and return it.
        $data = array();
        if (!empty($courses)) {
            foreach ($courses as $key => $row) {
                $instructor_details = $this->user_model->get_all_user($row->user_id)->row_array();
                $category_details = $this->crud_model->get_category_details_by_id($row->sub_category_id)->row_array();
                $sections = $this->crud_model->get_section('course', $row->id);
                $lessons = $this->crud_model->get_lessons('course', $row->id);
                $enroll_history = $this->crud_model->enrol_history($row->id);

                $status_badge = "badge-success-lighten";
                if ($row->status == 'pending') {
                    $status_badge = "badge-danger-lighten";
                } elseif ($row->status == 'draft') {
                    $status_badge = "badge-dark-lighten";
                }elseif($row->status == 'private'){
                    $status_badge = "badge-dark";
                }

                $price_badge = "badge-dark-lighten";
                $price = 0;
                if ($row->is_free_course == null) {
                    if ($row->discount_flag == 1) {
                        $price = currency($row->discounted_price);
                    } else {
                        $price = currency($row->price);
                    }
                } elseif ($row->is_free_course == 1) {
                    $price_badge = "badge-success-lighten";
                    $price = get_phrase('free');
                }

                $price_field = '<span class="badge ' . $price_badge . '">' . $price . '</span>';
                if($row->expiry_period > 0){
                    $price_field .= '<p class="text-12">'.$row->expiry_period .' ' . get_phrase('Months') . '</p>';
                }else{
                    $price_field .= '<p class="text-12">' . get_phrase('Lifetime') . '</p>';
                }

                $view_course_on_frontend_url = site_url('home/course/' . rawurlencode(slugify($row->title)) . '/' . $row->id);
                $go_to_course_playing_page = site_url('home/lesson/' . rawurlencode(slugify($row->title)) . '/' . $row->id);
                $edit_this_course_url = site_url('user/course_form/course_edit/' . $row->id);
                $section_and_lesson_url = site_url('user/course_form/course_edit/' . $row->id);
                $academic_progress_url = site_url('user/course_form/course_edit/' . $row->id.'?tab=academic_progress');

                if ($row->status == 'active' || $row->status == 'pending') {
                    $course_status_changing_action = "confirm_modal('" . site_url('user/course_actions/draft/' . $row->id) . "')";
                    $course_status_changing_message = get_phrase('mark_as_drafted');
                } else {
                    $course_status_changing_action = "confirm_modal('" . site_url('user/course_actions/publish/' . $row->id) . "')";
                    $course_status_changing_message = get_phrase('publish_this_course');
                }

                $delete_course_url = "confirm_modal('" . site_url('user/course_actions/delete/' . $row->id) . "')";

                if ($row->course_type == 'general') {
                    $section_and_lesson_menu = '<li><a class="dropdown-item" href="' . $section_and_lesson_url . '">' . get_phrase("section_and_lesson") . '</a></li>';
                } else {
                    $section_and_lesson_menu = "";
                }

                $action = '
                <div class="dropright dropright">
                <button type="button" class="btn btn-sm btn-outline-primary btn-rounded btn-icon" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false">
                <i class="mdi mdi-dots-vertical"></i>
                </button>
                <ul class="dropdown-menu">
                <li><a class="dropdown-item" href="' . $view_course_on_frontend_url . '" target="_blank">' . get_phrase("view_course_on_frontend") . '</a></li>
                <li><a class="dropdown-item" href="' . $go_to_course_playing_page . '" target="_blank">' . get_phrase("go_to_course_playing_page") . '</a></li>
                <li><a class="dropdown-item" href="' . $academic_progress_url . '">' . get_phrase("Academic progress") . '</a></li>
                <li><a class="dropdown-item" href="' . $edit_this_course_url . '">' . get_phrase("edit_this_course") . '</a></li>
                ' . $section_and_lesson_menu . '
                <li><a class="dropdown-item" href="javascript:;" onclick="' . $course_status_changing_action . '">' . $course_status_changing_message . '</a></li>
                <li><a class="dropdown-item" href="javascript:;" onclick="' . $delete_course_url . '">' . get_phrase("delete") . '</a></li>
                </ul>
                </div>
                ';

                $nestedData['#'] = $key + 1;

                $instructor_names = "";
                if ($row->multi_instructor) {
                    $instructors = $this->user_model->get_multi_instructor_details_with_csv($row->user_id);
                    foreach ($instructors as $counterForThis => $instructor) {
                        $instructor_names .= $instructor['first_name'] . ' ' . $instructor['last_name'];
                        $instructor_names .= $counterForThis + 1 == count($instructors) ? '' : ', ';
                    }
                } else {
                    $instructor_names = $instructor_details['first_name'] . ' ' . $instructor_details['last_name'];
                }

                $nestedData['title'] = '<strong><a href="' . site_url('user/course_form/course_edit/' . $row->id) . '">' . $row->title . '</a></strong><br>
                <small class="text-muted">' . get_phrase('instructor') . ': <b>' . $instructor_names . '</b></small>';


                $nestedData['category'] = '<span class="badge badge-dark-lighten">' . $category_details['name'] . '</span>';

                if ($row->course_type == 'scorm') {
                    $nestedData['lesson_and_section'] = '<span class="badge badge-info-lighten">' . get_phrase('scorm_course') . '</span>';
                } elseif ($row->course_type == 'h5p') {
                    $nestedData['lesson_and_section'] = '<span class="badge badge-info-lighten">' . get_phrase('h5p_course') . '</span>';
                } elseif ($row->course_type == 'general') {
                    $nestedData['lesson_and_section'] = '
                    <small class="text-muted"><b>' . get_phrase('total_section') . '</b>: ' . $sections->num_rows() . '</small><br>
                    <small class="text-muted"><b>' . get_phrase('total_lesson') . '</b>: ' . $lessons->num_rows() . '</small>';
                }

                $nestedData['enrolled_student'] = '<small class="text-muted"><b>' . get_phrase('total_enrolment') . '</b>: ' . $enroll_history->num_rows() . '</small>';


                $nestedData['status'] = '<span class="badge ' . $status_badge . '">' . get_phrase($row->status) . '</span>';

                $nestedData['price'] = $price_field;

                $nestedData['actions'] = $action;

                $nestedData['course_id'] = $row->id;

                $data[] = $nestedData;
            }
        }

        $json_data = array(
            "draw"            => intval($this->input->post('draw')),
            "recordsTotal"    => intval($totalData),
            "recordsFiltered" => intval($totalFiltered),
            "data"            => $data
        );

        echo json_encode($json_data);
    }

    public function course_actions($param1 = "", $param2 = "")
    {
        if ($this->session->userdata('user_login') != true) {
            redirect(site_url('login'), 'refresh');
        }

        if ($param1 == "add") {
            $course_id = $this->crud_model->add_course();
            redirect(site_url('user/course_form/course_edit/' . $course_id), 'refresh');
        } elseif ($param1 == "edit") {
            $this->is_the_course_belongs_to_current_instructor($param2);
            $this->crud_model->update_course($param2);

            // CHECK IF LIVE CLASS ADDON EXISTS, ADD OR UPDATE IT TO ADDON MODEL
            if (addon_status('live-class')) {
                $this->load->model('addons/Liveclass_model', 'liveclass_model');
                $this->liveclass_model->update_live_class($param2);
            }

            // CHECK IF JITSI LIVE CLASS ADDON EXISTS, ADD OR UPDATE IT TO ADDON MODEL
            if (addon_status('jitsi-live-class')) {
                $this->load->model('addons/jitsi_liveclass_model', 'jitsi_liveclass_model');
                $this->jitsi_liveclass_model->update_live_class($param2);
            }

            redirect(site_url('user/course_form/course_edit/' . $param2));
        } elseif ($param1 == 'add_shortcut') {
            echo $this->crud_model->add_shortcut_course();
        } elseif ($param1 == 'delete') {
            $this->is_the_course_belongs_to_current_instructor($param2);
            $this->crud_model->delete_course($param2);
            redirect(site_url('user/courses'), 'refresh');
        } elseif ($param1 == 'draft') {
            $this->is_the_course_belongs_to_current_instructor($param2);
            $this->crud_model->change_course_status('draft', $param2);
            redirect(site_url('user/courses'), 'refresh');
        } elseif ($param1 == 'publish') {
            $this->is_the_course_belongs_to_current_instructor($param2);
            $this->crud_model->change_course_status('pending', $param2);
            redirect(site_url('user/courses'), 'refresh');
        }
    }

    public function course_form($param1 = "", $param2 = "")
    {

        if ($this->session->userdata('user_login') != true) {
            redirect(site_url('login'), 'refresh');
        }

        if ($param1 == 'add_course') {
            $page_data['languages'] = $this->crud_model->get_all_languages();
            $page_data['categories'] = $this->crud_model->get_categories();
            $page_data['page_name'] = 'course_add';
            $page_data['page_title'] = get_phrase('add_course');
            $this->load->view('backend/index', $page_data);
        } elseif ($param1 == 'add_course_shortcut') {
            $page_data['languages'] = $this->crud_model->get_all_languages();
            $page_data['categories'] = $this->crud_model->get_categories();
            $this->load->view('backend/user/course_add_shortcut', $page_data);
        } elseif ($param1 == 'course_edit') {
            $this->is_the_course_belongs_to_current_instructor($param2);
            $page_data['page_name'] = 'course_edit';
            $page_data['course_id'] =  $param2;
            $page_data['page_title'] = get_phrase('edit_course');
            $page_data['languages'] = $this->crud_model->get_all_languages();
            $page_data['categories'] = $this->crud_model->get_categories();
            $this->load->view('backend/index', $page_data);
        }
    }

    public function payout_settings($param1 = "")
    {
        if ($this->session->userdata('user_login') != true) {
            redirect(site_url('login'), 'refresh');
        }

        if(isset($_POST['gateways'])){
            $data['payment_keys'] = json_encode($_POST['gateways']);
            $data['last_modified'] = time();
            $this->db->where('id', $this->session->userdata('user_id'));
            $this->db->update('users', $data);
            $this->session->set_flashdata('flash_message', get_phrase('payment_settings_has_been_updated'));
            redirect(site_url('user/payout_settings'), 'refresh');
        }

        $page_data['page_name'] = 'payment_settings';
        $page_data['page_title'] = get_phrase('payout_settings');
        $this->load->view('backend/index', $page_data);
    }

    public function sales_report($param1 = "")
    {
        if ($this->session->userdata('user_login') != true) {
            redirect(site_url('login'), 'refresh');
        }

        if ($param1 != "") {
            $date_range                   = $this->input->get('date_range');
            $date_range                   = explode(" - ", $date_range);
            $page_data['timestamp_start'] = strtotime($date_range[0] . ' 00:00:00');
            $page_data['timestamp_end']   = strtotime($date_range[1] . ' 23:59:59');
        } else {
            $page_data['timestamp_start'] = strtotime(date("m/01/Y 00:00:00"));
            $page_data['timestamp_end']   = strtotime(date("m/t/Y 23:59:59"));
        }

        $page_data['payment_history'] = $this->crud_model->get_instructor_revenue($this->session->userdata('user_id'), $page_data['timestamp_start'], $page_data['timestamp_end']);
        $page_data['page_name'] = 'sales_report';
        $page_data['page_title'] = get_phrase('sales_report');
        $this->load->view('backend/index', $page_data);
    }

    public function preview($course_id = '')
    {
        if ($this->session->userdata('user_login') != 1)
            redirect(site_url('login'), 'refresh');

        $this->is_the_course_belongs_to_current_instructor($course_id);
        if ($course_id > 0) {
            $courses = $this->crud_model->get_course_by_id($course_id);
            if ($courses->num_rows() > 0) {
                $course_details = $courses->row_array();
                redirect(site_url('home/lesson/' . rawurlencode(slugify($course_details['title'])) . '/' . $course_details['id']), 'refresh');
            }
        }
        redirect(site_url('user/courses'), 'refresh');
    }

    public function sections($param1 = "", $param2 = "", $param3 = "")
    {
        if ($this->session->userdata('user_login') != true) {
            redirect(site_url('login'), 'refresh');
        }

        if ($param2 == 'add') {
            $this->is_the_course_belongs_to_current_instructor($param1);
            $this->crud_model->add_section($param1);
            $this->session->set_flashdata('flash_message', get_phrase('section_has_been_added_successfully'));
        } elseif ($param2 == 'edit') {
            $this->is_the_course_belongs_to_current_instructor($param1, $param3, 'section');
            $this->crud_model->edit_section($param3);
            $this->session->set_flashdata('flash_message', get_phrase('section_has_been_updated_successfully'));
        } elseif ($param2 == 'delete') {
            $this->is_the_course_belongs_to_current_instructor($param1, $param3, 'section');
            $this->crud_model->delete_section($param1, $param3);
            $this->session->set_flashdata('flash_message', get_phrase('section_has_been_deleted_successfully'));
        }
        redirect(site_url('user/course_form/course_edit/' . $param1));
    }

    public function lessons($course_id = "", $param1 = "", $param2 = "")
    {
        if ($this->session->userdata('user_login') != true) {
            redirect(site_url('login'), 'refresh');
        }
        if ($param1 == 'add') {
            $valid_user = $this->is_the_course_belongs_to_current_instructor($course_id, null, null, true);
            if($valid_user > 0){
                $response = $this->crud_model->add_lesson();
            }else{
                $response = json_encode(['error' => get_phrase('you_do_not_have_right_to_access_this_course')]);
            }
            echo $response;
            return;
        } elseif ($param1 == 'edit') {
            $valid_user = +$this->is_the_course_belongs_to_current_instructor($course_id, $param2, 'lesson', true);
            
            if($valid_user > 0){
                $response = $this->crud_model->edit_lesson($param2);
            }else{
                $response = json_encode(['error' => get_phrase('you_do_not_have_right_to_access_this_course')]);
            }
            echo $response;
            return;
        } elseif ($param1 == 'delete') {
            $this->is_the_course_belongs_to_current_instructor($course_id, $param2, 'lesson');
            $this->crud_model->delete_lesson($param2);
            $this->session->set_flashdata('flash_message', get_phrase('lesson_has_been_deleted_successfully'));
            redirect('user/course_form/course_edit/' . $course_id);
        } elseif ($param1 == 'filter') {
            redirect('user/lessons/' . $this->input->post('course_id'));
        }
        $page_data['page_name'] = 'lessons';
        $page_data['lessons'] = $this->crud_model->get_lessons('course', $course_id);
        $page_data['course_id'] = $course_id;
        $page_data['page_title'] = get_phrase('lessons');
        $this->load->view('backend/index', $page_data);
    }

    // Manage Quizes
    public function quizes($course_id = "", $action = "", $quiz_id = "")
    {
        if ($this->session->userdata('user_login') != true) {
            redirect(site_url('login'), 'refresh');
        }

        if ($action == 'add') {
            $this->is_the_course_belongs_to_current_instructor($course_id);
            $this->crud_model->add_quiz($course_id);
            $this->session->set_flashdata('flash_message', get_phrase('quiz_has_been_added_successfully'));
        } elseif ($action == 'edit') {
            $this->is_the_course_belongs_to_current_instructor($course_id, $quiz_id, 'quize');
            $this->crud_model->edit_quiz($quiz_id);
            $this->session->set_flashdata('flash_message', get_phrase('quiz_has_been_updated_successfully'));
        } elseif ($action == 'delete') {
            $this->is_the_course_belongs_to_current_instructor($course_id, $quiz_id, 'quize');
            $this->crud_model->delete_lesson($quiz_id);
            $this->session->set_flashdata('flash_message', get_phrase('quiz_has_been_deleted_successfully'));
        }
        redirect(site_url('user/course_form/course_edit/' . $course_id));
    }

    // Manage Quize Questions
    public function quiz_questions($quiz_id = "", $action = "", $question_id = "")
    {
        if ($this->session->userdata('user_login') != true) {
            redirect(site_url('login'), 'refresh');
        }
        $quiz_details = $this->crud_model->get_lessons('lesson', $quiz_id)->row_array();

        if ($action == 'add' || $action == 'edit') {
            echo $this->crud_model->manage_quiz_questions($quiz_id, $question_id, $action);
        } elseif ($action == 'delete') {
            if ($this->db->get_where('question', array('id' => $question_id, 'quiz_id' => $quiz_id))->num_rows() <= 0) {
                $this->session->set_flashdata('error_message', get_phrase('you_do_not_have_right_to_access_this_quiz_question'));
                redirect(site_url('user/courses'), 'refresh');
            }

            $response = $this->crud_model->delete_quiz_question($question_id);
            $this->session->set_flashdata('flash_message', get_phrase('question_has_been_deleted'));
            redirect(site_url('user/course_form/course_edit/' . $quiz_details['course_id']), 'refresh');
        }
    }

    function manage_profile()
    {
        redirect(site_url('home/profile/user_profile'), 'refresh');
    }

    function invoice($payment_id = "")
    {
        if ($this->session->userdata('user_login') != true) {
            redirect(site_url('login'), 'refresh');
        }
        $page_data['page_name'] = 'invoice';
        $page_data['payment_details'] = $this->crud_model->get_payment_details_by_id($payment_id);
        $page_data['page_title'] = get_phrase('invoice');
        $this->load->view('backend/index', $page_data);
    }


    function become_an_instructor()
    {
        if ($this->session->userdata('user_login') != true) {
            redirect(site_url('login'), 'refresh');
        }

        $applications = $this->user_model->get_applications($this->session->userdata('user_id'), 'user');
        if ($applications->num_rows() == 0):
            redirect('home/become_an_instructor', 'refresh');
        endif;

        // CHEKING IF A FORM HAS BEEN SUBMITTED FOR REGISTERING AN INSTRUCTOR
        if (isset($_POST) && !empty($_POST)) {
            $this->user_model->post_instructor_application();
        }

        // CHECK USER AVAILABILITY
        $user_details = $this->user_model->get_all_user($this->session->userdata('user_id'));
        if ($user_details->num_rows() > 0) {
            $page_data['user_details'] = $user_details->row_array();
        } else {
            $this->session->set_flashdata('error_message', get_phrase('user_not_found'));
            $this->load->view('backend/index', $page_data);
        }
        $page_data['page_name'] = 'become_an_instructor';
        $page_data['page_title'] = get_phrase('become_an_instructor');
        $this->load->view('backend/index', $page_data);
    }


    // PAYOUT REPORT
    public function payout_report()
    {
        if ($this->session->userdata('user_login') != true) {
            redirect(site_url('login'), 'refresh');
        }

        $page_data['page_name'] = 'payout_report';
        $page_data['page_title'] = get_phrase('payout_report');

        $page_data['payouts'] = $this->crud_model->get_payouts($this->session->userdata('user_id'), 'user');
        $page_data['total_pending_amount'] = $this->crud_model->get_total_pending_amount($this->session->userdata('user_id'));
        $page_data['total_payout_amount'] = $this->crud_model->get_total_payout_amount($this->session->userdata('user_id'));
        $page_data['requested_withdrawal_amount'] = $this->crud_model->get_requested_withdrawal_amount($this->session->userdata('user_id'));

        if(addon_status('ebook')){
            $this->db->select_sum('instructor_revenue');
            $this->db->where('ebook.user_id', $this->session->userdata('user_id'));
            $this->db->where('ebook_payment.instructor_payment_status', 0);
            $this->db->from('ebook_payment');
            $this->db->join('ebook', 'ebook_payment.ebook_id = ebook.ebook_id'); 
            $ebook_total_pending_amount = $this->db->get()->row('instructor_revenue');

            $page_data['total_pending_amount'] = $page_data['total_pending_amount'] + $ebook_total_pending_amount;
        }

        if(addon_status('tutor_booking')){
            $this->db->select_sum('instructor_revenue');
            $this->db->where('tutor_id', $this->session->userdata('user_id'));
            $this->db->from('tutor_payment');
            $tutor_total_pending_amount = $this->db->get()->row('instructor_revenue');

            $page_data['total_pending_amount'] = $page_data['total_pending_amount'] + $tutor_total_pending_amount;
        }

        $this->load->view('backend/index', $page_data);
    }

    // HANDLED WITHDRAWAL REQUESTS
    public function withdrawal($action = "")
    {
        if ($this->session->userdata('user_login') != true) {
            redirect(site_url('login'), 'refresh');
        }

        if ($action == 'request') {
            $this->crud_model->add_withdrawal_request();
        }

        if ($action == 'delete') {
            $this->crud_model->delete_withdrawal_request();
        }

        redirect(site_url('user/payout_report'), 'refresh');
    }
    // Ajax Portion
    public function ajax_get_video_details()
    {
        $video_details = $this->video_model->getVideoDetails($_POST['video_url']);
        if(is_array($video_details)){
            echo $video_details['duration'];
        }
    }

    // AJAX PORTION
    // this function is responsible for managing multiple choice question
    function quiz_fields_type_wize()
    {
        $page_data['question_type'] = $this->input->post('question_type');
        $this->load->view('backend/user/quiz_fields_type_wize', $page_data);
    }

    // This function checks if this course belongs to current logged in instructor
    function is_the_course_belongs_to_current_instructor($course_id, $id = null, $type = null, $is_ajax_call = null)
    {
        $is_valid = 1;
        $course_details = $this->crud_model->get_course_by_id($course_id);

        if($course_details->num_rows() > 0){
            $course_details = $course_details->row_array();
            if ($course_details['multi_instructor']) {
                $instructor_ids = explode(',', $course_details['user_id']);
                if (!in_array($this->session->userdata('user_id'), $instructor_ids)) {
                    $this->session->set_flashdata('error_message', get_phrase('you_do_not_have_right_to_access_this_course'));
                    $is_valid = 0;

                    if($is_ajax_call == null){
                        redirect(site_url('user/courses'), 'refresh');
                    }
                }
            } else {
                if ($course_details['user_id'] != $this->session->userdata('user_id')) {
                    $this->session->set_flashdata('error_message', get_phrase('you_do_not_have_right_to_access_this_course'));
                    $is_valid = 0;
                    if($is_ajax_call == null){
                        redirect(site_url('user/courses'), 'refresh');
                    }
                }
            }
        }else{
            $this->session->set_flashdata('error_message', get_phrase('course_not_found'));
            $is_valid = 0;
            if($is_ajax_call == null){
                redirect(site_url('user/courses'), 'refresh');
            }
        }
        

        if ($type == 'section' && $this->db->get_where('section', array('id' => $id, 'course_id' => $course_id))->num_rows() <= 0) {
            $this->session->set_flashdata('error_message', get_phrase('you_do_not_have_right_to_access_this_section'));
            $is_valid = 0;
            if($is_ajax_call == null){
                redirect(site_url('user/courses'), 'refresh');
            }
        }
        if ($type == 'lesson' && $this->db->get_where('lesson', array('id' => $id, 'course_id' => $course_id))->num_rows() <= 0) {
            $this->session->set_flashdata('error_message', get_phrase('you_do_not_have_right_to_access_this_lesson'));
            $is_valid = 0;
            if($is_ajax_call == null){
                redirect(site_url('user/courses'), 'refresh');
            }
        }
        if ($type == 'quize' && $this->db->get_where('lesson', array('id' => $id, 'course_id' => $course_id))->num_rows() <= 0) {
            $this->session->set_flashdata('error_message', get_phrase('you_do_not_have_right_to_access_this_quize'));
            $is_valid = 0;
            if($is_ajax_call == null){
                redirect(site_url('user/courses'), 'refresh');
            }
        }

        return $is_valid;
    }

    public function ajax_sort_section()
    {
        $section_json = $this->input->post('itemJSON');
        $this->crud_model->sort_section($section_json);
    }
    public function ajax_sort_lesson()
    {
        $lesson_json = $this->input->post('itemJSON');
        $this->crud_model->sort_lesson($lesson_json);
    }
    public function ajax_sort_question()
    {
        $question_json = $this->input->post('itemJSON');
        $this->crud_model->sort_question($question_json);
    }

    

    // REMOVING INSTRUCTOR FROM COURSE
    public function remove_an_instructor($course_id, $instructor_id)
    {
        $course_details = $this->crud_model->get_course_by_id($course_id)->row_array();

        if ($course_details['creator'] == $instructor_id) {
            $this->session->set_flashdata('error_message', get_phrase('course_creator_can_be_removed'));
            redirect('admin/course_form/course_edit/' . $course_id);
        }

        if ($course_details['multi_instructor']) {
            $instructor_ids = explode(',', $course_details['user_id']);

            if (in_array($instructor_id, $instructor_ids) && in_array($this->session->userdata('user_id'), $instructor_ids)) {
                if (count($instructor_ids) > 1) {
                    if (($key = array_search($instructor_id, $instructor_ids)) !== false) {
                        unset($instructor_ids[$key]);

                        $data['user_id'] = implode(",", $instructor_ids);
                        $this->db->where('id', $course_id);
                        $this->db->update('course', $data);

                        $this->session->set_flashdata('flash_message', get_phrase('instructor_has_been_removed'));
                        if ($this->session->userdata('user_id') == $instructor_id) {
                            redirect('user/courses/');
                        } else {
                            redirect('user/course_form/course_edit/' . $course_id);
                        }
                    }
                } else {
                    $this->session->set_flashdata('error_message', get_phrase('a_course_should_have_at_least_one_instructor'));
                    redirect('user/course_form/course_edit/' . $course_id);
                }
            } else {
                $this->session->set_flashdata('error_message', get_phrase('invalid_instructor_id'));
                redirect('user/course_form/course_edit/' . $course_id);
            }
        } else {
            $this->session->set_flashdata('error_message', get_phrase('a_course_should_have_at_least_one_instructor'));
            redirect('user/course_form/course_edit/' . $course_id);
        }
    }


    //Blog start
    function add_blog(){
        $page_data['page_title'] = get_phrase('add_blog');
        $page_data['page_name'] = 'blog_add';
        $this->load->view('backend/index', $page_data);
    }

    function edit_blog($blog_id = ""){
        $page_data['blog'] = $this->crud_model->get_blogs($blog_id)->row_array();
        $page_data['page_title'] = get_phrase('edit_blog');
        $page_data['page_name'] = 'blog_edit';
        $this->load->view('backend/index', $page_data);
    }

    function blog($param1 = "", $param2 = ""){
        if (!get_frontend_settings('instructors_blog_permission')){
            $this->session->set_flashdata('error_message', get_phrase('access_to_the_blog_section_denied'));
            redirect(site_url('user/dashboard'), 'refresh');
        }


        if($param1 == 'add'){
            $this->crud_model->add_blog();
            $this->session->set_flashdata('flash_message', get_phrase('blog_added_successfully'));
            redirect(site_url('user/pending_blog'), 'refresh');
        }elseif($param1 == 'update'){
            if($this->check_validity($param2)){
                $this->crud_model->update_blog($param2);
            }
            $this->session->set_flashdata('flash_message', get_phrase('blog_updated_successfully'));
            redirect(site_url('user/blog'), 'refresh');
        }elseif($param1 == 'status'){
            if($this->check_validity($param2)){
                $this->crud_model->update_blog_status($param2);
            }
            $this->session->set_flashdata('flash_message', get_phrase('blog_status_has_been_updated'));
            redirect(site_url('user/blog'), 'refresh');
        }elseif($param1 == 'delete'){
            if($this->check_validity($param2)){
                $this->crud_model->blog_delete($param2);
            }
            $this->session->set_flashdata('flash_message', get_phrase('blog_deleted_successfully'));
            redirect(site_url('user/blog'), 'refresh');
        }
        $page_data['blogs'] = $this->crud_model->get_blogs_by_user_id($this->session->userdata('user_id'));
        $page_data['page_title'] = get_phrase('blog');
        $page_data['page_name'] = 'blog';
        $this->load->view('backend/index', $page_data);
    }

    function pending_blog($param1 = "", $param2 = ""){
        if($param1 == 'delete'){
            if($this->check_validity($param2)){
                $this->crud_model->blog_delete($param2);
            }
            $this->session->set_flashdata('flash_message', get_phrase('blog_deleted_successfully'));
            redirect(site_url('user/pending_blog'), 'refresh');
        }
        $page_data['pending_blogs'] = $this->crud_model->get_instructors_pending_blog($this->session->userdata('user_id'));
        $page_data['page_title'] = get_phrase('pending_blog');
        $page_data['page_name'] = 'pending_blog';
        $this->load->view('backend/index', $page_data);
    }

    function check_validity($blog_id = ""){
        $this->db->where('user_id', $this->session->userdata('user_id'));
        $this->db->where('blog_id', $blog_id);
        $query = $this->db->get('blogs');
        if($query->num_rows() > 0){
            return true;
        }else{
            return false;
        }
    }

    //End Blog


    function start_quiz($quiz_id = "", $retake = ""){
        $quiz_details = $this->crud_model->get_lessons('lesson', $quiz_id)->row_array();


        $data['quiz_id'] = $quiz_details['id'];
        $data['user_id'] = $this->session->userdata('user_id');
        $data['user_answers'] = json_encode(array());
        $data['correct_answers'] = json_encode(array());
        $data['date_added'] = time();


        $row = $this->db->get_where('quiz_results', array('user_id' => $data['user_id'], 'quiz_id' => $quiz_id));
        $total_attemped = $this->db->where('quiz_id', $quiz_id)->get('quiz_results')->num_rows();
        if($quiz_details['quiz_attempt'] == 0 && $row->num_rows() <= 0 || $quiz_details['quiz_attempt'] > ($total_attemped - 1)):

            if($this->db->get_where('quiz_results', array('user_id' => $data['user_id'], 'is_submitted' => 0, 'quiz_id' => $quiz_id))->num_rows() == 0):
                $this->db->insert('quiz_results', $data);
            endif;
        endif;

        if($retake != ""){
            $course_title = $this->crud_model->get_course_by_id($quiz_details['course_id'])->row('title');
            redirect(site_url('home/lesson/'.slugify($course_title).'/'.$quiz_details['course_id'].'/'.$quiz_details['id']), 'refresh');
        }

        $page_data['quiz_questions'] = $this->db->get_where('question', array('quiz_id' => $quiz_id));
        $page_data['quiz_id'] = $quiz_id;
        $this->load->view('lessons/quiz_answer_sheet', $page_data);
    }

    function submit_quiz_answer($quiz_id = "", $question_id = "", $question_type = ""){

        //Quize details
        $user_id = $this->session->userdata('user_id');
        $quiz_details = $this->crud_model->get_lessons('lesson', $quiz_id)->row_array();
        $total_seconds = time_to_seconds($quiz_details['duration']);
        $total_marks = json_decode($quiz_details['attachment'], true)['total_marks'];

        //Question details
        $question_details = $this->db->get_where('question', array('id' => $question_id))->row_array();


        $results = $this->db->order_by('quiz_result_id', 'desc')->get_where('quiz_results', array('quiz_id' => $quiz_id, 'user_id' => $user_id));
        
        if($results->num_rows() > 0 && ($total_seconds + $results->row('date_added')) > time() || $total_seconds == 0){
            $result = $results->row_array();
            $correct_answer_question_ids = json_decode($result['correct_answers'], true);

            $answers = $this->input->post('answer');

            $user_answers = json_decode($result['user_answers'], true);
            $user_answers[$question_id] = $answers;

            if($question_type == 'multiple_choice'){
                $is_correct_answer = 1;
                $currect_answers = json_decode($question_details['correct_answers'], true);
                foreach($answers as $answer){
                    if(!in_array($answer, $currect_answers)){
                        $is_correct_answer = 0;
                    }
                }
                if(!is_array($answers) || count($answers) <= 0 || count($currect_answers) != count($answers)){
                    $is_correct_answer = 0;
                }
            }elseif($question_type == 'single_choice'){
                $is_correct_answer = 0;
                $currect_answers = json_decode($question_details['correct_answers'], true);
                if(in_array($answers[0], $currect_answers)){
                    $is_correct_answer = 1;
                }
            }elseif($question_type == 'fill_in_the_blank'){
                $is_correct_answer = 1;
                $currect_answers = json_decode(strtolower($question_details['correct_answers']), true);
                foreach($answers as $key => $answer){
                    $answer = strtolower($answer);
                    if($answer != $currect_answers[$key]){
                        $is_correct_answer = 0;
                    }
                }
                if(!is_array($answers) || count($answers) <= 0 || count($currect_answers) != count($answers)){
                    $is_correct_answer = 0;
                }
            }

            if($is_correct_answer == 1){
                if(!in_array($question_id, $correct_answer_question_ids)){
                    array_push($correct_answer_question_ids, $question_id);
                }
            }else{
                $updated_correct_answer_question_ids = array();
                foreach($correct_answer_question_ids as $correct_answer_question_id){
                    if($correct_answer_question_id != $question_id){
                        array_push($updated_correct_answer_question_ids, $correct_answer_question_id);
                    }
                }
                $correct_answer_question_ids = $updated_correct_answer_question_ids;
            }

            $total_questions = $this->db->get_where('question', array('quiz_id' => $quiz_id))->num_rows();
            $data['total_obtained_marks'] = round(($total_marks/$total_questions)*count($correct_answer_question_ids), 1);

            $data['user_answers'] = json_encode($user_answers);
            $data['correct_answers'] = json_encode($correct_answer_question_ids);
            $data['date_updated'] = time();
            $this->db->where('user_id', $user_id);
            $this->db->where('quiz_id', $quiz_id);
            $this->db->where('is_submitted', 0);
            $this->db->update('quiz_results', $data);
        }else{
            $this->finish_quize_submission($quiz_id);
            $response['status'] = 'time_over';
            $response['message'] = site_phrase('time_over');
            echo json_encode($response);
        }
    }

    function finish_quize_submission($quiz_id = ""){
        $user_id = $this->session->userdata('user_id');
        $data['is_submitted'] = 1;
        $this->db->where('user_id', $user_id);
        $this->db->where('is_submitted', 0);
        $this->db->where('quiz_id', $quiz_id);
        $this->db->update('quiz_results', $data);

        //Mark this quiz as completed
        $course_id = $this->crud_model->get_lessons('lesson', $quiz_id)->row('course_id');
        $this->crud_model->update_watch_history_manually($quiz_id, $course_id, $user_id);

        $response['status'] = 'submit';
        $response['message'] = site_phrase('quiz_submission_successfully');
        echo json_encode($response);
    }

    function ai_img_download(){
        $this->load->model('addons/ai_model');
        $this->ai_model->ai_img_download();
    }

    function chat_gpt(){
        if (isset($_POST['service_type']) && !empty($_POST['service_type'])) {
            $this->load->model('addons/ai_model');
            echo $this->ai_model->chat_gpt();
        }else{
            $this->load->view('backend/user/chat_gpt');
        }
    }

    function student_academic_progress($course_id = ""){
        $course_details = $this->crud_model->get_course_by_id($course_id)->row_array();
        $multi_instructors = explode(',',$course_details['user_id']);

        if(!in_array($this->session->userdata('user_id'), $multi_instructors)){
            return false;
        }

        $page_data['course_details'] = $course_details;
        $this->load->view('backend/user/student_academic_progress', $page_data);
    }

    function student_academic_quiz_result($course_id = "", $student_id = ""){
        $course_details = $this->crud_model->get_course_by_id($course_id)->row_array();
        $multi_instructors = explode(',',$course_details['user_id']);

        if(!in_array($this->session->userdata('user_id'), $multi_instructors)){
            return false;
        }

        $page_data['course_details'] = $course_details;
        $page_data['student_id'] = $student_id;
        $this->load->view('backend/user/student_academic_quiz_result', $page_data);
    }

    function student_certificate($user_id = "", $course_id = ""){
        $this->load->model('addons/Certificate_model', 'certificate_model');
        $course_progress = $this->crud_model->get_watch_histories($user_id, $course_id)->row('course_progress');
        if ($course_progress >= 100) {
            $this->certificate_model->check_certificate_eligibility($course_id, $user_id);
            $certificate = $this->db->get_where('certificates', array('course_id' => $course_id, 'student_id' => $user_id));
            redirect(site_url('certificate/'.$certificate->row('shareable_url')));
        }else{
            $this->session->set_flashdata('error_message', get_phrase('The course is not over yet'));
            redirect(site_url('user/course_form/course_edit/'.$certificate->row('shareable_url')));
        }
    }

















}
