<?php
/* For licensing terms, see /license.txt */
exit;
/**
 * This tool allows platform admins to update course-user relations by uploading
 * a CSV file.
 */
/**
 * Validates the imported data.
 */
function validate_data($users_courses)
{
    $errors = [];
    $coursecodes = [];
    foreach ($users_courses as $index => $user_course) {
        $user_course['line'] = $index + 1;
        // 1. Check whether mandatory fields are set.
        $mandatory_fields = ['Email', 'CourseCode', 'Status'];
        foreach ($mandatory_fields as $key => $field) {
            if (!isset($user_course[$field]) || 0 == strlen($user_course[$field])) {
                $user_course['error'] = get_lang($field.'Mandatory');
                $errors[] = $user_course;
            }
        }

        // 2. Check whether coursecode exists.
        if (isset($user_course['CourseCode']) && 0 != strlen($user_course['CourseCode'])) {
            // 2.1 Check whethher code has been allready used by this CVS-file.
            if (!isset($coursecodes[$user_course['CourseCode']])) {
                // 2.1.1 Check whether course with this code exists in the system.
                $course_table = Database::get_main_table(TABLE_MAIN_COURSE);
                $sql = "SELECT * FROM $course_table
                        WHERE code = '".Database::escape_string($user_course['CourseCode'])."'";
                $res = Database::query($sql);
                if (0 == Database::num_rows($res)) {
                    $user_course['error'] = get_lang('This code does not exist');
                    $errors[] = $user_course;
                } else {
                    $coursecodes[$user_course['CourseCode']] = 1;
                }
            }
        }

        // 3. Check whether Email exists.
        if (isset($user_course['Email']) && 0 != strlen($user_course['Email'])) {
            $user = api_get_user_info_from_email($user_course['Email']);
            if (empty($user)) {
                $user_course['error'] = get_lang('Unknown user');
                $errors[] = $user_course;
            }
        }

        // 4. Check whether status is valid.
        if (isset($user_course['Status']) && 0 != strlen($user_course['Status'])) {
            if (COURSEMANAGER != $user_course['Status'] && STUDENT != $user_course['Status']) {
                $user_course['error'] = get_lang('Unknown status');
                $errors[] = $user_course;
            }
        }
    }

    return $errors;
}

/**
 * Saves imported data.
 */
function save_data($users_courses)
{
    $user_table = Database::get_main_table(TABLE_MAIN_USER);
    $course_user_table = Database::get_main_table(TABLE_MAIN_COURSE_USER);
    $csv_data = [];
    $inserted_in_course = [];

    foreach ($users_courses as $user_course) {
        $csv_data[$user_course['Email']][$user_course['CourseCode']] = $user_course['Status'];
    }

    foreach ($csv_data as $email => $csv_subscriptions) {
        $sql = "SELECT * FROM $user_table u
                WHERE u.email = '".Database::escape_string($email)."'
                LIMIT 1";
        $res = Database::query($sql);
        $obj = Database::fetch_object($res);
        $user_id = $obj->user_id;
        $sql = "SELECT * FROM $course_user_table cu
                WHERE cu.user_id = $user_id AND cu.relation_type <> ".COURSE_RELATION_TYPE_RRHH.' ';
        $res = Database::query($sql);
        $db_subscriptions = [];
        while ($obj = Database::fetch_object($res)) {
            $db_subscriptions[$obj->c_id] = $obj->status;
        }

        $to_subscribe = array_diff(array_keys($csv_subscriptions), array_keys($db_subscriptions));
        $to_unsubscribe = array_diff(array_keys($db_subscriptions), array_keys($csv_subscriptions));

        if (isset($_POST['subscribe']) && $_POST['subscribe']) {
            foreach ($to_subscribe as $courseId) {
                $courseInfo = api_get_course_info_by_id($courseId);
                $course_code = $courseInfo['code'];
                if (CourseManager::course_exists($course_code)) {
                    $course_info = api_get_course_info($course_code);
                    $inserted_in_course[$course_code] = $course_info['title'];

                    CourseManager::subscribeUser(
                        $user_id,
                        $courseId,
                        $csv_subscriptions[$course_code]
                    );
                    $inserted_in_course[$course_info['code']] = $course_info['title'];
                }
            }
        }

        if (isset($_POST['unsubscribe']) && $_POST['unsubscribe']) {
            foreach ($to_unsubscribe as $courseId) {
                $courseInfo = api_get_course_info_by_id($courseId);
                $course_code = $courseInfo['code'];
                if (CourseManager::course_exists($course_code)) {
                    CourseManager::unsubscribe_user($user_id, $course_code);
                    $course_info = api_get_course_info($course_code);
                    CourseManager::unsubscribe_user($user_id, $course_code);
                    $inserted_in_course[$course_info['code']] = $course_info['title'];
                }
            }
        }
    }

    return $inserted_in_course;
}

/**
 * Reads CSV-file.
 *
 * @param string $file Path to the CSV-file
 *
 * @return array All course-information read from the file
 */
function parse_csv_data($file)
{
    return Import::csv_reader($file);
}

$cidReset = true;

require_once __DIR__.'/../inc/global.inc.php';

// Setting the section (for the tabs).
$this_section = SECTION_PLATFORM_ADMIN;

// Protecting the admin section.
api_protect_admin_script();

$tool_name = get_lang('Add users to course').' CSV';

$interbreadcrumb[] = ['url' => 'index.php', 'name' => get_lang('Administration')];

set_time_limit(0);

// Creating the form.
$form = new FormValidator('course_user_import');
$form->addElement('header', '', $tool_name);
$form->addElement('file', 'import_file', get_lang('Import file'));
$form->addElement('checkbox', 'subscribe', get_lang('Action'), get_lang('Add user in the course only if not yet in'));
$form->addElement('checkbox', 'unsubscribe', '', get_lang('Remove user from course if his/her name is not in the list'));
$form->addButtonImport(get_lang('Import'));
$form->setDefaults(['subscribe' => '1', 'unsubscribe' => 1]);
$errors = [];

if ($form->validate()) {
    $users_courses = parse_csv_data($_FILES['import_file']['tmp_name']);
    $errors = validate_data($users_courses);
    if (0 == count($errors)) {
        $inserted_in_course = save_data($users_courses);
        // Build the alert message in case there were visual codes subscribed to.
        if ($_POST['subscribe']) {
            $warn = get_lang('The users have been subscribed to the following courses because several courses share the same visual code').': ';
        } else {
            $warn = get_lang('The users have been unsubscribed from the following courses because several courses share the same visual code').': ';
        }

        if (!empty($inserted_in_course)) {
            $warn .= ' '.get_lang('File imported');
            // The users have been inserted in more than one course.
            foreach ($inserted_in_course as $code => $info) {
                $warn .= ' '.$info.' ('.$code.') ';
            }
        } else {
            $warn = get_lang('Errors when importing file');
        }

        Security::clear_token();
        $tok = Security::get_token();
        Display::addFlash(Display::return_message($warn));
        header('Location: user_list.php?sec_token='.$tok);
        exit();
    }
}

// Displaying the header.
Display::display_header($tool_name);

if (0 != count($errors)) {
    $error_message = '<ul>';
    foreach ($errors as $index => $error_course) {
        $error_message .= '<li>'.get_lang('Line').' '.$error_course['line'].': <strong>'.$error_course['error'].'</strong>: ';
        $error_message .= $error_course['Code'].' '.$error_course['Title'];
        $error_message .= '</li>';
    }
    $error_message .= '</ul>';
    echo Display::return_message($error_message, 'error', false);
}

$form->display();

$content = '<p>'.get_lang('The CSV file must look like this').' ('.get_lang('Fields in <strong>bold</strong> are mandatory.').') :</p>
<blockquote>
<pre>
<b>Email</b>;<b>CourseCode</b>;<b>Status</b>
example1@example.org;course01;;'.COURSEMANAGER.'
example2@example.org;course01;'.STUDENT.'
</pre>
'.COURSEMANAGER.': '.get_lang('Trainer').'<br />
'.STUDENT.': '.get_lang('Learner').'<br />
</blockquote>
';

echo Display::prose($content);

Display::display_footer();
