<?php
// This file is part of Moodle - http://moodle.org/
//
// Moodle is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// Moodle is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with Moodle.  If not, see <http://www.gnu.org/licenses/>.

/**
 *
 * @package    tool_htmlbootstrapeditor
 * @copyright  2019 RECIT
 * @license    {@link http://www.gnu.org/licenses/gpl-3.0.html} GNU GPL v3 or later
 */

namespace tool_htmlbootstrapeditor\privacy;


use core_privacy\local\metadata\collection;
use core_privacy\local\request\approved_contextlist;
use core_privacy\local\request\context;
use core_privacy\local\request\contextlist;
use core_privacy\local\request\transform;
use core_privacy\local\request\writer;
use core_privacy\local\request\userlist;
use \core_privacy\local\request\approved_userlist;

defined('MOODLE_INTERNAL') || die();

class provider implements
        \core_privacy\local\metadata\provider,
        \core_privacy\local\request\core_userlist_provider,
        \core_privacy\local\request\plugin\provider {

    /**
     * Returns meta data about this system.
     *
     * @param   collection $collection The initialised collection to add items to.
     * @return  collection     A listing of user data stored through this system.
     */
    public static function get_metadata(collection $collection) : collection {
        $collection->add_database_table(
            'tool_htmlbootstrapeditor_tpl',
            [
                'name' => 'privacy:metadata:tool_htmlbootstrapeditor_templates:name',
                'type' => 'privacy:metadata:tool_htmlbootstrapeditor_templates:type',
                'userid' => 'privacy:metadata:tool_htmlbootstrapeditor_templates:userid',
                'htmlstr' => 'privacy:metadata:tool_htmlbootstrapeditor_templates:htmlstr',
                'img' => 'privacy:metadata:tool_htmlbootstrapeditor_templates:img',
            ],
            'privacy:metadata:tool_htmlbootstrapeditor_templates'
        );


        return $collection;
    }

    /**
     * Get the list of contexts that contain user information for the specified user.
     *
     * @param   int $userid The user to search.
     * @return  contextlist   $contextlist  The contextlist containing the list of contexts used in this plugin.
     */
    public static function get_contexts_for_userid(int $userid) : contextlist {
        $params = ['userid' => $userid, 'contextuser' => CONTEXT_USER];
        $sql = "SELECT id
                  FROM {context}
                 WHERE instanceid = :userid and contextlevel = :contextuser";
        $contextlist = new contextlist();
        $contextlist->add_from_sql($sql, $params);
        //Templates aren't tied to any context
        return $contextlist;
    }

    /**
     * Get the list of users within a specific context.
     *
     * @param userlist $userlist The userlist containing the list of users who have data in this context/plugin combination.
     */
    public static function get_users_in_context(userlist $userlist) {
        $context = $userlist->get_context();

        if (!$context instanceof \context_user) {
            return;
        }

        $sql = "SELECT userid
                  FROM {tool_htmlbootstrapeditor_tpl}
                 WHERE userid = ?";
        $params = [$context->instanceid];

        $userlist->add_from_sql('userid', $sql, $params);
    }

    /**
     * Export all user data for the specified user, in the specified contexts.
     *
     * @param   approved_contextlist $contextlist The approved contexts to export information for.
     */
    public static function export_user_data(approved_contextlist $contextlist) {
        global $DB;

        // If the user has repository_instances data, then only the User context should be present so get the first context.
        $contexts = $contextlist->get_contexts();
        if (count($contexts) == 0) {
            return;
        }
        $context = reset($contexts);

        // Sanity check that context is at the User context level, then get the userid.
        if ($context->contextlevel !== CONTEXT_USER) {
            return;
        }
        $userid = $context->instanceid;

        $sql = "SELECT *
                  FROM {tool_htmlbootstrapeditor_tpl}
                 WHERE userid = :userid";

        $params = [
            'userid' => $userid
        ];

        $instances = $DB->get_records_sql($sql, $params);

        foreach ($instances as $instance) {
            $subcontext = [
                get_string('pluginname', 'tool_htmlbootstrapeditor')
            ];

            writer::with_context($context)->export_data($subcontext, $instance);
        }
    }

    /**
     * Delete all data for all users in the specified context.
     *
     * @param   context $context The specific context to delete data for.
     */
    public static function delete_data_for_all_users_in_context(\context $context) {
        global $DB;

        // Sanity check that context is at the User context level, then get the userid.
        if ($context->contextlevel !== CONTEXT_USER) {
            return;
        }
        $userid = $context->instanceid;

        // Delete the records created for the userid.
        $DB->delete_records('tool_htmlbootstrapeditor_tpl', ['userid' => $userid]);
    }

    /**
     * Delete multiple users within a single context.
     *
     * @param approved_userlist $userlist The approved context and user information to delete information for.
     */
    public static function delete_data_for_users(approved_userlist $userlist) {
        global $DB;

        $context = $userlist->get_context();

        if ($context instanceof \context_user) {
            $DB->delete_records('tool_htmlbootstrapeditor_tpl', ['userid' => $context->instanceid]);
        }
    }

    /**
     * Delete all user data for the specified user, in the specified contexts.
     *
     * @param   approved_contextlist $contextlist The approved contexts and user information to delete information for.
     */
    public static function delete_data_for_user(approved_contextlist $contextlist) {
        global $DB;

        // If the user has data, then only the User context should be present so get the first context.
        $contexts = $contextlist->get_contexts();
        if (count($contexts) == 0) {
            return;
        }
        $context = reset($contexts);

        // Sanity check that context is at the User context level, then get the userid.
        if ($context->contextlevel !== CONTEXT_USER) {
            return;
        }
        $userid = $context->instanceid;

        $DB->delete_records('tool_htmlbootstrapeditor_tpl', ['userid' => $userid]);
    }

}