<?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/>.

namespace core_calendar\external;

use core\external\exporter;
use core_calendar\output\humantimeperiod;
use core_date;
use DateTimeImmutable;
use renderer_base;
use moodle_url;
use core_calendar\local\event\container;

/**
 * Class for displaying the day view.
 *
 * @package   core_calendar
 * @copyright 2017 Simey Lameze <simey@moodle.com>
 * @license   http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
 */
class calendar_day_exporter extends exporter {
    /**
     * @var \calendar_information $calendar The calendar to be rendered.
     */
    protected $calendar;

    /**
     * @var moodle_url $url The URL for the day view page.
     */
    protected $url;

    /**
     * Constructor for day exporter.
     *
     * @param \calendar_information $calendar The calendar being represented.
     * @param array $related The related information
     */
    public function __construct(\calendar_information $calendar, $related) {
        $this->calendar = $calendar;

        parent::__construct([], $related);
    }

    /**
     * Return the list of additional properties.
     *
     * @return array
     */
    protected static function define_other_properties() {
        return [
            'events' => [
                'type' => calendar_event_exporter::read_properties_definition(),
                'multiple' => true,
            ],
            'defaulteventcontext' => [
                'type' => PARAM_INT,
                'default' => 0,
            ],
            'filter_selector' => [
                'type' => PARAM_RAW,
            ],
            'courseid' => [
                'type' => PARAM_INT,
            ],
            'categoryid' => [
                'type' => PARAM_INT,
                'optional' => true,
                'default' => 0,
            ],
            'neweventtimestamp' => [
                'type' => PARAM_INT,
            ],
            'date' => [
                'type' => date_exporter::read_properties_definition(),
            ],
            'periodname' => [
                // Note: We must use RAW here because the calendar type returns the formatted month name based on a
                // calendar format.
                'type' => PARAM_RAW,
            ],
            'previousperiod' => [
                'type' => date_exporter::read_properties_definition(),
            ],
            'previousperiodlink' => [
                'type' => PARAM_URL,
            ],
            'previousperiodname' => [
                // Note: We must use RAW here because the calendar type returns the formatted month name based on a
                // calendar format.
                'type' => PARAM_RAW,
            ],
            'nextperiod' => [
                'type' => date_exporter::read_properties_definition(),
            ],
            'nextperiodname' => [
                // Note: We must use RAW here because the calendar type returns the formatted month name based on a
                // calendar format.
                'type' => PARAM_RAW,
            ],
            'nextperiodlink' => [
                'type' => PARAM_URL,
            ],
            'larrow' => [
                // The left arrow defined by the theme.
                'type' => PARAM_RAW,
            ],
            'rarrow' => [
                // The right arrow defined by the theme.
                'type' => PARAM_RAW,
            ],
        ];
    }

    /**
     * Get the additional values to inject while exporting.
     *
     * @param renderer_base $output The renderer.
     * @return array Keys are the property names, values are their values.
     */
    protected function get_other_values(renderer_base $output) {
        $timestamp = $this->calendar->time;

        $cache = $this->related['cache'];
        $url = new moodle_url('/calendar/view.php', [
            'view' => 'day',
            'time' => $timestamp,
        ]);
        if ($this->calendar->course && SITEID !== $this->calendar->course->id) {
            $url->param('course', $this->calendar->course->id);
        } else if ($this->calendar->categoryid) {
            $url->param('category', $this->calendar->categoryid);
        }
        $this->url = $url;
        $return['events'] = array_map(function($event) use ($cache, $output, $url) {
            $context = $cache->get_context($event);
            $course = $cache->get_course($event);
            $moduleinstance = $cache->get_module_instance($event);
            $exporter = new calendar_event_exporter($event, [
                'context' => $context,
                'course' => $course,
                'moduleinstance' => $moduleinstance,
                'daylink' => $url,
                'type' => $this->related['type'],
                'today' => $this->calendar->time,
            ]);

            $data = $exporter->export($output);

            // We need to override default formatted time because it differs from day view.
            // Formatted time for day view adds a link to the day view.
            $legacyevent = container::get_event_mapper()->from_event_to_legacy_event($event);
            $humanperiod = humantimeperiod::create_from_timestamp(
                starttimestamp: $legacyevent->timestart,
                endtimestamp: $legacyevent->timestart + $legacyevent->timeduration,
                link: new moodle_url(CALENDAR_URL . 'view.php'),
            );
            $data->formattedtime = $output->render($humanperiod);

            return $data;
        }, $this->related['events']);

        if ($context = $this->get_default_add_context()) {
            $return['defaulteventcontext'] = $context->id;
        }

        if ($this->calendar->categoryid) {
            $return['categoryid'] = $this->calendar->categoryid;
        }

        $return['filter_selector'] = $this->get_course_filter_selector($output);
        $return['courseid'] = $this->calendar->courseid;

        $previousperiod = $this->get_previous_day_data();
        $nextperiod = $this->get_next_day_data();
        $date = $this->related['type']->timestamp_to_date_array($this->calendar->time);

        $nextperiodlink = new moodle_url($this->url);
        $nextperiodlink->param('time', $nextperiod[0]);

        $previousperiodlink = new moodle_url($this->url);
        $previousperiodlink->param('time', $previousperiod[0]);

        $days = calendar_get_days();
        $return['date'] = (new date_exporter($date))->export($output);
        $return['periodname'] = userdate($this->calendar->time, get_string('strftimedaydate'));
        $return['previousperiod'] = (new date_exporter($previousperiod))->export($output);
        $return['previousperiodname'] = $days[$previousperiod['wday']]['fullname'];
        $return['previousperiodlink'] = $previousperiodlink->out(false);
        $return['nextperiod'] = (new date_exporter($nextperiod))->export($output);
        $return['nextperiodname'] = $days[$nextperiod['wday']]['fullname'];
        $return['nextperiodlink'] = $nextperiodlink->out(false);
        $return['larrow'] = $output->larrow();
        $return['rarrow'] = $output->rarrow();

        // Need to account for user's timezone.
        $usernow = usergetdate(time());
        $today = new DateTimeImmutable(
            timezone: core_date::get_user_timezone_object(),
        );

        // The start time should use the day's date but the current
        // time of the day (adjusted for user's timezone).
        $neweventtimestamp = $today->setTimestamp($date[0])->setTime(
            $usernow['hours'],
            $usernow['minutes'],
            $usernow['seconds']
        );
        $return['neweventtimestamp'] = $neweventtimestamp->getTimestamp();

        return $return;
    }

    /**
     * Get the default context for use when adding a new event.
     *
     * @return null|\context
     */
    protected function get_default_add_context() {
        if (calendar_user_can_add_event($this->calendar->course)) {
            return \context_course::instance($this->calendar->course->id);
        }

        return null;
    }

    /**
     * Get the course filter selector.
     *
     * @param renderer_base $output
     * @return string The html code for the course filter selector.
     */
    protected function get_course_filter_selector(renderer_base $output) {
        return $output->course_filter_selector($this->url, '', $this->calendar->course->id);
    }

    /**
     * Returns a list of objects that are related.
     *
     * @return array
     */
    protected static function define_related() {
        return [
            'events' => '\core_calendar\local\event\entities\event_interface[]',
            'cache' => '\core_calendar\external\events_related_objects_cache',
            'type' => '\core_calendar\type_base',
        ];
    }

    /**
     * Get the previous day timestamp.
     *
     * @return int The previous day timestamp.
     */
    protected function get_previous_day_data() {
        $type = $this->related['type'];
        $time = $type->get_prev_day($this->calendar->time);

        return $type->timestamp_to_date_array($time);
    }

    /**
     * Get the next day timestamp.
     *
     * @return int The next day timestamp.
     */
    protected function get_next_day_data() {
        $type = $this->related['type'];
        $time = $type->get_next_day($this->calendar->time);

        return $type->timestamp_to_date_array($time);
    }
}
