<?php
$strftimeDeprecated = version_compare(PHP_VERSION, '8.1.0', '>=');

if ($strftimeDeprecated) {
    require 'php-8.1-strftime.php';
}

$strftime = fn(...$args) => $strftimeDeprecated ? PHP81_BC\strftime(...$args) : \strftime(...$args);

function parseData($config, $data) {
    global $strftime;

	$languages = array(
		'en' => array(
			'name' => 'English',
			'locale' => 'en_US.UTF8'
		),
		'bg' => array(
			'name' => 'Български',
			'locale' => 'bg_BG.UTF8'
		)
	);

	if ($data === false) return false;

	// We need to set these so we actually parse properly the dates. WP fucks up both.
	date_default_timezone_set('Europe/Sofia');
	setlocale(LC_TIME, $languages[$config['lang']]['locale']);

	// Filter out invalid slots
	$data['slots'] = array_filter($data['slots'], function($slot) {
		return isset($slot['starts_at'], $slot['ends_at'], $slot['hall_id'], $slot['event_id']);
	});

	// Collect the slots for each hall, sort them in order of starting
	$slots = [];
	$timestamps = [];

	$filtered_type_id =
	array_key_exists('filterEventType', $config) &&
	array_key_exists($config['filterEventType'], $config['eventTypes']) ?
		$config['eventTypes'][$config['filterEventType']] :
		null;

	foreach ($data['halls'] as $hall_id => $hall) {
		$slots[$hall_id] = [];

		foreach ($data['slots'] as $slot_id => $slot) {
			if ($slot['hall_id'] !== $hall_id) {
				continue;
			}

			$eid = $slot['event_id'];
			$etype = $data['events'][$eid]['event_type_id'];
			if ($etype !== $filtered_type_id && !is_null($filtered_type_id)) {
				continue;
			}

			if (!in_array($slot['starts_at'], $timestamps)) {
				$timestamps[] = $slot['starts_at'];
			}

			if (!in_array($slot['ends_at'], $timestamps)) {
				$timestamps[] = $slot['ends_at'];
			}

			$slots[$hall_id][$slot['starts_at']] = $slot;
		}
		ksort($slots[$hall_id]);
		if (empty($slots[$hall_id])) unset($slots[$hall_id]);
	}

	sort($timestamps);

	// Find all microslots (the smallest time unit)
	$microslots = [];
	$lastTs = 0;
	$first = true;

	foreach ($timestamps as $ts) {
		if ($first) {
			$lastTs = $ts;
			$first = false;
			continue;
		}

		if (date('d.m', $lastTs) !== date('d.m', $ts)) {
			$lastTs = $ts;
			continue;
		}

		$microslots[] = [$lastTs, $ts];
		$lastTs = $ts;
	}
	// Fill in the event ID for each time slot in each hall
	$events = [];

	foreach ($data['halls'] as $hall_id => $hall) {
		$hall_data = [];

		foreach ($microslots as $timestamps) {
			$found = false;

			foreach ($data['slots'] as $slot_id => $slot) {
				if (
					$slot['hall_id'] === $hall_id &&
					$slot['starts_at'] <= $timestamps[0] &&
					$slot['ends_at'] >= $timestamps[1] &&
					array_key_exists($slot['event_id'], $data['events'])
				) {
					if (!is_null($filtered_type_id)) {
						if ($data['events'][$slot['event_id']]['event_type_id'] !== $filtered_type_id) {
							continue;
						}
					}

					$found = true;
					$hall_data[] = [
						'event_id' => $slot['event_id'],
						'hall_id' => $slot['hall_id'],
						'edge' => $slot['starts_at'] === $timestamps[0] || $slot['ends_at'] === $timestamps[1],
					];
					break;
				}
			}

			if (!$found) {
				$hall_data[] = null;
			}
		}

		$events[$hall_id] = $hall_data;
	}
	// Remove halls with no events after filtering
	foreach ($events as $i => $event) {
		$hasEvents = false;
		foreach ($event as $event_info) {
			if (!is_null($event_info)) {
				$hasEvents = true;
				break;
			}
		}
		if (!$hasEvents) {
			unset($events[$i]);
		}
	}

	// Transpose the matrix
	// rows->halls, cols->timeslots ===> rows->timeslots, cols->halls
	$events = array_map(null, ...$events);

	// Filter empty slots
	foreach($events as $i => $event) {
		$hall_count = count($event);
		$hasEvents = false;

		for ($j = 0; $j < $hall_count; ++$j) {
			if (!is_null($event[$j]) && $event[$j]['edge']) {
				$hasEvents = true;
				continue 2;
			}
		}

		if (!$hasEvents) {
			unset($events[$i]);
		}
	}

	// Merge events longer than one slot
	$prevEventId = [];
	$prevEventSlot = [];
	$prevSlotIndex = 0;
	$first = true;

	foreach ($events as $slot_index => &$events_data) {
		if ($first) {
			$prevEventId = array_map(function($event_info) {
				return is_null($event_info) ? null : $event_info['event_id'];
			}, $events_data);
			$prevEventSlot = array_fill(0, count($events_data), null);
			$prevSlotIndex = $slot_index;
			$first = false;
			continue;
		}

		foreach ($events_data as $hall_index => &$event_info) {
			if (is_null($event_info)) {
				$prevEventId[$hall_index] = null;
				$prevEventSlot[$hall_index] = null;
				continue;
			}

			if ($event_info['event_id'] !== $prevEventId[$hall_index]) {
				$prevEventId[$hall_index] = $event_info['event_id'];
				$prevEventSlot[$hall_index] = null;
				continue;
			}

            // We have a long event
			if (is_null($prevEventSlot[$hall_index])) {
				$prevEventSlot[$hall_index] = $prevSlotIndex;
			}

            $masterSlotIndex = $prevEventSlot[$hall_index];

            // check if the events spans on the next day
            if (date('d.m', $microslots[$slot_index][0]) !== date('d.m', $microslots[$masterSlotIndex][1])) {
                // not sure why this is needed, but it fixes things
                $prevEventSlot[$hall_index] = null;
                continue;
            }

            $master_slot = &$events[$masterSlotIndex][$hall_index];

			if (!array_key_exists('rowspan', $master_slot)) {
				$master_slot['rowspan'] = 2;
			}
			else {
				++$master_slot['rowspan'];
			}

			unset($master_slot);

			$event_info = false;
		}

		unset($event_info);

		$prevSlotIndex = $slot_index;
	}

	unset($events_data);

	// Build the HTML
	$schedule_body = '';
	$lastTs = 0;
	$fulltalks = '';
	$hall_ids = [];
	$now = time();

	$known_events = array();

	foreach ($events as $slot_index => $events_data) {
		$columns = [];

		if (date('d.m', $microslots[$slot_index][0]) !== date('d.m', $lastTs)) {
			$schedule_body .= '<tr><th colspan="' . (count($events_data) + 1) . '">' . $strftime('%d %B - %A', $microslots[$slot_index][0]) . '</th></tr>';
		}

		$lastTs = $microslots[$slot_index][0];
		$lastEventId = 0;
		$colspan = 1;

		foreach ($events_data as $event_info) {
			if ($event_info === false) {
				continue;
			}

			if (is_null($event_info) || is_null($event_info['event_id'])) {
				$columns[] = '<td>&nbsp;</td>';
				continue;
			}

			if (!in_array($event_info['hall_id'], $hall_ids)) {
				$hall_ids[] = $event_info['hall_id'];
			}

			$eid = &$event_info['event_id'];
			$event = &$data['events'][$eid];

#			var_dump($microslots[$slot_index]);
			$title = mb_substr($event['title'], 0, $config['cut_len']) . (mb_strlen($event['title']) > $config['cut_len'] ? '...' : '');
			$speakers = '';

			if (count($event['participant_user_ids']) > 0) {
				$spk = [];

				foreach ($event['participant_user_ids'] as $uid) {
					if (in_array($uid, $config['hidden_speakers']) || empty($data['speakers'][$uid])) {
						continue;
					}

					$name = $data['speakers'][$uid]['first_name'] . ' ' . $data['speakers'][$uid]['last_name'];
					$spk[] = '<a class="vt-p" href="#' . $name . '">' . $name . '</a>';
				}

				$speakers = implode (', ', $spk);
			}

			if ($microslots[$slot_index][0] < $now) {
				// talk has already started. Provide feedback links
				$fullfb = '<p align=right><strong><a href="https://cfp.openfest.org/events/' . $eid . '/feedback/new">'.pll__('Submit feedback').'</a></strong></p>';
				$progfb = '<p><i><a href="https://cfp.openfest.org/events/' . $eid . '/feedback/new">'.pll__('Submit feedback').'</a></i></p>';
			} else {
				$fullfb = "";
				$progfb = "";
			}
			$content = '<a href="#lecture-' . $eid . '">' . htmlspecialchars($title) . '</a><br>' . $speakers;

 			if (!isset($known_events[$eid])) {
 			//if (!in_array($data['events'][$event_info['event_id']]['track_id'], $config['hidden_language_tracks']) && !isset($known_events[$eid])) {
				$fulltalks .= '<section id="lecture-' . $eid . '">';

				// We don't want '()' when we don't have a speaker name
				$fulltalk_spkr = strlen($speakers) > 0 ? (' (' . $speakers . ')') : '';
				$fulltalks .= '<p><strong>' . htmlentities($event['title']) . ' ' . $fulltalk_spkr . '</strong></p>';
				$fulltalks .= '<p>' . htmlentities($event['abstract']) . '</p>';
				$fulltalks .= $fullfb;
				$fulltalks .= '<div class="separator"></div></section>';
				$known_events[$eid] = $eid;
			}

			if ($eid === $lastEventId) {
				array_pop($columns);
				++$colspan;
			}
			else {
				$colspan = 1;
			}

			$rowspan = array_key_exists('rowspan', $event_info) ? (' rowspan="' . $event_info['rowspan'] . '"') : '';

			// CSS
			$cssClasses = [];

			if (!in_array($event['track_id'], $config['hidden_language_tracks'])) {
				$cssClasses[] = 'schedule-' . $event['language'];
			}

			$cssClass = $data['tracks'][$event['track_id']]['css_class'];

			if (strlen($cssClass) > 0) {
				$cssClasses[] = $cssClass;
			}

			$cssClasses = count($cssClasses) > 0 ? (' class="' . implode(' ', $cssClasses) . '"') : '';

			// Render cell
			$columns[] = '<td' . ($colspan > 1 ? ' colspan="' . $colspan . '"' : $rowspan) . $cssClasses . '>' . $content . $progfb . '</td>';

			$lastEventId = $eid;
			unset($eid, $event);
		}

		$schedule_body .= '<tr><td>';
		$schedule_body .= date('H:i', $microslots[$slot_index][0]) . ' - ' . date('H:i', $microslots[$slot_index][1]);
		$schedule_body .= '</td>';
		$schedule_body .= implode('', $columns);
		$schedule_body .= '</tr>';
	}

	$schedule = '<table cellpadding="0" cellspacing="0" style="text-align: center;" class="schedule"><thead><tr><th></th>';

	foreach ($data['halls'] as $hall_id => $hall) {
		if (!in_array($hall_id, $hall_ids)) {
			continue;
		}

		$schedule .= '<th>' . $hall[$config['lang']] . '</th>';
	}

	$schedule .= '</tr></thead><tbody>';
	$schedule .= $schedule_body;
	$schedule .= '</tbody></table>';

	// Create the legend
	$legend = '';

	foreach($data['tracks'] as $track_id => $track) {
		if ( in_array($track_id, $config['hidden_language_tracks'])) {
			continue;
		}
		$legend .= '<tr><td class="' . $track['css_class'] . '">' . $track['name'][$config['lang']] . '</td></tr>';
	}

	foreach ($languages as $code => $lang) {
		$legend .= '<tr><td class="schedule-' . $code . '">' . $lang['name'] . '</td></tr>';
	}

	// Speaker list
	$gspk = '<div class="grid members">';
	$fspk = '';
	$types = [
		'twitter' => [
			'class' => 'twitter',
			'url' => 'https://twitter.com/',
		],
		'github' => [
			'class' => 'github',
			'url' => 'https://github.com/',
		],
		'email' => [
			'class' => 'envelope',
			'url' => 'mailto:',
		],
	];

	foreach ($data['speakers'] as $speaker) {
		$name = $speaker['first_name'] . ' ' . $speaker['last_name'];

		$gspk .= '<div class="member col4">';
		$gspk .= '<a href="#' . $name . '">';
		$gspk .= '<img width="100" height="100" src="' . $config['cfp_url'] . $speaker['picture']['schedule']['url'] . '" class="attachment-100x100 wp-post-image" alt="' . $name . '" />';
		$gspk .= '</a> </div>';

		$fspk .= '<div class="speaker" id="' . $name . '">';
		$fspk .= '<img width="100" height="100" src="' . $config['cfp_url'] . $speaker['picture']['schedule']['url'] . '" class="attachment-100x100 wp-post-image" alt="' . $name . '" />';
		$fspk .= '<h3>' . $name . '</h3>';
		$fspk .= '<div class="icons">';

		foreach ($types as $type => $param) {
			if (!empty($speaker[$type])) {
				$fspk .= '<a href="' . $param['url'] . $speaker[$type] . '"><i class="fa fa-' . $param['class'] . '"></i></a>';
			}
		}

		$fspk .= '</div>';
		$fspk .= '<p>' . htmlentities($speaker['biography']) . '</p>';
		$fspk .= '</div><div class="separator"></div>';
	}

	$gspk .= '</div>';

	return compact('slots', 'schedule', 'fulltalks', 'gspk', 'fspk', 'legend');
}