<?php
/**
 * MyAnythingList Care TV Playlist Generator
 * v003
 *
 * Run locally:
 *   php generate.php
 *
 * Example cron line, with slash escaped to avoid closing this PHP comment:
 *   *\/30 * * * * /usr/bin/php /path/to/generate.php >> /path/to/logs/cron.log 2>&1
 */
$config = require __DIR__ . '/config.php';

foreach (['output_dir','public_playlist_dir','cache_dir','log_dir'] as $k) {
    if (!is_dir($config[$k])) mkdir($config[$k], 0775, true);
}

function log_line($message, $data = null) {
    global $config;
    $line = '[' . date('c') . '] ' . $message;
    if ($data !== null) $line .= ' ' . json_encode($data, JSON_UNESCAPED_SLASHES | JSON_UNESCAPED_UNICODE);
    $line .= PHP_EOL;
    file_put_contents($config['log_dir'] . '/generate.log', $line, FILE_APPEND);
    echo $line;
}

function http_get($url, $ttl_seconds = 600) {
    global $config;
    $cache_file = $config['cache_dir'] . '/' . sha1($url) . '.cache';
    if (file_exists($cache_file) && (time() - filemtime($cache_file) < $ttl_seconds)) {
        return file_get_contents($cache_file);
    }
    $context = stream_context_create(['http' => [
        'method' => 'GET',
        'header' => "User-Agent: " . $config['user_agent'] . "\r\n",
        'timeout' => 20
    ]]);
    $body = @file_get_contents($url, false, $context);
    if ($body !== false && strlen($body) > 0) {
        file_put_contents($cache_file, $body);
        return $body;
    }
    return file_exists($cache_file) ? file_get_contents($cache_file) : false;
}

function normalize_handle($handle) {
    $handle = trim((string)$handle);
    $handle = preg_replace('#^https?://(www\.)?youtube\.com/#i', '', $handle);
    $handle = trim($handle, "/ \t\r\n");
    if ($handle === '') return '';
    if ($handle[0] !== '@' && !preg_match('#^(channel|c|user)/#i', $handle)) $handle = '@' . $handle;
    return $handle;
}

function resolve_channel_id($tile) {
    global $config;
    if (!empty($tile['channel_id'])) return $tile['channel_id'];

    $handle = normalize_handle($tile['channel_handle'] ?? $tile['handle'] ?? '');
    if (!$handle) return '';

    $id_cache = $config['cache_dir'] . '/channel_' . sha1($handle) . '.id';
    if (file_exists($id_cache)) {
        $id = trim(file_get_contents($id_cache));
        if (preg_match('/^UC[0-9A-Za-z_-]+$/', $id)) return $id;
    }

    $html = http_get('https://www.youtube.com/' . $handle, 86400);
    if (!$html) return '';

    foreach ([
        '/"channelId":"(UC[0-9A-Za-z_-]+)"/',
        '/"externalId":"(UC[0-9A-Za-z_-]+)"/',
        '/<meta itemprop="channelId" content="(UC[0-9A-Za-z_-]+)"/',
        '#feeds/videos\.xml\?channel_id=(UC[0-9A-Za-z_-]+)#'
    ] as $p) {
        if (preg_match($p, $html, $m)) {
            file_put_contents($id_cache, $m[1]);
            return $m[1];
        }
    }

    log_line('Could not resolve channel ID', ['handle' => $handle]);
    return '';
}

function parse_youtube_rss($xml_string) {
    $items = [];
    if (!$xml_string) return $items;
    libxml_use_internal_errors(true);
    $xml = simplexml_load_string($xml_string);
    if (!$xml) return $items;
    $ns = $xml->getNamespaces(true);

    foreach ($xml->entry as $entry) {
        $yt = $entry->children($ns['yt'] ?? 'http://www.youtube.com/xml/schemas/2015');
        $media = $entry->children($ns['media'] ?? 'http://search.yahoo.com/mrss/');
        $video_id = (string)($yt->videoId ?? '');
        if (!$video_id) continue;
        $desc = '';
        if (isset($media->group)) {
            $mg = $media->group->children($ns['media'] ?? 'http://search.yahoo.com/mrss/');
            $desc = (string)($mg->description ?? '');
        }
        $items[] = [
            'video_id' => $video_id,
            'title' => (string)($entry->title ?? ''),
            'published' => (string)($entry->published ?? ''),
            'url' => 'https://www.youtube.com/watch?v=' . $video_id,
            'description' => $desc
        ];
    }
    usort($items, fn($a, $b) => strcmp($b['published'], $a['published']));
    return $items;
}

function fetch_channel_items($tile) {
    global $config;
    $channel_id = resolve_channel_id($tile);
    if (!$channel_id) {
        log_line('Missing channel for tile', ['label' => $tile['label'] ?? '', 'tile' => $tile]);
        return [];
    }
    $xml = http_get('https://www.youtube.com/feeds/videos.xml?channel_id=' . rawurlencode($channel_id), 600);
    return array_slice(parse_youtube_rss($xml), 0, $config['max_items_per_feed']);
}

function fetch_playlist_items($playlist_id) {
    global $config;
    $playlist_id = trim((string)$playlist_id);
    if (!$playlist_id || empty($config['youtube_api_key'])) return [];
    $url = 'https://www.googleapis.com/youtube/v3/playlistItems?part=snippet&maxResults=25&playlistId=' .
        rawurlencode($playlist_id) . '&key=' . rawurlencode($config['youtube_api_key']);
    $json = http_get($url, 600);
    $data = json_decode($json, true);
    $items = [];
    foreach (($data['items'] ?? []) as $it) {
        $s = $it['snippet'] ?? [];
        $vid = $s['resourceId']['videoId'] ?? '';
        if ($vid) $items[] = [
            'video_id' => $vid,
            'title' => $s['title'] ?? '',
            'published' => $s['publishedAt'] ?? '',
            'url' => 'https://www.youtube.com/watch?v=' . $vid,
            'description' => $s['description'] ?? ''
        ];
    }
    usort($items, fn($a,$b) => strcmp($b['published'], $a['published']));
    return $items;
}

function contains_terms($text, $terms, $mode = 'any') {
    $terms = array_values(array_filter(array_map('trim', (array)$terms)));
    if (!$terms) return true;
    $text = mb_strtolower((string)$text);
    $hits = 0;
    foreach ($terms as $term) {
        if (mb_strpos($text, mb_strtolower($term)) !== false) $hits++;
    }
    return $mode === 'all' ? $hits === count($terms) : $hits > 0;
}

function is_excluded($text, $terms) {
    $text = mb_strtolower((string)$text);
    foreach ((array)$terms as $term) {
        $term = mb_strtolower(trim((string)$term));
        if ($term !== '' && mb_strpos($text, $term) !== false) return true;
    }
    return false;
}

function filter_items($items, $tile) {
    global $config;
    $include = $tile['include'] ?? [];
    $include_mode = $tile['include_mode'] ?? 'any';
    $exclude = array_merge($config['default_exclude'] ?? [], $tile['exclude'] ?? []);
    $out = [];
    foreach ($items as $it) {
        $hay = ($it['title'] ?? '') . ' ' . ($it['description'] ?? '');
        if (!contains_terms($hay, $include, $include_mode)) continue;
        if (is_excluded($hay, $exclude)) continue;
        $out[] = $it;
    }
    return $out;
}

function public_playlist_path($filename) {
    global $config;
    return rtrim($config['public_playlist_path_prefix'], '/') . '/' . rawurlencode($filename);
}

function app_url_for_playlist($playlist_path) {
    global $config;
    return $config['myanythinglist_app_url'] . '?MyAnythingList=' . rawurlencode($playlist_path);
}

function resolve_tile_url($tile) {
    $mode = $tile['mode'] ?? 'static_url';

    if ($mode === 'specific_video') {
        $id = trim((string)($tile['video_id'] ?? ''));
        return $id ? 'https://www.youtube.com/watch?v=' . $id : ($tile['fallback'] ?? '');
    }

    if ($mode === 'latest_channel_video' || $mode === 'latest_matching_video') {
        $items = filter_items(fetch_channel_items($tile), $tile);
        return $items[0]['url'] ?? ($tile['fallback'] ?? '');
    }

    if ($mode === 'latest_playlist_item') {
        $items = filter_items(fetch_playlist_items($tile['playlist_id'] ?? ''), $tile);
        return $items[0]['url'] ?? (!empty($tile['playlist_id']) ? 'https://www.youtube.com/playlist?list=' . rawurlencode($tile['playlist_id']) : ($tile['fallback'] ?? ''));
    }

    if ($mode === 'latest_matching_across_channels' || $mode === 'latest_from_channel_list') {
        $all = [];
        foreach (($tile['channels'] ?? []) as $ch) {
            $ch_tile = array_merge($tile, $ch);
            foreach (filter_items(fetch_channel_items($ch_tile), $ch_tile) as $it) $all[] = $it;
        }
        usort($all, fn($a,$b) => strcmp($b['published'], $a['published']));
        return $all[0]['url'] ?? ($tile['fallback'] ?? '');
    }

    if ($mode === 'channel_home') {
        if (!empty($tile['channel_handle'])) return 'https://www.youtube.com/' . normalize_handle($tile['channel_handle']);
        if (!empty($tile['handle'])) return 'https://www.youtube.com/' . normalize_handle($tile['handle']);
        if (!empty($tile['channel_id'])) return 'https://www.youtube.com/channel/' . $tile['channel_id'];
        return $tile['fallback'] ?? '';
    }

    if ($mode === 'playlist_home') {
        return !empty($tile['playlist_id']) ? 'https://www.youtube.com/playlist?list=' . rawurlencode($tile['playlist_id']) : ($tile['url'] ?? '');
    }

    if ($mode === 'subgrid') {
        $file = $tile['playlist_file'] ?? '';
        return $file ? app_url_for_playlist(public_playlist_path($file)) : ($tile['url'] ?? '');
    }

    return $tile['url'] ?? $tile['fallback'] ?? '';
}

function slugify($text) {
    $slug = preg_replace('/[^a-z0-9]+/i', '-', strtolower((string)$text));
    $slug = trim($slug, '-');
    return $slug ?: 'playlist';
}

function make_channel_subgrid_rule($tile, $parent_title) {
    $playlist_file = 'subgrid-' . slugify($tile['label'] ?? 'channel') . '.txt';

    return [
        'title' => ($tile['subgrid_title'] ?? (($tile['label'] ?? 'Channel') . ' — Latest 10 Videos')),
        'output_file' => $playlist_file,
        'grid' => intval($tile['subgrid_grid'] ?? 2),
        'show_qr' => false,
        'show_urls' => false,
        'footer' => 'Automatically generated channel sub-grid from ' . $parent_title . '.',
        'tiles' => [[
            'label' => $tile['label'] ?? 'Channel',
            'mode' => 'latest_channel_many',
            'channel_id' => $tile['channel_id'] ?? '',
            'channel_handle' => $tile['channel_handle'] ?? ($tile['handle'] ?? ''),
            'exclude' => $tile['exclude'] ?? [],
            'limit' => intval($tile['limit'] ?? 10)
        ]]
    ];
}

function write_playlist_from_rules($rules) {
    global $config;

    $title = $rules['title'] ?? 'MyAnythingList Playlist';
    $output_file = $rules['output_file'] ?? 'playlist.txt';
    $lines = [
        '#_GRID=' . intval($rules['grid'] ?? 3),
        '#_ShowQR=' . (!empty($rules['show_qr']) ? 'true' : 'false'),
        '#_ShowURLs=' . (!empty($rules['show_urls']) ? 'true' : 'false'),
        '#_HeaderText=' . $title
    ];
    if (!empty($rules['footer'])) $lines[] = '#_FooterText=' . $rules['footer'];
    if (!empty($rules['resolution'])) $lines[] = '#_Resolution=' . $rules['resolution'];
    if (!empty($rules['aspect_ratio'])) $lines[] = '#_Aspect_Ratio=' . $rules['aspect_ratio'];
    $lines[] = '';

    $seen = [];
    $selected = [];

    foreach (($rules['tiles'] ?? []) as $tile) {
        if (($tile['mode'] ?? '') === 'latest_channel_many') {
            $items = filter_items(fetch_channel_items($tile), $tile);
            $limit = intval($tile['limit'] ?? 10);
            foreach (array_slice($items, 0, $limit) as $it) {
                $url = $it['url'];
                if (!isset($seen[$url])) {
                    $seen[$url] = true;
                    $lines[] = $url;
                    $selected[] = ['label' => $tile['label'] ?? '', 'mode' => 'latest_channel_many', 'title' => $it['title'] ?? '', 'url' => $url];
                }
            }
            continue;
        }

        if (($tile['mode'] ?? '') === 'channel_subgrid') {
            $sub_rules = make_channel_subgrid_rule($tile, $title);
            write_playlist_from_rules($sub_rules);
            $tile = [
                'label' => $tile['label'] ?? 'Channel Subgrid',
                'mode' => 'subgrid',
                'playlist_file' => $sub_rules['output_file']
            ];
        }

        $url = trim((string)resolve_tile_url($tile));
        if (!$url || isset($seen[$url])) continue;
        $seen[$url] = true;
        $lines[] = $url;
        $selected[] = ['label' => $tile['label'] ?? '', 'mode' => $tile['mode'] ?? '', 'url' => $url];
    }

    $content = implode(PHP_EOL, $lines) . PHP_EOL;

    $paths = [
        rtrim($config['output_dir'], '/') . '/' . $output_file,
        rtrim($config['public_playlist_dir'], '/') . '/' . $output_file
    ];

    foreach ($paths as $path) {
        file_put_contents($path, $content);
    }

    log_line('Generated playlist', ['file' => $output_file, 'count' => count($selected), 'selected' => $selected]);
}

$files = glob(__DIR__ . '/rules/*.json');
sort($files);
foreach ($files as $file) {
    $rules = json_decode(file_get_contents($file), true);
    if (!$rules) {
        log_line('Invalid rule file', ['file' => $file]);
        continue;
    }
    write_playlist_from_rules($rules);
}
log_line('Done');