<?php
/**
 * api/artwork.php
 * ---------------
 * Optional album-art lookup. The browser calls this only when the stream
 * provider itself did not supply artwork and ARTWORK_SOURCE allows a lookup.
 * Tries Genius first, then Last.fm (whichever have keys configured). Returns:
 *
 *   { "art": "https://…" | "", "album": "…", "url": "…" }
 *
 * With nothing configured it returns empty fields and the front-end falls back
 * to the placeholder image.
 */

require_once __DIR__ . '/_bootstrap.php';

$empty = ['art' => '', 'album' => '', 'url' => ''];

$source = cfg('artwork.source');
if ($source === 'none' || $source === 'provider') {
    json_out($empty);
}

[$artist, $title] = request_track();
if ($artist === '' && $title === '') {
    json_out($empty);
}

/* -- Operator-defined overrides (config/overrides.json) -------------------- */
$overridesFile = __DIR__ . '/../config/overrides.json';
if (is_file($overridesFile)) {
    $ov = json_decode((string) file_get_contents($overridesFile), true);
    foreach (($ov['artwork'] ?? []) as $rule) {
        $ra = $rule['artist'] ?? null;
        $rt = $rule['title']  ?? null;
        $artistMatch = ($ra === null || strcasecmp($ra, $artist) === 0);
        $titleMatch  = ($rt === null || strcasecmp($rt, $title)  === 0);
        if ($artistMatch && $titleMatch && !empty($rule['art'])) {
            json_out(['art' => $rule['art'], 'album' => ($rule['album'] ?? ''), 'url' => '']);
        }
    }
}

/* -- Genius --------------------------------------------------------------- */
function genius_artwork($artist, $title) {
    $token = cfg('genius.token');
    if ($token === '') return null;
    $headers = ['Authorization: Bearer ' . $token];

    $query  = rawurlencode(trim($artist . ' - ' . $title, ' -'));
    $search = http_get('https://api.genius.com/search?q=' . $query, 5, $headers);
    if ($search === null) return null;

    $hit = dot_get(json_decode($search, true), 'response.hits.0.result', null);
    if (!$hit) return null;

    $out = [
        'art'   => (string) ($hit['song_art_image_url'] ?? $hit['header_image_url'] ?? ''),
        'album' => '',
        'url'   => (string) ($hit['url'] ?? ''),
    ];
    if (!empty($hit['id'])) {
        $songRaw = http_get('https://api.genius.com/songs/' . rawurlencode((string) $hit['id']), 5, $headers);
        if ($songRaw !== null) {
            $s = dot_get(json_decode($songRaw, true), 'response.song', null);
            if ($s) {
                $out['album'] = (string) dot_get($s, 'album.name', '');
                $better = (string) ($s['song_art_image_url'] ?? $s['header_image_url'] ?? '');
                if ($better !== '') $out['art'] = $better;
            }
        }
    }
    // Genius' generic default cover counts as "no art".
    if (strpos($out['art'], 'default_cover_image') !== false) $out['art'] = '';
    return ($out['art'] === '' && $out['album'] === '') ? null : $out;
}

/* -- Last.fm -------------------------------------------------------------- */
function lastfm_artwork($artist, $title) {
    $key = cfg('artwork.lastfm_key');
    if ($key === '' || $artist === '') return null;

    $url = 'https://ws.audioscrobbler.com/2.0/?method=track.getInfo&format=json&autocorrect=1'
         . '&api_key=' . rawurlencode($key)
         . '&artist=' . rawurlencode($artist)
         . '&track='  . rawurlencode($title);
    $raw = http_get($url, 5);
    if ($raw === null) return null;

    $data = json_decode($raw, true);
    $images = dot_get($data, 'track.album.image', []);
    $art = '';
    if (is_array($images)) {
        foreach ($images as $img) {                 // last non-empty = largest
            if (!empty($img['#text'])) $art = $img['#text'];
        }
    }
    if ($art === '') return null;
    return ['art' => $art, 'album' => (string) dot_get($data, 'track.album.title', ''), 'url' => ''];
}

/* -- Try providers in the configured order -------------------------------- */
$order = $source === 'lastfm' ? ['lastfm']
       : ($source === 'genius' ? ['genius'] : ['genius', 'lastfm']);

$album = '';
foreach ($order as $provider) {
    $res = ($provider === 'genius') ? genius_artwork($artist, $title) : lastfm_artwork($artist, $title);
    if ($res === null) continue;
    if ($album === '' && $res['album'] !== '') $album = $res['album'];
    if ($res['art'] !== '') {
        $res['album'] = $res['album'] ?: $album;
        json_out($res);
    }
}

json_out(['art' => '', 'album' => $album, 'url' => '']);