<?php
define('FNP_API_KEY', __DIR__ . '/../.apikey');
define('FNP_API_URL', 'https://ws.audioscrobbler.com');
define('FNP_ORIGINS', __DIR__ . '/../.cors');

define('FNP_FMT_JSON', 'json');
define('FNP_FMT_XML',  'xml');
define('FNP_FMTS', [
    FNP_FMT_JSON => 'application/json',
    FNP_FMT_XML  => 'application/xml',
]);

if(!empty($_SERVER['HTTP_ORIGIN']) && is_file(FNP_ORIGINS)) {
    $origin = parse_url($_SERVER['HTTP_ORIGIN'], PHP_URL_HOST);
    $allowedOrigins = file(FNP_ORIGINS, FILE_IGNORE_NEW_LINES | FILE_SKIP_EMPTY_LINES);

    if(in_array($origin, $allowedOrigins)) {
        header('Access-Control-Allow-Origin: ' . $_SERVER['HTTP_ORIGIN']);
        header('Vary: Origin');
    }
}

if(!isset($format))
    $format = (string)(filter_input(INPUT_GET, 'f') ?? 'json');
$pretty = !empty($_GET['p']);

if($format !== 'json' && $format !== 'xml') {
    http_response_code(400);
    return;
}

$charset = preg_match('#MSIE#i', $_SERVER['HTTP_USER_AGENT'] ?? '') ? '' : 'utf-8';

header('Content-Type: ' . FNP_FMTS[$format] . (empty($charset) ? '' : ('; charset=' . $charset)));

function errorResponse(string $text, int $code = -1): void {
    global $format, $charset;

    http_response_code(500);

    switch($format) {
        case FNP_FMT_JSON:
            echo json_encode(['error' => $text, 'code' => $code]);
            break;

        // Has strange formatting, but XML mode exists for backwards compatibility with an unreleased variation of get.php.
        case FNP_FMT_XML:
            $document = new DOMDocument('1.0', $charset);
            $tracks = $document->appendChild($document->createElement('Tracks'));
            $track = $tracks->appendChild($document->createElement('Track'));
            $track->setAttribute('error', $text);
            $track->setAttribute('code', $code);
            echo $document->saveXML();
            break;
    }

    exit;
}

if(!is_file(FNP_API_KEY))
    errorResponse('API key file missing! Create a file called ".apikey" in the root directory and place your last.fm api key in there.');

$apiKey = trim(file_get_contents(FNP_API_KEY));
$userName = (string)filter_input(INPUT_GET, 'u', FILTER_SANITIZE_STRING);

$curl = curl_init(FNP_API_URL . '/2.0/?method=user.getrecenttracks&format=json&limit=1&api_key=' . $apiKey . '&user=' . rawurlencode($userName));
curl_setopt_array($curl, [
    CURLOPT_AUTOREFERER => false,
    CURLOPT_COOKIESESSION => false,
    CURLOPT_VERBOSE => false,
    CURLOPT_FAILONERROR => false,
    CURLOPT_FOLLOWLOCATION => false,
    CURLOPT_TCP_NODELAY => true,
    CURLOPT_HEADER => false,
    CURLOPT_RETURNTRANSFER => true,
    CURLOPT_TCP_FASTOPEN => true,
    CURLOPT_VERBOSE => false,
    CURLOPT_CONNECTTIMEOUT => 2,
    CURLOPT_PROTOCOLS => CURLPROTO_HTTP | CURLPROTO_HTTPS,
    CURLOPT_TIMEOUT => 2,
    CURLOPT_USERAGENT => 'NowListening v2 (' . $_SERVER['HTTP_HOST'] . ')',
]);
$response = json_decode(curl_exec($curl));
curl_close($curl);

if($response === null)
    errorResponse('API request failed.');
if(isset($response->message))
    errorResponse($response->message, $response->error ?? -1);

switch($format) {
    case FNP_FMT_JSON:
        $tracks = [];

        if(!empty($response->recenttracks?->track))
            foreach($response->recenttracks->track as $recentTrack) {
                $tracks[] = $track = new stdClass;
                $track->name = $recentTrack->name;
                if(!empty($recentTrack->{"@attr"}?->nowplaying))
                    $track->nowplaying = true;
                $track->mbid = $recentTrack->mbid;
                $track->url = $recentTrack->url;
                $track->date = $recentTrack->date?->uts ?? '';
                $track->streamable = $recentTrack->streamable;

                $track->artist = new stdClass;
                $track->artist->name = $recentTrack->artist?->{"#text"} ?? '';
                $track->artist->mbid = $recentTrack->artist?->mbid ?? '';
                $track->artist->url = explode('/_/', $track->url, 2)[0];

                $track->album = new stdClass;
                $track->album->name = $recentTrack->album?->{"#text"};
                $track->album->mbid = $recentTrack->album?->mbid ?? '';

                $track->images = new stdClass;
                foreach($recentTrack->image as $trackImage)
                    $track->images->{$trackImage->size} = $trackImage->{"#text"};
            }

        echo json_encode($tracks, $pretty ? JSON_PRETTY_PRINT : 0);
        break;

    case FNP_FMT_XML:
        $document = new DOMDocument('1.0', $charset);
        $document->formatOutput = $pretty;
        $tracks = $document->appendChild($document->createElement('Tracks'));

        if(!empty($response->recenttracks?->track))
            foreach($response->recenttracks->track as $recentTrack) {
                $elem = $tracks->appendChild($document->createElement('Track'));

                $elem->appendChild($document->createElement('Name', htmlspecialchars($recentTrack->name)));
                $elem->appendChild($document->createElement('Mbid', $recentTrack->mbid));
                $elem->appendChild($document->createElement('Url', htmlspecialchars($recentTrack->url)));
                $elem->appendChild($document->createElement('Date', empty($recentTrack->date?->uts) ? '' : date('c', $recentTrack->date->uts)));
                $elem->appendChild($document->createElement('Streamable', empty($recentTrack->streamable) ? '0' : '1'));
                $elem->appendChild($document->createElement('IsPlaying', empty($recentTrack->{"@attr"}?->nowplaying) ? '0' : '1'));

                $artist = $elem->appendChild($document->createElement('Artist'));
                $artist->appendChild($document->createElement('Name', htmlspecialchars($recentTrack->artist?->{"#text"} ?? '')));
                $artist->appendChild($document->createElement('Mbid', $recentTrack->artist?->mbid ?? ''));

                $album = $elem->appendChild($document->createElement('Album'));
                $album->appendChild($document->createElement('Name', htmlspecialchars($recentTrack->album?->{"#text"} ?? '')));
                $album->appendChild($document->createElement('Mbid', $recentTrack->album?->mbid ?? ''));

                $images = $elem->appendChild($document->createElement('Images'));
                foreach($recentTrack->image as $trackImage) {
                    $name = $trackImage->size;
                    if($name === 'extralarge')
                        $name = 'ExtraLarge';
                    else
                        $name = ucfirst($name);
                    $images->appendChild($document->createElement($name, htmlspecialchars($trackImage->{"#text"})));
                }
            }

        echo $document->saveXML();
        break;
}