vk music downloader (однопоточный)

m3u_content_downloader.php

<?php
# Download m3u with https://t.me/BeatSpotBot
ini_set('memory_limit', '1G').

$PATH_DOWNLOAD = './download';
$PLAYLIST_FILENAME = 'playlist.m3u8';
$EXIT_ON_DOUBLE = false;
$STRIP_SOURCE = true;
$STRIP_NAME = true;
$SKIP_DOWNLOAD_REPEAT = true;

if (!is_dir($PATH_DOWNLOAD) && !mkdir($PATH_DOWNLOAD, 0777, true) && !is_dir($PATH_DOWNLOAD)) {
    throw new \RuntimeException(sprintf('Directory "%s" was not created', $PATH_DOWNLOAD));
}

$tracks = preg_split(
    '~#EXTINF:\d+,~',
    preg_replace(
        '~^#EXTM3U\n~',
        '',
        file_get_contents($PLAYLIST_FILENAME)
    )
);

$prepared_tracks = [];
$error = 0;
$double = 0;
foreach ($tracks as $track) {
    if ($track === '') {
        continue;
    }
    $track_fields = explode("\n", trim($track));

    if (
        array_key_exists(2, $track_fields)
        || !array_key_exists(1, $track_fields)
        || !preg_match('~^https?://[^\s]+~', $track_fields[1])
        || !$track_fields[0]
    ) {
        echo 'ERROR: ';
        var_dump($track, $track_fields);
        ++$error;
    }
    list($name, $url) = $track_fields;
    $orig_name = $name;

    if ($STRIP_SOURCE) {
        $name = preg_replace('~\[(\s*(OST|ост|Remix|feat|\d{2})[^\]\[]*)\]~iu', '($1)', $name);
        $name = preg_replace('~\[[^\]\[]*\]~', '', $name);
    }

    if ($STRIP_NAME) {
        $name = preg_replace('~[^a-z0-9а-яёЁ\-\(\)\.!`\'$&,#+]+~iu', ' ', $name);
        $name = preg_replace('~\s+\)~iu', ')', $name);
        $name = preg_replace('~\(\s+~iu', '(', $name);
        $name = mb_substr($name, 0, 250);
    }
    $name = trim($name);

    $key = strtolower($name);
    if (
        !empty($prepared_tracks[$key])
        && $prepared_tracks[$key]['url'] !== $url
    ) {
        echo "DOUBLE: {$name}\n";
        ++$double;
    } else {
        $prepared_tracks[$key] = [
            'name' => $name,
            'url' => $url,
            'orig_name' => $orig_name,
        ];
    }
}

if (
    $error
    || ($EXIT_ON_DOUBLE && $double)
) {
    exit;
}
unset($tracks);

foreach ($prepared_tracks as $track) {
    $filename = "{$PATH_DOWNLOAD}/{$track['name']}.mp3";
    if (!$SKIP_DOWNLOAD_REPEAT || !file_exists($filename) || !filesize($filename)) {
        file_put_contents(
            $filename,
            file_get_contents($track['url'])
        );
        echo '.';
    } else {
        echo '-';
    }
}