// Resolve playlist files (.pls / .m3u) to a direct stream URL.
// HLS (.m3u8) is left as-is so hls.js can fetch it.

export function detectFormatFromUrl(url) {
    const u = url.toLowerCase().split('?')[0];
    if (u.endsWith('.m3u8')) return 'hls';
    if (u.endsWith('.m3u')) return 'm3u';
    if (u.endsWith('.pls')) return 'pls';
    if (u.endsWith('.aac')) return 'aac';
    if (u.endsWith('.mp3')) return 'mp3';
    if (u.endsWith('.ogg') || u.endsWith('.opus')) return 'ogg';
    return 'unknown';
}

function parsePls(text) {
    const m = text.match(/^File\d+\s*=\s*(.+)$/im);
    return m ? m[1].trim() : null;
}

function parseM3u(text) {
    const lines = text.split(/\r?\n/).map((l) => l.trim()).filter(Boolean);
    return lines.find((l) => !l.startsWith('#')) || null;
}

export async function resolveStream({ url, format }) {
    const fmt = format && format !== 'unknown' ? format : detectFormatFromUrl(url);
    if (fmt === 'pls' || fmt === 'm3u') {
        try {
            const res = await fetch(url, { redirect: 'follow' });
            if (!res.ok) throw new Error(`HTTP ${res.status}`);
            const text = await res.text();
            const direct = fmt === 'pls' ? parsePls(text) : parseM3u(text);
            if (!direct) throw new Error('No direct URL found in playlist');
            return { url: direct, format: detectFormatFromUrl(direct) };
        } catch (err) {
            return { url, format: fmt, error: String(err.message || err) };
        }
    }
    return { url, format: fmt };
}