require('dotenv').config();
const express = require('express');
const axios = require('axios');

const app = express();
const port = process.env.PORT || 3000;

// Parse channels from .env
// Expected format: CHANNELS=id1:Name1,id2:Name2
const parseChannels = () => {
    const channelsString = process.env.CHANNELS || '';
    if (!channelsString) return [];
    
    return channelsString.split(',').map(ch => {
        const [id, ...nameParts] = ch.split(':');
        return { id: id.trim(), name: nameParts.join(':').trim() };
    }).filter(ch => ch.id && ch.name);
};

app.get('/playlist.m3u', (req, res) => {
    const channels = parseChannels();
    const host = req.get('host');
    const protocol = req.protocol;
    
    let m3u = "#EXTM3U\n";
    
    channels.forEach(ch => {
        m3u += `#EXTINF:-1 tvg-id="${ch.id}" tvg-name="${ch.name}" group-title="Chzzk",${ch.name}\n`;
        m3u += `${protocol}://${host}/stream/${ch.id}\n`;
    });
    
    res.header('Content-Type', 'application/vnd.apple.mpegurl');
    res.send(m3u);
});

app.get('/stream/:channelId', async (req, res) => {
    const { channelId } = req.params;
    
    try {
        const headers = {
            'User-Agent': 'Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/120.0.0.0 Safari/537.36'
        };

        const cookies = [];
        if (process.env.NID_AUT) cookies.push(`NID_AUT=${process.env.NID_AUT}`);
        if (process.env.NID_SES) cookies.push(`NID_SES=${process.env.NID_SES}`);
        if (cookies.length > 0) {
            headers['Cookie'] = cookies.join('; ');
        }

        const response = await axios.get(`https://api.chzzk.naver.com/service/v3/channels/${channelId}/live-detail`, {
            headers
        });
        
        const data = response.data;
        const content = data && data.content;
        const playbackJsonString = content && (content.livePlaybackJson || content.previewPlaybackJson);

        if (!playbackJsonString) {
            return res.status(404).send('Stream not found, offline, or region blocked');
        }
        
        const livePlayback = JSON.parse(playbackJsonString);
        const media = livePlayback.media || [];
        
        // Find HLS or LLHLS stream
        const hlsMedia = media.find(m => m.mediaId === 'HLS' || m.mediaId === 'LLHLS');
        
        if (hlsMedia && hlsMedia.path) {
            // Redirect Jellyfin to our proxy endpoint to intercept keys
            const host = req.get('host');
            const protocol = req.protocol;
            res.redirect(302, `${protocol}://${host}/m3u8?url=${encodeURIComponent(hlsMedia.path)}`);
        } else {
            res.status(404).send('HLS stream not found in playback info');
        }
    } catch (error) {
        console.error(`Error fetching stream for channel ${channelId}:`, error.message);
        res.status(500).send('Error fetching stream from Chzzk API');
    }
});

app.get('/m3u8', async (req, res) => {
    const m3u8Url = req.query.url;
    if (!m3u8Url) return res.status(400).send('Missing url parameter');

    try {
        const response = await axios.get(m3u8Url);
        let m3u8Data = response.data;
        const host = req.get('host');
        const protocol = req.protocol;
        const baseUrl = `${protocol}://${host}`;

        // Process m3u8 lines
        const lines = m3u8Data.split('\n');
        const processedLines = lines.map(line => {
            let processed = line.trim();
            if (!processed) return processed;

            // Rewrite AES Key URIs to use our proxy
            if (processed.startsWith('#EXT-X-KEY:')) {
                processed = processed.replace(/URI="(https?:\/\/[^"]+)"/, (match, keyUrl) => {
                    return `URI="${baseUrl}/key?url=${encodeURIComponent(keyUrl)}"`;
                });
                return processed;
            }

            // If it's a tag with a URI (like #EXT-X-MEDIA:URI="..."), make it absolute and proxy it if it's an m3u8
            if (processed.startsWith('#EXT-X-MEDIA:') && processed.includes('URI=')) {
                processed = processed.replace(/URI="(.*?)"/, (match, uri) => {
                    if (uri && !uri.startsWith('http')) {
                        uri = new URL(uri, m3u8Url).toString();
                    }
                    if (uri.includes('.m3u8')) {
                        uri = `${baseUrl}/m3u8?url=${encodeURIComponent(uri)}`;
                    }
                    return `URI="${uri}"`;
                });
                return processed;
            }

            // If it's a URL (variant playlist or segment)
            if (!processed.startsWith('#')) {
                let uri = processed;
                if (!uri.startsWith('http')) {
                    uri = new URL(uri, m3u8Url).toString();
                }
                // If it's a variant playlist, proxy it
                if (uri.includes('.m3u8')) {
                    uri = `${baseUrl}/m3u8?url=${encodeURIComponent(uri)}`;
                }
                return uri;
            }

            return processed;
        });

        res.header('Content-Type', 'application/vnd.apple.mpegurl');
        res.send(processedLines.join('\n'));
    } catch (error) {
        console.error(`Error proxying m3u8: ${error.message}`);
        res.status(500).send('Error proxying m3u8');
    }
});

app.get('/key', async (req, res) => {
    const keyUrl = req.query.url;
    if (!keyUrl) return res.status(400).send('Missing url parameter');

    try {
        const headers = {
            'User-Agent': 'Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/120.0.0.0 Safari/537.36'
        };

        const cookies = [];
        if (process.env.NID_AUT) cookies.push(`NID_AUT=${process.env.NID_AUT}`);
        if (process.env.NID_SES) cookies.push(`NID_SES=${process.env.NID_SES}`);
        if (cookies.length > 0) {
            headers['Cookie'] = cookies.join('; ');
        }

        const response = await axios.get(keyUrl, { headers, responseType: 'arraybuffer' });
        res.header('Content-Type', 'application/octet-stream');
        res.send(response.data);
    } catch (error) {
        console.error(`Error fetching key: ${error.message}`);
        res.status(500).send('Error fetching key');
    }
});

app.listen(port, () => {
    console.log(`Chzzk IPTV Proxy running on port ${port}`);
    console.log(`Playlist URL: http://localhost:${port}/playlist.m3u`);
});