const express = require('express');
const app = express();
const path = require('path');
const SoundCloud = require('soundcloud-scraper');
const client = new SoundCloud.Client();
const fs = require('fs');
const PORT = process.env.PORT || 6767;

let tracks = []; // Store the tracks globally
const CACHE_FILE = path.join(__dirname, 'cache.json');

// Helper function to create a slug from track title
function generateSlug(title) {
    return title
        .toLowerCase() // Ensure lowercase
        .replace(/[^a-z0-9]+/g, '-') // Replace non-alphanumeric characters with hyphens
        .replace(/(^-|-$)/g, ''); // Remove leading and trailing hyphens
}

// Helper function to read the cache
function readCache() {
    if (fs.existsSync(CACHE_FILE)) {
        const data = fs.readFileSync(CACHE_FILE, 'utf8');
        return JSON.parse(data);
    }
    return null;
}

// Helper function to save cache
function saveCache(data) {
    fs.writeFileSync(CACHE_FILE, JSON.stringify(data), 'utf8');
}

// Fetch playlist tracks from SoundCloud
async function fetchPlaylist() {
    const playlist = await client.getPlaylist('https://soundcloud.com/snxraven/sets/raven-scott-metal');
    
    return playlist.tracks.map(track => {
        const slug = generateSlug(track.title); // Generate slug here
        return {
            title: track.title,
            description: track.description || 'No description available',
            url: track.url,
            playCount: track.playCount || 0,
            publishedAt: track.publishedAt || new Date().toISOString(),
            slug // Save the slug in the track object
        };
    });
}

// Get tracks from cache or SoundCloud
async function getTracks(fetch = false) {
    const cache = readCache();
    const oneWeekInMs = 7 * 24 * 60 * 60 * 1000; // One week in milliseconds
    const now = Date.now();

    if (fetch || !cache || (now - cache.timestamp) > oneWeekInMs) {
        // Fetch fresh tracks from SoundCloud
        tracks = await fetchPlaylist();
        saveCache({ tracks, timestamp: now });
    } else {
        // Load from cache
        tracks = cache.tracks;

        // Ensure slug generation in case it is missing from the cached data
        tracks = tracks.map(track => {
            if (!track.slug) {
                track.slug = generateSlug(track.title);
            }
            return track;
        });
    }

    // Sort by playCount first, then by publishedAt
    tracks.sort((a, b) => {
        if (b.playCount !== a.playCount) return b.playCount - a.playCount;
        return new Date(b.publishedAt) - new Date(a.publishedAt);
    });

    return tracks;
}

// Serve static files from public directory
app.use(express.static(path.join(__dirname, 'public')));

// Set EJS as templating engine
app.set('view engine', 'ejs');
app.set('views', path.join(__dirname, 'views'));

// Home page route
app.get('/', async (req, res) => {
    const allTracks = await getTracks();
    res.render('index', { tracks: allTracks });
});

// Individual track page route
app.get('/track/:slug', async (req, res) => {
    const allTracks = await getTracks();
    const track = allTracks.find(t => t.slug === req.params.slug);

    if (!track) {
        return res.status(404).send('Track not found');
    }

    res.render('track', { track });
});

// JSON endpoint to return cached tracks
app.get('/json', async (req, res) => {
    const allTracks = await getTracks();
    res.json(allTracks);
});

// Sitemap endpoint
app.get('/sitemap.xml', async (req, res) => {
    const allTracks = await getTracks();
    let sitemap = `<?xml version="1.0" encoding="UTF-8"?>\n`;
    sitemap += `<urlset xmlns="http://www.sitemaps.org/schemas/sitemap/0.9">\n`;

    // Home page
    sitemap += `<url>\n  <loc>https://raven-scott.rocks/</loc>\n  <priority>1.0</priority>\n</url>\n`;

    // Track pages
    allTracks.forEach(track => {
        sitemap += `<url>\n  <loc>https://raven-scott.rocks/track/${track.slug}</loc>\n  <priority>0.8</priority>\n</url>\n`;
    });

    sitemap += `</urlset>`;
    
    res.header('Content-Type', 'application/xml');
    res.send(sitemap);
});

// Listen on the specified port
app.listen(PORT, () => {
    console.log(`Server is running on port ${PORT}`);
});