const axios = require('axios');
const crypto = require('crypto');

async function savetube(url, format = '720') {
    try {
        if (!/^https?:\/\//i.test(url)) throw new Error('Invalid URL.');
        
        const id = [
            /youtube\.com\/watch\?v=([a-zA-Z0-9_-]{11})/,
            /youtube\.com\/embed\/([a-zA-Z0-9_-]{11})/,
            /youtube\.com\/v\/([a-zA-Z0-9_-]{11})/,
            /youtube\.com\/shorts\/([a-zA-Z0-9_-]{11})/,
            /youtu\.be\/([a-zA-Z0-9_-]{11})/
        ].find(p => p.test(url))?.[Symbol.match](url)?.[1];
        
        if (!id) throw new Error('Failed to extract link.');
        if (!['144', '240', '360', '480', '720', '1080', 'mp3'].includes(format)) throw new Error('Available formats: 144, 240, 360, 480, 720, 1080, mp3.');
    
        const api = axios.create({
            headers: {
                'content-type': 'application/json',
                'origin': 'https://yt.savetube.me',
                'user-agent': 'Mozilla/5.0 (Linux; Android 15; SM-F958 Build/AP3A.240905.015) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/130.0.6723.86 Mobile Safari/537.36'
            }
        });
        
        const { data: { cdn } } = await api.get('https://media.savetube.vip/api/random-cdn');
        const { data: { data: encryptedData } } = await api.post(`https://${cdn}/v2/info`, {
            url: `https://www.youtube.com/watch?v=${id}`
        });
        
        const encrypted = Buffer.from(encryptedData, 'base64');
        const decipher = crypto.createDecipheriv('aes-128-cbc', Buffer.from('C5D58EF67A7584E4A29F6C35BBC4EB12', 'hex'), encrypted.slice(0, 16));
        const decrypted = JSON.parse(Buffer.concat([decipher.update(encrypted.slice(16)), decipher.final()]).toString());
        
        const { data: { data: { downloadUrl } } } = await api.post(`https://${cdn}/download`, {
            id,
            downloadType: format === 'mp3' ? 'audio' : 'video',
            quality: format === 'mp3' ? '128' : format,
            key: decrypted.key
        });
    
        return {
            title: decrypted.title || null,
            type: format === 'mp3' ? 'audio' : 'video',
            quality: format === 'mp3' ? '128' : format,
            duration: `${Math.floor(decrypted.duration/60).toString().padStart(2,'0')}:${(decrypted.duration%60).toString().padStart(2,'0')}`,
            cover: decrypted.thumbnail || `https://i.ytimg.com/vi/${id}/maxresdefault.jpg`,
            download_url: downloadUrl
        };
    } catch (error) {
        throw new Error(error.message);
    }
}

// Usage:
savetube('https://youtu.be/xMHJGd3wwZk?si=QtRsd1joHi7Z0_KO').then(console.log);