const express = require('express');
const bodyParser = require('body-parser');
const axios = require('axios');
const { execSync } = require('child_process');
const path = require('path');
const fs = require('fs');

const app = express();
app.use(bodyParser.json({ limit: '100mb' }));

// File Dummy lokal sebagai cadangan jika dummy_url tidak dikirim
const DUMMY_ZIP = 'dummy_lite.zepeto.zip';

if (!fs.existsSync('uploads')) fs.mkdirSync('uploads', { recursive: true });

function getTS() { return new Date().toLocaleTimeString(); }

// Fungsi sakti untuk mencari file/folder di kedalaman mana pun
function findPath(base, targetName, isFolder = false) {
    if (!fs.existsSync(base)) return null;
    const items = fs.readdirSync(base);
    for (const item of items) {
        const fullPath = path.join(base, item);
        const stat = fs.lstatSync(fullPath);
        if (isFolder && stat.isDirectory() && item.toLowerCase() === targetName.toLowerCase()) return fullPath;
        if (!isFolder && stat.isFile() && item.toLowerCase().endsWith(targetName.toLowerCase())) return fullPath;
        if (stat.isDirectory()) {
            const found = findPath(fullPath, targetName, isFolder);
            if (found) return found;
        }
    }
    return null;
}

app.post('/convert', async (req, res) => {
    const targetFilename = req.body.filename || 'result.zepeto';
    
    // KUNCI UTAMA: dummy_url wajib dari draft yang sama agar KTP GUID cocok!
    const hpUrl = req.body.file_url;
    const dummyUrl = req.body.dummy_url; 

    console.log(`\n[${getTS()}] 🔥 REQUEST MASUK: Eksekusi ICU Clone (Native Packing) -> ${targetFilename}`);

    const timeId = Date.now();
    const tempHP = path.join(__dirname, 'uploads', `hp_${timeId}.zepeto`);
    const tempDummy = path.join(__dirname, 'uploads', `dummy_${timeId}.zepeto`);
    
    const extHP = path.join(__dirname, 'uploads', `ext_hp_${timeId}`);
    const extDummy = path.join(__dirname, 'uploads', `ext_dummy_${timeId}`);
    const stagePath = path.join(__dirname, 'uploads', `stage_${timeId}`); 
    const finalOut = path.join(__dirname, 'uploads', `final_${timeId}.zepeto`);

    try {
        console.log(`[${getTS()}] [1] Mendownload Baju Raksasa...`);
        const resHP = await axios({ method: 'GET', url: hpUrl, responseType: 'stream' });
        const writerHP = fs.createWriteStream(tempHP);
        resHP.data.pipe(writerHP);
        await new Promise(resolve => writerHP.on('finish', resolve));

        console.log(`[${getTS()}] [2] Menyiapkan File Dummy...`);
        if (dummyUrl) {
            const resDummy = await axios({ method: 'GET', url: dummyUrl, responseType: 'stream' });
            const writerDummy = fs.createWriteStream(tempDummy);
            resDummy.data.pipe(writerDummy);
            await new Promise(resolve => writerDummy.on('finish', resolve));
        } else {
            // Gunakan dummy lokal jika tidak dikirim dari CURL
            fs.copyFileSync(DUMMY_ZIP, tempDummy); 
        }

        console.log(`[${getTS()}] [3] Mengekstrak File...`);
        fs.mkdirSync(extHP, { recursive: true });
        fs.mkdirSync(extDummy, { recursive: true });
        fs.mkdirSync(stagePath, { recursive: true }); // Ruang Operasi Bersih

        execSync(`unzip -q -o "${tempHP}" -d "${extHP}"`);
        execSync(`unzip -q -o "${tempDummy}" -d "${extDummy}"`);

        console.log(`[${getTS()}] [4] Eksekusi Transplantasi Murni...`);

        // 1. AMBIL KTP & BLUEPRINT DARI DUMMY
        const dummyMetaPath = findPath(extDummy, '.prefab.meta');
        const dummyPrefabPath = findPath(extDummy, '.prefab');
        if (!dummyMetaPath || !dummyPrefabPath) throw new Error("File .prefab/.meta Dummy hilang!");

        fs.copyFileSync(dummyPrefabPath, path.join(stagePath, 'untitled.prefab'));
        fs.copyFileSync(dummyMetaPath, path.join(stagePath, 'untitled.prefab.meta'));
        console.log(`[${getTS()}]  -> Kertas Blueprint & KTP Dummy terpasang bersih.`);

        // 2. AMBIL BRANKAS BINER DARI RAKSASA
        const hpBundleDir = findPath(extHP, 'assetbundles', true);
        if (!hpBundleDir) throw new Error("Folder assetbundles Raksasa tidak ditemukan!");

        const stageBundles = path.join(stagePath, 'assetbundles');
        fs.mkdirSync(stageBundles, { recursive: true });

        let fileCount = 0;
        fs.readdirSync(hpBundleDir).forEach(p => {
            const src = path.join(hpBundleDir, p);
            if (fs.lstatSync(src).isFile()) {
                fs.copyFileSync(src, path.join(stageBundles, p));
                fileCount++;
            }
        });
        console.log(`[${getTS()}]  -> ${fileCount} File Biner Raksasa berhasil diselundupkan utuh.`);

        // 3. PEMBUNGKUSAN NATIVE LINUX (SOLUSI MUTLAK)
        console.log(`[${getTS()}] [5] Membungkus dengan Algoritma ZIP Native (Level 0 / Store)...`);
        
        // Memastikan sistem Linux memiliki package zip terinstal
        try {
            execSync('zip -v', { stdio: 'ignore' });
        } catch (e) {
            console.log(`[${getTS()}]  -> Menginstal library zip native...`);
            execSync('apt-get update && apt-get install -y zip', { stdio: 'ignore' });
        }

        // Mengeksekusi perintah packing asli sistem operasi!
        // -r = Rekursif ke dalam folder
        // -0 = STORE ONLY (Dilarang keras melakukan kompresi DEFLATE agar Zepeto tidak error)
        execSync(`cd "${stagePath}" && zip -r -0 "${finalOut}" ./*`);
        
        console.log(`[${getTS()}] ✅ SELESAI! Packing ZIP 100% Identik dengan Web ICU.`);
        
        res.download(finalOut, targetFilename, () => {
            try {
                fs.rmSync(extHP, { recursive: true, force: true });
                fs.rmSync(extDummy, { recursive: true, force: true });
                fs.rmSync(stagePath, { recursive: true, force: true });
                fs.unlinkSync(tempHP);
                fs.unlinkSync(tempDummy);
                fs.unlinkSync(finalOut);
            } catch(e) {}
        });

    } catch (err) {
        console.error(`[FATAL ERROR]`, err);
        res.status(500).json({ error: err.message });
    }
});

const PORT = 7860;
app.listen(PORT, () => console.log(`[${getTS()}] 🚀 Server Native Packing (ICU Clone) Aktif di Port ${PORT}`));