server.js

// ==========================================
// PIXELDRIVE v3.3 - SERVER.JS (ESM)
// ==========================================
import express from 'express';
import session from 'express-session';
import Database from 'better-sqlite3';
import multer from 'multer';
import { createHash, randomBytes, scrypt, createCipheriv, createDecipheriv } from 'crypto';
import { promisify } from 'util';
import { createReadStream, unlinkSync, existsSync } from 'fs';
import { join, extname } from 'path';
import { v4 as uuidv4 } from 'uuid';
import LRUCache from 'quick-lru';
import sharp from 'sharp';
import * as tf from '@tensorflow/tfjs';
import * as nsfwjs from 'nsfwjs';
import axios from 'axios';
import FormData from 'form-data';
import { fileURLToPath } from 'url';

const __dirname = fileURLToPath(new URL('.', import.meta.url));
const PORT = 7860;
const DATA_DIR = '/data';
const TEMP_DIR = join(DATA_DIR, 'temp');
const THUMB_DIR = join(DATA_DIR, 'thumbs');
const DB_PATH = join(DATA_DIR, 'pixeldrive.db');
const CHUNK_SIZE = 30 * 1024 * 1024;
const MAX_CONCURRENT_UPLOADS = 2;
const CACHE_MAX_BYTES = 12 * 1024 * 1024 * 1024;
const KEY_LEN = 32;
const IV_LEN = 12;
const TAG_LEN = 16;
const OVERHEAD = IV_LEN + TAG_LEN;

const IMGBB_API_KEY = process.env.IMGBB_API_KEY;
const SESSION_SECRET = process.env.SESSION_SECRET;
const ADMIN_USER = process.env.ADMIN_USER || 'admin';

if (!IMGBB_API_KEY || !SESSION_SECRET) {
    console.error('❌ ERREUR: Variables manquantes: IMGBB_API_KEY, SESSION_SECRET');
    process.exit(1);
}

const db = new Database(DB_PATH);
db.pragma('journal_mode = WAL');
db.pragma('busy_timeout = 5000');

// --- CRYPTO ---
const scryptAsync = promisify(scrypt);
async function deriveKey(password, salt) { return scryptAsync(password, salt, KEY_LEN); }
function encryptChunk(dataBuffer, key) { const iv = randomBytes(IV_LEN); const cipher = createCipheriv('aes-256-gcm', key, iv); const encrypted = Buffer.concat([cipher.update(dataBuffer), cipher.final()]); const tag = cipher.getAuthTag(); return Buffer.concat([iv, encrypted, tag]); }
function decryptChunk(encBuffer, key) { if (encBuffer.length < OVERHEAD) throw new Error('Buffer trop court'); const iv = encBuffer.subarray(0, IV_LEN); const tag = encBuffer.subarray(encBuffer.length - TAG_LEN); const data = encBuffer.subarray(IV_LEN, encBuffer.length - TAG_LEN); const decipher = createDecipheriv('aes-256-gcm', key, iv); decipher.setAuthTag(tag); return Buffer.concat([decipher.update(data), decipher.final()]); }

// --- PNG STEGO (OPTIMISÉ) ---
function bufferToPng(buffer) {
    const byteLen = buffer.length;
    const pixelsNeeded = Math.ceil(byteLen / 3);
    const width = Math.ceil(Math.sqrt(pixelsNeeded));
    const height = Math.ceil(pixelsNeeded / width);
    const rgbBuffer = Buffer.alloc(width * height * 3);
    buffer.copy(rgbBuffer);
    return sharp(rgbBuffer, { raw: { width, height, channels: 3 } }).png({ compressionLevel: 9, palette: false }).withMetadata(false).toBuffer();
}
async function pngToBuffer(pngBuffer, expectedLen) {
    const { data, info } = await sharp(pngBuffer).raw().toBuffer({ resolveWithObject: true });
    const channels = info.channels;
    const rgb = Buffer.alloc(info.width * info.height * 3);
    if (channels === 3) { data.copy(rgb, 0, 0, Math.min(data.length, rgb.length)); }
    else if (channels === 4) { for (let i = 0, j = 0; i < data.length && j < rgb.length; i += 4, j += 3) { rgb[j] = data[i]; rgb[j+1] = data[i+1]; rgb[j+2] = data[i+2]; } }
    else if (channels === 1) { for (let i = 0, j = 0; i < data.length && j < rgb.length; i++, j += 3) { rgb[j] = rgb[j+1] = rgb[j+2] = data[i]; } }
    return rgb.subarray(0, expectedLen);
}

// ==========================================
// SCHÉMA
// ==========================================
db.exec(`
CREATE TABLE IF NOT EXISTS users (id INTEGER PRIMARY KEY AUTOINCREMENT, username TEXT UNIQUE NOT NULL, password_hash BLOB NOT NULL, salt BLOB NOT NULL, is_admin INTEGER DEFAULT 0, tos_accepted INTEGER DEFAULT 0, created_at INTEGER DEFAULT (strftime('%s','now')));
CREATE TABLE IF NOT EXISTS folders (id INTEGER PRIMARY KEY AUTOINCREMENT, parent_id INTEGER REFERENCES folders(id) ON DELETE CASCADE, owner_id INTEGER NOT NULL REFERENCES users(id) ON DELETE CASCADE, name TEXT NOT NULL, created_at INTEGER DEFAULT (strftime('%s','now')), UNIQUE(parent_id, owner_id, name));
CREATE TABLE IF NOT EXISTS files (id TEXT PRIMARY KEY, folder_id INTEGER REFERENCES folders(id) ON DELETE SET NULL, owner_id INTEGER NOT NULL REFERENCES users(id) ON DELETE CASCADE, name TEXT NOT NULL, mime TEXT NOT NULL, size INTEGER NOT NULL, chunk_count INTEGER DEFAULT 1, status TEXT DEFAULT 'pending', progress REAL DEFAULT 0, error_msg TEXT, encryption_key_hash TEXT NOT NULL, master_key_enc BLOB, created_at INTEGER DEFAULT (strftime('%s','now')), updated_at INTEGER DEFAULT (strftime('%s','now')));
CREATE TABLE IF NOT EXISTS file_chunks (id INTEGER PRIMARY KEY AUTOINCREMENT, file_id TEXT NOT NULL REFERENCES files(id) ON DELETE CASCADE, chunk_index INTEGER NOT NULL, imgbb_url TEXT, imgbb_delete_url TEXT, imgbb_id TEXT, size INTEGER NOT NULL, encrypted_len INTEGER NOT NULL, UNIQUE(file_id, chunk_index));
CREATE TABLE IF NOT EXISTS share_links (token TEXT PRIMARY KEY, file_id TEXT NOT NULL REFERENCES files(id) ON DELETE CASCADE, owner_id INTEGER NOT NULL REFERENCES users(id) ON DELETE CASCADE, type TEXT NOT NULL, created_at INTEGER DEFAULT (strftime('%s','now')), expires_at INTEGER);
CREATE TABLE IF NOT EXISTS user_shares (id INTEGER PRIMARY KEY AUTOINCREMENT, file_id TEXT REFERENCES files(id) ON DELETE CASCADE, folder_id INTEGER REFERENCES folders(id) ON DELETE CASCADE, owner_id INTEGER NOT NULL REFERENCES users(id) ON DELETE CASCADE, shared_with INTEGER NOT NULL REFERENCES users(id) ON DELETE CASCADE, created_at INTEGER DEFAULT (strftime('%s','now')));
CREATE INDEX IF NOT EXISTS idx_files_owner ON files(owner_id);
CREATE INDEX IF NOT EXISTS idx_chunks_file ON file_chunks(file_id);
CREATE INDEX IF NOT EXISTS idx_share_owner ON share_links(owner_id);
CREATE INDEX IF NOT EXISTS idx_ushares_with ON user_shares(shared_with);
`);

// ==========================================
// MIGRATIONS
// ==========================================
function runMigrations() {
    console.log('🔍 Vérification migrations BDD...');
    const usersCols = db.prepare("PRAGMA table_info(users)").all().map(c => c.name);
    if (!usersCols.includes('tos_accepted')) db.exec(`ALTER TABLE users ADD COLUMN tos_accepted INTEGER DEFAULT 0;`);

    const filesCols = db.prepare("PRAGMA table_info(files)").all().map(c => c.name);
    const filesDefs = [
        { name: 'folder_id', def: 'INTEGER REFERENCES folders(id) ON DELETE SET NULL' },
        { name: 'master_key_enc', def: 'BLOB' },
        { name: 'encryption_key_hash', def: 'TEXT' },
        { name: 'status', def: "TEXT DEFAULT 'pending'" },
        { name: 'progress', def: 'REAL DEFAULT 0' },
        { name: 'error_msg', def: 'TEXT' },
        { name: 'chunk_count', def: 'INTEGER DEFAULT 1' },
        { name: 'updated_at', def: 'INTEGER DEFAULT 0' },
    ];
    let updatedAdded = false;
    for (const col of filesDefs) {
        if (!filesCols.includes(col.name)) {
            db.exec(`ALTER TABLE files ADD COLUMN ${col.name} ${col.def};`);
            if (col.name === 'updated_at') updatedAdded = true;
        }
    }
    if (updatedAdded) db.exec(`UPDATE files SET updated_at = strftime('%s','now') WHERE updated_at = 0;`);

    const tables = db.prepare("SELECT name FROM sqlite_master WHERE type='table'").all().map(t => t.name);
    if (!tables.includes('folders')) db.exec(`CREATE TABLE folders (id INTEGER PRIMARY KEY AUTOINCREMENT, parent_id INTEGER REFERENCES folders(id) ON DELETE CASCADE, owner_id INTEGER NOT NULL REFERENCES users(id) ON DELETE CASCADE, name TEXT NOT NULL, created_at INTEGER DEFAULT (strftime('%s','now')), UNIQUE(parent_id, owner_id, name));`);
    if (!tables.includes('share_links')) db.exec(`CREATE TABLE share_links (token TEXT PRIMARY KEY, file_id TEXT NOT NULL REFERENCES files(id) ON DELETE CASCADE, owner_id INTEGER NOT NULL REFERENCES users(id) ON DELETE CASCADE, type TEXT NOT NULL, created_at INTEGER DEFAULT (strftime('%s','now')), expires_at INTEGER);`);
    if (!tables.includes('user_shares')) db.exec(`CREATE TABLE user_shares (id INTEGER PRIMARY KEY AUTOINCREMENT, file_id TEXT REFERENCES files(id) ON DELETE CASCADE, folder_id INTEGER REFERENCES folders(id) ON DELETE CASCADE, owner_id INTEGER NOT NULL REFERENCES users(id) ON DELETE CASCADE, shared_with INTEGER NOT NULL REFERENCES users(id) ON DELETE CASCADE, created_at INTEGER DEFAULT (strftime('%s','now'))); CREATE INDEX idx_ushares_with ON user_shares(shared_with);`);

    const sessionsCols = tables.includes('sessions') ? db.prepare("PRAGMA table_info(sessions)").all().map(c => c.name) : [];
    if (tables.includes('sessions') && (!sessionsCols.includes('data') || !sessionsCols.includes('expires_at'))) {
        db.exec(`DROP TABLE sessions; CREATE TABLE sessions (sid TEXT PRIMARY KEY, data TEXT NOT NULL, expires_at INTEGER NOT NULL); CREATE INDEX idx_sessions_expires ON sessions(expires_at);`);
    } else if (!tables.includes('sessions')) {
        db.exec(`CREATE TABLE sessions (sid TEXT PRIMARY KEY, data TEXT NOT NULL, expires_at INTEGER NOT NULL); CREATE INDEX idx_sessions_expires ON sessions(expires_at);`);
    }
    console.log('✅ Migrations terminées.');
}
runMigrations();

db.exec(`
CREATE INDEX IF NOT EXISTS idx_files_folder ON files(folder_id);
DROP TRIGGER IF EXISTS update_file_ts;
CREATE TRIGGER update_file_ts AFTER UPDATE ON files BEGIN UPDATE files SET updated_at = strftime('%s','now') WHERE id = NEW.id; END;
`);

// --- SESSION STORE ---
class SQLiteStore extends session.Store {
    get(sid, cb) { try { const r = db.prepare('SELECT data, expires_at FROM sessions WHERE sid=?').get(sid); if(!r) return cb(null, null); if(r.expires_at < Date.now()){ db.prepare('DELETE FROM sessions WHERE sid=?').run(sid); return cb(null, null); } cb(null, JSON.parse(r.data)); } catch(e){ cb(e); } }
    set(sid, sess, cb) { try { const exp = sess.cookie?.expires ? new Date(sess.cookie.expires).getTime() : Date.now() + 30*24*60*60*1000; db.prepare('INSERT OR REPLACE INTO sessions(sid,data,expires_at) VALUES(?,?,?)').run(sid, JSON.stringify(sess), exp); cb(null); } catch(e){ cb(e); } }
    destroy(sid, cb) { try { db.prepare('DELETE FROM sessions WHERE sid=?').run(sid); cb(null); } catch(e){ cb(e); } }
    clear(cb) { try { db.prepare('DELETE FROM sessions').run(); cb(null); } catch(e){ cb(e); } }
    length(cb) { try { const r = db.prepare('SELECT COUNT(*) as c FROM sessions').get(); cb(null, r.c); } catch(e){ cb(e); } }
    touch(sid, sess, cb) { this.set(sid, sess, cb); }
}
const sessionStore = new SQLiteStore();

// --- ADMIN ---
const adminRow = db.prepare('SELECT * FROM users WHERE username=?').get(ADMIN_USER);
if (!adminRow) {
    const salt = randomBytes(16);
    const hash = await deriveKey(process.env.ADMIN_PASS || 'ChangeMeNow!', salt);
    db.prepare('INSERT INTO users(username,password_hash,salt,is_admin,tos_accepted) VALUES(?,?,?,1,1)').run(ADMIN_USER, hash, salt);
    console.log(`👑 Admin: ${ADMIN_USER} / Pass: ${process.env.ADMIN_PASS || 'ChangeMeNow!'}`);
}

// --- EXPRESS ---
const app = express();
app.set('trust proxy', 1);
app.use(express.json({ limit: '50mb' }));
app.use(express.urlencoded({ extended: true, limit: '50mb' }));
app.use(session({ secret: SESSION_SECRET, store: sessionStore, resave: false, saveUninitialized: false, cookie: { secure: false, httpOnly: true, maxAge: 30*24*60*60*1000, sameSite: 'lax' } }));

const requireAuth = (req, res, next) => { if(!req.session.userId) return res.status(401).json({error:'Non authentifié'}); next(); };
const requireTos = (req, res, next) => { if(!req.session.tosAccepted) return res.status(403).json({error:'CGU non acceptées', needTos:true}); next(); };

// --- CACHE ---
class ByteLRUCache extends LRUCache { constructor(){ super({maxSize:CACHE_MAX_BYTES, sizeCalculation:v=>v.size}); } }
const fileCache = new ByteLRUCache();
setInterval(()=>{ const m = process.memoryUsage(); if(m.rss > 13*1024*1024*1024){ fileCache.clear(); if(global.gc) global.gc(); } }, 30000);

// --- NSFW ---
let nsfwModel = null;
async function loadNsfwModel(){ try{ await tf.setBackend('wasm'); tf.wasm.setWasmPaths('/app/tfjs_wasm/','tfjs-backend-wasm.wasm'); await tf.ready(); nsfwModel = await nsfwjs.load('/app/tfjs_wasm/',{type:'mobilenet_v2',size:224}); console.log('🛡️ NSFW WASM chargé'); }catch(e){ console.error('❌ NSFW load fail:',e.message); } }
loadNsfwModel();
async function checkNsfw(buf){ if(!nsfwModel) return {safe:true}; try{ const t=tf.node.decodeImage(buf,3).resizeNearestNeighbor([224,224]).expandDims(0); const p=await nsfwModel.classify(t); t.dispose(); const porn=p.find(x=>x.className==='Porn'||x.className==='Sexual Activity')?.probability||0; const hentai=p.find(x=>x.className==='Hentai')?.probability||0; if(porn>0.85||hentai>0.9) return {safe:false}; return {safe:true}; }catch(e){ return {safe:true}; } }

// --- QUEUE ---
class UploadQueue{ constructor(c){ this.c=c; this.r=0; this.q=[]; } add(t){ return new Promise((res,rej)=>{ this.q.push({t,res,rej}); this.proc(); }); } async proc(){ if(this.r>=this.c||!this.q.length) return; this.r++; const {t,res,rej}=this.q.shift(); try{ res(await t()); }catch(e){ rej(e); }finally{ this.r--; this.proc(); } } }
const uploadQueue = new UploadQueue(MAX_CONCURRENT_UPLOADS);

// --- IMGBB ---
async function imgbbUpload(buf){ const f=new FormData(); f.append('image',buf.toString('base64')); const {data}=await axios.post(`https://api.imgbb.com/1/upload?key=${IMGBB_API_KEY}`,f,{headers:f.getHeaders(),timeout:120000,maxContentLength:Infinity,maxBodyLength:Infinity}); if(!data.success) throw new Error(data.error?.message||'ImgBB fail'); return {url:data.data.url,deleteUrl:data.data.delete_url,id:data.data.id}; }
async function imgbbDelete(u){ try{await axios.get(u,{timeout:10000});}catch(_){} }

// --- KEYS ---
const SERVER_MASTER_KEY = createHash('sha256').update(SESSION_SECRET+'|PixelDriveMaster').digest();
function encryptMasterKey(k){ const iv=randomBytes(12); const c=createCipheriv('aes-256-gcm',SERVER_MASTER_KEY,iv); return Buffer.concat([iv,c.update(k),c.final(),c.getAuthTag()]); }
function decryptMasterKey(b){ const iv=b.subarray(0,12), tag=b.subarray(-16), d=b.subarray(12,-16); const dc=createDecipheriv('aes-256-gcm',SERVER_MASTER_KEY,iv); dc.setAuthTag(tag); return Buffer.concat([dc.update(d),dc.final()]); }
async function getMasterKey(fid){ const r=db.prepare('SELECT master_key_enc FROM files WHERE id=?').get(fid); if(!r?.master_key_enc) throw new Error('Clé manquante'); return decryptMasterKey(r.master_key_enc); }

// ==========================================
// ✅ CONTRÔLE D'ACCÈS (partage entre utilisateurs)
// ==========================================
function canAccessFolder(userId, folderId){
    let cur = db.prepare('SELECT * FROM folders WHERE id=?').get(folderId);
    let depth = 0;
    while (cur && depth < 50) {
        if (cur.owner_id === userId) return true;
        if (db.prepare('SELECT 1 FROM user_shares WHERE folder_id=? AND shared_with=?').get(cur.id, userId)) return true;
        cur = cur.parent_id ? db.prepare('SELECT * FROM folders WHERE id=?').get(cur.parent_id) : null;
        depth++;
    }
    return false;
}
function canAccessFile(userId, fileId){
    const f = db.prepare('SELECT * FROM files WHERE id=?').get(fileId);
    if (!f) return null;
    if (f.owner_id === userId) return f;
    if (db.prepare('SELECT 1 FROM user_shares WHERE file_id=? AND shared_with=?').get(fileId, userId)) return f;
    if (f.folder_id && canAccessFolder(userId, f.folder_id)) return f;
    return null;
}

// --- THUMB ---
async function genThumb(fid,mime,key){
    if(!mime.startsWith('image/')&&!mime.startsWith('video/')) return;
    try{
        const c = db.prepare('SELECT imgbb_url, size FROM file_chunks WHERE file_id=? AND chunk_index=0').get(fid);
        if(!c) return;
        const {data} = await axios.get(c.imgbb_url,{responseType:'arraybuffer',timeout:30000});
        const enc = await pngToBuffer(Buffer.from(data), c.size + OVERHEAD);
        const dec = decryptChunk(enc,key);
        let buf;
        if(mime.startsWith('image/')) buf = await sharp(dec).rotate().resize(256,256,{fit:'inside'}).jpeg({quality:80}).toBuffer();
        else buf = await sharp({create:{width:256,height:144,channels:3,background:'#1e1e2f'}}).jpeg().toBuffer();
        await sharp(buf).toFile(join(THUMB_DIR,`${fid}.jpg`));
    }catch(e){ console.warn(`Thumb ${fid}:`,e.message); }
}

// --- STREAM ---
async function streamFile(res,file,key,range){
    const chunks = db.prepare('SELECT chunk_index,imgbb_url,size FROM file_chunks WHERE file_id=? ORDER BY chunk_index').all(file.id);
    const total = file.size;
    let s = 0, e = total - 1;
    if(range){ const p = range.replace('bytes=','').split('-'); s = parseInt(p[0]); e = p[1] ? parseInt(p[1]) : total - 1; }
    if(s >= total || e >= total) return res.status(416).send('Range Not Satisfiable');
    res.set({'Content-Type':file.mime,'Content-Length':e-s+1,'Accept-Ranges':'bytes','Content-Disposition':`inline; filename="${encodeURIComponent(file.name)}"`});
    if(range){ res.status(206); res.set('Content-Range', `bytes ${s}-${e}/${total}`); }
    console.log(`📥 Stream ${file.name} (${((e-s+1)/1024/1024).toFixed(2)} MB, ${chunks.length} chunk(s))`);
    let cur = 0;
    for(const c of chunks){
        const cs = cur, ce = cur + c.size - 1;
        if(ce >= s && cs <= e){
            const off = Math.max(0, s - cs), len = Math.min(c.size - off, e - Math.max(s, cs) + 1);
            try{
                const ck = `chunk:${file.id}:${c.chunk_index}`;
                let dec = fileCache.get(ck)?.data;
                if(!dec){
                    const t0 = Date.now();
                    const {data} = await axios.get(c.imgbb_url,{responseType:'arraybuffer',timeout:120000});
                    const t1 = Date.now();
                    console.log(`  ⬇️  Chunk ${c.chunk_index}: ${(data.byteLength/1024/1024).toFixed(2)} MB en ${t1-t0}ms`);
                    const enc = await pngToBuffer(Buffer.from(data), c.size + OVERHEAD);
                    const t2 = Date.now();
                    console.log(`  🖼️  PNG→Buffer: ${t2-t1}ms`);
                    dec = decryptChunk(enc, key);
                    console.log(`  🔓 Decrypt: ${Date.now()-t2}ms`);
                    fileCache.set(ck, {data: dec, size: dec.length});
                }
                const sl = dec.subarray(off, off + len);
                if(!res.write(sl)) await new Promise(r => res.once('drain', r));
            }catch(err){ console.error(`❌ Stream chunk ${c.chunk_index}:`, err.message); return res.destroy(err); }
        }
        cur += c.size;
        if(cs > e) break;
    }
    res.end();
}

// --- SSE ---
const sseClients = new Map();
function broadcast(fid,d){ const cs = sseClients.get(fid); if(cs){ const p = `data: ${JSON.stringify(d)}\n\n`; for(const r of cs) r.write(p); } }

// ==========================================
// ROUTES
// ==========================================
app.post('/api/register',async(req,res)=>{const{u,p,t}=req.body;if(!u||!p||!t)return res.status(400).json({error:'Champs manquants'});if(db.prepare('SELECT 1 FROM users WHERE username=?').get(u))return res.status(409).json({error:'Existe'});const s=randomBytes(16);const h=await deriveKey(p,s);db.prepare('INSERT INTO users(username,password_hash,salt,tos_accepted) VALUES(?,?,?,1)').run(u,h,s);res.json({ok:true});});
app.post('/api/login',async(req,res)=>{const{u,p}=req.body;const usr=db.prepare('SELECT * FROM users WHERE username=?').get(u);if(!usr)return res.status(401).json({error:'Invalide'});const h=await deriveKey(p,usr.salt);if(!h.equals(usr.password_hash))return res.status(401).json({error:'Invalide'});req.session.userId=usr.id;req.session.isAdmin=!!usr.is_admin;req.session.tosAccepted=!!usr.tos_accepted;req.session.username=usr.username;res.json({ok:true,user:{id:usr.id,username:usr.username,isAdmin:!!usr.is_admin,tosAccepted:!!usr.tos_accepted}});});
app.post('/api/logout',(req,res)=>req.session.destroy(()=>res.json({ok:true})));
app.get('/api/me',(req,res)=>req.session.userId?res.json({id:req.session.userId,username:req.session.username,isAdmin:req.session.isAdmin,tosAccepted:req.session.tosAccepted}):res.status(401).json({error:'Non connecté'}));
app.get('/api/tos',(_,res)=>res.send(`PIXELDRIVE CGU\n1. RESPONSABILITÉ TOTALE\n2. AUCUNE GARANTIE (Projet test)\n3. INTERDITS: Illégal, NSFW, Abus\n4. CHIFFRÉ AES-256-GCM + Filtre NSFW Local\n5. ACCEPTATION = Responsabilité légale`));
app.post('/api/tos/accept',requireAuth,(req,res)=>{db.prepare('UPDATE users SET tos_accepted=1 WHERE id=?').run(req.session.userId);req.session.tosAccepted=true;res.json({ok:true});});

// ✅ Folders (avec accès partagé)
app.get('/api/folders',requireAuth,(req,res)=>{
    const p = req.query.parent_id ? parseInt(req.query.parent_id) : null;
    if (p !== null) {
        if (!canAccessFolder(req.session.userId, p)) return res.status(403).json({error:'Accès refusé'});
        return res.json(db.prepare('SELECT * FROM folders WHERE parent_id=? ORDER BY name COLLATE NOCASE').all(p));
    }
    res.json(db.prepare('SELECT * FROM folders WHERE owner_id=? AND parent_id IS NULL ORDER BY name COLLATE NOCASE').all(req.session.userId));
});
app.post('/api/folders',requireAuth,requireTos,(req,res)=>{const{n,p}=req.body;if(!n)return res.status(400).json({error:'Nom requis'});try{const i=db.prepare('INSERT INTO folders(name,parent_id,owner_id) VALUES(?,?,?)').run(n,p||null,req.session.userId);res.json({id:i.lastInsertRowid,name:n,parent_id:p});}catch(e){res.status(409).json({error:'Existe'});}});
app.delete('/api/folders/:id',requireAuth,(req,res)=>{db.prepare('DELETE FROM folders WHERE id=? AND owner_id=?').run(req.params.id,req.session.userId);res.json({ok:true});});

// ✅ Files (avec accès partagé)
app.get('/api/files',requireAuth,(req,res)=>{
    const f = req.query.folder_id ? parseInt(req.query.folder_id) : null;
    if (f !== null) {
        if (!canAccessFolder(req.session.userId, f)) return res.status(403).json({error:'Accès refusé'});
        return res.json(db.prepare('SELECT * FROM files WHERE folder_id=? ORDER BY name COLLATE NOCASE').all(f));
    }
    res.json(db.prepare('SELECT * FROM files WHERE owner_id=? AND folder_id IS NULL ORDER BY name COLLATE NOCASE').all(req.session.userId));
});

// ✅ PARTAGE ENTRE UTILISATEURS
app.post('/api/share-user',requireAuth,requireTos,(req,res)=>{
    const { type, id, username } = req.body;
    if (!type || !id || !username) return res.status(400).json({error:'Champs manquants'});
    const target = db.prepare('SELECT id FROM users WHERE username=?').get(username.trim());
    if (!target) return res.status(404).json({error:'Utilisateur introuvable'});
    if (target.id === req.session.userId) return res.status(400).json({error:'Impossible de partager avec vous-même'});
    if (type === 'file') {
        const f = db.prepare('SELECT id FROM files WHERE id=? AND owner_id=?').get(id, req.session.userId);
        if (!f) return res.status(404).json({error:'Fichier introuvable'});
        if (db.prepare('SELECT 1 FROM user_shares WHERE file_id=? AND shared_with=?').get(id, target.id)) return res.status(409).json({error:'Déjà partagé'});
        db.prepare('INSERT INTO user_shares(file_id,owner_id,shared_with) VALUES(?,?,?)').run(id, req.session.userId, target.id);
    } else {
        const fo = db.prepare('SELECT id FROM folders WHERE id=? AND owner_id=?').get(id, req.session.userId);
        if (!fo) return res.status(404).json({error:'Dossier introuvable'});
        if (db.prepare('SELECT 1 FROM user_shares WHERE folder_id=? AND shared_with=?').get(id, target.id)) return res.status(409).json({error:'Déjà partagé'});
        db.prepare('INSERT INTO user_shares(folder_id,owner_id,shared_with) VALUES(?,?,?)').run(id, req.session.userId, target.id);
    }
    res.json({ok:true});
});

app.get('/api/shared-with-me',requireAuth,(req,res)=>{
    res.json(db.prepare(`
        SELECT us.id as share_id, us.created_at as shared_at, u.username as owner_name,
               us.file_id, us.folder_id,
               f.name as file_name, f.mime, f.size, f.status,
               fo.name as folder_name
        FROM user_shares us
        JOIN users u ON u.id = us.owner_id
        LEFT JOIN files f ON f.id = us.file_id
        LEFT JOIN folders fo ON fo.id = us.folder_id
        WHERE us.shared_with = ?
        ORDER BY us.created_at DESC
    `).all(req.session.userId));
});

app.delete('/api/shared-with-me/:id',requireAuth,(req,res)=>{
    db.prepare('DELETE FROM user_shares WHERE id=? AND shared_with=?').run(req.params.id, req.session.userId);
    res.json({ok:true});
});

// Liens publics
app.get('/api/share-links',requireAuth,(req,res)=>{
    res.json(db.prepare(`SELECT sl.*, f.name as file_name, f.mime, f.size FROM share_links sl LEFT JOIN files f ON sl.file_id = f.id WHERE sl.owner_id = ? ORDER BY sl.created_at DESC`).all(req.session.userId));
});
app.delete('/api/share-links/:token',requireAuth,(req,res)=>{
    const r = db.prepare('DELETE FROM share_links WHERE token=? AND owner_id=?').run(req.params.token, req.session.userId);
    if (r.changes === 0) return res.status(404).json({error:'Lien introuvable'});
    res.json({ok:true});
});

// Upload
const upload = multer({dest:TEMP_DIR,limits:{fileSize:5*1024*1024*1024}});
app.post('/api/files/upload',requireAuth,requireTos,upload.single('file'),async(req,res)=>{
    if(!req.file)return res.status(400).json({error:'Fichier manquant'});
    const fid=uuidv4(),fpath=req.file.path,fsize=req.file.size,cc=Math.ceil(fsize/CHUNK_SIZE),mk=randomBytes(KEY_LEN),kh=createHash('sha256').update(mk).digest('hex'),mke=encryptMasterKey(mk),fidParam=req.body.folder_id?parseInt(req.body.folder_id):null;
    db.prepare(`INSERT INTO files(id,folder_id,owner_id,name,mime,size,chunk_count,status,encryption_key_hash,master_key_enc) VALUES(?,?,?,?,?,?,?,'pending',?,?)`).run(fid,fidParam,req.session.userId,req.file.originalname,req.file.mimetype,fsize,cc,kh,mke);
    const stmt=db.prepare('INSERT INTO file_chunks(file_id,chunk_index,size,encrypted_len) VALUES(?,?,?,?)');
    const tx=db.transaction((arr)=>{for(const c of arr)stmt.run(...c);});
    const cd=[];
    for(let i=0;i<cc;i++){const sz=Math.min(CHUNK_SIZE,fsize-i*CHUNK_SIZE);cd.push([fid,i,sz,sz+OVERHEAD]);}
    tx(cd);
    res.json({fileId:fid,status:'pending',chunkCount:cc});
    uploadQueue.add(()=>processUpload(fid,fpath,mk,cc,req.file.mimetype));
});

async function processUpload(fid,path,mk,cc,mime){
    try{
        db.prepare("UPDATE files SET status='uploading' WHERE id=?").run(fid);
        for(let i=0;i<cc;i++){
            const off=i*CHUNK_SIZE;
            const ci=db.prepare('SELECT size,encrypted_len FROM file_chunks WHERE file_id=? AND chunk_index=?').get(fid,i);
            const raw=await readChunk(path,off,ci.size);
            const enc=encryptChunk(raw,mk);
            if(enc.length>ci.encrypted_len)throw new Error(`Overflow chunk ${i}`);
            const png=await bufferToPng(enc);
            const{url,deleteUrl,id}=await imgbbUpload(png);
            db.prepare('UPDATE file_chunks SET imgbb_url=?,imgbb_delete_url=?,imgbb_id=? WHERE file_id=? AND chunk_index=?').run(url,deleteUrl,id,fid,i);
            const prog=((i+1)/cc)*50;
            db.prepare('UPDATE files SET progress=?,status=? WHERE id=?').run(prog,'uploading',fid);
            broadcast(fid,{type:'progress',progress:prog,status:'uploading'});
            if(i<cc-1)await new Promise(r=>setTimeout(r,3200));
        }
        unlinkSync(path);
        db.prepare("UPDATE files SET status='processing',progress=50 WHERE id=?").run(fid);
        broadcast(fid,{type:'progress',progress:50,status:'processing'});
        await genThumb(fid,mime,mk);
        db.prepare("UPDATE files SET status='ready',progress=100 WHERE id=?").run(fid);
        broadcast(fid,{type:'progress',progress:100,status:'ready',type:'done'});
    }catch(e){
        console.error(`Upload ${fid}`,e);
        db.prepare("UPDATE files SET status='error',error_msg=? WHERE id=?").run(e.message,fid);
        broadcast(fid,{type:'error',error:e.message});
        const cs=db.prepare('SELECT imgbb_delete_url FROM file_chunks WHERE file_id=?').all(fid);
        for(const c of cs)if(c.imgbb_delete_url)await imgbbDelete(c.imgbb_delete_url);
    }
}
function readChunk(p,o,l){return new Promise((res,rej)=>{const s=createReadStream(p,{start:o,end:o+l-1}),c=[];s.on('data',d=>c.push(d)).on('end',()=>res(Buffer.concat(c,l))).on('error',rej);});}

// ✅ Download (accès partagé autorisé)
app.get('/api/files/:id/download',requireAuth,async(req,res)=>{
    const f = canAccessFile(req.session.userId, req.params.id);
    if(!f)return res.status(404).json({error:'Introuvable'});
    if(f.status!=='ready')return res.status(409).json({error:'Pas prêt',status:f.status});
    const k = await getMasterKey(f.id);
    await streamFile(res,f,k,req.headers.range);
});

app.post('/api/files/:id/share',requireAuth,async(req,res)=>{
    const f=db.prepare('SELECT * FROM files WHERE id=? AND owner_id=?').get(req.params.id,req.session.userId);
    if(!f||f.status!=='ready') return res.status(404).json({error:'Fichier non disponible'});
    const pt=uuidv4(), dt2=uuidv4(), expires=Date.now()+7*24*3600000;
    db.prepare('INSERT INTO share_links(token,file_id,owner_id,type,expires_at) VALUES(?,?,?,?,?)').run(pt,f.id,req.session.userId,'embed',expires);
    db.prepare('INSERT INTO share_links(token,file_id,owner_id,type,expires_at) VALUES(?,?,?,?,?)').run(dt2,f.id,req.session.userId,'download',expires);
    res.json({preview:`/s/${pt}`,download:`/d/${dt2}`,expires});
});

app.get('/api/files/:id/preview',requireAuth,async(req,res)=>{
    const f=db.prepare('SELECT * FROM files WHERE id=? AND owner_id=?').get(req.params.id,req.session.userId);
    if(!f||f.status!=='ready')return res.status(404).json({error:'Pas prêt'});
    const t=uuidv4();
    db.prepare('INSERT INTO share_links(token,file_id,owner_id,type,expires_at) VALUES(?,?,?,?,?)').run(t,f.id,req.session.userId,'embed',Date.now()+3600000);
    res.json({url:`/s/${t}`});
});

app.get('/s/:token',async(req,res)=>{
    const l=db.prepare('SELECT * FROM share_links WHERE token=? AND type=? AND (expires_at IS NULL OR expires_at>?)').get(req.params.token,'embed',Date.now());
    if(!l)return res.status(404).send(html('Lien invalide/expiré'));
    const f=db.prepare('SELECT * FROM files WHERE id=?').get(l.file_id);
    if(!f)return res.status(404).send(html('Fichier supprimé'));
    const dt=uuidv4();
    db.prepare('INSERT INTO share_links(token,file_id,owner_id,type,expires_at) VALUES(?,?,?,?,?)').run(dt,f.id,l.owner_id,'download',Date.now()+3600000);
    const v=f.mime.startsWith('video/'),a=f.mime.startsWith('audio/'),i=f.mime.startsWith('image/'),p=f.mime==='application/pdf';
    res.send(html(`<title>${f.name}</title><style>body{margin:0;background:#000;color:#fff;display:flex;align-items:center;justify-content:center;height:100vh;font-family:sans-serif;overflow:hidden}.wrap{max-width:90vw;max-height:90vh;text-align:center}video,audio{max-width:100%;max-height:80vh;background:#111}img{max-width:100%;max-height:80vh}.info{margin-top:1rem;opacity:.8}a{color:#4da3ff}</style><div class="wrap">${v?`<video controls autoplay playsinline src="/d/${dt}"></video>`:''}${a?`<audio controls src="/d/${dt}"></audio>`:''}${i?`<img src="/d/${dt}" alt="${f.name}">`:''}${p?`<iframe src="/d/${dt}" style="width:100%;height:80vh;border:none"></iframe>`:''}<div class="info">${f.name} • ${(f.size/1e6).toFixed(1)} MB • <a href="/d/${dt}" download>Télécharger</a></div></div>`));
});

app.get('/d/:token',async(req,res)=>{
    const l=db.prepare('SELECT * FROM share_links WHERE token=? AND type=? AND (expires_at IS NULL OR expires_at>?)').get(req.params.token,'download',Date.now());
    if(!l)return res.status(404).json({error:'Invalide'});
    const f=db.prepare('SELECT * FROM files WHERE id=?').get(l.file_id);
    if(!f||f.status!=='ready')return res.status(404).json({error:'Indisponible'});
    const mk=decryptMasterKey(db.prepare('SELECT master_key_enc FROM files WHERE id=?').get(f.id).master_key_enc);
    await streamFile(res,f,mk,req.headers.range);
});

app.delete('/api/files/:id',requireAuth,async(req,res)=>{const f=db.prepare('SELECT * FROM files WHERE id=? AND owner_id=?').get(req.params.id,req.session.userId);if(!f)return res.status(404).json({error:'Introuvable'});const cs=db.prepare('SELECT imgbb_delete_url FROM file_chunks WHERE file_id=?').all(f.id);for(const c of cs)if(c.imgbb_delete_url)await imgbbDelete(c.imgbb_delete_url);db.prepare('DELETE FROM files WHERE id=?').run(f.id);fileCache.delete(`chunk:${f.id}:0`);try{unlinkSync(join(THUMB_DIR,`${f.id}.jpg`));}catch(_){}res.json({ok:true});});

app.get('/api/files/:id/thumb',requireAuth,(req,res)=>{
    if(!canAccessFile(req.session.userId, req.params.id)) return res.status(404).json({error:'Introuvable'});
    const p=join(THUMB_DIR,`${req.params.id}.jpg`);
    if(existsSync(p))return res.sendFile(p);
    res.set('Content-Type','image/svg+xml');
    res.send(`<svg xmlns="http://www.w3.org/2000/svg" width="256" height="144"><rect fill="#2a2a3e" width="100%" height="100%"/><text x="50%" y="50%" dominant-baseline="middle" text-anchor="middle" fill="#666" font-family="sans-serif" font-size="16">FILE</text></svg>`);
});

app.get('/api/files/:id/progress',requireAuth,(req,res)=>{res.set({'Content-Type':'text/event-stream','Cache-Control':'no-cache','Connection':'keep-alive'});res.flushHeaders();const id=req.params.id;if(!sseClients.has(id))sseClients.set(id,new Set());sseClients.get(id).add(res);req.on('close',()=>sseClients.get(id)?.delete(res));});

app.get('/api/admin/users',requireAuth,(req,res)=>{if(!req.session.isAdmin)return res.status(403).json({error:'Admin only'});res.json(db.prepare('SELECT id,username,is_admin,tos_accepted,created_at FROM users').all());});
app.get('/health',(_,res)=>res.json({ok:true,cache:fileCache.size,mem:process.memoryUsage()}));

app.use(express.static(__dirname));
app.get('*', (req, res) => {
    if (/\.[a-zA-Z0-9]+$/.test(req.path)) return res.status(404).send('Not Found');
    res.sendFile(join(__dirname, 'public.html'));
});

// ERROR HANDLER
app.use((err, req, res, next) => {
    if (err.type === 'entity.parse.failed' || err instanceof SyntaxError) return res.status(400).json({ error: 'Bad Request' });
    console.error('❌ Server Error:', err.message);
    res.status(500).json({ error: 'Internal Server Error' });
});

const server = app.listen(PORT, '0.0.0.0', () => console.log(`🚀 PixelDrive v3.3 on http://0.0.0.0:${PORT} | Cache: 12GB LRU`));
process.on('SIGTERM', () => { console.log('SIGTERM'); server.close(() => process.exit(0)); });

function html(b){return `<!DOCTYPE html><html><head><meta charset="utf-8"/><meta name="viewport" content="width=device-width, initial-scale=1"/><title>PixelDrive</title><style>body{margin:0;font-family:system-ui,sans-serif;background:#0d0d12;color:#eee;display:flex;align-items:center;justify-content:center;height:100vh}</style></head><body>${b}</body></html>`;}