// ============================================================
// HangOut Main Backend — SINGLE FILE EDITION
// ============================================================
// Express + Mongoose (MongoDB Atlas) + JWT + Nodemailer (Gmail)
// + Google Drive (avatars/images) + All 28+ REST routes
// Designed for Hugging Face Docker Space (port 7860, mobile deploy)
// Presented by RVK EDITION · v1.0.0
// ============================================================
// यह फाइल पूरा backend है — config, models, middleware, routes सब एक जगह।
// बस यह फाइल + package.json + Dockerfile HF Space पर push करो।
// ============================================================

require('dotenv').config()

const express = require('express')
const cors = require('cors')
const helmet = require('helmet')
const rateLimit = require('express-rate-limit')
const mongoose = require('mongoose')
const multer = require('multer')
const stream = require('stream')
const jwt = require('jsonwebtoken')
const bcrypt = require('bcryptjs')
const cookieParser = require('cookie-parser')
const { google } = require('googleapis')
const { nanoid } = require('nanoid')
const nodemailer = require('nodemailer')

const PORT = process.env.PORT || 7860
const HOST = process.env.HOST || '0.0.0.0'
const JWT_SECRET = process.env.JWT_SECRET || 'change-this-to-a-32-char-random-string'
const TOKEN_COOKIE = 'hangout_token'

// Reels backend URL (already deployed on HF Space)
const REELS_BACKEND_URL = process.env.REELS_BACKEND_URL || 'https://iosrvk0-hangout-reels-backend.hf.space'

// ============================================================
// SECTION 1 — CONFIG (MongoDB, Google Drive, Nodemailer)
// ============================================================

// ─── MongoDB Atlas Connection (Mongoose, non-blocking) ───
let dbConnected = false
async function connectDB() {
  if (dbConnected && mongoose.connection.readyState === 1) return
  const MONGODB_URI = process.env.MONGODB_URI
  if (!MONGODB_URI) {
    console.warn('[db] MONGODB_URI not set — endpoints will error')
    return
  }
  try {
    console.log('[db] Connecting to MongoDB Atlas...')
    await mongoose.connect(MONGODB_URI, {
      serverSelectionTimeoutMS: 10000,
      maxPoolSize: 10,
      minPoolSize: 1,
      socketTimeoutMS: 45000,
      family: 4,
    })
    dbConnected = true
    console.log('[db] ✓ Connected to MongoDB Atlas')
    mongoose.connection.on('error', (err) => console.error('[db] error:', err.message))
    mongoose.connection.on('disconnected', () => {
      dbConnected = false
      console.warn('[db] disconnected')
    })
  } catch (err) {
    console.error('[db] ✗ MongoDB connect failed:', err.message)
  }
}

// ─── Google Drive Client (for avatars + post images) ───
let cachedDrive = null
let cachedAuth = null

function getCredentials() {
  const raw = process.env.GOOGLE_CREDENTIALS_JSON
  if (!raw) throw new Error('GOOGLE_CREDENTIALS_JSON env var is not set')
  try {
    return typeof raw === 'string' ? JSON.parse(raw) : raw
  } catch (err) {
    throw new Error(`GOOGLE_CREDENTIALS_JSON invalid JSON: ${err.message}`)
  }
}

function getAuthClient() {
  if (cachedAuth) return cachedAuth
  cachedAuth = new google.auth.GoogleAuth({
    credentials: getCredentials(),
    scopes: ['https://www.googleapis.com/auth/drive.file'],
  })
  return cachedAuth
}

function getDriveClient() {
  if (cachedDrive) return cachedDrive
  cachedDrive = google.drive({ version: 'v3', auth: getAuthClient() })
  return cachedDrive
}

function getDriveFolderId() {
  const fid = process.env.GOOGLE_DRIVE_FOLDER_ID
  if (!fid) throw new Error('GOOGLE_DRIVE_FOLDER_ID env var is not set')
  return fid
}

// Upload buffer to Drive (for avatars/post images)
async function uploadBufferToDrive(buffer, fileName, mimeType) {
  const drive = getDriveClient()
  const folderId = getDriveFolderId()
  const readable = stream.Readable.from(buffer)
  const response = await drive.files.create({
    requestBody: { name: fileName, parents: [folderId] },
    media: { mimeType, body: readable },
    fields: 'id, name',
  })
  if (!response.data?.id) throw new Error('Drive upload returned no file ID')
  return response.data.id
}

// ─── Nodemailer Transporter (Gmail App Password) ───
let cachedTransporter = null
function getMailer() {
  if (cachedTransporter) return cachedTransporter
  const user = process.env.EMAIL_USER
  const pass = process.env.EMAIL_APP_PASSWORD
  if (!user || !pass) {
    console.warn('[mailer] EMAIL_USER or EMAIL_APP_PASSWORD not set — OTP will fall back to console.log')
    return null
  }
  cachedTransporter = nodemailer.createTransport({
    service: 'gmail',
    auth: { user, pass },
  })
  return cachedTransporter
}

async function sendOtpEmail(toEmail, code) {
  const transporter = getMailer()
  if (!transporter) {
    // Fallback: console.log
    console.log(`\n=========== HANGOUT OTP (console fallback) ===========`)
    console.log(`  To: ${toEmail}`)
    console.log(`  OTP: ${code}`)
    console.log(`=====================================================\n`)
    return { fallback: true }
  }
  try {
    await transporter.sendMail({
      from: `"HangOut · RVK EDITION" <${process.env.EMAIL_USER}>`,
      to: toEmail,
      subject: `HangOut — Your OTP is ${code}`,
      text: `Your HangOut verification code is: ${code}\n\nThis code expires in 10 minutes.\n\nIf you didn't request this, ignore this email.\n\n— RVK EDITION`,
      html: `
        <div style="font-family: -apple-system, BlinkMacSystemFont, sans-serif; max-width: 480px; margin: 0 auto; background: #0a0e14; color: #e8edf5; padding: 32px; border-radius: 16px;">
          <h1 style="color: #00d9a3; margin: 0 0 8px; font-size: 24px;">HangOut</h1>
          <p style="color: #8a93a5; margin: 0 0 24px; font-size: 13px;">Presented by RVK EDITION</p>
          <h2 style="margin: 0 0 16px; font-size: 18px;">Your verification code</h2>
          <div style="background: #161b24; padding: 24px; border-radius: 12px; text-align: center; margin: 0 0 16px;">
            <div style="font-size: 36px; font-weight: 800; color: #00d9a3; letter-spacing: 8px; font-family: monospace;">${code}</div>
          </div>
          <p style="color: #8a93a5; font-size: 12px; margin: 0;">This code expires in 10 minutes. If you didn't request this, you can safely ignore this email.</p>
        </div>
      `,
    })
    console.log(`[mailer] ✓ OTP email sent to ${toEmail}`)
    return { fallback: false }
  } catch (err) {
    console.error(`[mailer] ✗ Failed to send email to ${toEmail}:`, err.message)
    // Fallback to console.log so user can still get OTP
    console.log(`\n=========== HANGOUT OTP (send failed, console fallback) ===========`)
    console.log(`  To: ${toEmail}`)
    console.log(`  OTP: ${code}`)
    console.log(`===================================================================\n`)
    return { fallback: true, error: err.message }
  }
}

// ============================================================
// SECTION 2 — MONGOOSE MODELS
// ============================================================

const { Schema, model } = mongoose

// ─── User ───
const UserSchema = new Schema({
  userId:   { type: String, required: true, unique: true, index: true, default: () => `u_${nanoid(10)}` },
  email:    { type: String, required: true, unique: true, lowercase: true, index: true },
  phone:    { type: String, default: null, index: true },
  password: { type: String, required: true },
  profileName: { type: String, required: true },
  avatar:   { type: String, default: null },  // Drive file ID — fetched via /api/file/:fileId
  bio:      { type: String, default: null },
  about:    { type: String, default: null },
  language: { type: String, default: 'en' },
  theme:    { type: String, default: 'dark' },
  wallpaper:{ type: String, default: 'default' },
  isOnline: { type: Boolean, default: false },
  lastSeen: { type: Date, default: Date.now },
  createdAt:{ type: Date, default: Date.now },
  updatedAt:{ type: Date, default: Date.now },
})
const User = model('User', UserSchema)

// ─── UserSettings ───
const UserSettingsSchema = new Schema({
  userId: { type: Schema.Types.ObjectId, ref: 'User', required: true, unique: true, index: true },
  lastSeenVisible:    { type: Boolean, default: true },
  profilePhotoVisible:{ type: String, default: 'everyone' },
  statusVisible:      { type: String, default: 'contacts' },
  readReceipts:       { type: Boolean, default: true },
  groupsEveryone:     { type: Boolean, default: true },
  notifMessages:      { type: Boolean, default: true },
  notifCalls:         { type: Boolean, default: true },
  notifReactions:     { type: Boolean, default: true },
  notifSound:         { type: Boolean, default: true },
  notifVibrate:       { type: Boolean, default: true },
  enterToSend:        { type: Boolean, default: true },
  showOnlineStatus:   { type: Boolean, default: true },
  fontScale:          { type: Number, default: 1.0 },
  mediaAutoDownload:  { type: Boolean, default: true },
  dataSaver:          { type: Boolean, default: false },
  updatedAt:          { type: Date, default: Date.now },
})
const UserSettings = model('UserSettings', UserSettingsSchema)

// ─── Friendship ───
const FriendshipSchema = new Schema({
  requesterId: { type: Schema.Types.ObjectId, ref: 'User', required: true, index: true },
  receiverId:  { type: Schema.Types.ObjectId, ref: 'User', required: true, index: true },
  status:      { type: String, default: 'pending' },  // pending | accepted | declined | blocked
  createdAt:   { type: Date, default: Date.now },
  updatedAt:   { type: Date, default: Date.now },
})
FriendshipSchema.index({ requesterId: 1, receiverId: 1 }, { unique: true })
const Friendship = model('Friendship', FriendshipSchema)

// ─── Block ───
const BlockSchema = new Schema({
  blockerId: { type: Schema.Types.ObjectId, ref: 'User', required: true, index: true },
  blockedId: { type: Schema.Types.ObjectId, ref: 'User', required: true, index: true },
  createdAt: { type: Date, default: Date.now },
})
BlockSchema.index({ blockerId: 1, blockedId: 1 }, { unique: true })
const Block = model('Block', BlockSchema)

// ─── Conversation ───
const ConversationSchema = new Schema({
  userAId: { type: Schema.Types.ObjectId, ref: 'User', required: true, index: true },
  userBId: { type: Schema.Types.ObjectId, ref: 'User', required: true, index: true },
  lastMessageId: { type: Schema.Types.ObjectId, ref: 'Message', default: null },
  lastMessageAt: { type: Date, default: Date.now },
  unreadA: { type: Number, default: 0 },
  unreadB: { type: Number, default: 0 },
  createdAt: { type: Date, default: Date.now },
  updatedAt: { type: Date, default: Date.now },
})
ConversationSchema.index({ userAId: 1, userBId: 1 }, { unique: true })
const Conversation = model('Conversation', ConversationSchema)

// ─── Message ───
const MessageSchema = new Schema({
  conversationId: { type: Schema.Types.ObjectId, ref: 'Conversation', required: true, index: true },
  senderId:    { type: Schema.Types.ObjectId, ref: 'User', required: true, index: true },
  receiverId:  { type: Schema.Types.ObjectId, ref: 'User', required: true, index: true },
  content:     { type: String, default: '' },
  type:        { type: String, default: 'text' },  // text | image | video | audio | file | system
  mediaUrl:    { type: String, default: null },  // Drive file ID for media messages
  replyToId:   { type: Schema.Types.ObjectId, ref: 'Message', default: null },
  status:      { type: String, default: 'sent' },  // sent | delivered | read
  starred:     { type: Boolean, default: false },
  deleted:     { type: Boolean, default: false },
  createdAt:   { type: Date, default: Date.now },
})
MessageSchema.index({ conversationId: 1, createdAt: 1 })
const Message = model('Message', MessageSchema)

// ─── Status ───
const StatusSchema = new Schema({
  userId: { type: Schema.Types.ObjectId, ref: 'User', required: true, index: true },
  type:   { type: String, default: 'text' },  // text | image | video
  content:{ type: String, default: '' },
  bgColor:{ type: String, default: '#0f172a' },
  mediaUrl: { type: String, default: null },  // Drive file ID
  caption: { type: String, default: null },
  expiresAt: { type: Date, required: true },
  createdAt: { type: Date, default: Date.now },
})
StatusSchema.index({ userId: 1, createdAt: -1 })
const Status = model('Status', StatusSchema)

// ─── StatusView ───
const StatusViewSchema = new Schema({
  statusId: { type: Schema.Types.ObjectId, ref: 'Status', required: true, index: true },
  userId:   { type: Schema.Types.ObjectId, ref: 'User', required: true, index: true },
  createdAt:{ type: Date, default: Date.now },
})
StatusViewSchema.index({ statusId: 1, userId: 1 }, { unique: true })
const StatusView = model('StatusView', StatusViewSchema)

// ─── Post ───
const PostSchema = new Schema({
  userId: { type: Schema.Types.ObjectId, ref: 'User', required: true, index: true },
  content:{ type: String, default: '' },
  mediaUrl: { type: String, default: null },  // Drive file ID
  mediaType:{ type: String, default: null },  // image | video
  location:{ type: String, default: null },
  feeling: { type: String, default: null },
  createdAt: { type: Date, default: Date.now },
  updatedAt: { type: Date, default: Date.now },
})
PostSchema.index({ createdAt: -1 })
const Post = model('Post', PostSchema)

// ─── PostLike ───
const PostLikeSchema = new Schema({
  postId: { type: Schema.Types.ObjectId, ref: 'Post', required: true, index: true },
  userId: { type: Schema.Types.ObjectId, ref: 'User', required: true, index: true },
  createdAt: { type: Date, default: Date.now },
})
PostLikeSchema.index({ postId: 1, userId: 1 }, { unique: true })
const PostLike = model('PostLike', PostLikeSchema)

// ─── PostComment ───
const PostCommentSchema = new Schema({
  postId: { type: Schema.Types.ObjectId, ref: 'Post', required: true, index: true },
  userId: { type: Schema.Types.ObjectId, ref: 'User', required: true },
  content:{ type: String, required: true },
  createdAt: { type: Date, default: Date.now },
})
PostCommentSchema.index({ postId: 1, createdAt: -1 })
const PostComment = model('PostComment', PostCommentSchema)

// ─── Reel ───
const ReelSchema = new Schema({
  userId: { type: Schema.Types.ObjectId, ref: 'User', required: true, index: true },
  // videoId — HF reels backend का unique ID (असली video वहाँ है)
  videoId: { type: String, required: true, index: true },
  driveFileId: { type: String, default: null },  // HF reels backend का Drive ID
  caption: { type: String, default: null },
  musicName: { type: String, default: null },
  createdAt: { type: Date, default: Date.now },
})
ReelSchema.index({ createdAt: -1 })
const Reel = model('Reel', ReelSchema)

// ─── ReelLike ───
const ReelLikeSchema = new Schema({
  reelId: { type: Schema.Types.ObjectId, ref: 'Reel', required: true, index: true },
  userId: { type: Schema.Types.ObjectId, ref: 'User', required: true, index: true },
  createdAt: { type: Date, default: Date.now },
})
ReelLikeSchema.index({ reelId: 1, userId: 1 }, { unique: true })
const ReelLike = model('ReelLike', ReelLikeSchema)

// ─── ReelComment ───
const ReelCommentSchema = new Schema({
  reelId: { type: Schema.Types.ObjectId, ref: 'Reel', required: true, index: true },
  userId: { type: Schema.Types.ObjectId, ref: 'User', required: true },
  content:{ type: String, required: true },
  createdAt: { type: Date, default: Date.now },
})
ReelCommentSchema.index({ reelId: 1, createdAt: -1 })
const ReelComment = model('ReelComment', ReelCommentSchema)

// ─── Call ───
const CallSchema = new Schema({
  callerId: { type: Schema.Types.ObjectId, ref: 'User', required: true, index: true },
  receiverId: { type: Schema.Types.ObjectId, ref: 'User', required: true, index: true },
  type:    { type: String, default: 'audio' },  // audio | video
  status:  { type: String, default: 'missed' },  // missed | answered | declined | failed
  duration:{ type: Number, default: 0 },
  startedAt: { type: Date, default: Date.now },
  endedAt: { type: Date, default: null },
})
CallSchema.index({ callerId: 1, startedAt: -1 })
CallSchema.index({ receiverId: 1, startedAt: -1 })
const Call = model('Call', CallSchema)

// ─── OtpCode ───
const OtpCodeSchema = new Schema({
  identifier: { type: String, required: true, index: true },  // email or phone
  code: { type: String, required: true },
  purpose: { type: String, default: 'signup' },  // signup | login
  consumed: { type: Boolean, default: false },
  expiresAt: { type: Date, required: true },
  createdAt: { type: Date, default: Date.now },
})
OtpCodeSchema.index({ identifier: 1, createdAt: -1 })
const OtpCode = model('OtpCode', OtpCodeSchema)

// ============================================================
// SECTION 3 — HELPER FUNCTIONS
// ============================================================

// Sign JWT for a user
function signToken(user) {
  return jwt.sign(
    {
      id: user._id.toString(),
      userId: user.userId,
      email: user.email,
      profileName: user.profileName,
      avatar: user.avatar,
    },
    JWT_SECRET,
    { expiresIn: '30d' }
  )
}

// Verify JWT
function verifyToken(token) {
  try {
    return jwt.verify(token, JWT_SECRET)
  } catch {
    return null
  }
}

// Get authenticated user from request
async function getAuthUser(req) {
  let token = null
  // Try cookie first
  if (req.cookies && req.cookies[TOKEN_COOKIE]) {
    token = req.cookies[TOKEN_COOKIE]
  }
  // Then Authorization header
  if (!token && req.headers.authorization?.startsWith('Bearer ')) {
    token = req.headers.authorization.slice(7)
  }
  if (!token) return null
  const decoded = verifyToken(token)
  if (!decoded) return null
  // Fetch fresh user from DB (avatar/name may have changed)
  const user = await User.findById(decoded.id).lean()
  return user
}

// Set auth cookie
function setAuthCookie(res, token) {
  res.cookie(TOKEN_COOKIE, token, {
    httpOnly: false,  // APK WebView को JS से access करने देना है
    sameSite: 'none',  // cross-origin (APK → HF Space)
    secure: true,  // HTTPS required
    path: '/',
    maxAge: 60 * 60 * 24 * 30,  // 30 days
  })
}

function clearAuthCookie(res) {
  res.clearCookie(TOKEN_COOKIE, { path: '/' })
}

// Hash password
async function hashPassword(p) {
  return bcrypt.hash(p, 10)
}

async function comparePassword(p, hash) {
  return bcrypt.compare(p, hash)
}

// Generate 6-digit OTP
function generateOtp() {
  return Math.floor(100000 + Math.random() * 900000).toString()
}

// Find user by email or phone
async function findUserByIdentifier(identifier) {
  const isEmail = identifier.includes('@')
  if (isEmail) {
    return User.findOne({ email: identifier.toLowerCase() }).lean()
  }
  return User.findOne({ phone: identifier }).lean()
}

// Initialize default settings for new user
async function initUserSettings(userId) {
  const existing = await UserSettings.findOne({ userId })
  if (!existing) {
    await UserSettings.create({ userId })
  }
}

// Get or create conversation between two users
async function getOrCreateConversation(userAId, userBId) {
  // Sort IDs to ensure consistent ordering
  const [a, b] = userAId < userBId ? [userAId, userBId] : [userBId, userAId]
  let conv = await Conversation.findOne({ userAId: a, userBId: b })
  if (!conv) {
    conv = await Conversation.create({ userAId: a, userBId: b })
  }
  return conv
}

// Public-safe user object (no password)
function publicUser(u) {
  if (!u) return null
  return {
    id: u._id.toString(),
    userId: u.userId,
    profileName: u.profileName,
    avatar: u.avatar ? `/api/file/${u.avatar}` : null,  // proxy via our stream route
    bio: u.bio,
    about: u.about,
    isOnline: u.isOnline,
    lastSeen: u.lastSeen,
  }
}

// ============================================================
// SECTION 4 — MIDDLEWARE
// ============================================================

// Auth middleware (for protected routes)
function authMiddleware(req, res, next) {
  getAuthUser(req)
    .then((user) => {
      if (!user) {
        return res.status(401).json({ error: 'Unauthorized' })
      }
      req.user = user
      next()
    })
    .catch((err) => {
      console.error('[auth] error:', err.message)
      res.status(500).json({ error: 'Auth error' })
    })
}

// Multer config — STRICT memoryStorage (no disk)
const MAX_UPLOAD_SIZE = 10 * 1024 * 1024  // 10 MB for images/avatars
const ALLOWED_IMAGE_MIME = ['image/jpeg', 'image/png', 'image/webp', 'image/gif']

const upload = multer({
  storage: multer.memoryStorage(),
  limits: { fileSize: MAX_UPLOAD_SIZE, files: 1 },
  fileFilter: (req, file, cb) => {
    if (ALLOWED_IMAGE_MIME.includes(file.mimetype)) {
      cb(null, true)
    } else {
      cb(new Error(`Unsupported MIME: ${file.mimetype}. Allowed: ${ALLOWED_IMAGE_MIME.join(', ')}`), false)
    }
  },
})

// ============================================================
// SECTION 5 — ROUTES (all 28+ in one place)
// ============================================================

const app = express()

// ─── GLOBAL MIDDLEWARE (must be before routes) ───
// Security headers
app.use(
  helmet({
    crossOriginResourcePolicy: { policy: 'cross-origin' },
    contentSecurityPolicy: false,
  })
)

// CORS (configurable for APK WebView)
const allowedOrigins = (process.env.CORS_ORIGINS || '*')
  .split(',')
  .map((s) => s.trim())
  .filter(Boolean)

app.use(
  cors({
    origin: allowedOrigins.includes('*') ? true : allowedOrigins,
    methods: ['GET', 'POST', 'PUT', 'DELETE', 'HEAD', 'OPTIONS'],
    allowedHeaders: ['Content-Type', 'Authorization', 'X-API-Key', 'Range', 'Cookie'],
    exposedHeaders: ['Content-Length', 'Content-Range', 'Accept-Ranges', 'Content-Type', 'Set-Cookie'],
    credentials: true,  // ⚠️ Required for cookies to work cross-origin (APK → HF Space)
    maxAge: 86400,
  })
)

app.set('trust proxy', 1)

// Cookie parser (needed for JWT cookie auth)
app.use(cookieParser())

// Body parsers (must be before routes!)
app.use(express.json({ limit: '5mb' }))
app.use(express.urlencoded({ extended: true, limit: '5mb' }))

// ─── Health & Info Routes ───
app.get('/health', (req, res) => {
  res.json({
    status: 'ok',
    service: 'hangout-main-backend',
    version: '1.0.0',
    timestamp: new Date().toISOString(),
    uptime: process.uptime(),
  })
})

app.get('/health/deep', async (req, res) => {
  const checks = { service: 'ok', database: 'unknown', drive: 'unknown', mailer: 'unknown' }
  try {
    await connectDB()
    checks.database = dbConnected ? 'ok' : 'error'
  } catch (err) {
    checks.database = `error: ${err.message}`
  }
  try {
    getDriveClient()
    getDriveFolderId()
    checks.drive = 'configured'
  } catch (err) {
    checks.drive = `error: ${err.message}`
  }
  checks.mailer = getMailer() ? 'configured' : 'fallback-console'
  const isHealthy = checks.database === 'ok' && checks.drive === 'configured'
  res.status(isHealthy ? 200 : 503).json({
    status: isHealthy ? 'ok' : 'degraded',
    checks,
    timestamp: new Date().toISOString(),
  })
})

app.get('/info', (req, res) => {
  res.json({
    service: 'hangout-main-backend',
    version: '1.0.0',
    reelsBackendUrl: REELS_BACKEND_URL,
    upload: {
      maxFileSize: MAX_UPLOAD_SIZE,
      maxFileSizeMB: MAX_UPLOAD_SIZE / 1024 / 1024,
      allowedMimeTypes: ALLOWED_IMAGE_MIME,
      fieldName: 'file',
    },
    authMode: 'jwt-cookie',
    otpTransport: getMailer() ? 'email' : 'console',
  })
})

app.get('/', (req, res) => {
  res.json({
    name: 'HangOut Main Backend',
    version: '1.0.0',
    description: 'Single-file Express backend for HangOut — auth, chats, friends, posts, reels, calls, settings',
    author: 'RVK EDITION',
    endpoints: {
      auth: '/api/auth/{register,login,verify-otp,me,logout}',
      chats: '/api/chats/{list,messages,send}',
      friends: '/api/friends/{list,search,request,accept,decline,remove,requests}',
      status: '/api/status/{list,create,view}',
      posts: '/api/posts/{list,create,like,comment}',
      reels: '/api/reels/{list,create,like,comment}',
      calls: '/api/calls/{list,log}',
      settings: '/api/settings',
      profile: '/api/profile/{update,block,blocked,unblock}',
      file: '/api/file/:fileId (stream from Drive)',
      upload: '/api/upload (image to Drive)',
      discover: '/api/discover/users',
      seed: '/api/seed',
      health: '/health, /health/deep, /info',
    },
  })
})

// ─── AUTH ROUTES ───

// POST /api/auth/register — send OTP
app.post('/api/auth/register', async (req, res) => {
  try {
    const { identifier, password, userId, profileName } = req.body
    if (!identifier || !password || !userId || !profileName) {
      return res.status(400).json({ error: 'All fields required: identifier, password, userId, profileName' })
    }
    if (password.length < 6) {
      return res.status(400).json({ error: 'Password must be at least 6 characters' })
    }
    if (userId.length < 3) {
      return res.status(400).json({ error: 'User ID must be at least 3 characters' })
    }
    const isEmail = identifier.includes('@')
    if (isEmail) {
      const emailRegex = /^[^\s@]+@[^\s@]+\.[^\s@]+$/
      if (!emailRegex.test(identifier)) {
        return res.status(400).json({ error: 'Invalid email format' })
      }
    } else {
      const phoneRegex = /^\+?[0-9]{10,15}$/
      if (!phoneRegex.test(identifier)) {
        return res.status(400).json({ error: 'Invalid phone format' })
      }
    }
    const existing = await findUserByIdentifier(identifier)
    if (existing) {
      return res.status(409).json({ error: 'This email/phone is already registered' })
    }
    const existingUserId = await User.findOne({ userId })
    if (existingUserId) {
      return res.status(409).json({ error: 'This user ID is taken' })
    }

    const otp = generateOtp()
    const expiresAt = new Date(Date.now() + 10 * 60 * 1000)
    await OtpCode.create({ identifier, code: otp, purpose: 'signup', expiresAt })

    // Send OTP
    if (isEmail) {
      const result = await sendOtpEmail(identifier, otp)
      return res.json({
        message: result.fallback
          ? 'OTP generated (email send failed — check server console)'
          : 'OTP sent to your email',
        identifier,
        otp: result.fallback ? otp : undefined,  // only return OTP if fallback
        expiresAt: expiresAt.toISOString(),
      })
    } else {
      // Phone — console fallback (no SMS gateway)
      console.log(`\n=========== HANGOUT OTP (phone, console) ===========`)
      console.log(`  To: ${identifier}`)
      console.log(`  OTP: ${otp}`)
      console.log(`====================================================\n`)
      return res.json({
        message: 'OTP generated (phone — check server console)',
        identifier,
        otp,
        expiresAt: expiresAt.toISOString(),
      })
    }
  } catch (e) {
    console.error('[auth/register] error:', e)
    res.status(500).json({ error: e?.message || 'Server error' })
  }
})

// POST /api/auth/login — verify password + send OTP
app.post('/api/auth/login', async (req, res) => {
  try {
    const { identifier, password } = req.body
    if (!identifier || !password) {
      return res.status(400).json({ error: 'identifier and password required' })
    }
    const user = await findUserByIdentifier(identifier)
    if (!user) {
      return res.status(404).json({ error: 'No account found with this email/phone' })
    }
    const ok = await comparePassword(password, user.password)
    if (!ok) {
      return res.status(401).json({ error: 'Incorrect password' })
    }

    const otp = generateOtp()
    const expiresAt = new Date(Date.now() + 10 * 60 * 1000)
    await OtpCode.create({ identifier, code: otp, purpose: 'login', expiresAt })

    const isEmail = identifier.includes('@')
    if (isEmail) {
      const result = await sendOtpEmail(identifier, otp)
      return res.json({
        message: result.fallback ? 'OTP generated (email failed — console)' : 'OTP sent to your email',
        requireOtp: true,
        identifier,
        otp: result.fallback ? otp : undefined,
        expiresAt: expiresAt.toISOString(),
      })
    } else {
      console.log(`\n=========== HANGOUT LOGIN OTP (phone) ===========`)
      console.log(`  To: ${identifier}`)
      console.log(`  OTP: ${otp}`)
      console.log(`=================================================\n`)
      return res.json({
        message: 'OTP sent (phone — check console)',
        requireOtp: true,
        identifier,
        otp,
        expiresAt: expiresAt.toISOString(),
      })
    }
  } catch (e) {
    console.error('[auth/login] error:', e)
    res.status(500).json({ error: e?.message || 'Server error' })
  }
})

// POST /api/auth/verify-otp — verify + create/login user
app.post('/api/auth/verify-otp', async (req, res) => {
  try {
    const { purpose = 'signup', identifier, otp, password, userId, profileName } = req.body
    if (!identifier || !otp) {
      return res.status(400).json({ error: 'identifier and otp are required' })
    }

    const record = await OtpCode.findOne({
      identifier,
      consumed: false,
      purpose,
    }).sort({ createdAt: -1 })

    if (!record) {
      return res.status(404).json({ error: 'No active OTP found. Please request a new one.' })
    }
    if (record.expiresAt < new Date()) {
      return res.status(410).json({ error: 'OTP expired. Please request a new one.' })
    }
    if (record.code !== otp) {
      return res.status(400).json({ error: 'Invalid OTP code' })
    }

    // Mark OTP as consumed
    record.consumed = true
    await record.save()

    if (purpose === 'signup') {
      if (!password || !userId || !profileName) {
        return res.status(400).json({ error: 'password, userId, profileName required for signup' })
      }
      const isEmail = identifier.includes('@')
      const existing = await findUserByIdentifier(identifier)
      if (existing) {
        return res.status(409).json({ error: 'User already exists' })
      }
      const existingUserId = await User.findOne({ userId })
      if (existingUserId) {
        return res.status(409).json({ error: 'User ID taken' })
      }
      const passwordHash = await hashPassword(password)
      const newUser = await User.create({
        userId,
        email: isEmail ? identifier.toLowerCase() : `${identifier}@phone.hangout`,
        phone: isEmail ? null : identifier,
        password: passwordHash,
        profileName,
      })
      await initUserSettings(newUser._id)
      const token = signToken(newUser)
      setAuthCookie(res, token)
      return res.json({
        token,
        user: {
          id: newUser._id.toString(),
          userId: newUser.userId,
          email: newUser.email,
          phone: newUser.phone,
          profileName: newUser.profileName,
          avatar: newUser.avatar,
          bio: newUser.bio,
          about: newUser.about,
          language: newUser.language,
        },
      })
    } else if (purpose === 'login') {
      const user = await findUserByIdentifier(identifier)
      if (!user) {
        return res.status(404).json({ error: 'User not found' })
      }
      const token = signToken(user)
      setAuthCookie(res, token)
      return res.json({
        token,
        user: {
          id: user._id.toString(),
          userId: user.userId,
          email: user.email,
          phone: user.phone,
          profileName: user.profileName,
          avatar: user.avatar,
          bio: user.bio,
          about: user.about,
          language: user.language,
        },
      })
    } else {
      return res.status(400).json({ error: 'Invalid purpose' })
    }
  } catch (e) {
    console.error('[auth/verify-otp] error:', e)
    res.status(500).json({ error: e?.message || 'Server error' })
  }
})

// GET /api/auth/me
app.get('/api/auth/me', async (req, res) => {
  const user = await getAuthUser(req)
  if (!user) return res.json({ user: null })
  const settings = await UserSettings.findOne({ userId: user._id }).lean()
  return res.json({
    user: {
      id: user._id.toString(),
      userId: user.userId,
      email: user.email,
      phone: user.phone,
      profileName: user.profileName,
      avatar: user.avatar ? `/api/file/${user.avatar}` : null,
      bio: user.bio,
      about: user.about,
      language: user.language,
      theme: user.theme,
      wallpaper: user.wallpaper,
      isOnline: user.isOnline,
      lastSeen: user.lastSeen,
      createdAt: user.createdAt,
      settings,
    },
  })
})

// POST /api/auth/logout
app.post('/api/auth/logout', (req, res) => {
  clearAuthCookie(res)
  res.json({ ok: true })
})

// ─── FILE ROUTE — Stream image from Google Drive (avatars, post images) ───

app.get('/api/file/:fileId', async (req, res) => {
  const { fileId } = req.params
  if (!fileId) return res.status(400).json({ error: 'fileId required' })
  try {
    const drive = getDriveClient()
    // Get metadata for Content-Type + size
    const meta = await drive.files.get({ fileId, fields: 'size, mimeType, name' })
    const mimeType = meta.data.mimeType || 'application/octet-stream'
    const size = parseInt(meta.data.size || '0', 10)

    // Stream file content
    const driveResponse = await drive.files.get(
      { fileId, alt: 'media' },
      { responseType: 'stream' }
    )
    const driveStream = driveResponse.data

    res.set({
      'Content-Type': mimeType,
      'Cache-Control': 'public, max-age=86400',  // 24h browser cache
    })
    if (size > 0) res.set('Content-Length', String(size))

    // Memory leak prevention
    const onClose = () => {
      if (driveStream && !driveStream.destroyed) driveStream.destroy()
    }
    req.on('close', onClose)
    req.on('aborted', onClose)
    driveStream.on('error', (err) => {
      console.error('[file] stream error:', err.message)
      if (!res.headersSent) res.status(502).json({ error: 'Drive stream error' })
      else res.end()
      onClose()
    })
    driveStream.pipe(res)
    res.on('finish', () => {
      req.removeListener('close', onClose)
      req.removeListener('aborted', onClose)
      onClose()
    })
  } catch (err) {
    console.error('[file] error:', err.message)
    if (!res.headersSent) res.status(502).json({ error: 'Failed to fetch file', detail: err.message })
  }
})

// ─── UPLOAD ROUTE — Image upload to Google Drive ───

app.post('/api/upload', authMiddleware, upload.single('file'), async (req, res) => {
  if (!req.file) {
    return res.status(400).json({ error: 'No file uploaded. Field name must be "file".' })
  }
  try {
    const { buffer, originalname, mimetype, size } = req.file
    const ext = (originalname.split('.').pop() || 'jpg').toLowerCase()
    const fileName = `uploads/${req.user._id}/${Date.now()}-${nanoid(10)}.${ext}`
    const fileId = await uploadBufferToDrive(buffer, fileName, mimetype)
    return res.json({
      fileId,
      url: `/api/file/${fileId}`,
      fileName,
      mimeType: mimetype,
      size,
    })
  } catch (err) {
    console.error('[upload] error:', err.message)
    res.status(502).json({ error: 'Upload failed', detail: err.message })
  }
})

// ─── CHATS ROUTES ───

// GET /api/chats/list
app.get('/api/chats/list', authMiddleware, async (req, res) => {
  try {
    const convs = await Conversation.find({
      $or: [{ userAId: req.user._id }, { userBId: req.user._id }],
    })
      .populate('userAId')
      .populate('userBId')
      .populate('lastMessageId')
      .sort({ lastMessageAt: -1 })
      .lean()

    const result = convs.map((c) => {
      const other = c.userAId._id.toString() === req.user._id.toString() ? c.userBId : c.userAId
      const unread = c.userAId._id.toString() === req.user._id.toString() ? c.unreadA : c.unreadB
      return {
        id: c._id.toString(),
        otherUser: publicUser(other),
        lastMessage: c.lastMessageId
          ? {
              id: c.lastMessageId._id.toString(),
              content: c.lastMessageId.content,
              type: c.lastMessageId.type,
              senderId: c.lastMessageId.senderId.toString(),
              createdAt: c.lastMessageId.createdAt,
              status: c.lastMessageId.status,
            }
          : null,
        lastMessageAt: c.lastMessageAt,
        unread,
      }
    })
    res.json({ conversations: result })
  } catch (e) {
    console.error('[chats/list] error:', e)
    res.status(500).json({ error: e?.message || 'Server error' })
  }
})

// GET /api/chats/messages?userId=xxx
app.get('/api/chats/messages', authMiddleware, async (req, res) => {
  try {
    const otherUserId = req.query.userId
    if (!otherUserId) return res.status(400).json({ error: 'userId required' })
    const otherUser = await User.findById(otherUserId).lean()
    if (!otherUser) return res.status(404).json({ error: 'User not found' })

    const conv = await getOrCreateConversation(req.user._id, otherUserId)
    const limit = Math.min(parseInt(req.query.limit || '200', 10), 500)
    const messages = await Message.find({ conversationId: conv._id, deleted: false })
      .sort({ createdAt: 1 })
      .limit(limit)
      .lean()

    // Mark messages from other user as read
    await Message.updateMany(
      { conversationId: conv._id, receiverId: req.user._id, status: { $ne: 'read' } },
      { $set: { status: 'read' } }
    )
    // Reset unread counter for current user
    const isUserA = conv.userAId.toString() === req.user._id.toString()
    if (isUserA) {
      await Conversation.updateOne({ _id: conv._id }, { $set: { unreadA: 0 } })
    } else {
      await Conversation.updateOne({ _id: conv._id }, { $set: { unreadB: 0 } })
    }

    res.json({
      conversation: { id: conv._id.toString() },
      messages: messages.map((m) => ({
        id: m._id.toString(),
        conversationId: m.conversationId.toString(),
        senderId: m.senderId.toString(),
        receiverId: m.receiverId.toString(),
        content: m.content,
        type: m.type,
        mediaUrl: m.mediaUrl ? `/api/file/${m.mediaUrl}` : null,
        status: m.status,
        starred: m.starred,
        createdAt: m.createdAt,
      })),
    })
  } catch (e) {
    console.error('[chats/messages] error:', e)
    res.status(500).json({ error: e?.message || 'Server error' })
  }
})

// POST /api/chats/send
app.post('/api/chats/send', authMiddleware, async (req, res) => {
  try {
    const { receiverId, content, type = 'text', mediaUrl, replyToId } = req.body
    if (!receiverId || (!content && !mediaUrl)) {
      return res.status(400).json({ error: 'receiverId and content/mediaUrl required' })
    }
    const receiver = await User.findById(receiverId).lean()
    if (!receiver) return res.status(404).json({ error: 'Receiver not found' })

    const conv = await getOrCreateConversation(req.user._id, receiverId)
    const message = await Message.create({
      conversationId: conv._id,
      senderId: req.user._id,
      receiverId,
      content: content || '',
      type,
      mediaUrl: mediaUrl || null,
      replyToId: replyToId || null,
      status: 'sent',
    })

    const isUserA = conv.userAId.toString() === req.user._id.toString()
    const update = {
      lastMessageId: message._id,
      lastMessageAt: new Date(),
    }
    if (isUserA) update.$inc = { unreadB: 1 }
    else update.$inc = { unreadA: 1 }
    await Conversation.updateOne({ _id: conv._id }, update)

    res.json({
      message: {
        id: message._id.toString(),
        conversationId: message.conversationId.toString(),
        senderId: message.senderId.toString(),
        receiverId: message.receiverId.toString(),
        content: message.content,
        type: message.type,
        mediaUrl: message.mediaUrl ? `/api/file/${message.mediaUrl}` : null,
        status: message.status,
        createdAt: message.createdAt,
        clientId: req.body.clientId || null,
      },
    })
  } catch (e) {
    console.error('[chats/send] error:', e)
    res.status(500).json({ error: e?.message || 'Server error' })
  }
})

// ─── FRIENDS ROUTES ───

// GET /api/friends/list
app.get('/api/friends/list', authMiddleware, async (req, res) => {
  try {
    const friendships = await Friendship.find({
      $or: [{ requesterId: req.user._id }, { receiverId: req.user._id }],
      status: 'accepted',
    })
      .populate('requesterId')
      .populate('receiverId')
      .lean()
    const friends = friendships.map((f) =>
      f.requesterId._id.toString() === req.user._id.toString() ? f.receiverId : f.requesterId
    )
    res.json({ friends: friends.map(publicUser) })
  } catch (e) {
    console.error('[friends/list] error:', e)
    res.status(500).json({ error: e?.message || 'Server error' })
  }
})

// GET /api/friends/search?q=keyword
app.get('/api/friends/search', authMiddleware, async (req, res) => {
  try {
    const q = (req.query.q || '').trim()
    if (q.length < 1) return res.json({ users: [] })

    const users = await User.find({
      _id: { $ne: req.user._id },
      $or: [
        { userId: { $regex: q, $options: 'i' } },
        { profileName: { $regex: q, $options: 'i' } },
        { email: { $regex: q, $options: 'i' } },
        { phone: { $regex: q, $options: 'i' } },
      ],
    }).limit(30).lean()

    const ids = users.map((u) => u._id)
    const friendships = await Friendship.find({
      $or: [
        { requesterId: req.user._id, receiverId: { $in: ids } },
        { receiverId: req.user._id, requesterId: { $in: ids } },
      ],
    }).lean()
    const statusMap = new Map()
    for (const f of friendships) {
      const otherId = f.requesterId.toString() === req.user._id.toString() ? f.receiverId : f.requesterId
      statusMap.set(otherId.toString(), f.status)
    }
    const blocks = await Block.find({
      $or: [{ blockerId: req.user._id }, { blockedId: req.user._id }],
    }).lean()
    const blockSet = new Set()
    for (const b of blocks) {
      if (b.blockerId.toString() === req.user._id.toString()) blockSet.add(b.blockedId.toString())
      else blockSet.add(b.blockerId.toString())
    }

    res.json({
      users: users.map((u) => ({
        ...publicUser(u),
        friendStatus: statusMap.get(u._id.toString()) || 'none',
        isBlocked: blockSet.has(u._id.toString()),
      })),
    })
  } catch (e) {
    console.error('[friends/search] error:', e)
    res.status(500).json({ error: e?.message || 'Server error' })
  }
})

// GET /api/friends/requests?direction=received|sent
app.get('/api/friends/requests', authMiddleware, async (req, res) => {
  try {
    const direction = req.query.direction || 'received'
    let where, includeOther
    if (direction === 'sent') {
      where = { requesterId: req.user._id, status: 'pending' }
      includeOther = 'receiverId'
    } else {
      where = { receiverId: req.user._id, status: 'pending' }
      includeOther = 'requesterId'
    }
    const requests = await Friendship.find(where).populate(includeOther).sort({ createdAt: -1 }).lean()
    res.json({
      requests: requests.map((r) => ({
        id: r._id.toString(),
        user: publicUser(r[includeOther]),
        createdAt: r.createdAt,
      })),
    })
  } catch (e) {
    console.error('[friends/requests] error:', e)
    res.status(500).json({ error: e?.message || 'Server error' })
  }
})

// POST /api/friends/request
app.post('/api/friends/request', authMiddleware, async (req, res) => {
  try {
    const { receiverId } = req.body
    if (!receiverId) return res.status(400).json({ error: 'receiverId required' })
    if (receiverId === req.user._id.toString()) {
      return res.status(400).json({ error: 'Cannot friend yourself' })
    }
    const block = await Block.findOne({
      $or: [
        { blockerId: req.user._id, blockedId: receiverId },
        { blockerId: receiverId, blockedId: req.user._id },
      ],
    })
    if (block) return res.status(403).json({ error: 'Cannot send request — blocked' })

    const existing = await Friendship.findOne({
      $or: [
        { requesterId: req.user._id, receiverId: receiverId },
        { requesterId: receiverId, receiverId: req.user._id },
      ],
    })
    if (existing) {
      if (existing.status === 'accepted') {
        return res.status(409).json({ error: 'Already friends' })
      }
      if (existing.status === 'pending') {
        if (existing.receiverId.toString() === req.user._id.toString()) {
          await Friendship.updateOne({ _id: existing._id }, { $set: { status: 'accepted' } })
          return res.json({ status: 'accepted', message: 'You are now friends' })
        }
        return res.status(409).json({ error: 'Request already sent' })
      }
    }
    const friend = await Friendship.create({
      requesterId: req.user._id,
      receiverId: receiverId,
      status: 'pending',
    })
    res.json({ status: 'pending', id: friend._id.toString() })
  } catch (e) {
    console.error('[friends/request] error:', e)
    res.status(500).json({ error: e?.message || 'Server error' })
  }
})

// POST /api/friends/accept
app.post('/api/friends/accept', authMiddleware, async (req, res) => {
  try {
    const { requestId, userId } = req.body
    let friendship
    if (requestId) {
      friendship = await Friendship.findById(requestId)
    } else if (userId) {
      friendship = await Friendship.findOne({ requesterId: userId, receiverId: req.user._id, status: 'pending' })
    }
    if (!friendship) return res.status(404).json({ error: 'Friend request not found' })
    if (friendship.receiverId.toString() !== req.user._id.toString()) {
      return res.status(403).json({ error: 'Not your request to accept' })
    }
    await Friendship.updateOne({ _id: friendship._id }, { $set: { status: 'accepted' } })
    res.json({ status: 'accepted' })
  } catch (e) {
    console.error('[friends/accept] error:', e)
    res.status(500).json({ error: e?.message || 'Server error' })
  }
})

// POST /api/friends/decline
app.post('/api/friends/decline', authMiddleware, async (req, res) => {
  try {
    const { requestId, userId } = req.body
    if (requestId) {
      await Friendship.deleteOne({ _id: requestId, receiverId: req.user._id })
    } else if (userId) {
      await Friendship.deleteOne({ requesterId: userId, receiverId: req.user._id })
    } else {
      return res.status(400).json({ error: 'requestId or userId required' })
    }
    res.json({ status: 'declined' })
  } catch (e) {
    console.error('[friends/decline] error:', e)
    res.status(500).json({ error: e?.message || 'Server error' })
  }
})

// POST /api/friends/remove
app.post('/api/friends/remove', authMiddleware, async (req, res) => {
  try {
    const { userId } = req.body
    if (!userId) return res.status(400).json({ error: 'userId required' })
    await Friendship.deleteOne({
      $or: [
        { requesterId: req.user._id, receiverId: userId },
        { requesterId: userId, receiverId: req.user._id },
      ],
    })
    res.json({ status: 'removed' })
  } catch (e) {
    console.error('[friends/remove] error:', e)
    res.status(500).json({ error: e?.message || 'Server error' })
  }
})

// ─── STATUS ROUTES ───

// GET /api/status/list
app.get('/api/status/list', authMiddleware, async (req, res) => {
  try {
    const friendships = await Friendship.find({
      $or: [{ requesterId: req.user._id }, { receiverId: req.user._id }],
      status: 'accepted',
    }).lean()
    const friendIds = friendships.map((f) =>
      f.requesterId.toString() === req.user._id.toString() ? f.receiverId : f.requesterId
    )
    const visibleUserIds = [req.user._id, ...friendIds]
    const since = new Date(Date.now() - 24 * 60 * 60 * 1000)

    const statuses = await Status.find({
      userId: { $in: visibleUserIds },
      expiresAt: { $gt: new Date() },
      createdAt: { $gt: since },
    })
      .populate('userId')
      .lean()

    // Get views for these statuses
    const statusIds = statuses.map((s) => s._id)
    const views = await StatusView.find({ statusId: { $in: statusIds } }).populate('userId').lean()
    const viewsByStatus = new Map()
    for (const v of views) {
      if (!viewsByStatus.has(v.statusId.toString())) viewsByStatus.set(v.statusId.toString(), [])
      viewsByStatus.get(v.statusId.toString()).push(v)
    }

    // Group by user
    const byUser = new Map()
    for (const s of statuses) {
      const uid = s.userId._id.toString()
      if (!byUser.has(uid)) {
        byUser.set(uid, { user: publicUser(s.userId), statuses: [], hasUnviewed: false, allViewed: true })
      }
      const viewed = (viewsByStatus.get(s._id.toString()) || []).some((v) => v.userId._id.toString() === req.user._id.toString())
      if (!viewed) {
        byUser.get(uid).allViewed = false
        byUser.get(uid).hasUnviewed = true
      }
      byUser.get(uid).statuses.push({
        id: s._id.toString(),
        type: s.type,
        content: s.content,
        bgColor: s.bgColor,
        mediaUrl: s.mediaUrl ? `/api/file/${s.mediaUrl}` : null,
        caption: s.caption,
        createdAt: s.createdAt,
        expiresAt: s.expiresAt,
        viewed,
        views: (viewsByStatus.get(s._id.toString()) || []).map((v) => ({
          userId: v.userId._id.toString(),
          name: v.userId.profileName,
          avatar: v.userId.avatar ? `/api/file/${v.userId.avatar}` : null,
          viewedAt: v.createdAt,
        })),
      })
    }

    const arr = Array.from(byUser.values())
    arr.sort((a, b) => {
      if (a.user.id === req.user._id.toString()) return -1
      if (b.user.id === req.user._id.toString()) return 1
      if (a.hasUnviewed && !b.hasUnviewed) return -1
      if (!a.hasUnviewed && b.hasUnviewed) return 1
      return 0
    })
    res.json({ statuses: arr })
  } catch (e) {
    console.error('[status/list] error:', e)
    res.status(500).json({ error: e?.message || 'Server error' })
  }
})

// POST /api/status/create
app.post('/api/status/create', authMiddleware, async (req, res) => {
  try {
    const { type = 'text', content, bgColor = '#0f172a', mediaUrl, caption } = req.body
    if (!content && !mediaUrl) {
      return res.status(400).json({ error: 'content or mediaUrl required' })
    }
    const status = await Status.create({
      userId: req.user._id,
      type,
      content: content || '',
      bgColor,
      mediaUrl: mediaUrl || null,
      caption: caption || null,
      expiresAt: new Date(Date.now() + 24 * 60 * 60 * 1000),
    })
    res.json({ status })
  } catch (e) {
    console.error('[status/create] error:', e)
    res.status(500).json({ error: e?.message || 'Server error' })
  }
})

// POST /api/status/view
app.post('/api/status/view', authMiddleware, async (req, res) => {
  try {
    const { statusId } = req.body
    if (!statusId) return res.status(400).json({ error: 'statusId required' })
    await StatusView.updateOne(
      { statusId, userId: req.user._id },
      { $setOnInsert: { statusId, userId: req.user._id, createdAt: new Date() } },
      { upsert: true }
    )
    res.json({ ok: true })
  } catch (e) {
    console.error('[status/view] error:', e)
    res.status(500).json({ error: e?.message || 'Server error' })
  }
})

// ─── POSTS ROUTES ───

// GET /api/posts/list
app.get('/api/posts/list', authMiddleware, async (req, res) => {
  try {
    const limit = Math.min(parseInt(req.query.limit || '50', 10), 100)
    const posts = await Post.find().sort({ createdAt: -1 }).limit(limit).populate('userId').lean()
    const postIds = posts.map((p) => p._id)
    const likes = await PostLike.find({ postId: { $in: postIds } }).lean()
    const likesByPost = new Map()
    for (const l of likes) {
      if (!likesByPost.has(l.postId.toString())) likesByPost.set(l.postId.toString(), [])
      likesByPost.get(l.postId.toString()).push(l)
    }
    const comments = await PostComment.find({ postId: { $in: postIds } })
      .sort({ createdAt: -1 })
      .limit(50)
      .populate('userId')
      .lean()
    const commentsByPost = new Map()
    for (const c of comments) {
      if (!commentsByPost.has(c.postId.toString())) commentsByPost.set(c.postId.toString(), [])
      commentsByPost.get(c.postId.toString()).push(c)
    }

    res.json({
      posts: posts.map((p) => ({
        id: p._id.toString(),
        content: p.content,
        mediaUrl: p.mediaUrl ? `/api/file/${p.mediaUrl}` : null,
        mediaType: p.mediaType,
        location: p.location,
        feeling: p.feeling,
        createdAt: p.createdAt,
        user: publicUser(p.userId),
        likeCount: (likesByPost.get(p._id.toString()) || []).length,
        likedByMe: (likesByPost.get(p._id.toString()) || []).some((l) => l.userId.toString() === req.user._id.toString()),
        comments: (commentsByPost.get(p._id.toString()) || []).map((c) => ({
          id: c._id.toString(),
          content: c.content,
          createdAt: c.createdAt,
          user: publicUser(c.userId),
        })),
      })),
    })
  } catch (e) {
    console.error('[posts/list] error:', e)
    res.status(500).json({ error: e?.message || 'Server error' })
  }
})

// POST /api/posts/create
app.post('/api/posts/create', authMiddleware, async (req, res) => {
  try {
    const { content, mediaUrl, mediaType, location, feeling } = req.body
    if (!content && !mediaUrl) {
      return res.status(400).json({ error: 'content or mediaUrl required' })
    }
    const post = await Post.create({
      userId: req.user._id,
      content: content || '',
      mediaUrl: mediaUrl || null,
      mediaType: mediaType || null,
      location: location || null,
      feeling: feeling || null,
    })
    res.json({ post })
  } catch (e) {
    console.error('[posts/create] error:', e)
    res.status(500).json({ error: e?.message || 'Server error' })
  }
})

// POST /api/posts/like (toggle)
app.post('/api/posts/like', authMiddleware, async (req, res) => {
  try {
    const { postId } = req.body
    if (!postId) return res.status(400).json({ error: 'postId required' })
    const existing = await PostLike.findOne({ postId, userId: req.user._id })
    if (existing) {
      await PostLike.deleteOne({ _id: existing._id })
      return res.json({ liked: false })
    } else {
      await PostLike.create({ postId, userId: req.user._id })
      return res.json({ liked: true })
    }
  } catch (e) {
    console.error('[posts/like] error:', e)
    res.status(500).json({ error: e?.message || 'Server error' })
  }
})

// POST /api/posts/comment
app.post('/api/posts/comment', authMiddleware, async (req, res) => {
  try {
    const { postId, content } = req.body
    if (!postId || !content) return res.status(400).json({ error: 'postId and content required' })
    const comment = await PostComment.create({ postId, userId: req.user._id, content })
    const populated = await PostComment.findById(comment._id).populate('userId').lean()
    res.json({
      comment: {
        id: populated._id.toString(),
        content: populated.content,
        createdAt: populated.createdAt,
        user: publicUser(populated.userId),
      },
    })
  } catch (e) {
    console.error('[posts/comment] error:', e)
    res.status(500).json({ error: e?.message || 'Server error' })
  }
})

// ─── REELS ROUTES ───

// GET /api/reels/list
app.get('/api/reels/list', authMiddleware, async (req, res) => {
  try {
    const limit = Math.min(parseInt(req.query.limit || '50', 10), 100)
    const reels = await Reel.find().sort({ createdAt: -1 }).limit(limit).populate('userId').lean()
    const reelIds = reels.map((r) => r._id)
    const likes = await ReelLike.find({ reelId: { $in: reelIds } }).lean()
    const likesByReel = new Map()
    for (const l of likes) {
      if (!likesByReel.has(l.reelId.toString())) likesByReel.set(l.reelId.toString(), [])
      likesByReel.get(l.reelId.toString()).push(l)
    }
    const comments = await ReelComment.find({ reelId: { $in: reelIds } })
      .sort({ createdAt: -1 })
      .limit(30)
      .populate('userId')
      .lean()
    const commentsByReel = new Map()
    for (const c of comments) {
      if (!commentsByReel.has(c.reelId.toString())) commentsByReel.set(c.reelId.toString(), [])
      commentsByReel.get(c.reelId.toString()).push(c)
    }

    res.json({
      reels: reels.map((r) => {
        const streamUrl = r.videoId ? `${REELS_BACKEND_URL}/api/stream/${r.videoId}` : null
        return {
          id: r._id.toString(),
          videoId: r.videoId,
          videoUrl: streamUrl,  // HF reels backend stream URL
          streamUrl,
          caption: r.caption,
          musicName: r.musicName,
          createdAt: r.createdAt,
          user: publicUser(r.userId),
          likeCount: (likesByReel.get(r._id.toString()) || []).length,
          likedByMe: (likesByReel.get(r._id.toString()) || []).some((l) => l.userId.toString() === req.user._id.toString()),
          comments: (commentsByReel.get(r._id.toString()) || []).map((c) => ({
            id: c._id.toString(),
            content: c.content,
            createdAt: c.createdAt,
            user: publicUser(c.userId),
          })),
        }
      }),
    })
  } catch (e) {
    console.error('[reels/list] error:', e)
    res.status(500).json({ error: e?.message || 'Server error' })
  }
})

// POST /api/reels/create — accept videoId from frontend (after HF reels backend upload)
app.post('/api/reels/create', authMiddleware, async (req, res) => {
  try {
    const { videoId, driveFileId, caption, musicName } = req.body
    if (!videoId) {
      return res.status(400).json({ error: 'videoId is required (upload to reels backend first)' })
    }
    const reel = await Reel.create({
      userId: req.user._id,
      videoId,
      driveFileId: driveFileId || null,
      caption: caption || null,
      musicName: musicName || null,
    })
    res.json({
      reel: {
        id: reel._id.toString(),
        videoId: reel.videoId,
        driveFileId: reel.driveFileId,
        streamUrl: `${REELS_BACKEND_URL}/api/stream/${reel.videoId}`,
      },
    })
  } catch (e) {
    console.error('[reels/create] error:', e)
    res.status(500).json({ error: e?.message || 'Server error' })
  }
})

// POST /api/reels/like (toggle)
app.post('/api/reels/like', authMiddleware, async (req, res) => {
  try {
    const { reelId } = req.body
    if (!reelId) return res.status(400).json({ error: 'reelId required' })
    const existing = await ReelLike.findOne({ reelId, userId: req.user._id })
    if (existing) {
      await ReelLike.deleteOne({ _id: existing._id })
      return res.json({ liked: false })
    } else {
      await ReelLike.create({ reelId, userId: req.user._id })
      return res.json({ liked: true })
    }
  } catch (e) {
    console.error('[reels/like] error:', e)
    res.status(500).json({ error: e?.message || 'Server error' })
  }
})

// POST /api/reels/comment
app.post('/api/reels/comment', authMiddleware, async (req, res) => {
  try {
    const { reelId, content } = req.body
    if (!reelId || !content) return res.status(400).json({ error: 'reelId and content required' })
    const comment = await ReelComment.create({ reelId, userId: req.user._id, content })
    const populated = await ReelComment.findById(comment._id).populate('userId').lean()
    res.json({
      comment: {
        id: populated._id.toString(),
        content: populated.content,
        createdAt: populated.createdAt,
        user: publicUser(populated.userId),
      },
    })
  } catch (e) {
    console.error('[reels/comment] error:', e)
    res.status(500).json({ error: e?.message || 'Server error' })
  }
})

// ─── CALLS ROUTES ───

// GET /api/calls/list
app.get('/api/calls/list', authMiddleware, async (req, res) => {
  try {
    const calls = await Call.find({
      $or: [{ callerId: req.user._id }, { receiverId: req.user._id }],
    })
      .populate('callerId')
      .populate('receiverId')
      .sort({ startedAt: -1 })
      .limit(200)
      .lean()

    res.json({
      calls: calls.map((c) => {
        const isCaller = c.callerId._id.toString() === req.user._id.toString()
        const other = isCaller ? c.receiverId : c.callerId
        return {
          id: c._id.toString(),
          type: c.type,
          status: c.status,
          duration: c.duration,
          startedAt: c.startedAt,
          endedAt: c.endedAt,
          direction: isCaller ? 'outgoing' : 'incoming',
          otherUser: publicUser(other),
        }
      }),
    })
  } catch (e) {
    console.error('[calls/list] error:', e)
    res.status(500).json({ error: e?.message || 'Server error' })
  }
})

// POST /api/calls/log
app.post('/api/calls/log', authMiddleware, async (req, res) => {
  try {
    const { receiverId, type = 'audio', status = 'answered', duration = 0, endedAt } = req.body
    if (!receiverId) return res.status(400).json({ error: 'receiverId required' })
    const call = await Call.create({
      callerId: req.user._id,
      receiverId,
      type,
      status,
      duration,
      endedAt: endedAt ? new Date(endedAt) : new Date(),
    })
    res.json({ call })
  } catch (e) {
    console.error('[calls/log] error:', e)
    res.status(500).json({ error: e?.message || 'Server error' })
  }
})

// ─── SETTINGS ROUTES ───

// GET /api/settings
app.get('/api/settings', authMiddleware, async (req, res) => {
  try {
    const user = await User.findById(req.user._id).lean()
    let settings = await UserSettings.findOne({ userId: req.user._id }).lean()
    if (!settings) {
      settings = await UserSettings.create({ userId: req.user._id })
      settings = settings.toObject()
    }
    res.json({
      profile: {
        id: user._id.toString(),
        userId: user.userId,
        email: user.email,
        phone: user.phone,
        profileName: user.profileName,
        avatar: user.avatar ? `/api/file/${user.avatar}` : null,
        bio: user.bio,
        about: user.about,
        language: user.language,
        theme: user.theme,
        wallpaper: user.wallpaper,
      },
      settings,
    })
  } catch (e) {
    console.error('[settings/get] error:', e)
    res.status(500).json({ error: e?.message || 'Server error' })
  }
})

// PUT /api/settings
app.put('/api/settings', authMiddleware, async (req, res) => {
  try {
    const { profile, settings } = req.body

    if (profile) {
      const allowed = {}
      const profileFields = ['profileName', 'avatar', 'bio', 'about', 'language', 'theme', 'wallpaper']
      for (const k of profileFields) {
        if (k in profile) allowed[k] = profile[k]
      }
      if (Object.keys(allowed).length > 0) {
        await User.updateOne({ _id: req.user._id }, { $set: allowed })
      }
    }

    if (settings) {
      const allowed = {}
      const settingFields = [
        'lastSeenVisible', 'profilePhotoVisible', 'statusVisible', 'readReceipts', 'groupsEveryone',
        'notifMessages', 'notifCalls', 'notifReactions', 'notifSound', 'notifVibrate',
        'enterToSend', 'showOnlineStatus', 'fontScale', 'mediaAutoDownload', 'dataSaver',
      ]
      for (const k of settingFields) {
        if (k in settings) allowed[k] = settings[k]
      }
      if (Object.keys(allowed).length > 0) {
        await UserSettings.updateOne(
          { userId: req.user._id },
          { $set: { ...allowed, updatedAt: new Date() } },
          { upsert: true }
        )
      }
    }

    const refreshedUser = await User.findById(req.user._id).lean()
    const refreshedSettings = await UserSettings.findOne({ userId: req.user._id }).lean()
    res.json({
      profile: {
        id: refreshedUser._id.toString(),
        userId: refreshedUser.userId,
        email: refreshedUser.email,
        phone: refreshedUser.phone,
        profileName: refreshedUser.profileName,
        avatar: refreshedUser.avatar ? `/api/file/${refreshedUser.avatar}` : null,
        bio: refreshedUser.bio,
        about: refreshedUser.about,
        language: refreshedUser.language,
        theme: refreshedUser.theme,
        wallpaper: refreshedUser.wallpaper,
      },
      settings: refreshedSettings,
    })
  } catch (e) {
    console.error('[settings/put] error:', e)
    res.status(500).json({ error: e?.message || 'Server error' })
  }
})

// ─── PROFILE ROUTES ───

// PUT /api/profile/update
app.put('/api/profile/update', authMiddleware, async (req, res) => {
  try {
    const allowed = {}
    const fields = ['profileName', 'avatar', 'bio', 'about', 'language', 'theme', 'wallpaper']
    for (const k of fields) {
      if (k in req.body) allowed[k] = req.body[k]
    }
    if (Object.keys(allowed).length === 0) {
      return res.status(400).json({ error: 'No updatable fields provided' })
    }
    const user = await User.findByIdAndUpdate(req.user._id, { $set: allowed }, { new: true }).lean()
    res.json({
      user: {
        id: user._id.toString(),
        profileName: user.profileName,
        avatar: user.avatar ? `/api/file/${user.avatar}` : null,
        bio: user.bio,
        about: user.about,
      },
    })
  } catch (e) {
    console.error('[profile/update] error:', e)
    res.status(500).json({ error: e?.message || 'Server error' })
  }
})

// POST /api/profile/block
app.post('/api/profile/block', authMiddleware, async (req, res) => {
  try {
    const { userId } = req.body
    if (!userId || userId === req.user._id.toString()) {
      return res.status(400).json({ error: 'Invalid userId' })
    }
    await Friendship.deleteOne({
      $or: [
        { requesterId: req.user._id, receiverId: userId },
        { requesterId: userId, receiverId: req.user._id },
      ],
    })
    await Block.updateOne(
      { blockerId: req.user._id, blockedId: userId },
      { $setOnInsert: { blockerId: req.user._id, blockedId: userId, createdAt: new Date() } },
      { upsert: true }
    )
    res.json({ status: 'blocked' })
  } catch (e) {
    console.error('[profile/block] error:', e)
    res.status(500).json({ error: e?.message || 'Server error' })
  }
})

// GET /api/profile/blocked
app.get('/api/profile/blocked', authMiddleware, async (req, res) => {
  try {
    const blocks = await Block.find({ blockerId: req.user._id })
      .populate('blockedId')
      .sort({ createdAt: -1 })
      .lean()
    res.json({ blocked: blocks.map((b) => publicUser(b.blockedId)) })
  } catch (e) {
    console.error('[profile/blocked] error:', e)
    res.status(500).json({ error: e?.message || 'Server error' })
  }
})

// POST /api/profile/unblock
app.post('/api/profile/unblock', authMiddleware, async (req, res) => {
  try {
    const { userId } = req.body
    if (!userId) return res.status(400).json({ error: 'userId required' })
    await Block.deleteOne({ blockerId: req.user._id, blockedId: userId })
    res.json({ status: 'unblocked' })
  } catch (e) {
    console.error('[profile/unblock] error:', e)
    res.status(500).json({ error: e?.message || 'Server error' })
  }
})

// ─── DISCOVER ROUTE ───

// GET /api/discover/users
app.get('/api/discover/users', authMiddleware, async (req, res) => {
  try {
    const friendships = await Friendship.find({
      $or: [{ requesterId: req.user._id }, { receiverId: req.user._id }],
    }).lean()
    const excludeIds = new Set([req.user._id.toString()])
    for (const f of friendships) {
      if (f.requesterId.toString() === req.user._id.toString()) excludeIds.add(f.receiverId.toString())
      else excludeIds.add(f.requesterId.toString())
    }
    const blocks = await Block.find({
      $or: [{ blockerId: req.user._id }, { blockedId: req.user._id }],
    }).lean()
    for (const b of blocks) {
      if (b.blockerId.toString() === req.user._id.toString()) excludeIds.add(b.blockedId.toString())
      else excludeIds.add(b.blockerId.toString())
    }
    const users = await User.find({ _id: { $nin: Array.from(excludeIds) } })
      .sort({ createdAt: -1 })
      .limit(30)
      .lean()
    res.json({ users: users.map(publicUser) })
  } catch (e) {
    console.error('[discover/users] error:', e)
    res.status(500).json({ error: e?.message || 'Server error' })
  }
})

// ─── SEED ROUTE ───

// POST /api/seed
app.post('/api/seed', async (req, res) => {
  try {
    const userCount = await User.countDocuments()
    if (userCount >= 5) {
      return res.json({ message: 'Already seeded', userCount })
    }
    const passwordHash = await hashPassword('demo1234')
    const demoUsers = [
      { userId: 'aarav_07', profileName: 'Aarav Sharma', email: 'aarav@hangout.app', avatar: null, bio: 'Photographer & traveler', about: 'Living one moment at a time' },
      { userId: 'priya_s', profileName: 'Priya Singh', email: 'priya@hangout.app', avatar: null, bio: 'Foodie | Dancer', about: 'Spice lover, chai enthusiast' },
      { userId: 'rahul_d', profileName: 'Rahul Das', email: 'rahul@hangout.app', avatar: null, bio: 'Cricket | Code', about: 'Building cool stuff' },
      { userId: 'meera_22', profileName: 'Meera Iyer', email: 'meera@hangout.app', avatar: null, bio: 'Artist & dreamer', about: 'Painting my world' },
      { userId: 'karan_x', profileName: 'Karan Verma', email: 'karan@hangout.app', avatar: null, bio: 'Music is life', about: 'Guitarist' },
      { userId: 'sara_11', profileName: 'Sara Khan', email: 'sara@hangout.app', avatar: null, bio: 'Bookworm', about: 'Lost in stories' },
      { userId: 'vikas_ji', profileName: 'Vikas Reddy', email: 'vikas@hangout.app', avatar: null, bio: 'Fitness coach', about: 'No pain, no gain' },
      { userId: 'neha_88', profileName: 'Neha Gupta', email: 'neha@hangout.app', avatar: null, bio: 'Travel blogger', about: 'Wanderlust soul' },
    ]
    const createdUsers = []
    for (const u of demoUsers) {
      const user = await User.create({ ...u, password: passwordHash, phone: null })
      await initUserSettings(user._id)
      createdUsers.push(user)
    }
    const samplePosts = [
      { userId: createdUsers[0]._id, content: 'Caught the most beautiful sunset today 🌅', location: 'Goa, India', feeling: 'feeling peaceful' },
      { userId: createdUsers[1]._id, content: 'Made authentic butter chicken from scratch today! 🍛', location: 'Mumbai', feeling: 'feeling hungry' },
      { userId: createdUsers[2]._id, content: 'Shipped a new feature today. Late-night coding sessions hit different 🚀', feeling: 'feeling productive' },
      { userId: createdUsers[3]._id, content: 'Working on a new watercolor series. Sneak peek coming soon 🎨', location: 'Bangalore', feeling: 'feeling creative' },
      { userId: createdUsers[4]._id, content: 'New cover on the guitar. Check it out! 🎸🎶', feeling: 'feeling musical' },
      { userId: createdUsers[5]._id, content: 'Currently reading "The Midnight Library". Mind-blowing so far 📚', feeling: 'feeling thoughtful' },
      { userId: createdUsers[6]._id, content: 'Morning workout done. 5km run + 100 pushups 💪', location: 'Hyderabad', feeling: 'feeling strong' },
      { userId: createdUsers[7]._id, content: 'Just got back from Manali. The mountains are calling 🏔️', location: 'Manali', feeling: 'feeling adventurous' },
    ]
    for (const p of samplePosts) {
      await Post.create(p)
    }
    const sampleStatuses = [
      { userId: createdUsers[0]._id, content: 'Good morning everyone! Have a great day ☀️', bgColor: '#7c3aed' },
      { userId: createdUsers[1]._id, content: 'Cooking up a storm today 🍳', bgColor: '#dc2626' },
      { userId: createdUsers[2]._id, content: 'Coffee + Code = ❤️', bgColor: '#059669' },
      { userId: createdUsers[4]._id, content: 'New song dropping soon 🎵', bgColor: '#ea580c' },
      { userId: createdUsers[7]._id, content: 'On top of the world 🏔️', bgColor: '#2563eb' },
    ]
    for (const s of sampleStatuses) {
      await Status.create({
        ...s,
        type: 'text',
        expiresAt: new Date(Date.now() + 24 * 60 * 60 * 1000),
      })
    }
    res.json({
      message: 'Seed complete',
      usersCreated: createdUsers.length,
      postsCreated: samplePosts.length,
      statusesCreated: sampleStatuses.length,
      demoCredentials: { email: 'aarav@hangout.app', password: 'demo1234' },
    })
  } catch (e) {
    console.error('[seed] error:', e)
    res.status(500).json({ error: e?.message || 'Server error' })
  }
})

// ============================================================
// SECTION 6 — EXPRESS APP SETUP (Error handlers + Start)
// ============================================================
// Note: All global middleware (helmet, cors, cookieParser, body parsers)
// are already applied in SECTION 5 before routes.

// Rate limiters (defined but not enforced per-route for simplicity —
// auth middleware already protects sensitive endpoints)
const authLimiter = rateLimit({
  windowMs: 15 * 60 * 1000,
  max: 50,
  standardHeaders: true,
  legacyHeaders: false,
  message: { error: 'Too many auth attempts, please try later' },
})

const apiLimiter = rateLimit({
  windowMs: 15 * 60 * 1000,
  max: 500,
  standardHeaders: true,
  legacyHeaders: false,
  message: { error: 'Too many requests, please try later' },
})

// 404 handler
app.use((req, res) => {
  res.status(404).json({
    error: 'Route not found',
    path: req.path,
    method: req.method,
  })
})

// Multer-specific error handler
// eslint-disable-next-line no-unused-vars
app.use((err, req, res, next) => {
  if (err.name === 'MulterError') {
    let message = err.message
    if (err.code === 'LIMIT_FILE_SIZE') {
      message = `File too large. Max size: ${(err.limit / 1024 / 1024).toFixed(0)} MB`
    } else if (err.code === 'LIMIT_UNEXPECTED_FILE') {
      message = `Unexpected field name: ${err.field}. Use field name "file".`
    }
    return res.status(400).json({ error: 'Upload error', code: err.code, detail: message })
  }
  console.error('[server] Unhandled error:', err)
  return res.status(500).json({ error: 'Internal server error', detail: err.message })
})

// ============================================================
// SECTION 7 — START SERVER + GRACEFUL SHUTDOWN
// ============================================================

async function start() {
  console.log('==========================================')
  console.log('  HangOut Main Backend v1.0.0')
  console.log('  Single File Edition')
  console.log('  Presented by RVK EDITION')
  console.log('==========================================')
  console.log(`  Port: ${PORT}`)
  console.log(`  Host: ${HOST}`)
  console.log(`  CORS_ORIGINS: ${process.env.CORS_ORIGINS || '*'}`)
  console.log(`  REELS_BACKEND_URL: ${REELS_BACKEND_URL}`)
  console.log(`  OTP transport: ${getMailer() ? 'email (Gmail)' : 'console (fallback)'}`)
  console.log('==========================================')

  // Start HTTP server FIRST (non-blocking)
  app.listen(PORT, HOST, () => {
    console.log(`[server] ✓ Listening on http://${HOST}:${PORT}`)
    console.log('[server] Endpoints:')
    console.log('  Auth:    /api/auth/{register,login,verify-otp,me,logout}')
    console.log('  Chats:   /api/chats/{list,messages,send}')
    console.log('  Friends: /api/friends/{list,search,request,accept,decline,remove,requests}')
    console.log('  Status:  /api/status/{list,create,view}')
    console.log('  Posts:   /api/posts/{list,create,like,comment}')
    console.log('  Reels:   /api/reels/{list,create,like,comment}')
    console.log('  Calls:   /api/calls/{list,log}')
    console.log('  Settings:/api/settings')
    console.log('  Profile: /api/profile/{update,block,blocked,unblock}')
    console.log('  File:    /api/file/:fileId (stream from Drive)')
    console.log('  Upload:  /api/upload (image to Drive)')
    console.log('  Discover:/api/discover/users')
    console.log('  Seed:    /api/seed')
    console.log('  Health:  /health, /health/deep, /info')

    // Connect to MongoDB in background
    connectDB()
      .then(() => console.log('[server] ✓ MongoDB connected (background)'))
      .catch((err) => console.error('[server] ⚠ MongoDB failed — endpoints will error:', err.message))
  })
}

async function shutdown(signal) {
  console.log(`[server] ${signal} received, shutting down...`)
  try {
    if (dbConnected) await mongoose.disconnect()
  } catch (e) {
    /* ignore */
  }
  process.exit(0)
}

process.on('SIGTERM', () => shutdown('SIGTERM'))
process.on('SIGINT', () => shutdown('SIGINT'))
process.on('unhandledRejection', (err) => console.error('[server] Unhandled rejection:', err))
process.on('uncaughtException', (err) => {
  console.error('[server] Uncaught exception:', err)
  shutdown('uncaughtException')
})

start()