const mongoose = require('mongoose')
const { Schema } = mongoose

const messageSchema = new Schema({
  senderId: {
    type: mongoose.Schema.Types.ObjectId,
    ref: 'User',
    required: true
  },
  receiverId: {
    type: mongoose.Schema.Types.ObjectId,
    ref: 'User',
    required: true
  },
  content: {
    type: String,
    required: false,
    trim: true
  },
  file: {
    type: String,
    required: false
  },
  fileType: {
    type: String,
    enum: ['image', 'video', 'file', 'voice', 'location'],
    required: false
  },
  replyToId: {
    type: mongoose.Schema.Types.ObjectId,
    ref: 'Message',
    required: false
  },
  forwardedFrom: {
    userId: { type: mongoose.Schema.Types.ObjectId, ref: 'User' },
    userName: String,
    displayName: String
  },
  createdAt: {
    type: Date,
    default: Date.now
  },
  readStatus: {
    type: Number,
    default: 0
  },
  /** Countdown length in seconds — timer starts when receiver views the message */
  selfDestructSeconds: {
    type: Number,
    required: false
  },
  /** When the receiver opened the message and the self-destruct timer started */
  selfDestructStartedAt: {
    type: Date,
    required: false
  },
  /** Auto-delete after this time (self-destruct messages) */
  expiresAt: {
    type: Date,
    required: false,
    index: true
  },
  /** View-once photo / video / voice */
  viewOnce: {
    type: Boolean,
    default: false
  },
  viewOnceOpenedAt: {
    type: Date,
    required: false
  },
  reactions: [
    {
      userId: {
        type: mongoose.Schema.Types.ObjectId,
        ref: 'User',
        required: true
      },
      emoji: { type: String, required: true, trim: true }
    }
  ]
})

// GET /api/v1/chat فیلتر $or روی هر دو جهتِ {senderId,receiverId} می‌زنه و createdAt
// رو سورت می‌کنه؛ messageController.js هم شمارشِ نخونده‌ها رو با {receiverId,senderId,
// readStatus} و {receiverId,readStatus} می‌زنه — همه‌ی این‌ها روی هر بارِ باز کردنِ
// لیستِ چت/یه ترد اجرا می‌شن، بدونِ ایندکس یعنی scan کاملِ کالکشن
messageSchema.index({ senderId: 1, receiverId: 1, createdAt: -1 })
messageSchema.index({ receiverId: 1, senderId: 1, createdAt: -1 })
messageSchema.index({ receiverId: 1, readStatus: 1 })

const MessageModel = mongoose.model('Message', messageSchema)

module.exports = MessageModel