// /components/payments/paymentModel.js
'use strict';

const mongoose = require('mongoose');

const { getPayableAmount, normalizeDiscount } = require('../../utils/paymentAmount');
const uniqueCodePlugin = require('../../utils/mongooseUniqueCodePlugin');
require('./transactionModel');

const paymentSchema = new mongoose.Schema({
  user: {
    type: mongoose.Schema.Types.ObjectId,
    ref: 'User',
    required: true,
    index: true
  },
  classes: [{
    type: mongoose.Schema.Types.ObjectId,
    ref: 'Class'
  }],
  course: {
    type: mongoose.Schema.Types.ObjectId,
    ref: 'Course'
  },
  amount: {
    type: Number,
    required: true,
    min: 0
  },
  discount: {
    type: Number,
    default: 0,
    min: 0
  },
  paidAmount: {
    type: Number,
    default: 0,
    min: 0
  },
  dueDate: {
    type: Date
  },
  status: {
    type: String,
    enum: ['pending', 'partial', 'paid', 'overdue', 'cancelled', 'reverted'],
    default: 'pending'
  },
  type: {
    type: String,
    enum: ['regular', 'waiting_list'],
    default: 'regular',
    index: true
  },
  notes: { type: String, trim: true, maxlength: 5000 },
  isDeleted: {
    type: Boolean,
    default: false,
    index: true
  },
  deletedAt: {
    type: Date,
    default: null
  }
}, {
  timestamps: true,
  toJSON: { virtuals: true },
  toObject: { virtuals: true }
});

paymentSchema.plugin(uniqueCodePlugin);

paymentSchema.virtual('transactions', {
  ref: 'Transaction',
  localField: '_id',
  foreignField: 'payment'
});

paymentSchema.pre('save', function (next) {
  this.discount = normalizeDiscount(this.discount, this.amount);
  const payable = getPayableAmount(this);
  if (this.status === 'cancelled' || this.status === 'reverted') {
    return next();
  }
  if (this.paidAmount >= payable) {
    this.status = 'paid';
  } else if (this.paidAmount > 0) {
    this.status = 'partial';
  } else if (this.dueDate && new Date() > this.dueDate) {
    this.status = 'overdue';
  } else {
    this.status = 'pending';
  }
  next();
});

module.exports = mongoose.model('Payment', paymentSchema);