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

/**
 * 商品模型
 */
const ShopItemSchema = new Schema({
  // 基本信息
  itemId: {
    type: String,
    required: true,
    unique: true,
    index: true
  },
  name: {
    type: String,
    required: true,
    trim: true
  },
  description: {
    type: String,
    trim: true
  },
  
  // 价格（单位：分）
  price: {
    type: Number,
    required: true,
    min: 1
  },
  originalPrice: {
    type: Number
  },
  
  // 商品类型
  type: {
    type: String,
    enum: ['skin', 'noad', 'subscription'],
    required: true
  },
  
  // 订阅天数（仅订阅商品）
  duration: {
    type: Number,
    default: 30
  },
  
  // 图片
  imageUrl: String,
  previewUrl: String,
  
  // 统计
  purchaseCount: {
    type: Number,
    default: 0
  },
  
  // 状态
  status: {
    type: String,
    enum: ['active', 'inactive', 'discontinued'],
    default: 'active',
    index: true
  },
  
  // 排序
  sortOrder: {
    type: Number,
    default: 0
  },
  
  // 促销
  isOnSale: {
    type: Boolean,
    default: false
  },
  saleEndTime: Date,
  
  // 时间戳
  createdAt: {
    type: Date,
    default: Date.now
  },
  updatedAt: {
    type: Date,
    default: Date.now
  }
}, {
  timestamps: true,
  toJSON: { virtuals: true },
  toObject: { virtuals: true }
})

// 索引
ShopItemSchema.index({ status: 1, sortOrder: 1 })
ShopItemSchema.index({ type: 1 })

// 虚拟字段：是否在促销中
ShopItemSchema.virtual('isOnSaleActive').get(function() {
  return this.isOnSale && this.saleEndTime && new Date() < this.saleEndTime
})

// 中间件：保存前更新 updatedAt
ShopItemSchema.pre('save', function(next) {
  this.updatedAt = Date.now()
  next()
})

module.exports = mongoose.model('ShopItem', ShopItemSchema)