// 商品浏览停留时长埋点工具
// 用法（商品详情页）：
//   onLoad:   startProductDwell()
//   onUnload: flushProductDwell(this.product)
// 后端接口：POST /api/stats/product-view（StatsController.recordProductView）
import { reportProductDwell } from './api.js'

let _startTs = 0

export function startProductDwell() {
  _startTs = Date.now()
}

export function flushProductDwell(product) {
  var start = _startTs
  _startTs = 0
  if (!product || !product.id) return
  var duration = Math.round((Date.now() - start) / 1000)
  if (duration <= 0) return
  var userId = 0
  try {
    userId = uni.getStorageSync('userId') || 0
  } catch (e) {}
  var payload = {
    userId: userId,
    productId: product.id,
    productName: product.name || '',
    productType: product.productType || '',
    durationSeconds: duration,
    source: 'miniprogram'
  }
  try {
    reportProductDwell(payload)
  } catch (e) {}
}