import * as echarts from 'echarts'
import { getShopChannelDiversity, getShopDepartmentEfficiency } from '@/api/order'

const EMPTY_DATA_HINTS = ['未上传', '请先上传', '暂无数据', '无数据', 'not found', 'no data']

function createChartState(defaultTitle) {
  return {
    loading: true,
    title: defaultTitle,
    message: '',
    isError: false
  }
}

export default {
  name: 'OrderEfficiency',
  data() {
    return {
      barChartInstance: null,
      pieChartInstance: null,
      barChart: createChartState('部门效率数据暂不可用'),
      pieChart: createChartState('渠道多样性数据暂不可用')
    }
  },
  mounted() {
    this.loadCharts()
    window.addEventListener('resize', this.handleResize)
  },
  beforeDestroy() {
    window.removeEventListener('resize', this.handleResize)
    this.disposeCharts()
  },
  methods: {
    async loadCharts() {
      await Promise.all([this.initBarChart(), this.initPieChart()])
    },
    disposeCharts() {
      if (this.barChartInstance) {
        this.barChartInstance.dispose()
        this.barChartInstance = null
      }
      if (this.pieChartInstance) {
        this.pieChartInstance.dispose()
        this.pieChartInstance = null
      }
    },
    resetChartState(target, title) {
      target.loading = true
      target.title = title
      target.message = ''
      target.isError = false
    },
    getErrorMessage(error, fallback) {
      return (
        error?.response?.data?.message ||
        error?.response?.data?.msg ||
        error?.message ||
        fallback
      )
    },
    isEmptyDataMessage(message) {
      const normalized = String(message || '').toLowerCase()
      return EMPTY_DATA_HINTS.some(item => normalized.includes(item.toLowerCase()))
    },
    setChartStatus(target, title, message, isError = false) {
      target.title = title
      target.message = message
      target.isError = isError
    },
    normalizeBarData(response) {
      if (!response || response.success !== true || !response.data) {
        throw new Error((response && response.message) || '部门效率数据加载失败')
      }

      const rows = Object.entries(response.data)
        .map(([name, value]) => ({
          name,
          value: Number(value)
        }))
        .filter(item => Number.isFinite(item.value))

      if (!rows.length) {
        throw new Error('请先上传店铺价值 CSV 文件')
      }

      return rows
    },
    normalizePieData(response) {
      if (!response || response.success !== true || !response.data) {
        throw new Error((response && response.message) || '渠道多样性数据加载失败')
      }

      const rows = Object.entries(response.data)
        .map(([name, value]) => ({
          name,
          value: Number(value)
        }))
        .filter(item => Number.isFinite(item.value) && item.value > 0)

      if (!rows.length) {
        throw new Error('请先上传店铺价值 CSV 文件')
      }

      return rows
    },
    initBarChartInstance() {
      const chartEl = this.$refs.barChartRef
      if (!chartEl) return null
      this.barChartInstance = echarts.getInstanceByDom(chartEl) || echarts.init(chartEl)
      return this.barChartInstance
    },
    initPieChartInstance() {
      const chartEl = this.$refs.pieChartRef
      if (!chartEl) return null
      this.pieChartInstance = echarts.getInstanceByDom(chartEl) || echarts.init(chartEl)
      return this.pieChartInstance
    },
    async initBarChart() {
      this.resetChartState(this.barChart, '部门效率数据暂不可用')
      try {
        const response = await getShopDepartmentEfficiency()
        const chartData = this.normalizeBarData(response)

        await this.$nextTick()
        const chart = this.initBarChartInstance()
        if (!chart) return

        chart.setOption({
          title: { text: '部门效率分析', left: 'center' },
          tooltip: {
            trigger: 'axis',
            axisPointer: { type: 'shadow' },
            formatter: '{b}<br/>平均销售额: {c} 元'
          },
          grid: { left: '3%', right: '4%', bottom: '15%', containLabel: true },
          xAxis: {
            type: 'category',
            data: chartData.map(item => item.name),
            axisLabel: { rotate: 30, interval: 0 }
          },
          yAxis: {
            type: 'value',
            name: '平均销售额(元)'
          },
          series: [{
            name: '平均销售额',
            type: 'bar',
            data: chartData.map(item => Number(item.value.toFixed(2))),
            barWidth: '40%',
            itemStyle: {
              borderRadius: [5, 5, 0, 0],
              color: new echarts.graphic.LinearGradient(0, 0, 0, 1, [
                { offset: 0, color: '#83bff6' },
                { offset: 1, color: '#188df0' }
              ])
            }
          }]
        }, true)
      } catch (error) {
        const message = this.getErrorMessage(error, '部门效率数据加载失败')
        this.setChartStatus(
          this.barChart,
          this.isEmptyDataMessage(message) ? '暂无部门效率数据' : '部门效率数据加载失败',
          this.isEmptyDataMessage(message) ? '请先在店铺价值页面上传 CSV 文件，再查看该图表。' : message,
          !this.isEmptyDataMessage(message)
        )
      } finally {
        this.barChart.loading = false
      }
    },
    async initPieChart() {
      this.resetChartState(this.pieChart, '渠道多样性数据暂不可用')
      try {
        const response = await getShopChannelDiversity()
        const chartData = this.normalizePieData(response)

        await this.$nextTick()
        const chart = this.initPieChartInstance()
        if (!chart) return

        chart.setOption({
          title: { text: '渠道商品多样性', left: 'center' },
          tooltip: { trigger: 'item', formatter: '{a}<br/>{b}: {c} ({d}%)' },
          legend: { orient: 'vertical', left: 'left', top: '10%' },
          series: [{
            name: '渠道',
            type: 'pie',
            radius: [20, 140],
            center: ['50%', '60%'],
            roseType: 'area',
            itemStyle: { borderRadius: 5 },
            data: chartData
          }]
        }, true)
      } catch (error) {
        const message = this.getErrorMessage(error, '渠道多样性数据加载失败')
        this.setChartStatus(
          this.pieChart,
          this.isEmptyDataMessage(message) ? '暂无渠道多样性数据' : '渠道多样性数据加载失败',
          this.isEmptyDataMessage(message) ? '请先在店铺价值页面上传 CSV 文件，再查看该图表。' : message,
          !this.isEmptyDataMessage(message)
        )
      } finally {
        this.pieChart.loading = false
      }
    },
    handleResize() {
      if (this.barChartInstance) {
        this.barChartInstance.resize()
      }
      if (this.pieChartInstance) {
        this.pieChartInstance.resize()
      }
    }
  }
}