<template>
  <div class="trend-chart">
    <div class="chart-legend">
      <span><i style="background:#10b981"></i>申请量（单）</span>
      <span><i style="background:#3b82f6"></i>审批完成量（单）</span>
      <span><i style="background:#8b5cf6"></i>平均审批时长（小时）</span>
    </div>
    <div class="chart-body">
      <Bar :data="chartData" :options="chartOptions" />
    </div>
  </div>
</template>

<script setup>
import { computed } from 'vue'
import { Bar } from 'vue-chartjs'
import {
  Chart as ChartJS,
  CategoryScale,
  LinearScale,
  BarElement,
  PointElement,
  LineElement,
  Filler,
  Tooltip,
  Legend
} from 'chart.js'
import { useAnimationProgress } from '../../composables/useAnimationProgress.js'

ChartJS.register(CategoryScale, LinearScale, BarElement, PointElement, LineElement, Filler, Tooltip, Legend)

const props = defineProps({
  labels: { type: Array, required: true },
  applications: { type: Array, required: true },
  approved: { type: Array, required: true },
  avgHours: { type: Array, required: true }
})

const progress = useAnimationProgress([
  () => props.labels,
  () => props.applications,
  () => props.approved,
  () => props.avgHours
], 1200)

const scaleSeries = (series, decimals = 0) =>
  series.map((value) => Number((Number(value) * progress.value).toFixed(decimals)))

const chartData = computed(() => ({
  labels: props.labels,
  datasets: [
    {
      label: '申请量（单）',
      data: scaleSeries(props.applications),
      backgroundColor: '#10b981',
      borderRadius: 4,
      barPercentage: 0.6,
      categoryPercentage: 0.5,
      order: 2
    },
    {
      label: '审批完成量（单）',
      data: scaleSeries(props.approved),
      backgroundColor: '#3b82f6',
      borderRadius: 4,
      barPercentage: 0.6,
      categoryPercentage: 0.5,
      order: 2
    },
    {
      label: '平均审批时长（小时）',
      data: scaleSeries(props.avgHours, 1),
      borderColor: '#8b5cf6',
      backgroundColor: 'transparent',
      borderWidth: 2,
      pointBackgroundColor: '#ffffff',
      pointBorderColor: '#8b5cf6',
      pointBorderWidth: 2,
      pointRadius: 3,
      pointHoverRadius: 5,
      type: 'line',
      yAxisID: 'y1',
      order: 1
    }
  ]
}))

const chartOptions = {
  responsive: true,
  maintainAspectRatio: false,
  animation: {
    duration: 900,
    easing: 'easeOutQuart'
  },
  interaction: {
    mode: 'index',
    intersect: false
  },
  events: ['click', 'mousemove', 'mouseout'],
  plugins: {
    legend: {
      display: false
    },
    tooltip: {
      enabled: false,
      external: externalTooltip
    }
  },
  scales: {
    x: {
      grid: { display: false },
      ticks: {
        color: '#64748b',
        font: { size: 11 }
      }
    },
    y: {
      beginAtZero: true,
      max: 250,
      grid: { color: '#f1f5f9' },
      ticks: {
        color: '#64748b',
        font: { size: 11 },
        stepSize: 50
      }
    },
    y1: {
      position: 'right',
      beginAtZero: true,
      max: 15,
      grid: { display: false },
      ticks: {
        color: '#64748b',
        font: { size: 11 },
        stepSize: 3
      }
    }
  }
}

function externalTooltip(context) {
  const { chart, tooltip } = context

  let el = chart.canvas.parentNode.querySelector('.chart-tooltip')
  if (!el) {
    el = document.createElement('div')
    el.classList.add('chart-tooltip')
    el.style.cssText =
      'position:absolute;background:#fff;border:1px solid #e2e8f0;border-radius:8px;padding:12px 16px;pointer-events:none;transition:opacity .15s,transform .15s;font-family:Inter,system-ui,sans-serif;font-size:13px;box-shadow:0 4px 12px rgba(0,0,0,.08);z-index:10;opacity:0;transform:translateY(4px)'
    chart.canvas.parentNode.appendChild(el)
  }

  if (tooltip.opacity === 0) {
    el.style.opacity = '0'
    return
  }

  if (tooltip.body) {
    const titleLines = tooltip.title || []
    const bodyLines = tooltip.body.map((b) => b.lines)

    const colors = tooltip.labelColors
    const dot = (color, text) =>
      `<div style="display:flex;align-items:center;gap:6px;margin-top:4px"><span style="width:8px;height:8px;border-radius:50%;background:${color};flex-shrink:0"></span><span style="color:#64748b">${text}</span></div>`

    el.innerHTML =
      `<div style="font-weight:600;color:#1e293b;margin-bottom:4px">${titleLines.join('')}</div>` +
      bodyLines
        .map((lines, i) =>
          lines.map((line) => dot(colors[i]?.backgroundColor || colors[i]?.borderColor || '#999', line))
        )
        .join('')
  }

  const { offsetLeft, offsetTop } = chart.canvas
  const left = offsetLeft + tooltip.caretX
  const top = offsetTop + tooltip.caretY

  el.style.opacity = '1'
  el.style.transform = 'translateY(0)'
  el.style.left = `${left}px`
  el.style.top = `${top - el.offsetHeight - 12}px`
  el.style.transform = `translate(-50%, 0)`
}
</script>

<style scoped>
.trend-chart {
  height: 280px;
  display: flex;
  flex-direction: column;
}

.chart-legend {
  display: flex;
  align-items: center;
  gap: 16px;
  color: #475569;
  font-size: 12px;
  margin-bottom: 12px;
}

.chart-legend i {
  display: inline-block;
  width: 8px;
  height: 8px;
  border-radius: 2px;
  margin-right: 4px;
  vertical-align: middle;
}

.chart-body {
  flex: 1;
  min-height: 0;
}
</style>
