<template>
  <div
    class="el-progress"
    :class="[
      `el-progress--${type}`,
      status ? `is-${status}` : '',
      {
        'el-progress--without-text': !showText,
        'el-progress--text-inside': textInside,
      }
    ]"
    role="progressbar"
    :aria-valuenow="percentage"
    aria-valuemin="0"
    aria-valuemax="100"
  >
    <div v-if="type === 'line'" class="el-progress-bar">
      <div class="el-progress-bar__outer" :style="{height: `${strokeWidth}px`}">
        <div class="el-progress-bar__inner" :style="barStyle">
          <div v-if="(showText || $slots.default) && textInside" class="el-progress-bar__innerText">
            <slot v-bind="slotData">
              <span>{{ content }}</span>
            </slot>
          </div>
        </div>
      </div>
    </div>
    <div v-else class="el-progress-circle" :style="{height: `${width}px`, width: `${width}px`}">
      <svg viewBox="0 0 100 100">
        <path
          class="el-progress-circle__track"
          :d="trackPath"
          stroke="#e5e9f2"
          :stroke-width="relativeStrokeWidth"
          fill="none"
          :style="trailPathStyle"
        />
        <path
          class="el-progress-circle__path"
          :d="trackPath"
          :stroke="stroke"
          fill="none"
          :stroke-linecap="strokeLinecap"
          :stroke-width="percentage ? relativeStrokeWidth : 0"
          :style="circlePathStyle"
        />
      </svg>
    </div>
    <div
      v-if="(showText || $slots.default) && !textInside"
      class="el-progress__text"
      :style="{fontSize: `${progressTextSize}px`}"
    >
      <slot v-bind="slotData">
        <span v-if="!status">{{ content }}</span>
        <i v-else :class="iconClass"></i>
      </slot>
    </div>
  </div>
</template>

<script lang="ts">
import { computed, defineComponent } from 'vue'

type ProgressFuncType = (percentage: number) => string;

interface IProgressProps {
  type: string
  percentage: number
  status: string
  strokeWidth: number
  strokeLinecap: string
  textInside: boolean
  width: number
  showText: boolean
  color: string | Array<string | { color: string; percentage: number; }> | ProgressFuncType
  format: ProgressFuncType
}

export default defineComponent({
  name: 'ElProgress',
  props: {
    type: {
      type: String,
      default: 'line',
      validator: (val: string): boolean => ['line', 'circle', 'dashboard'].indexOf(val) > -1,
    },
    percentage: {
      type: Number,
      default: 0,
      required: true,
      validator: (val: number): boolean => val >= 0 && val <= 100,
    },
    status: {
      type: String,
      default: '',
      validator: (val: string): boolean => ['', 'success', 'exception', 'warning'].indexOf(val) > -1,
    },
    strokeWidth: {
      type: Number,
      default: 6,
    },
    strokeLinecap: {
      type: String,
      default: 'round',
    },
    textInside: {
      type: Boolean,
      default: false,
    },
    width: {
      type: Number,
      default: 126,
    },
    showText: {
      type: Boolean,
      default: true,
    },
    color: {
      type: [String, Array, Function],
      default: '',
    },
    format: {
      type: Function,
      default: (percentage: number): string => `${percentage}%`,
    },
  },
  setup(props: IProgressProps) {
    const barStyle = computed(() => {
      return {
        width: `${props.percentage}%`,
        backgroundColor: getCurrentColor(props.percentage),
      }
    })

    const relativeStrokeWidth = computed(() => {
      return (props.strokeWidth / props.width * 100).toFixed(1)
    })

    const radius = computed(() => {
      if (props.type === 'circle' || props.type === 'dashboard') {
        return parseInt(`${50 - parseFloat(relativeStrokeWidth.value) / 2}`, 10)
      } else {
        return 0
      }
    })

    const trackPath = computed(() => {
      const r = radius.value
      const isDashboard = props.type === 'dashboard'
      return `
          M 50 50
          m 0 ${isDashboard ? '' : '-'}${r}
          a ${r} ${r} 0 1 1 0 ${isDashboard ? '-' : ''}${r * 2}
          a ${r} ${r} 0 1 1 0 ${isDashboard ? '' : '-'}${r * 2}
          `
    })

    const perimeter = computed(() => {
      return 2 * Math.PI * radius.value
    })

    const rate = computed(() => {
      return props.type === 'dashboard' ? 0.75 : 1
    })

    const strokeDashoffset = computed(() => {
      const offset = -1 * perimeter.value * (1 - rate.value) / 2
      return `${offset}px`
    })

    const trailPathStyle = computed(() => {
      return {
        strokeDasharray: `${(perimeter.value * rate.value)}px, ${perimeter.value}px`,
        strokeDashoffset: strokeDashoffset.value,
      }
    })

    const circlePathStyle = computed(() => {
      return {
        strokeDasharray: `${perimeter.value * rate.value * (props.percentage / 100)}px, ${perimeter.value}px`,
        strokeDashoffset: strokeDashoffset.value,
        transition: 'stroke-dasharray 0.6s ease 0s, stroke 0.6s ease',
      }
    })

    const stroke = computed(() => {
      let ret
      if (props.color) {
        ret = getCurrentColor(props.percentage)
      } else {
        switch (props.status) {
          case 'success':
            ret = '#13ce66'
            break
          case 'exception':
            ret = '#ff4949'
            break
          case 'warning':
            ret = '#e6a23c'
            break
          default:
            ret = '#20a0ff'
        }
      }
      return ret
    })

    const iconClass = computed(() => {
      if (props.status === 'warning') {
        return 'el-icon-warning'
      }
      if (props.type === 'line') {
        return props.status === 'success' ? 'el-icon-circle-check' : 'el-icon-circle-close'
      } else {
        return props.status === 'success' ? 'el-icon-check' : 'el-icon-close'
      }
    })

    const progressTextSize = computed(() => {
      return props.type === 'line'
        ? 12 + props.strokeWidth * 0.4
        : props.width * 0.111111 + 2
    })

    const content = computed(() => {
      return props.format(props.percentage)
    })

    const getCurrentColor = percentage => {
      const { color } = props
      if (typeof color === 'function') {
        return color(percentage)
      } else if (typeof color === 'string') {
        return color
      } else {
        const span = 100 / color.length
        const seriesColors = color.map((seriesColor, index) => {
          if (typeof seriesColor === 'string') {
            return {
              color: seriesColor,
              percentage: (index + 1) * span,
            }
          }
          return seriesColor
        })
        const colorArray = seriesColors.sort((a, b) => a.percentage - b.percentage)

        for (let i = 0; i < colorArray.length; i++) {
          if (colorArray[i].percentage > percentage) {
            return colorArray[i].color
          }
        }
        return colorArray[colorArray.length - 1]?.color
      }
    }

    const slotData = computed(() => {
      return {
        percentage: props.percentage,
      }
    })

    return {
      barStyle,
      relativeStrokeWidth,
      radius,
      trackPath,
      perimeter,
      rate,
      strokeDashoffset,
      trailPathStyle,
      circlePathStyle,
      stroke,
      iconClass,
      progressTextSize,
      content,
      getCurrentColor,
      slotData,
    }
  },
})
</script>
