import type { Area } from '../../../../utils/area'

Component({
  //@ts-ignore
  codeList: [],
  options: {
    multipleSlots: true,
  },
  properties: {
    show: {
      type: Boolean,
      observer(show) {
        if (!show) return
        this.setData({ pickerValue: [] }, () => {
          this.codeList = this.splitCode(this.data.value)
          this.updateDivisions()
        })
      },
    },
    title: {
      type: String,
      value: '选择地区',
    },
    value: {
      type: String,
      value: '',
    },
    areaData: {
      type: Array,
      value: [],
      observer() {
        if (!this.data.show) return
        this.updateDivisions()
      },
    },
    columns: {
      type: Number,
      value: 3,
    },
    columnsName: {
      type: Array,
      value: ['省市/地区', '城市', '区'],
    },
    useLoadingSlot: Boolean,
  },
  data: {
    pickerValue: [] as Area[],
    pickerColumnData: [] as Area[],
    hightLightIndex: [] as number[],
    loading: false,
    scrollTop: 0,
  },
  methods: {
    splitCode(value: string) {
      const codeList = []
      for (let i = 1; i <= this.data.columns; i++) {
        let code = value.slice(0, i * 2)
        if (code.length < i * 2) {
          code = `${value.slice(0, (i - 1) * 2)}00`
        }
        while (code.length < this.data.value.length) {
          code += '0'
        }
        codeList.push(code)
      }
      return codeList
    },
    updateDivisions() {
      const { pickerValue } = this.data
      const area = pickerValue[pickerValue.length - 1]
      let currentAreaData = []
      if (pickerValue.length === 0) {
        currentAreaData = this.data.areaData
      } else {
        if (area && area.children && area.children.length > 0) {
          currentAreaData = [...area.children]
        } else if (area && !area.children) {
          const newArea = this.getNewAreaByPickerValue(pickerValue).area
          if (newArea && newArea.children) {
            area.children = newArea.children
            currentAreaData = [...(area.children || [])]
          }
        }
      }
      if (currentAreaData.length > 0) {
        const pickerColumnData = currentAreaData[0].code
          ? [{ name: '', children: currentAreaData }]
          : currentAreaData
        let oldPickedIndexes = [-1, -1]
        if (this.codeList.length > pickerValue.length) {
          for (const gi in pickerColumnData) {
            for (const ai in pickerColumnData[gi].children) {
              //@ts-ignore
              if (pickerColumnData[gi].children[ai].code === this.codeList[pickerValue.length]) {
                oldPickedIndexes = [+gi, +ai]
                break
              }
            }
            if (oldPickedIndexes[0] > -1) break
          }
        }
        this.setData({ loading: false, pickerColumnData }, () => {
          return new Promise<number>((resolve) => {
            if (oldPickedIndexes[0] > -1) {
              this.createSelectorQuery()
                .select('#area-item-0-0')
                .boundingClientRect()
                .select(`#area-item-${oldPickedIndexes.join('-')}`)
                .boundingClientRect()
                .exec((res) => {
                  if (res[0] && res[1]) {
                    const offsetTop = res[1].top - res[0].top
                    const diff = res[1].height
                    resolve(offsetTop > diff ? offsetTop - diff : 0)
                  } else {
                    resolve(0)
                  }
                })
            } else resolve(0)
          }).then((scrollTop) => {
            this.setData({
              hightLightIndex: oldPickedIndexes,
              scrollTop,
            })
          })
        })
      } else {
        this.setData({ loading: true, pickerColumnData: [] }, () => {
          if (area && area.code) {
            this.triggerEvent('pullchildren', { parentCode: area.code })
          } else {
            this.triggerEvent('pullchildren', {})
          }
        })
      }
    },
    getNewAreaByPickerValue(pickerValue: Area[]) {
      let { areaData } = this.data as any
      const areas = []
      for (const pickedArea of pickerValue) {
        const _areaData =
          areaData.length > 0 && areaData[0].code ? [{ name: '', children: areaData }] : areaData
        let newArea
        for (const gi in _areaData) {
          for (const ai in _areaData[gi].children) {
            if (_areaData[gi].children[ai].code === pickedArea.code) {
              newArea = _areaData[gi].children[ai]
              break
            }
          }
          if (newArea) break
        }
        if (!newArea) break
        areaData = newArea.children || []
        areas.push(newArea)
      }
      return { area: areas[areas.length - 1], areas }
    },
    onChange(e: WechatMiniprogram.CustomEvent<{}, {}, { gi: number; ai: number }>) {
      const { gi, ai } = e.currentTarget.dataset
      const area = this.data.pickerColumnData[gi].children![ai]
      const pickerValue = this.data.pickerValue.concat(area)
      if (pickerValue.length < this.data.columns) {
        this.setData({ pickerValue }, () => {
          this.updateDivisions()
        })
        this.triggerEvent('change', { value: area.code, areas: pickerValue })
      } else {
        this.setData({ show: false })
        this.triggerEvent('confirm', { value: area.code, areas: pickerValue })
      }
    },
    onPickerClick(e: WechatMiniprogram.CustomEvent<{}, {}, { index: number }>) {
      const { index } = e.currentTarget.dataset
      if (index > this.data.pickerValue.length - 1) return
      const pickerValue = this.data.pickerValue.slice(0, index)
      this.setData({ pickerValue }, () => {
        this.updateDivisions()
      })
      this.triggerEvent('change', {
        value: pickerValue[pickerValue.length - 1]?.code,
        areas: pickerValue,
      })
    },

    onClose() {
      this.setData({ show: false })
      this.triggerEvent('close')
    },
  },
})