import { getCurrentInstance, ref } from 'vue'
import mitt from './bus'

export default function () {
  const tempColOptions = ref([])
  const elTableNode = ref(null)
  const selectionArr = ref([])
  let lastAll = []

  const { props } = getCurrentInstance() as any
  const key = props.selectionKey
  if (props.selection) {
    tempColOptions.value = [
      { type: 'selection', width: '55' },
      ...props.colOption,
    ]
  } else {
    tempColOptions.value = props.colOption
  }

  function include (arr, data) {
    return arr.filter(item => item[key] === data[key]).length > 0
  }

  function addSelections(data) {
    if (!include(selectionArr.value, data))
      selectionArr.value.push(data)
  }
  function subSelections(data) {
    if (include(selectionArr.value, data)) {
      let index = -1
      for (let i = 0; i < selectionArr.value.length; i++) {
        if (selectionArr.value[i][key] === data.id) {
          index = i
        }
      }
      index !== -1 && selectionArr.value.splice(index, 1)
    }
  }

  const handleSelect = (selection, row) => {
    if (include(selection, row))
      addSelections(row)
    else
      subSelections(row)
  }
  const handleSelectAll = selection => {
    if (selection.length > 0) {
      lastAll = selection
      selection.forEach(item => {
        handleSelect(selection, item)
      })
    } else {
      lastAll.forEach(item => {
        subSelections(item)
      })
    }
  }

  mitt.on('dataChange', value => {
    fillBack(value)
  })

  function fillBack (value) {
    const length = value.length
    const tempArr = []
    let index = 0
    selectionArr.value.forEach(item => {
      value.forEach(ii => {
        if (item.id === ii.id) {
          index++
          tempArr.push(ii)
        }
      })
    })
    if (length === index) lastAll = tempArr
    tempArr.forEach(item => {
      elTableNode.value.toggleRowSelection(item)
    })
  }

  return {
    tempColOptions,
    elTableNode,
    handleSelect,
    handleSelectAll,
  }
}