import PropTypes from '../_util/vue-types'
import Trigger from '../trigger'
import Menus from './Menus'
import KeyCode from '../_util/KeyCode'
import arrayTreeFilter from 'array-tree-filter'
import shallowEqualArrays from 'shallow-equal/arrays'
import { hasProp, getEvents } from '../_util/props-util'
import BaseMixin from '../_util/BaseMixin'
import { cloneElement } from '../_util/vnode'

const BUILT_IN_PLACEMENTS = {
  bottomLeft: {
    points: ['tl', 'bl'],
    offset: [0, 4],
    overflow: {
      adjustX: 1,
      adjustY: 1,
    },
  },
  topLeft: {
    points: ['bl', 'tl'],
    offset: [0, -4],
    overflow: {
      adjustX: 1,
      adjustY: 1,
    },
  },
  bottomRight: {
    points: ['tr', 'br'],
    offset: [0, 4],
    overflow: {
      adjustX: 1,
      adjustY: 1,
    },
  },
  topRight: {
    points: ['br', 'tr'],
    offset: [0, -4],
    overflow: {
      adjustX: 1,
      adjustY: 1,
    },
  },
}

export default {
  props: {
    value: PropTypes.array,
    defaultValue: PropTypes.array,
    options: PropTypes.array.def([]).isRequired,
    // onChange: PropTypes.func,
    // onPopupVisibleChange: PropTypes.func,
    popupVisible: PropTypes.bool,
    disabled: PropTypes.bool.def(false),
    transitionName: PropTypes.string.def(''),
    popupClassName: PropTypes.string.def(''),
    popupStyle: PropTypes.object.def({}),
    popupPlacement: PropTypes.string.def('bottomLeft'),
    prefixCls: PropTypes.string.def('rc-cascader'),
    dropdownMenuColumnStyle: PropTypes.object,
    builtinPlacements: PropTypes.object.def(BUILT_IN_PLACEMENTS),
    loadData: PropTypes.func,
    changeOnSelect: PropTypes.bool,
    // onKeyDown: PropTypes.func,
    expandTrigger: PropTypes.string.def('click'),
  },
  mixins: [BaseMixin],
  model: {
    prop: 'value',
    event: 'change',
  },
  data () {
    let initialValue = []
    const { value, defaultValue, popupVisible } = this
    if (hasProp(this, 'value')) {
      initialValue = value || []
    } else if (hasProp(this, 'defaultValue')) {
      initialValue = defaultValue || []
    }
    return {
      sPopupVisible: popupVisible,
      sActiveValue: initialValue,
      sValue: initialValue,
    }
  },
  watch: {
    value (val, oldValue) {
      if (!shallowEqualArrays(val, oldValue)) {
        const newValues = {
          value: oldValue || [],
          activeValue: oldValue || [],
        }
        // allow activeValue diff from value
        // https://github.com/ant-design/ant-design/issues/2767
        if (hasProp(this, 'loadData')) {
          delete newValues.activeValue
        }
        this.setState(newValues)
      }
    },
    popupVisible (val) {
      this.setState({
        sPopupVisible: val,
      })
    },
  },
  methods: {
    getPopupDOMNode () {
      return this.$refs.trigger.getPopupDomNode()
    },
    getCurrentLevelOptions () {
      const { options, sActiveValue = [] } = this
      const result = arrayTreeFilter(options, (o, level) => o.value === sActiveValue[level])
      if (result[result.length - 2]) {
        return result[result.length - 2].children
      }
      return [...options].filter(o => !o.disabled)
    },
    getActiveOptions (activeValue) {
      return arrayTreeFilter(this.options, (o, level) => o.value === activeValue[level])
    },
    setPopupVisible (popupVisible) {
      if (!hasProp(this, 'popupVisible')) {
        this.setState({ sPopupVisible: popupVisible })
      }
      // sync activeValue with value when panel open
      if (popupVisible && !this.sVisible) {
        this.setState({
          sActiveValue: this.sValue,
        })
      }
      this.__emit('popupVisibleChange', popupVisible)
    },
    handleChange (options, setProps, e) {
      if (e.type !== 'keydown' || e.keyCode === KeyCode.ENTER) {
        this.__emit('change', options.map(o => o.value), options)
        this.setPopupVisible(setProps.visible)
      }
    },
    handlePopupVisibleChange (popupVisible) {
      this.setPopupVisible(popupVisible)
    },
    handleMenuSelect (targetOption, menuIndex, e) {
    // Keep focused state for keyboard support
      const triggerNode = this.$refs.trigger.getRootDomNode()
      if (triggerNode && triggerNode.focus) {
        triggerNode.focus()
      }
      const { changeOnSelect, loadData, expandTrigger } = this
      if (!targetOption || targetOption.disabled) {
        return
      }
      let { sActiveValue } = this
      sActiveValue = sActiveValue.slice(0, menuIndex + 1)
      sActiveValue[menuIndex] = targetOption.value
      const activeOptions = this.getActiveOptions(sActiveValue)
      if (targetOption.isLeaf === false && !targetOption.children && loadData) {
        if (changeOnSelect) {
          this.handleChange(activeOptions, { visible: true }, e)
        }
        this.setState({ sActiveValue })
        loadData(activeOptions)
        return
      }
      const newState = {}
      if (!targetOption.children || !targetOption.children.length) {
        this.handleChange(activeOptions, { visible: false }, e)
        // set value to activeValue when select leaf option
        newState.sValue = sActiveValue
      // add e.type judgement to prevent `onChange` being triggered by mouseEnter
      } else if (changeOnSelect && (e.type === 'click' || e.type === 'keydown')) {
        if (expandTrigger === 'hover') {
          this.handleChange(activeOptions, { visible: false }, e)
        } else {
          this.handleChange(activeOptions, { visible: true }, e)
        }
        // set value to activeValue on every select
        newState.sValue = sActiveValue
      }
      newState.sActiveValue = sActiveValue
      //  not change the value by keyboard
      if (hasProp(this, 'value') ||
        (e.type === 'keydown' && e.keyCode !== KeyCode.ENTER)) {
        delete newState.sValue
      }
      this.setState(newState)
    },
    handleKeyDown  (e) {
      const { $slots } = this
      const children = $slots.default && $slots.default[0]
      // https://github.com/ant-design/ant-design/issues/6717
      // Don't bind keyboard support when children specify the onKeyDown
      if (children) {
        const keydown = getEvents(children).keydown
        if (keydown) {
          keydown(e)
          return
        }
      }
      const activeValue = [...this.sActiveValue]
      const currentLevel = activeValue.length - 1 < 0 ? 0 : activeValue.length - 1
      const currentOptions = this.getCurrentLevelOptions()
      const currentIndex = currentOptions.map(o => o.value).indexOf(activeValue[currentLevel])
      if (e.keyCode !== KeyCode.DOWN &&
        e.keyCode !== KeyCode.UP &&
        e.keyCode !== KeyCode.LEFT &&
        e.keyCode !== KeyCode.RIGHT &&
        e.keyCode !== KeyCode.ENTER &&
        e.keyCode !== KeyCode.BACKSPACE &&
        e.keyCode !== KeyCode.ESC) {
        return
      }
      // Press any keys above to reopen menu
      if (!this.sPopupVisible &&
        e.keyCode !== KeyCode.BACKSPACE &&
        e.keyCode !== KeyCode.LEFT &&
        e.keyCode !== KeyCode.RIGHT &&
        e.keyCode !== KeyCode.ESC) {
        this.setPopupVisible(true)
        return
      }
      if (e.keyCode === KeyCode.DOWN || e.keyCode === KeyCode.UP) {
        let nextIndex = currentIndex
        if (nextIndex !== -1) {
          if (e.keyCode === KeyCode.DOWN) {
            nextIndex += 1
            nextIndex = nextIndex >= currentOptions.length ? 0 : nextIndex
          } else {
            nextIndex -= 1
            nextIndex = nextIndex < 0 ? currentOptions.length - 1 : nextIndex
          }
        } else {
          nextIndex = 0
        }
        activeValue[currentLevel] = currentOptions[nextIndex].value
      } else if (e.keyCode === KeyCode.LEFT || e.keyCode === KeyCode.BACKSPACE) {
        activeValue.splice(activeValue.length - 1, 1)
      } else if (e.keyCode === KeyCode.RIGHT) {
        if (currentOptions[currentIndex] && currentOptions[currentIndex].children) {
          activeValue.push(currentOptions[currentIndex].children[0].value)
        }
      } else if (e.keyCode === KeyCode.ESC) {
        this.setPopupVisible(false)
        return
      }
      if (!activeValue || activeValue.length === 0) {
        this.setPopupVisible(false)
      }
      const activeOptions = this.getActiveOptions(activeValue)
      const targetOption = activeOptions[activeOptions.length - 1]
      this.handleMenuSelect(targetOption, activeOptions.length - 1, e)
      this.__emit('keydown', e)
    },
  },

  render () {
    const {
      $props, $slots, sValue, sActiveValue, handleMenuSelect,
      sPopupVisible, handlePopupVisibleChange, handleKeyDown,
    } = this
    const {
      prefixCls, transitionName, popupClassName, options, disabled,
      builtinPlacements, popupPlacement, ...restProps } = $props
    // Did not show popup when there is no options
    let menus = <div />
    let emptyMenuClassName = ''
    if (options && options.length > 0) {
      const menusProps = {
        props: {
          ...$props,
          value: sValue,
          activeValue: sActiveValue,
          visible: sPopupVisible,
        },
        on: {
          select: handleMenuSelect,
        },
      }
      menus = (
        <Menus
          {...menusProps}
        />
      )
    } else {
      emptyMenuClassName = ` ${prefixCls}-menus-empty`
    }
    const triggerProps = {
      props: {
        ...restProps,
        disabled: disabled,
        popupPlacement: popupPlacement,
        builtinPlacements: builtinPlacements,
        popupTransitionName: transitionName,
        action: disabled ? [] : ['click'],
        popupVisible: disabled ? false : sPopupVisible,
        prefixCls: `${prefixCls}-menus`,
        popupClassName: popupClassName + emptyMenuClassName,
      },
      on: {
        popupVisibleChange: handlePopupVisibleChange,
      },
      ref: 'trigger',
    }
    return (
      <Trigger {...triggerProps}>
        {$slots.default && cloneElement($slots.default[0], {
          on: {
            keydown: handleKeyDown,
          },
          attrs: {
            tabIndex: disabled ? undefined : 0,
          },
        })}
        <template slot='popup'>
          {menus}
        </template>
      </Trigger>
    )
  },
}