import PropTypes from '../_util/vue-types'
import BaseMixin from '../_util/BaseMixin'
import { getStyle } from '../_util/props-util'
import omit from 'omit.js'

function getNumberArray (num) {
  return num
    ? num.toString()
      .split('')
      .reverse()
      .map(i => Number(i)) : []
}

const ScrollNumberProps = {
  prefixCls: PropTypes.string.def('ant-scroll-number'),
  count: PropTypes.oneOfType([PropTypes.number, PropTypes.string, null]).def(null),
  component: PropTypes.string,
  title: PropTypes.oneOfType([PropTypes.number, PropTypes.string]),
}

export default {
  mixins: [BaseMixin],
  props: ScrollNumberProps,
  data () {
    return {
      animateStarted: true,
      sCount: this.count,
    }
  },
  watch: {
    count (val) {
      if (this.sCount !== val) {
        this.lastCount = this.sCount
        // 复原数字初始位置
        this.setState({
          animateStarted: true,
        }, () => {
        // 等待数字位置复原完毕
        // 开始设置完整的数字
          setTimeout(() => {
            this.setState({
              animateStarted: false,
              sCount: val,
            }, () => {
              this.$emit('animated')
            })
          }, 5)
        })
      }
    },
  },
  methods: {
    getPositionByNum (num, i) {
      if (this.animateStarted) {
        return 10 + num
      }
      const currentDigit = getNumberArray(this.sCount)[i]
      const lastDigit = getNumberArray(this.lastCount)[i]
      // 同方向则在同一侧切换数字
      if (this.sCount > this.lastCount) {
        if (currentDigit >= lastDigit) {
          return 10 + num
        }
        return 20 + num
      }
      if (currentDigit <= lastDigit) {
        return 10 + num
      }
      return num
    },
    renderNumberList (position) {
      const childrenToReturn = []
      for (let i = 0; i < 30; i++) {
        const currentClassName = (position === i) ? 'current' : ''
        childrenToReturn.push(<p key={i.toString()} class={currentClassName}>{i % 10}</p>)
      }
      return childrenToReturn
    },

    renderCurrentNumber (num, i) {
      const position = this.getPositionByNum(num, i)
      const removeTransition = this.animateStarted || getNumberArray(this.lastCount)[i] === undefined
      const style = {
        transition: removeTransition ? 'none' : undefined,
        msTransform: `translateY(${-position * 100}%)`,
        WebkitTransform: `translateY(${-position * 100}%)`,
        transform: `translateY(${-position * 100}%)`,
      }
      return (
        <span class={`${this.prefixCls}-only`} style={style} key={i}>
          {this.renderNumberList(position)}
        </span>
      )
    },

    renderNumberElement () {
      const { sCount } = this
      if (!sCount || isNaN(sCount)) {
        return sCount
      }
      return getNumberArray(sCount)
        .map((num, i) => this.renderCurrentNumber(num, i)).reverse()
    },
  },

  render () {
    const { prefixCls, title, component: Tag = 'sup' } = this
    const style = getStyle(this, true)
    // fix https://fb.me/react-unknown-prop
    const restProps = omit(this.$props, [
      'count',
      'component',
      'prefixCls',
    ])
    const newProps = {
      props: {
        ...restProps,
        title,
      },
      class: prefixCls,
      style,
    }
    // allow specify the border
    // mock border-color by box-shadow for compatible with old usage:
    // <Badge count={4} style={{ backgroundColor: '#fff', color: '#999', borderColor: '#d9d9d9' }} />
    if (style && style.borderColor) {
      newProps.style.boxShadow = `0 0 0 1px ${style.borderColor} inset`
    }
    return (
      <Tag {...newProps}>
        { this.renderNumberElement()}
      </Tag>
    )
  },
}