import Icon from '../icon'

export default {
  name: 'AAvatar',
  props: {
    prefixCls: {
      type: String,
      default: 'ant-avatar',
    },
    shape: {
      validator: (val) => (['circle', 'square'].includes(val)),
      default: 'circle',
    },
    size: {
      validator: (val) => {
        return typeof val === 'number' || ['small', 'large', 'default'].includes(val)
      },
      default: 'default',
    },
    src: String,
    icon: String,
    alt: String,
    loadError: Function,
  },
  data () {
    return {
      isImgExist: true,
      scale: 1,
    }
  },
  mounted () {
    this.prevChildren = this.$slots.default
    this.prevState = { ...this.$data }
    this.$nextTick(() => {
      this.setScale()
    })
  },
  updated () {
    if (this.preChildren !== this.$slots.default ||
      (this.prevState.scale !== this.$data.scale && this.$data.scale === 1) ||
      (this.prevState.isImgExist !== this.$data.isImgExist)) {
      this.$nextTick(() => {
        this.setScale()
      })
    }
    this.preChildren = this.$slots.default
    this.prevState = { ...this.$data }
  },
  methods: {
    setScale () {
      const childrenNode = this.$refs.avatarChildren
      if (childrenNode) {
        const childrenWidth = childrenNode.offsetWidth
        const avatarWidth = this.$el.getBoundingClientRect().width
        if (avatarWidth - 8 < childrenWidth) {
          this.scale = (avatarWidth - 8) / childrenWidth
        } else {
          this.scale = 1
        }
        this.$forceUpdate()
      }
    },
    handleImgLoadError () {
      const { loadError } = this.$props
      const errorFlag = loadError ? loadError() : undefined
      if (errorFlag !== false) {
        this.isImgExist = false
      }
    },
  },
  render () {
    const {
      prefixCls, shape, size, src, icon, alt,
    } = this.$props

    const { isImgExist, scale } = this.$data

    const sizeCls = {
      [`${prefixCls}-lg`]: size === 'large',
      [`${prefixCls}-sm`]: size === 'small',
    }

    const classString = {
      [prefixCls]: true,
      ...sizeCls,
      [`${prefixCls}-${shape}`]: shape,
      [`${prefixCls}-image`]: src && isImgExist,
      [`${prefixCls}-icon`]: icon,
    }

    const sizeStyle = typeof size === 'number' ? {
      width: `${size}px`,
      height: `${size}px`,
      lineHeight: `${size}px`,
      fontSize: icon ? `${size / 2}px` : '18px',
    } : {}

    let children = this.$slots.default
    if (src && isImgExist) {
      children = (
        <img
          src={src}
          onError={this.handleImgLoadError}
          alt={alt}
        />
      )
    } else if (icon) {
      children = <Icon type={icon} />
    } else {
      const childrenNode = this.$refs.avatarChildren
      if (childrenNode || (scale !== 1 && childrenNode)) {
        const transformString = `scale(${scale}) translateX(-50%)`
        const childrenStyle = {
          msTransform: transformString,
          WebkitTransform: transformString,
          transform: transformString,
        }
        const sizeChildrenStyle = typeof size === 'number' ? {
          lineHeight: `${size}px`,
        } : {}
        children = (
          <span
            class={`${prefixCls}-string`}
            ref='avatarChildren'
            style={{ ...sizeChildrenStyle, ...childrenStyle }}
          >
            {children}
          </span>
        )
      } else {
        children = (
          <span
            class={`${prefixCls}-string`}
            ref='avatarChildren'
          >
            {children}
          </span>
        )
      }
    }
    return (
      <span {...{ on: this.$listeners, class: classString, style: sizeStyle }}>
        {children}
      </span>
    )
  },
}