import type { App, ExtractPropTypes, PropType } from 'vue'
import { computed, defineComponent, shallowRef, watch } from 'vue'

import type { KeyboardEventHandler } from '../_util/EventInterface'
import classNames from '../_util/classNames'
import omit from '../_util/omit'
import { flattenChildren, getOptionProps } from '../_util/props-util'
import type { InputStatus } from '../_util/statusUtils'
import { getMergedStatus, getStatusClassNames } from '../_util/statusUtils'
import type { CustomSlotsType } from '../_util/type'
import PropTypes from '../_util/vue-types'
import warning from '../_util/warning'
import useConfigInject from '../config-provider/hooks/useConfigInject'
import { FormItemInputContext, useInjectFormItemContext } from '../form/FormItemContext'
import { useProvideOverride } from '../menu/src/OverrideContext'
import Spin from '../spin'
import VcMentions from '../vc-mentions'
import { optionOptions, optionProps } from '../vc-mentions/src/Option'
import { mentionsProps as baseMentionsProps } from '../vc-mentions/src/mentionsProps'
import devWarning from '../vc-util/devWarning'
import useStyle from './style'

interface MentionsConfig {
  prefix?: string | string[]
  split?: string
}

export interface MentionsOptionProps {
  value: string
  disabled?: boolean
  label?: string | number | ((o: MentionsOptionProps) => any)
  [key: string]: any
}

interface MentionsEntity {
  prefix: string
  value: string
}

export type MentionPlacement = 'top' | 'bottom'

function loadingFilterOption() {
  return true
}
const getMentions = (value = '', config: MentionsConfig = {}): MentionsEntity[] => {
  const { prefix = '@', split = ' ' } = config
  const prefixList: string[] = Array.isArray(prefix) ? prefix : [prefix]

  return value
    .split(split)
    .map((str = ''): MentionsEntity | null => {
      let hitPrefix: string | null = null

      prefixList.some((prefixStr) => {
        const startStr = str.slice(0, prefixStr.length)
        if (startStr === prefixStr) {
          hitPrefix = prefixStr
          return true
        }
        return false
      })

      if (hitPrefix !== null) {
        return {
          prefix: hitPrefix,
          value: str.slice((hitPrefix as string).length),
        }
      }
      return null
    })
    .filter((entity): entity is MentionsEntity => !!entity && !!entity.value)
}

export const mentionsProps = () => ({
  ...baseMentionsProps,
  loading: { type: Boolean, default: undefined },
  onFocus: {
    type: Function as PropType<(e: FocusEvent) => void>,
  },
  onBlur: {
    type: Function as PropType<(e: FocusEvent) => void>,
  },
  onSelect: {
    type: Function as PropType<(option: MentionsOptionProps, prefix: string) => void>,
  },
  onChange: {
    type: Function as PropType<(text: string) => void>,
  },
  onPressenter: {
    type: Function as PropType<KeyboardEventHandler>,
  },
  'onUpdate:value': {
    type: Function as PropType<(text: string) => void>,
  },
  notFoundContent: PropTypes.any,
  defaultValue: String,
  id: String,
  status: String as PropType<InputStatus>,
})

export type MentionsProps = Partial<ExtractPropTypes<ReturnType<typeof mentionsProps>>>

const Mentions = defineComponent({
  compatConfig: { MODE: 3 },
  name: 'AMentions',
  inheritAttrs: false,
  props: mentionsProps(),
  slots: Object as CustomSlotsType<{
    notFoundContent?: any
    option?: any
    default?: any
  }>,
  setup(props, { slots, emit, attrs, expose }) {
    // =================== Warning =====================
    if (process.env.NODE_ENV !== 'production') {
      devWarning(
        !flattenChildren(slots.default?.() || []).length,
        'Mentions',
        '`Mentions.Option` is deprecated. Please use `options` instead.',
      )
    }
    const { prefixCls, renderEmpty, direction } = useConfigInject('mentions', props)
    const [wrapSSR, hashId] = useStyle(prefixCls)
    const focused = shallowRef(false)
    const vcMentions = shallowRef(null)
    const value = shallowRef(props.value ?? props.defaultValue ?? '')
    const formItemContext = useInjectFormItemContext()
    const formItemInputContext = FormItemInputContext.useInject()
    const mergedStatus = computed(() => getMergedStatus(formItemInputContext.status, props.status))
    useProvideOverride({
      prefixCls: computed(() => `${prefixCls.value}-menu`),
      mode: computed(() => 'vertical'),
      selectable: computed(() => false),
      onClick: () => {},
      validator: ({ mode }) => {
        // Warning if use other mode
        warning(
          !mode || mode === 'vertical',
          'Mentions',
          `mode="${mode}" is not supported for Mentions's Menu.`,
        )
      },
    })
    watch(
      () => props.value,
      (val) => {
        value.value = val
      },
    )
    const handleFocus = (e: FocusEvent) => {
      focused.value = true
      emit('focus', e)
    }

    const handleBlur = (e: FocusEvent) => {
      focused.value = false
      emit('blur', e)
      formItemContext.onFieldBlur()
    }

    const handleSelect = (...args: [MentionsOptionProps, string]) => {
      emit('select', ...args)
      focused.value = true
    }

    const handleChange = (val: string) => {
      if (props.value === undefined) {
        value.value = val
      }
      emit('update:value', val)
      emit('change', val)
      formItemContext.onFieldChange()
    }

    const getNotFoundContent = () => {
      const notFoundContent = props.notFoundContent
      if (notFoundContent !== undefined) {
        return notFoundContent
      }
      if (slots.notFoundContent) {
        return slots.notFoundContent()
      }
      return renderEmpty('Select')
    }

    const getOptions = () => {
      return flattenChildren(slots.default?.() || []).map((item) => {
        return { ...getOptionProps(item), label: (item.children as any)?.default?.() }
      })
    }

    const focus = () => {
      ;(vcMentions.value as HTMLTextAreaElement).focus()
    }

    const blur = () => {
      ;(vcMentions.value as HTMLTextAreaElement).blur()
    }

    expose({ focus, blur })
    const mentionsfilterOption = computed(() =>
      props.loading ? loadingFilterOption : props.filterOption,
    )
    return () => {
      const {
        disabled,
        getPopupContainer,
        rows = 1,
        id = formItemContext.id.value,
        ...restProps
      } = props
      const { hasFeedback, feedbackIcon } = formItemInputContext
      const { class: className, ...otherAttrs } = attrs
      const otherProps = omit(restProps, ['defaultValue', 'onUpdate:value', 'prefixCls'])

      const mergedClassName = classNames(
        {
          [`${prefixCls.value}-disabled`]: disabled,
          [`${prefixCls.value}-focused`]: focused.value,
          [`${prefixCls.value}-rtl`]: direction.value === 'rtl',
        },
        getStatusClassNames(prefixCls.value, mergedStatus.value),
        !hasFeedback && className,
        hashId.value,
      )

      const mentionsProps = {
        prefixCls: prefixCls.value,
        ...otherProps,
        disabled,
        direction: direction.value,
        filterOption: mentionsfilterOption.value,
        getPopupContainer,
        options: props.loading
          ? [
              {
                value: 'ANTDV_SEARCHING',
                disabled: true,
                label: <Spin size="small" />,
              },
            ]
          : props.options || getOptions(),
        class: mergedClassName,
        ...otherAttrs,
        rows,
        onChange: handleChange,
        onSelect: handleSelect,
        onFocus: handleFocus,
        onBlur: handleBlur,
        ref: vcMentions,
        value: value.value,
        id,
      }
      const mentions = (
        <VcMentions
          {...mentionsProps}
          dropdownClassName={hashId.value}
          v-slots={{ notFoundContent: getNotFoundContent, option: slots.option }}
        ></VcMentions>
      )
      if (hasFeedback) {
        return wrapSSR(
          <div
            class={classNames(
              `${prefixCls.value}-affix-wrapper`,
              getStatusClassNames(
                `${prefixCls.value}-affix-wrapper`,
                mergedStatus.value,
                hasFeedback,
              ),
              className,
              hashId.value,
            )}
          >
            {mentions}
            <span class={`${prefixCls.value}-suffix`}>{feedbackIcon}</span>
          </div>,
        )
      }
      return wrapSSR(mentions)
    }
  },
})

/* istanbul ignore next */
export const MentionsOption = defineComponent({
  compatConfig: { MODE: 3 },
  ...optionOptions,
  name: 'AMentionsOption',
  props: optionProps,
})

export default Object.assign(Mentions, {
  Option: MentionsOption,
  getMentions,
  install: (app: App) => {
    app.component(Mentions.name, Mentions)
    app.component(MentionsOption.name, MentionsOption)
    return app
  },
})
