import { computed, ref } from 'vue'
import {
  addSlashSuppressedLine,
  clampSlashHighlightedIndex,
  filterSlashCommands,
  removeSlashSuppressedLine
} from '../lib/markdown-slash-commands.js'

/**
 * 관리자 Markdown 에디터의 슬래시 메뉴 상태를 관리한다.
 * @returns {{
 *   liveSlashSourceLine: import('vue').Ref<number|null>,
 *   liveSlashQuery: import('vue').Ref<string>,
 *   liveSlashHighlightedIndex: import('vue').Ref<number>,
 *   liveSlashMenuPosition: import('vue').Ref<{ top: number, left: number }>,
 *   liveSlashMenuRef: import('vue').Ref<HTMLElement|null>,
 *   liveSlashInsertLine: import('vue').Ref<number|null>,
 *   liveSlashSuppressedLines: import('vue').Ref<Set<number>>,
 *   liveSlashSuppressedLineValues: import('vue').Ref<Record<string, string>>,
 *   liveSlashKeyboardNav: import('vue').Ref<boolean>,
 *   liveSlashVisible: import('vue').ComputedRef<boolean>,
 *   liveSlashSuppressedLineList: import('vue').ComputedRef<number[]>,
 *   visibleLiveSlashCommands: import('vue').ComputedRef<import('../lib/markdown-slash-commands.js').MarkdownSlashCommand[]>,
 *   clearLiveSlashState: () => void,
 *   openLiveSlashMenu: (sourceLine: number, query: string) => void,
 *   isLiveSlashLineSuppressed: (line: number, lineValue?: string) => boolean,
 *   suppressLiveSlashLine: (line: number, lineValue?: string) => void,
 *   releaseLiveSlashLine: (line: number) => void,
 *   resetLiveSlashHighlightedIndex: () => void,
 *   clampLiveSlashHighlightedIndex: (commandCount: number) => void,
 *   startLiveSlashKeyboardNavigation: (durationMs?: number) => void,
 *   stopLiveSlashKeyboardNavigation: () => void
 * }} 슬래시 메뉴 상태와 액션
 */
export const useAdminMarkdownSlashMenu = () => {
  const liveSlashSourceLine = ref(null)
  const liveSlashQuery = ref('')
  const liveSlashHighlightedIndex = ref(0)
  const liveSlashMenuPosition = ref({ top: 0, left: 0 })
  const liveSlashMenuRef = ref(null)
  const liveSlashInsertLine = ref(null)
  const liveSlashSuppressedLines = ref(new Set())
  const liveSlashSuppressedLineValues = ref({})
  const liveSlashKeyboardNav = ref(false)
  let liveSlashKeyboardNavTimer = null

  const liveSlashVisible = computed(() => liveSlashSourceLine.value !== null)
  const liveSlashSuppressedLineList = computed(() => [...liveSlashSuppressedLines.value])
  const visibleLiveSlashCommands = computed(() => filterSlashCommands(liveSlashQuery.value))

  /**
   * 슬래시 메뉴 입력 상태를 초기화한다.
   * @returns {void}
   */
  const clearLiveSlashState = () => {
    liveSlashSourceLine.value = null
    liveSlashQuery.value = ''
    liveSlashHighlightedIndex.value = 0
  }

  /**
   * 슬래시 메뉴를 지정 줄과 검색어로 연다.
   * @param {number} sourceLine - 슬래시 명령이 입력된 줄
   * @param {string} query - 검색어
   * @returns {void}
   */
  const openLiveSlashMenu = (sourceLine, query) => {
    liveSlashSourceLine.value = sourceLine
    liveSlashQuery.value = String(query ?? '')
  }

  /**
   * 슬래시 메뉴가 억제된 줄인지 확인한다.
   * @param {number} line - 줄 번호
   * @returns {boolean} 억제 여부
   */
  const isLiveSlashLineSuppressed = (line, lineValue) => {
    if (!liveSlashSuppressedLines.value.has(line)) {
      return false
    }

    const suppressedValue = liveSlashSuppressedLineValues.value[String(line)]

    if (suppressedValue === undefined || lineValue === undefined) {
      return true
    }

    return suppressedValue === lineValue
  }

  /**
   * 지정 줄에서 슬래시 메뉴가 다시 열리지 않도록 억제한다.
   * @param {number} line - 줄 번호
   * @param {string} [lineValue] - 억제 당시 줄 내용
   * @returns {void}
   */
  const suppressLiveSlashLine = (line, lineValue) => {
    liveSlashSuppressedLines.value = addSlashSuppressedLine(liveSlashSuppressedLines.value, line)

    if (Number.isFinite(line)) {
      liveSlashSuppressedLineValues.value = {
        ...liveSlashSuppressedLineValues.value,
        [String(line)]: String(lineValue ?? '')
      }
    }
  }

  /**
   * 지정 줄의 슬래시 메뉴 억제를 해제한다.
   * @param {number} line - 줄 번호
   * @returns {void}
   */
  const releaseLiveSlashLine = (line) => {
    liveSlashSuppressedLines.value = removeSlashSuppressedLine(liveSlashSuppressedLines.value, line)

    if (Number.isFinite(line)) {
      const nextValues = { ...liveSlashSuppressedLineValues.value }
      delete nextValues[String(line)]
      liveSlashSuppressedLineValues.value = nextValues
    }
  }

  /**
   * 슬래시 메뉴 하이라이트를 첫 항목으로 되돌린다.
   * @returns {void}
   */
  const resetLiveSlashHighlightedIndex = () => {
    liveSlashHighlightedIndex.value = 0
  }

  /**
   * 슬래시 메뉴 하이라이트를 명령 개수 안으로 보정한다.
   * @param {number} commandCount - 표시 가능한 명령 개수
   * @returns {void}
   */
  const clampLiveSlashHighlightedIndex = (commandCount) => {
    liveSlashHighlightedIndex.value = clampSlashHighlightedIndex(liveSlashHighlightedIndex.value, commandCount)
  }

  /**
   * 키보드 탐색 중 mouseenter 하이라이트를 잠시 무시한다.
   * @param {number} [durationMs=200] - 유지 시간(ms)
   * @returns {void}
   */
  const startLiveSlashKeyboardNavigation = (durationMs = 200) => {
    liveSlashKeyboardNav.value = true
    globalThis.clearTimeout(liveSlashKeyboardNavTimer)
    liveSlashKeyboardNavTimer = globalThis.setTimeout(() => {
      liveSlashKeyboardNav.value = false
    }, durationMs)
  }

  /**
   * 슬래시 메뉴 키보드 탐색 타이머를 정리한다.
   * @returns {void}
   */
  const stopLiveSlashKeyboardNavigation = () => {
    globalThis.clearTimeout(liveSlashKeyboardNavTimer)
    liveSlashKeyboardNavTimer = null
    liveSlashKeyboardNav.value = false
  }

  return {
    liveSlashSourceLine,
    liveSlashQuery,
    liveSlashHighlightedIndex,
    liveSlashMenuPosition,
    liveSlashMenuRef,
    liveSlashInsertLine,
    liveSlashSuppressedLines,
    liveSlashSuppressedLineValues,
    liveSlashKeyboardNav,
    liveSlashVisible,
    liveSlashSuppressedLineList,
    visibleLiveSlashCommands,
    clearLiveSlashState,
    openLiveSlashMenu,
    isLiveSlashLineSuppressed,
    suppressLiveSlashLine,
    releaseLiveSlashLine,
    resetLiveSlashHighlightedIndex,
    clampLiveSlashHighlightedIndex,
    startLiveSlashKeyboardNavigation,
    stopLiveSlashKeyboardNavigation
  }
}