import assert from 'node:assert/strict'
import test from 'node:test'
import { effectScope, nextTick, ref } from 'vue'
import { useAdminMarkdownTextareaFocus } from '../composables/useAdminMarkdownTextareaFocus.js'

/**
 * 테스트용 textarea DOM 대역을 만든다.
 * @param {Object} options - textarea 옵션
 * @returns {Object} textarea 대역
 */
const createTextareaStub = (options = {}) => {
  const calls = {
    focus: 0,
    selections: []
  }

  const textarea = {
    value: options.value ?? '첫 줄\n둘째 줄\n셋째 줄',
    selectionStart: options.selectionStart ?? 0,
    selectionEnd: options.selectionEnd ?? options.selectionStart ?? 0,
    scrollHeight: options.scrollHeight ?? 700,
    scrollTop: options.scrollTop ?? 0,
    clientWidth: options.clientWidth ?? 720,
    style: {
      height: ''
    },
    focus: () => {
      calls.focus += 1
    },
    setSelectionRange: (start, end) => {
      calls.selections.push([start, end])
      textarea.selectionStart = start
      textarea.selectionEnd = end
    },
    getBoundingClientRect: () => ({
      top: 0,
      bottom: 700,
      height: 700
    }),
    calls
  }

  return textarea
}

/**
 * 테스트용 textarea 포커스 composable 상태를 만든다.
 * @param {Object} options - 테스트 옵션
 * @returns {Object} 테스트 상태
 */
const createTextareaFocusState = (options = {}) => {
  const scope = effectScope()
  const value = ref(options.value ?? '첫 줄\n둘째 줄\n셋째 줄')
  const activeMode = ref(options.activeMode ?? 'write')
  const writeModeContextValue = ref(null)
  const lastSelectionState = ref(options.lastSelectionState ?? { start: 0, end: 0 })
  const activeLogicalLineIndex = ref(0)
  const gutterLineHeights = ref([28, 28, 28])
  const editorRootRef = ref(null)
  const textarea = options.textarea ?? createTextareaStub({ value: value.value })
  const calls = {
    syncBlockPanelState: 0,
    syncWriteSlashState: 0
  }
  let focusState

  scope.run(() => {
    focusState = useAdminMarkdownTextareaFocus({
      value,
      activeMode,
      writeModeContextValue,
      lastSelectionState,
      activeLogicalLineIndex,
      gutterLineHeights,
      editorRootRef,
      minTextareaHeight: 620,
      getWriteTextareaElement: () => textarea,
      getLineStartOffset: (lineIndex) => {
        const lines = String(value.value).split('\n')
        return lines.slice(0, lineIndex).join('\n').length + (lineIndex > 0 ? 1 : 0)
      },
      syncBlockPanelState: () => {
        calls.syncBlockPanelState += 1
      },
      syncWriteSlashState: () => {
        calls.syncWriteSlashState += 1
      }
    })
  })

  return {
    activeLogicalLineIndex,
    calls,
    focusState,
    lastSelectionState,
    textarea,
    value,
    writeModeContextValue,
    stop: () => scope.stop()
  }
}

/**
 * composable 내부 nextTick을 비운다.
 * @returns {Promise<void>}
 */
const flushTextareaFocusTicks = async () => {
  await nextTick()
  await nextTick()
  await nextTick()
}

test('textarea 선택 영역을 마지막 선택 상태로 기억한다', () => {
  const textarea = createTextareaStub({
    value: 'abc\ndef',
    selectionStart: 5,
    selectionEnd: 7
  })
  const state = createTextareaFocusState({
    value: 'abc\ndef',
    textarea
  })

  state.focusState.rememberTextareaSelection()

  assert.deepEqual(state.lastSelectionState.value, {
    start: 5,
    end: 7
  })
  state.stop()
})

test('커서 위치 기준으로 작성 컨텍스트와 활성 줄을 갱신한다', async () => {
  const textarea = createTextareaStub({
    value: '첫 줄\n둘째 줄\n셋째 줄',
    selectionStart: 8,
    selectionEnd: 8
  })
  const state = createTextareaFocusState({ textarea })

  state.focusState.refreshCaretLogicalLine()
  await flushTextareaFocusTicks()

  assert.equal(state.writeModeContextValue.value, '첫 줄\n둘째 줄\n셋째 줄')
  assert.deepEqual(state.lastSelectionState.value, {
    start: 8,
    end: 8
  })
  assert.equal(state.activeLogicalLineIndex.value, 1)
  assert.equal(state.calls.syncBlockPanelState, 1)
  assert.equal(textarea.style.height, '700px')
  state.stop()
})

test('지정 줄로 textarea 포커스와 커서를 이동한다', async () => {
  const textarea = createTextareaStub()
  const state = createTextareaFocusState({ textarea })

  state.focusState.focusTextareaAtLine(2)
  await flushTextareaFocusTicks()

  assert.equal(textarea.calls.focus, 1)
  assert.deepEqual(textarea.calls.selections[0], [9, 9])
  assert.equal(state.activeLogicalLineIndex.value, 2)
  state.stop()
})

test('마지막 선택 상태로 textarea 포커스를 복원한다', async () => {
  const textarea = createTextareaStub()
  const state = createTextareaFocusState({
    textarea,
    lastSelectionState: {
      start: 5,
      end: 8
    }
  })

  state.focusState.restoreTextareaFocus()
  await flushTextareaFocusTicks()

  assert.equal(textarea.calls.focus, 1)
  assert.deepEqual(textarea.calls.selections[0], [5, 8])
  assert.equal(state.activeLogicalLineIndex.value, 1)
  state.stop()
})