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

/**
 * 테스트용 관리자 Markdown 포커스 브리지를 만든다.
 * @param {Object} options - 테스트 옵션
 * @returns {Object} 테스트 상태
 */
const createFocusBridgeState = (options = {}) => {
  const scope = effectScope()
  const activeMode = ref(options.activeMode ?? 'write')
  const value = ref(options.value ?? '첫 줄\n둘째 줄\n셋째 줄')
  const lastSelectionState = ref(options.selection ?? { start: 0, end: 0 })
  const activeLogicalLineIndex = ref(options.activeLogicalLineIndex ?? 1)
  const textarea = options.textarea ?? { selectionStart: 0 }
  const calls = {
    syncTextareaHeight: 0,
    focusTextareaAtLine: [],
    restoreTextareaFocus: 0,
    scrollPreviewToTop: 0,
    focusPreviewEditableAtLine: []
  }
  let currentPreviewSourceLine = options.currentPreviewSourceLine ?? null
  let bridge

  scope.run(() => {
    bridge = useAdminMarkdownFocusBridge({
      activeMode,
      value,
      lastSelectionState,
      activeLogicalLineIndex,
      getWriteTextareaElement: () => textarea,
      getLineIndexAtOffset: (offset) => String(value.value).slice(0, offset).split('\n').length - 1,
      getLineStartOffset: (lineIndex) => {
        const lines = String(value.value).split('\n')
        return lines.slice(0, lineIndex).join('\n').length + (lineIndex > 0 ? 1 : 0)
      },
      resolvePreviewFocusPosition: (line, offset) => ({
        line: line + 10,
        offset: offset + 1
      }),
      getCurrentPreviewSourceLine: () => currentPreviewSourceLine,
      syncTextareaHeight: () => {
        calls.syncTextareaHeight += 1
      },
      focusTextareaAtLine: (lineIndex) => {
        calls.focusTextareaAtLine.push(lineIndex)
      },
      restoreTextareaFocus: () => {
        calls.restoreTextareaFocus += 1
      },
      scrollPreviewToTop: () => {
        calls.scrollPreviewToTop += 1
      },
      focusPreviewEditableAtLine: (...args) => {
        calls.focusPreviewEditableAtLine.push(args)
      }
    })
  })

  return {
    activeMode,
    calls,
    bridge,
    setCurrentPreviewSourceLine: (line) => {
      currentPreviewSourceLine = line
    },
    stop: () => scope.stop()
  }
}

/**
 * 포커스 브리지 watch와 내부 nextTick을 모두 비운다.
 * @returns {Promise<void>}
 */
const flushFocusBridgeTicks = async () => {
  await nextTick()
  await nextTick()
  await nextTick()
}

test('작성 위치를 라이브 포커스 대상으로 저장하고 preview 전환 시 소비한다', async () => {
  const state = createFocusBridgeState({
    textarea: { selectionStart: 6 }
  })

  state.bridge.rememberWritePositionForPreview()
  assert.deepEqual(state.bridge.pendingPreviewFocus.value, {
    line: 11,
    offset: 3
  })

  state.activeMode.value = 'preview'
  await flushFocusBridgeTicks()

  assert.equal(state.bridge.pendingPreviewFocus.value, null)
  assert.deepEqual(state.calls.focusPreviewEditableAtLine, [[11, 0, 'auto', 3, 'center']])
  state.stop()
})

test('라이브 위치를 작성 포커스 대상으로 저장하고 write 전환 시 소비한다', async () => {
  const state = createFocusBridgeState({
    activeMode: 'preview',
    currentPreviewSourceLine: 4
  })

  state.bridge.rememberPreviewPosition()
  assert.equal(state.bridge.pendingWriteFocusLine.value, 4)

  state.activeMode.value = 'write'
  await flushFocusBridgeTicks()

  assert.equal(state.bridge.pendingWriteFocusLine.value, null)
  assert.equal(state.calls.syncTextareaHeight, 1)
  assert.deepEqual(state.calls.focusTextareaAtLine, [4])
  assert.equal(state.calls.restoreTextareaFocus, 0)
  state.stop()
})

test('작성 복원 대상이 없으면 마지막 textarea 선택을 복원한다', async () => {
  const state = createFocusBridgeState({
    activeMode: 'preview'
  })

  state.activeMode.value = 'write'
  await flushFocusBridgeTicks()

  assert.equal(state.calls.syncTextareaHeight, 1)
  assert.deepEqual(state.calls.focusTextareaAtLine, [])
  assert.equal(state.calls.restoreTextareaFocus, 1)
  state.stop()
})

test('라이브 복원 대상이 없으면 미리보기를 상단으로 이동한다', async () => {
  const state = createFocusBridgeState()

  state.activeMode.value = 'preview'
  await flushFocusBridgeTicks()

  assert.equal(state.calls.scrollPreviewToTop, 1)
  assert.deepEqual(state.calls.focusPreviewEditableAtLine, [])
  state.stop()
})

test('요청한 라이브 포커스는 다음 preview 전환 때 사용한다', async () => {
  const state = createFocusBridgeState()

  state.bridge.requestPreviewFocus({ line: 3, offset: 7 })
  assert.deepEqual(state.bridge.pendingPreviewFocus.value, {
    line: 3,
    offset: 7
  })

  state.activeMode.value = 'preview'
  await flushFocusBridgeTicks()

  assert.deepEqual(state.calls.focusPreviewEditableAtLine, [[3, 0, 'auto', 7, 'center']])
  state.stop()
})