import { ref } from 'vue'

import {
  APPLICATION_TRANSPORT_MODE_OPTIONS,
  applyApplicationPolicyEstimateError,
  applyApplicationPolicyEstimateResult,
  buildApplicationPreviewRows,
  buildApplicationPolicyEstimateRequest,
  buildLocalApplicationPreviewMessage,
  normalizeApplicationPreview,
  resolveApplicationDaysFromDateRange,
  refreshApplicationPreviewTransportEstimate
} from '../../utils/expenseApplicationPreview.js'
import {
  buildWorkbenchDateLabel,
  canApplyWorkbenchDateSelection,
  getTodayDateValue
} from '../../utils/workbenchComposerDate.js'

function parseEditorDateValue(value) {
  const text = String(value || '').trim()
  const matches = [...text.matchAll(/20\d{2}-\d{1,2}-\d{1,2}/g)].map((item) => item[0])
  const startDate = matches[0] || getTodayDateValue()
  const endDate = matches[1] || startDate
  return {
    dateMode: matches.length > 1 && startDate !== endDate ? 'range' : 'single',
    singleDate: startDate,
    rangeStartDate: startDate,
    rangeEndDate: endDate
  }
}

function buildEmptyEditor() {
  return {
    messageId: '',
    fieldKey: '',
    draftValue: '',
    dateMode: 'single',
    singleDate: getTodayDateValue(),
    rangeStartDate: getTodayDateValue(),
    rangeEndDate: getTodayDateValue(),
    committing: false
  }
}

function shouldRefreshTransportEstimate(fieldKey) {
  return ['transportMode', 'time', 'location', 'days'].includes(fieldKey)
}

function resolveEditorCurrentUser(currentUser) {
  if (currentUser && typeof currentUser === 'object' && 'value' in currentUser) {
    return currentUser.value || {}
  }
  return currentUser || {}
}

function buildEditedApplicationPreviewFields(fields = {}, editor = {}, nextValue = '') {
  const nextFields = {
    ...fields,
    [editor.fieldKey]: nextValue
  }
  if (editor.fieldKey === 'time') {
    const resolvedDays = resolveApplicationDaysFromDateRange(nextValue)
    if (resolvedDays) {
      nextFields.days = resolvedDays
    }
  }
  return nextFields
}

function buildTransportEstimatePendingPreview(preview = {}) {
  const fields = preview?.fields || {}
  return normalizeApplicationPreview({
    ...preview,
    fields: {
      ...fields,
      transportPolicy: '正在预估交通费用...',
      policyEstimate: '正在同步费用测算...',
      transportEstimatedAmount: '查询中'
    }
  })
}

export function useApplicationPreviewEditor({
  persistSessionState,
  toast,
  calculateTravelReimbursement,
  currentUser
} = {}) {
  const applicationPreviewEditor = ref(buildEmptyEditor())

  async function refreshApplicationPreviewEstimate(preview = {}) {
    const user = resolveEditorCurrentUser(currentUser)
    const estimateRequest = buildApplicationPolicyEstimateRequest(preview, user)
    if (estimateRequest.canCalculate && typeof calculateTravelReimbursement === 'function') {
      try {
        const result = await calculateTravelReimbursement(estimateRequest.payload)
        return applyApplicationPolicyEstimateResult(preview, result, user)
      } catch (error) {
        console.warn('Application preview estimate refresh failed:', error)
        return applyApplicationPolicyEstimateError(preview, error, user)
      }
    }
    return refreshApplicationPreviewTransportEstimate(preview)
  }

  function resolveApplicationPreviewRows(message) {
    return buildApplicationPreviewRows(message?.applicationPreview || {})
  }

  function resolveApplicationPreviewEditorControl(fieldKey) {
    if (fieldKey === 'transportMode') return 'select'
    if (fieldKey === 'time') return 'date'
    return 'text'
  }

  function resolveApplicationPreviewEditorOptions(fieldKey) {
    return fieldKey === 'transportMode' ? APPLICATION_TRANSPORT_MODE_OPTIONS : []
  }

  function isApplicationPreviewEditing(message, fieldKey) {
    return (
      String(applicationPreviewEditor.value.messageId || '') === String(message?.id || '') &&
      applicationPreviewEditor.value.fieldKey === fieldKey
    )
  }

  function openApplicationPreviewEditor(message, fieldKey, value) {
    if (!message?.applicationPreview || !fieldKey) return
    const targetRow = buildApplicationPreviewRows(message.applicationPreview)
      .find((row) => row.key === fieldKey)
    if (targetRow && targetRow.editable === false) return
    const normalizedValue = String(value || '').trim() === '待补充' ? '' : String(value || '')
    const dateState = fieldKey === 'time' ? parseEditorDateValue(normalizedValue) : {}
    applicationPreviewEditor.value = {
      messageId: String(message.id || ''),
      fieldKey,
      draftValue: fieldKey === 'transportMode' && !APPLICATION_TRANSPORT_MODE_OPTIONS.includes(normalizedValue)
        ? ''
        : normalizedValue,
      committing: false,
      ...dateState
    }
  }

  function cancelApplicationPreviewEditor() {
    applicationPreviewEditor.value = buildEmptyEditor()
  }

  function isApplicationPreviewDateEditorOpen(message) {
    return isApplicationPreviewEditing(message, 'time')
  }

  function setApplicationPreviewDateMode(mode) {
    applicationPreviewEditor.value.dateMode = mode === 'range' ? 'range' : 'single'
  }

  function canApplyApplicationPreviewDateSelection() {
    const editor = applicationPreviewEditor.value
    return canApplyWorkbenchDateSelection({
      mode: editor.dateMode,
      singleDate: editor.singleDate,
      rangeStartDate: editor.rangeStartDate,
      rangeEndDate: editor.rangeEndDate
    })
  }

  function buildApplicationPreviewDateDraftValue() {
    const editor = applicationPreviewEditor.value
    return buildWorkbenchDateLabel({
      mode: editor.dateMode,
      singleDate: editor.singleDate,
      rangeStartDate: editor.rangeStartDate,
      rangeEndDate: editor.rangeEndDate
    })
  }

  async function commitApplicationPreviewEditor(message) {
    const editor = applicationPreviewEditor.value
    if (editor.committing) {
      return false
    }
    if (!message?.applicationPreview || String(editor.messageId || '') !== String(message.id || '') || !editor.fieldKey) {
      cancelApplicationPreviewEditor()
      return false
    }
    applicationPreviewEditor.value = {
      ...editor,
      committing: true
    }

    const nextValue = editor.fieldKey === 'time'
      ? buildApplicationPreviewDateDraftValue()
      : String(editor.draftValue || '').trim()
    if (editor.fieldKey === 'time' && !nextValue) {
      toast?.('请先选择有效日期。')
      applicationPreviewEditor.value = {
        ...applicationPreviewEditor.value,
        committing: false
      }
      return false
    }
    const nextPreview = normalizeApplicationPreview({
      ...message.applicationPreview,
      fields: buildEditedApplicationPreviewFields(
        message.applicationPreview.fields || {},
        editor,
        nextValue
      )
    })
    const needRefreshEstimate = shouldRefreshTransportEstimate(editor.fieldKey)
    message.applicationPreview = needRefreshEstimate
      ? buildTransportEstimatePendingPreview(nextPreview)
      : nextPreview
    message.text = buildLocalApplicationPreviewMessage(message.applicationPreview)
    cancelApplicationPreviewEditor()
    persistSessionState?.()
    if (needRefreshEstimate) {
      const refreshedPreview = await refreshApplicationPreviewEstimate(nextPreview)
      message.applicationPreview = refreshedPreview
      message.text = buildLocalApplicationPreviewMessage(refreshedPreview)
      persistSessionState?.()
      toast?.('已更新出行方式和费用测算。')
      return true
    }
    toast?.('已更新核对表内容。')
    return true
  }

  async function commitApplicationPreviewDateEditor(message) {
    if (!canApplyApplicationPreviewDateSelection()) {
      toast?.('请确认结束日期不早于开始日期。')
      return false
    }
    return commitApplicationPreviewEditor(message)
  }

  function handleApplicationPreviewEditorKeydown(event, message) {
    if (event.key === 'Enter') {
      event.preventDefault()
      commitApplicationPreviewEditor(message)
      return
    }
    if (event.key === 'Escape') {
      event.preventDefault()
      cancelApplicationPreviewEditor()
    }
  }

  return {
    applicationPreviewEditor,
    resolveApplicationPreviewRows,
    resolveApplicationPreviewEditorControl,
    resolveApplicationPreviewEditorOptions,
    refreshApplicationPreviewEstimate,
    isApplicationPreviewEditing,
    isApplicationPreviewDateEditorOpen,
    openApplicationPreviewEditor,
    commitApplicationPreviewEditor,
    commitApplicationPreviewDateEditor,
    cancelApplicationPreviewEditor,
    setApplicationPreviewDateMode,
    canApplyApplicationPreviewDateSelection,
    handleApplicationPreviewEditorKeydown
  }
}