import { fetchExpenseClaims } from '../../services/reimbursements.js'
import { runOrchestrator } from '../../services/orchestrator.js'
import {
  applyAiExpenseAnswer,
  buildAiExpenseStepPrompt,
  buildAiExpenseSummary,
  createAiExpenseDraft,
  isAiExpenseDraftComplete
} from '../../utils/aiExpenseDraftModel.js'
import {
  buildExpenseSceneSelectionMessage,
  SESSION_TYPE_EXPENSE
} from '../../views/scripts/travelReimbursementConversationModel.js'
import { buildExpenseSceneSelectionActions } from '../../utils/expenseAssistantActions.js'
import {
  buildRequiredApplicationActions,
  buildRequiredApplicationMissingText,
  buildRequiredApplicationSelectionText,
  filterRequiredApplicationCandidates,
  resolveRequiredApplicationReimbursementType
} from '../../views/scripts/travelReimbursementApplicationLinkModel.js'
import {
  buildReimbursementAssociationActions,
  buildReimbursementAssociationMissingText,
  buildReimbursementAssociationSubmitOptions,
  buildReimbursementAssociationThinkingEvents,
  buildReimbursementAssociationSelectionText,
  buildReimbursementAssociationQueryFailedText,
  buildReimbursementDraftActions,
  buildReimbursementDraftSelectionText,
  fetchReimbursementAssociationClaims,
  filterReimbursementAssociationCandidates,
  filterReimbursementDraftCandidates,
  REIMBURSEMENT_ASSOCIATION_QUERY_TIMEOUT_MS
} from '../../views/scripts/travelReimbursementAssociationGateModel.js'

export { SESSION_TYPE_EXPENSE }

const AI_REIMBURSEMENT_ASSOCIATION_STEP_DELAY_MS = 320

function waitForReimbursementAssociationStep() {
  return new Promise((resolve) => {
    globalThis.setTimeout(resolve, AI_REIMBURSEMENT_ASSOCIATION_STEP_DELAY_MS)
  })
}

export function useWorkbenchAiExpenseFlow({
  activateInlineConversation,
  aiExpenseDraft,
  assistantDraft,
  clearAiModeFiles,
  closeWorkbenchDatePicker,
  conversationMessages,
  conversationStarted,
  createInlineMessage,
  currentUser,
  persistCurrentConversation,
  pushInlineUserMessage,
  replaceInlineMessage = (id, nextMessage) => {
    const index = conversationMessages.value.findIndex((item) => item.id === id)
    if (index === -1) {
      conversationMessages.value.push(nextMessage)
      return
    }
    conversationMessages.value.splice(index, 1, nextMessage)
  },
  removeWorkbenchDateTag,
  resolveLatestInlineUserPrompt,
  scrollInlineConversationToBottom,
  startAiApplicationPreview,
  fetchExpenseClaimsForAi = fetchExpenseClaims,
  runOrchestratorForAi = runOrchestrator,
  associationQueryTimeoutMs = REIMBURSEMENT_ASSOCIATION_QUERY_TIMEOUT_MS
}) {
  function replaceInlineAssistantMessage(messageId, content = '', options = {}) {
    const nextMessage = createInlineMessage('assistant', content, {
      id: messageId,
      pending: Boolean(options.pending),
      stewardPlan: options.stewardPlan || null,
      suggestedActions: Array.isArray(options.suggestedActions) ? options.suggestedActions : [],
      draftPayload: options.draftPayload || null,
      text: options.text || content
    })
    replaceInlineMessage(messageId, nextMessage)
    return nextMessage
  }

  function pushInlineExpenseSceneSelectionPrompt(originalMessage, selectedLabel = '') {
    const sourceText = String(originalMessage || '我要报销').trim()
    if (!conversationStarted.value) {
      activateInlineConversation({
        title: String(selectedLabel || sourceText || '报销').trim().slice(0, 18) || '报销'
      })
    }
    assistantDraft.value = ''
    removeWorkbenchDateTag()
    closeWorkbenchDatePicker()
    conversationMessages.value.push(createInlineMessage('user', String(selectedLabel || sourceText).trim()))
    conversationMessages.value.push(createInlineMessage('assistant', buildExpenseSceneSelectionMessage(sourceText), {
      suggestedActions: buildExpenseSceneSelectionActions(sourceText)
    }))
    persistCurrentConversation()
    scrollInlineConversationToBottom()
  }

  function startAiApplicationPreviewFromAction(payload = {}, fallbackLabel = '') {
    const expenseType = String(payload.expense_type || '').trim()
    const expenseTypeLabel = String(payload.expense_type_label || fallbackLabel || '').trim()
    return startAiApplicationPreview(
      expenseType,
      expenseTypeLabel,
      payload.carry_text || resolveLatestInlineUserPrompt()
    )
  }

  async function startAiReimbursementAssociationGate(originalMessage = '我要报销', selectedLabel = '', options = {}) {
    const sourceText = String(originalMessage || '我要报销').trim() || '我要报销'
    if (!conversationStarted.value) {
      activateInlineConversation({
        title: String(selectedLabel || sourceText || '报销').trim().slice(0, 18) || '报销'
      })
    }
    assistantDraft.value = ''
    removeWorkbenchDateTag()
    closeWorkbenchDatePicker()
    clearAiModeFiles()
    aiExpenseDraft.value = null
    pushInlineUserMessage(String(selectedLabel || sourceText).trim())
    const pendingMessage = createInlineMessage('assistant', '', {
      pending: true,
      stewardPlan: {
        streamStatus: 'streaming',
        thinkingEvents: buildReimbursementAssociationThinkingEvents('intent')
      },
      suggestedActions: []
    })
    conversationMessages.value.push(pendingMessage)
    const pendingMessageId = pendingMessage.id
    persistCurrentConversation()
    scrollInlineConversationToBottom()
    await waitForReimbursementAssociationStep()

    replaceInlineAssistantMessage(pendingMessageId, '', {
      pending: true,
      stewardPlan: {
        streamStatus: 'streaming',
        thinkingEvents: buildReimbursementAssociationThinkingEvents('query')
      },
      suggestedActions: []
    })
    scrollInlineConversationToBottom()

    let claims = null
    try {
      claims = await fetchReimbursementAssociationClaims({
        fetchExpenseClaims: fetchExpenseClaimsForAi,
        timeoutMs: associationQueryTimeoutMs
      })
    } catch (error) {
      replaceInlineAssistantMessage(pendingMessageId, buildReimbursementAssociationQueryFailedText(error), {
        stewardPlan: {
          streamStatus: 'failed',
          thinkingEvents: buildReimbursementAssociationThinkingEvents('failed')
        },
        suggestedActions: buildReimbursementAssociationActions([], sourceText)
      })
      persistCurrentConversation()
      scrollInlineConversationToBottom()
      return
    }

    const draftCandidates = options.skipDraftCheck
      ? []
      : filterReimbursementDraftCandidates(claims, currentUser.value || {})
    if (draftCandidates.length) {
      replaceInlineAssistantMessage(pendingMessageId, '', {
        pending: true,
        stewardPlan: {
          streamStatus: 'streaming',
          thinkingEvents: buildReimbursementAssociationThinkingEvents('filter', { candidateCount: draftCandidates.length })
        },
        suggestedActions: []
      })
      scrollInlineConversationToBottom()
      await waitForReimbursementAssociationStep()

      const content = buildReimbursementDraftSelectionText(draftCandidates)
      replaceInlineAssistantMessage(pendingMessageId, content, {
        stewardPlan: {
          streamStatus: 'completed',
          thinkingEvents: buildReimbursementAssociationThinkingEvents('completed', { candidateCount: draftCandidates.length })
        },
        suggestedActions: buildReimbursementDraftActions(draftCandidates, sourceText)
      })
      persistCurrentConversation()
      scrollInlineConversationToBottom()
      return
    }

    const candidates = filterReimbursementAssociationCandidates(claims, currentUser.value || {})
    replaceInlineAssistantMessage(pendingMessageId, '', {
      pending: true,
      stewardPlan: {
        streamStatus: 'streaming',
        thinkingEvents: buildReimbursementAssociationThinkingEvents('filter', { candidateCount: candidates.length })
      },
      suggestedActions: []
    })
    scrollInlineConversationToBottom()
    await waitForReimbursementAssociationStep()

    const content = candidates.length
      ? buildReimbursementAssociationSelectionText(candidates)
      : buildReimbursementAssociationMissingText()
    replaceInlineAssistantMessage(pendingMessageId, content, {
      stewardPlan: {
        streamStatus: 'completed',
        thinkingEvents: buildReimbursementAssociationThinkingEvents('completed', { candidateCount: candidates.length })
      },
      suggestedActions: buildReimbursementAssociationActions(candidates, sourceText)
    })
    persistCurrentConversation()
    scrollInlineConversationToBottom()
  }

  function startAiExpenseDraft(expenseType, expenseTypeLabel, requiresApplicationBeforeReimbursement) {
    if (!conversationStarted.value) {
      activateInlineConversation({ title: String(expenseTypeLabel || '报销').trim().slice(0, 18) || '报销' })
    }
    assistantDraft.value = ''
    removeWorkbenchDateTag()
    closeWorkbenchDatePicker()
    clearAiModeFiles()
    pushInlineUserMessage(`选择${expenseTypeLabel || expenseType || '报销'}`)

    if (requiresApplicationBeforeReimbursement) {
      void resolveAiExpenseApplicationLink(expenseType, expenseTypeLabel)
      return
    }

    const draft = createAiExpenseDraft(expenseType, expenseTypeLabel)
    aiExpenseDraft.value = draft
    conversationMessages.value.push(createInlineMessage('assistant', buildAiExpenseStepPrompt(draft)))
    persistCurrentConversation()
    scrollInlineConversationToBottom()
  }

  function advanceAiExpenseDraft(answer, files = []) {
    const fileNames = Array.from(files || [])
    pushInlineUserMessage(answer || (fileNames.length ? `上传 ${fileNames.length} 份附件` : ''))
    assistantDraft.value = ''
    clearAiModeFiles()

    const next = applyAiExpenseAnswer(aiExpenseDraft.value, answer, fileNames)
    aiExpenseDraft.value = next

    if (isAiExpenseDraftComplete(next)) {
      conversationMessages.value.push(createInlineMessage('assistant', `${buildAiExpenseSummary(next)}\n\n如果哪一项需要修改，直接告诉我；确认无误后我再帮你生成报销草稿。`))
      aiExpenseDraft.value = null
    } else {
      conversationMessages.value.push(createInlineMessage('assistant', buildAiExpenseStepPrompt(next)))
    }
    persistCurrentConversation()
    scrollInlineConversationToBottom()
  }

  async function resolveAiExpenseApplicationLink(expenseType, expenseTypeLabel) {
    let claims = null
    try {
      claims = await fetchExpenseClaimsForAi()
    } catch {
      aiExpenseDraft.value = null
      conversationMessages.value.push(createInlineMessage('assistant', '查询可关联申请单时出现异常，请稍后再试，我先暂停这次报销流程。'))
      persistCurrentConversation()
      scrollInlineConversationToBottom()
      return
    }

    const candidates = filterRequiredApplicationCandidates(claims, expenseType, currentUser.value || {})
    aiExpenseDraft.value = createAiExpenseDraft(expenseType, expenseTypeLabel)

    if (!candidates.length) {
      conversationMessages.value.push(createInlineMessage('assistant', buildRequiredApplicationMissingText(expenseType), {
        suggestedActions: [{
          label: '确认发起出差申请',
          description: '生成完整申请表，并预填已识别的时间、地点和事由',
          icon: 'mdi mdi-file-plus-outline',
          action_type: 'ai_application_start_inline',
          payload: {
            expense_type: expenseType,
            expense_type_label: expenseTypeLabel
          }
        }]
      }))
      persistCurrentConversation()
      scrollInlineConversationToBottom()
      return
    }

    conversationMessages.value.push(createInlineMessage('assistant', buildRequiredApplicationSelectionText(expenseType, candidates), {
      suggestedActions: buildRequiredApplicationActions(candidates, 'select_required_application')
    }))
    persistCurrentConversation()
    scrollInlineConversationToBottom()
  }

  function buildWorkbenchUserContext() {
    const user = currentUser.value || {}
    return {
      role_codes: Array.isArray(user.roleCodes) ? user.roleCodes : [],
      is_admin: Boolean(user.isAdmin),
      name: user.name || '',
      role: user.role || '',
      department: user.department || user.departmentName || '',
      department_name: user.department || user.departmentName || '',
      position: user.position || '',
      employee_position: user.position || user.employeePosition || user.employee_position || '',
      employee_no: user.employeeNo || user.employee_no || '',
      employeeNo: user.employeeNo || user.employee_no || '',
      session_type: SESSION_TYPE_EXPENSE,
      entry_source: 'workbench-ai'
    }
  }

  function buildLinkedDraftAction(draftPayload = {}) {
    const claimNo = String(draftPayload.claim_no || draftPayload.claimNo || '').trim()
    const claimId = String(draftPayload.claim_id || draftPayload.claimId || '').trim()
    if (!claimNo && !claimId) {
      return []
    }
    return [{
      label: '查看报销草稿',
      description: '打开草稿详情继续上传票据或补充信息。',
      icon: 'mdi mdi-file-document-outline',
      action_type: 'open_application_detail',
      payload: {
        claim_id: claimId,
        claim_no: claimNo
      }
    }]
  }

  async function linkAiExpenseApplication(application = {}) {
    const draft = aiExpenseDraft.value || (() => {
      const resolved = resolveRequiredApplicationReimbursementType(application)
      return createAiExpenseDraft(resolved.expenseType, resolved.expenseTypeLabel)
    })()
    const claimNo = String(application.application_claim_no || '').trim()
    pushInlineUserMessage(`关联申请单 ${claimNo}`.trim())

    const linked = {
      ...draft,
      applicationClaim: application,
      values: {
        ...draft.values,
        reason: String(application.application_reason || '').trim(),
        location: String(application.application_location || '').trim(),
        time_range: String(application.application_business_time || '').trim(),
        amount: String(application.application_amount_label || application.application_amount || '').trim()
      },
      stepKey: 'attachments'
    }
    aiExpenseDraft.value = linked
    const pendingMessage = createInlineMessage('assistant', `已关联申请单${claimNo ? ` ${claimNo}` : ''}，正在生成报销草稿...`, {
      pending: true,
      suggestedActions: []
    })
    conversationMessages.value.push(pendingMessage)
    const pendingMessageId = pendingMessage.id
    persistCurrentConversation()
    scrollInlineConversationToBottom()

    try {
      const submitOptions = buildReimbursementAssociationSubmitOptions(
        application,
        application.original_message || resolveLatestInlineUserPrompt() || '我要报销'
      )
      const user = currentUser.value || {}
      const payload = await runOrchestratorForAi(
        {
          source: 'user_message',
          user_id: user.username || user.name || 'anonymous',
          conversation_id: null,
          message: submitOptions.rawText,
          context_json: {
            ...buildWorkbenchUserContext(),
            ...submitOptions.extraContext
          }
        },
        {
          timeoutMs: 120000,
          timeoutMessage: '生成报销草稿超时，请稍后重试。'
        }
      )
      const draftPayload = payload?.result?.draft_payload || null
      const draftClaimNo = String(draftPayload?.claim_no || draftPayload?.claimNo || '').trim()
      const content = draftClaimNo
        ? `报销草稿 ${draftClaimNo} 已生成，并已关联申请单 ${claimNo || '所选申请单'}。后续可以在草稿详情中上传票据或补充信息。`
        : `报销草稿已生成，并已关联申请单 ${claimNo || '所选申请单'}。后续可以在草稿详情中上传票据或补充信息。`
      replaceInlineAssistantMessage(pendingMessageId, content, {
        draftPayload,
        suggestedActions: buildLinkedDraftAction(draftPayload)
      })
      aiExpenseDraft.value = null
      persistCurrentConversation()
      scrollInlineConversationToBottom()
    } catch {
      replaceInlineAssistantMessage(
        pendingMessageId,
        '生成报销草稿时出现异常。申请单关联信息我先保留在当前会话里，你可以稍后重试或单独新建报销单。',
        {
          suggestedActions: []
        }
      )
      persistCurrentConversation()
      scrollInlineConversationToBottom()
    }
  }

  return {
    advanceAiExpenseDraft,
    linkAiExpenseApplication,
    pushInlineExpenseSceneSelectionPrompt,
    startAiApplicationPreviewFromAction,
    startAiReimbursementAssociationGate,
    startAiExpenseDraft
  }
}