import { computed, reactive, ref } from 'vue'

import { fetchExpenseClaims } from '../services/reimbursements.js'

const EXPENSE_TYPE_LABELS = {
  travel: '差旅费',
  entertainment: '业务招待费',
  office: '办公费',
  meeting: '会务费',
  training: '培训费',
  hotel: '住宿费',
  transport: '交通费',
  meal: '餐费',
  other: '其他费用'
}

const REIMBURSEMENT_PROGRESS_LABELS = [
  '保存草稿',
  '待提交',
  'AI验审',
  '直属领导审批',
  '财务审批',
  '归档入账'
]

function parseNumber(value) {
  const nextValue = Number(value)
  return Number.isFinite(nextValue) ? nextValue : 0
}

function toDate(value) {
  if (!value) {
    return null
  }

  const nextDate = new Date(value)
  return Number.isNaN(nextDate.getTime()) ? null : nextDate
}

function formatDate(value) {
  const nextDate = toDate(value)
  if (!nextDate) {
    return ''
  }

  const year = nextDate.getFullYear()
  const month = String(nextDate.getMonth() + 1).padStart(2, '0')
  const day = String(nextDate.getDate()).padStart(2, '0')
  return `${year}-${month}-${day}`
}

function formatDateTime(value) {
  const nextDate = toDate(value)
  if (!nextDate) {
    return ''
  }

  const hours = String(nextDate.getHours()).padStart(2, '0')
  const minutes = String(nextDate.getMinutes()).padStart(2, '0')
  return `${formatDate(nextDate)} ${hours}:${minutes}`
}

function formatAmount(value) {
  return new Intl.NumberFormat('zh-CN', {
    style: 'currency',
    currency: 'CNY',
    minimumFractionDigits: 0,
    maximumFractionDigits: Number.isInteger(value) ? 0 : 2
  }).format(parseNumber(value))
}

function resolveTypeLabel(typeCode) {
  return EXPENSE_TYPE_LABELS[String(typeCode || '').trim()] || EXPENSE_TYPE_LABELS.other
}

function resolveApprovalMeta(status) {
  const normalized = String(status || '').trim().toLowerCase()

  if (normalized === 'draft') {
    return { key: 'draft', label: '草稿', tone: 'draft' }
  }

  if (['supplement', 'returned'].includes(normalized)) {
    return { key: 'supplement', label: '待补充', tone: 'warning' }
  }

  if (['approved', 'completed', 'paid'].includes(normalized)) {
    return { key: 'completed', label: '已完成', tone: 'success' }
  }

  if (['rejected', 'cancelled'].includes(normalized)) {
    return { key: 'rejected', label: '已退回', tone: 'danger' }
  }

  return { key: 'in_progress', label: '审批中', tone: 'info' }
}

function resolveWorkflowNode(claim, approvalMeta) {
  const rawNode = String(claim?.approval_stage || '').trim()

  if (rawNode) {
    if (rawNode === '审批流转') {
      return 'AI验审'
    }
    if (rawNode === '待补充') {
      return approvalMeta.key === 'draft' ? '待提交' : 'AI验审'
    }
    return rawNode
  }

  if (approvalMeta.key === 'draft' || approvalMeta.key === 'supplement' || approvalMeta.key === 'rejected') {
    return '待提交'
  }

  if (approvalMeta.key === 'completed') {
    return '归档入账'
  }

  return 'AI验审'
}

function stringifyRiskFlag(value) {
  if (typeof value === 'string') {
    return value.trim()
  }

  if (!value || typeof value !== 'object') {
    return ''
  }

  for (const key of ['message', 'label', 'reason', 'name']) {
    const nextValue = String(value[key] || '').trim()
    if (nextValue) {
      return nextValue
    }
  }

  return ''
}

function buildRiskSummary(riskFlags) {
  if (!Array.isArray(riskFlags) || !riskFlags.length) {
    return '无'
  }

  const items = riskFlags.map((item) => stringifyRiskFlag(item)).filter(Boolean)
  return items.length ? items.join('；') : '无'
}

function buildOccurredDisplay(claim) {
  const itemDates = Array.isArray(claim?.items)
    ? claim.items.map((item) => formatDate(item?.item_date)).filter(Boolean)
    : []

  if (!itemDates.length) {
    return formatDate(claim?.occurred_at) || '待补充'
  }

  const sortedDates = [...new Set(itemDates)].sort()
  if (sortedDates.length === 1) {
    return sortedDates[0]
  }

  return `${sortedDates[0]} ~ ${sortedDates[sortedDates.length - 1]}`
}

function resolveProgressCurrentIndex(approvalMeta, workflowNode) {
  const normalizedNode = String(workflowNode || '').trim()

  if (approvalMeta.key === 'completed') {
    return 5
  }

  if (normalizedNode.includes('归档') || normalizedNode.includes('入账')) {
    return 5
  }
  if (normalizedNode.includes('财务')) {
    return 4
  }
  if (
    normalizedNode.includes('直属领导')
    || normalizedNode.includes('领导审批')
    || normalizedNode.includes('部门负责人')
    || normalizedNode.includes('负责人审批')
  ) {
    return 3
  }
  if (normalizedNode.includes('AI验审') || normalizedNode.includes('审批流转')) {
    return 2
  }
  if (normalizedNode.includes('待提交')) {
    return 1
  }

  if (approvalMeta.key === 'draft' || approvalMeta.key === 'supplement' || approvalMeta.key === 'rejected') {
    return 1
  }

  return 2
}

function buildProgressSteps(approvalMeta, workflowNode) {
  const currentIndex = resolveProgressCurrentIndex(approvalMeta, workflowNode)
  const currentTime =
    approvalMeta.key === 'completed'
      ? '已完成'
      : approvalMeta.key === 'supplement'
        ? '待补充'
        : approvalMeta.key === 'rejected'
          ? '已退回'
          : '进行中'

  return REIMBURSEMENT_PROGRESS_LABELS.map((label, index) => {
    if (approvalMeta.key === 'completed') {
      return {
        index: index + 1,
        label,
        time: '已完成',
        done: true,
        active: true,
        current: false
      }
    }

    if (index < currentIndex) {
      return {
        index: index + 1,
        label,
        time: '已完成',
        done: true,
        active: true,
        current: false
      }
    }

    if (index === currentIndex) {
      return {
        index: index + 1,
        label,
        time: currentTime,
        done: false,
        active: true,
        current: true
      }
    }

    return {
      index: index + 1,
      label,
      time: '待处理',
      done: false,
      active: false,
      current: false
    }
  })
}

function buildExpenseItems(claim, riskSummary) {
  if (!Array.isArray(claim?.items)) {
    return []
  }

  return claim.items.map((item, index) => {
    const attachments = String(item?.invoice_id || '').trim() ? [String(item.invoice_id).trim()] : []
    const itemTypeLabel = resolveTypeLabel(item?.item_type || claim?.expense_type)

    return {
      id: String(item?.id || `${claim?.id || 'claim'}-item-${index}`),
      time: formatDate(item?.item_date) || '待补充',
      itemDate: formatDate(item?.item_date) || '',
      itemType: String(item?.item_type || claim?.expense_type || '').trim() || 'other',
      itemReason: String(item?.item_reason || claim?.reason || '').trim(),
      itemLocation: String(item?.item_location || claim?.location || '').trim(),
      itemAmount: parseNumber(item?.item_amount),
      invoiceId: String(item?.invoice_id || '').trim(),
      dayLabel: claim?.expense_type === 'travel' ? `第 ${index + 1} 项` : '业务发生项',
      name: itemTypeLabel,
      category: itemTypeLabel,
      desc: String(item?.item_reason || claim?.reason || '').trim() || '待补充',
      detail: String(item?.item_location || claim?.location || '').trim() || '待补充',
      amount: formatAmount(item?.item_amount),
      status: attachments.length ? '已识别' : '待补充',
      tone: attachments.length ? 'ok' : 'bad',
      attachmentStatus: attachments.length ? `${attachments.length} 份附件` : '待上传',
      attachmentHint: attachments.length ? attachments[0] : '暂无关联票据',
      attachmentTone: attachments.length ? 'ok' : 'missing',
      attachments,
      riskLabel: riskSummary === '无' ? '无' : '待关注',
      riskText: riskSummary === '无' ? '' : riskSummary,
      riskTone: riskSummary === '无' ? 'low' : 'medium'
    }
  })
}

function mapExpenseClaimToRequest(claim) {
  const typeCode = String(claim?.expense_type || '').trim() || 'other'
  const typeLabel = resolveTypeLabel(typeCode)
  const approvalMeta = resolveApprovalMeta(claim?.status)
  const workflowNode = resolveWorkflowNode(claim, approvalMeta)
  const invoiceCount = Math.max(0, parseNumber(claim?.invoice_count))
  const riskSummary = buildRiskSummary(claim?.risk_flags_json)
  const expenseItems = buildExpenseItems(claim, riskSummary)
  const applyDateTime = claim?.submitted_at || claim?.created_at

  return {
    id: String(claim?.claim_no || claim?.id || '').trim(),
    claimNo: String(claim?.claim_no || claim?.id || '').trim(),
    claimId: String(claim?.id || '').trim(),
    status: String(claim?.status || '').trim(),
    person: String(claim?.employee_name || '').trim() || '待补充',
    dept: String(claim?.department_name || '').trim() || '待补充',
    departmentName: String(claim?.department_name || '').trim() || '待补充',
    employeeName: String(claim?.employee_name || '').trim() || '待补充',
    entity: '',
    typeCode,
    typeLabel,
    detailVariant: typeCode === 'travel' ? 'travel' : 'general',
    title: String(claim?.reason || '').trim() || `${typeLabel}报销`,
    sceneLabel: typeLabel,
    sceneTarget: String(claim?.location || '').trim() || '待补充',
    location: String(claim?.location || '').trim() || '待补充',
    relatedCustomer: '',
    occurredDisplay: buildOccurredDisplay(claim),
    occurredAt: claim?.occurred_at || '',
    applyTime: formatDateTime(applyDateTime) || '待补充',
    submittedAt: applyDateTime || '',
    createdAt: claim?.created_at || '',
    amount: parseNumber(claim?.amount),
    workflowNode,
    approvalKey: approvalMeta.key,
    approvalStatus: approvalMeta.label,
    approvalTone: approvalMeta.tone,
    secondaryStatusLabel: typeCode === 'travel' ? '行程状态' : '票据状态',
    secondaryStatusValue: invoiceCount > 0 ? `已关联 ${invoiceCount} 张票据` : '待上传票据',
    secondaryStatusTone: invoiceCount > 0 ? 'success' : 'warning',
    riskSummary,
    attachmentSummary: invoiceCount > 0 ? `${invoiceCount} 张票据` : '无',
    expenseTableSummary: expenseItems.length
      ? (invoiceCount > 0
        ? `共 ${expenseItems.length} 条费用明细，已关联 ${invoiceCount} 张票据`
        : `共 ${expenseItems.length} 条费用明细，待补充票据`)
      : '暂无费用明细',
    note: String(claim?.reason || '').trim(),
    progressSteps: buildProgressSteps(approvalMeta, workflowNode),
    expenseItems
  }
}

function getWeekStart(date) {
  const nextDate = new Date(date)
  const day = nextDate.getDay() || 7
  nextDate.setHours(0, 0, 0, 0)
  nextDate.setDate(nextDate.getDate() - day + 1)
  return nextDate
}

function resolveRangeMatch(activeRange, item) {
  if (activeRange === 'custom' || activeRange === '本月') {
    if (activeRange !== '本月') {
      return true
    }
  }

  const targetDate = toDate(item?.submittedAt || item?.createdAt || item?.occurredAt)
  if (!targetDate) {
    return true
  }

  const now = new Date()
  const targetDay = formatDate(targetDate)

  if (activeRange === '今日') {
    return targetDay === formatDate(now)
  }

  if (activeRange === '本周') {
    const weekStart = getWeekStart(now)
    const nextWeekStart = new Date(weekStart)
    nextWeekStart.setDate(nextWeekStart.getDate() + 7)
    return targetDate >= weekStart && targetDate < nextWeekStart
  }

  if (activeRange === '本月') {
    return (
      targetDate.getFullYear() === now.getFullYear()
      && targetDate.getMonth() === now.getMonth()
    )
  }

  return true
}

export function useRequests() {
  const requests = ref([])
  const loading = ref(false)
  const error = ref('')
  const search = ref('')
  const filters = reactive({ entity: '全部主体', category: '全部类型', risk: '全部状态' })
  const ranges = ['今日', '本周', '本月']
  const activeRange = ref('本周')

  const filteredRequests = computed(() => {
    const key = search.value.trim().toLowerCase()

    return requests.value.filter((item) => {
      const searchText = [
        item.id,
        item.person,
        item.typeLabel,
        item.title,
        item.sceneTarget,
        item.riskSummary
      ]
        .filter(Boolean)
        .join('')
        .toLowerCase()

      const matchesSearch = !key || searchText.includes(key)
      const matchesRange = resolveRangeMatch(activeRange.value, item)

      return matchesSearch && matchesRange
    })
  })

  async function reload() {
    loading.value = true
    error.value = ''

    try {
      const payload = await fetchExpenseClaims()
      requests.value = Array.isArray(payload) ? payload.map((item) => mapExpenseClaimToRequest(item)) : []
    } catch (nextError) {
      requests.value = []
      error.value = nextError instanceof Error ? nextError.message : '个人报销列表加载失败。'
    } finally {
      loading.value = false
    }
  }

  function approveRequest(request) {
    return `${request.id} 未执行本地状态变更，列表当前只展示后端真实数据。`
  }

  function rejectRequest(request) {
    return `${request.id} 未执行本地状态变更，列表当前只展示后端真实数据。`
  }

  void reload()

  return {
    requests,
    loading,
    error,
    search,
    filters,
    ranges,
    activeRange,
    filteredRequests,
    approveRequest,
    rejectRequest,
    reload
  }
}