import { computed, ref } from 'vue'

import TableEmptyState from '../../components/shared/TableEmptyState.vue'
import { mapExpenseClaimToRequest } from '../../composables/useRequests.js'
import { useSystemState } from '../../composables/useSystemState.js'
import { fetchExpenseClaims } from '../../services/reimbursements.js'

const DEFAULT_SLA_HOURS = 24
const tabs = ['全部待审', '高风险', '即将超时', '已处理']
const filters = ['法人主体', '费用类型', '风险等级', '金额区间', '所属部门']
const RISK_LABELS = {
  low: '低风险',
  medium: '中风险',
  high: '高风险'
}

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

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

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

function resolveRiskTone(riskFlags, riskSummary) {
  if (Array.isArray(riskFlags)) {
    const severities = riskFlags
      .map((item) => String(item?.severity || '').trim().toLowerCase())
      .filter(Boolean)

    if (severities.includes('high')) {
      return 'high'
    }
    if (severities.includes('medium')) {
      return 'medium'
    }
    if (severities.includes('low')) {
      return 'low'
    }
  }

  if (String(riskSummary || '').trim() && String(riskSummary || '').trim() !== '无') {
    return 'medium'
  }

  return 'low'
}

function resolveRiskItems(request) {
  const riskFlags = Array.isArray(request?.riskFlags) ? request.riskFlags : []
  const items = riskFlags
    .map((item) => {
      const tone = resolveRiskTone([item], '')
      const text = String(item?.message || item?.label || item?.reason || '').trim()
      if (!text) {
        return null
      }
      return {
        text,
        level: tone === 'high' ? '高' : tone === 'medium' ? '中' : '低',
        tone,
        icon: tone === 'high' ? 'mdi mdi-alert-circle' : tone === 'medium' ? 'mdi mdi-alert' : 'mdi mdi-shield-check'
      }
    })
    .filter(Boolean)

  if (items.length) {
    return items
  }

  const summary = String(request?.riskSummary || '').trim()
  if (summary && summary !== '无') {
    return summary.split('；').filter(Boolean).map((text) => ({
      text,
      level: '中',
      tone: 'medium',
      icon: 'mdi mdi-alert'
    }))
  }

  return [
    {
      text: 'AI预审已通过，当前未发现额外风险。',
      level: '低',
      tone: 'low',
      icon: 'mdi mdi-shield-check'
    }
  ]
}

function resolveAttachmentMeta(name) {
  const normalized = String(name || '').trim()
  const lowerName = normalized.toLowerCase()
  if (lowerName.endsWith('.pdf')) {
    return { icon: 'mdi mdi-file-pdf-box', iconClass: 'pdf' }
  }
  if (/\.(png|jpg|jpeg|webp|bmp)$/i.test(lowerName)) {
    return { icon: 'mdi mdi-image', iconClass: 'img' }
  }
  return { icon: 'mdi mdi-file-document-outline', iconClass: 'file' }
}

function buildAttachments(expenseItems) {
  const seen = new Set()
  const attachments = []

  for (const item of Array.isArray(expenseItems) ? expenseItems : []) {
    for (const fileName of Array.isArray(item?.attachments) ? item.attachments : []) {
      const normalized = String(fileName || '').trim()
      if (!normalized || seen.has(normalized)) {
        continue
      }
      seen.add(normalized)
      attachments.push({
        name: normalized,
        size: '已识别',
        ...resolveAttachmentMeta(normalized)
      })
    }
  }

  if (attachments.length) {
    return attachments
  }

  return [
    {
      name: '当前无附件',
      size: '待补充',
      icon: 'mdi mdi-file-document-outline',
      iconClass: 'miss',
      missing: true
    }
  ]
}

function resolveSlaMeta(submittedAt) {
  const startAt = toDate(submittedAt)
  if (!startAt) {
    return { label: '待处理', tone: 'safe', urgent: false }
  }

  const deadline = new Date(startAt.getTime() + DEFAULT_SLA_HOURS * 60 * 60 * 1000)
  const diffMs = deadline.getTime() - Date.now()
  if (diffMs <= 0) {
    return { label: '已超时', tone: 'danger', urgent: true }
  }

  const diffHours = diffMs / (60 * 60 * 1000)
  const diffMinutes = Math.max(1, Math.ceil(diffMs / (60 * 1000)))
  const label = diffHours >= 1 ? `${diffHours.toFixed(diffHours >= 10 ? 0 : 1)}h` : `${diffMinutes}m`
  if (diffHours <= 2) {
    return { label, tone: 'danger', urgent: true }
  }
  if (diffHours <= 8) {
    return { label, tone: 'warning', urgent: false }
  }
  return { label, tone: 'safe', urgent: false }
}

function buildHeroSummaryItems(request) {
  return [
    { label: '单号', value: request.id || '-', icon: 'mdi mdi-pound-box-outline' },
    { label: '报销类型', value: request.typeLabel || '-', icon: 'mdi mdi-briefcase-outline' },
    { label: '业务地点', value: request.sceneTarget || '待补充', icon: 'mdi mdi-map-marker-outline' },
    { label: '发生时间', value: request.occurredDisplay || '待补充', icon: 'mdi mdi-calendar-range' },
    { label: '票据关联', value: request.attachmentSummary || '无', icon: 'mdi mdi-paperclip' },
    { label: '事由', value: request.title || '待补充', icon: 'mdi mdi-text-box-outline' }
  ]
}

function buildFlowItems(request) {
  return Array.isArray(request?.progressSteps)
    ? request.progressSteps.map((item) => ({
      label: item.label,
      desc: item.current ? '当前处理节点' : item.done ? '已完成' : '待处理',
      time: item.time,
      icon: item.current ? 'mdi mdi-circle-slice-8' : item.done ? 'mdi mdi-check' : 'mdi mdi-circle-outline',
      current: item.current,
      pending: !item.done && !item.current
    }))
    : []
}

function canCurrentUserProcessRequest(request, currentUser) {
  const node = String(request?.workflowNode || '').trim()
  const roleCodes = Array.isArray(currentUser?.roleCodes) ? currentUser.roleCodes.filter(Boolean) : []
  const currentName = String(currentUser?.name || '').trim()
  const applicantName = String(request?.person || request?.employeeName || '').trim()

  if (currentName && applicantName && currentName === applicantName) {
    return false
  }

  if (currentUser?.isAdmin || roleCodes.includes('finance')) {
    return node.includes('财务')
  }

  return (
    node.includes('直属领导')
    || node.includes('领导审批')
    || node.includes('部门负责人')
    || node.includes('负责人审批')
  )
}

function buildApprovalRow(request) {
  const riskTone = resolveRiskTone(request.riskFlags, request.riskSummary)
  const riskItems = resolveRiskItems(request)
  const expenseItems = Array.isArray(request.expenseItems) ? request.expenseItems : []
  const slaMeta = resolveSlaMeta(request.submittedAt || request.createdAt)
  const statusTone = slaMeta.urgent ? 'urgent' : 'pending'

  return {
    ...request,
    applicant: request.person,
    avatar: String(request.person || '?').trim().slice(0, 1) || '?',
    department: request.dept,
    type: request.typeLabel,
    amount: formatCurrency(request.amount),
    time: request.applyTime,
    risk: RISK_LABELS[riskTone] || RISK_LABELS.low,
    riskTone,
    sla: slaMeta.label,
    slaTone: slaMeta.tone,
    node: request.workflowNode || '审批中',
    status: statusTone === 'urgent' ? '即将超时' : '待审批',
    statusTone,
    spotlight: riskTone === 'high' || statusTone === 'urgent',
    heroSummaryItems: buildHeroSummaryItems(request),
    summaryItems: buildHeroSummaryItems(request).slice(2),
    progressSteps: Array.isArray(request.progressSteps) ? request.progressSteps : [],
    expenseItems,
    attachments: buildAttachments(expenseItems),
    riskItems,
    flowItems: buildFlowItems(request)
  }
}

export default {
  name: 'ApprovalCenterView',
  components: {
    TableEmptyState
  },
  setup() {
    const { currentUser } = useSystemState()
    const activeTab = ref('全部待审')
    const selectedClaimId = ref('')
    const expandedExpenseId = ref(null)
    const listKeyword = ref('')
    const rows = ref([])
    const loading = ref(false)
    const error = ref('')

    const selectedRow = computed({
      get() {
        return rows.value.find((row) => row.claimId === selectedClaimId.value) || null
      },
      set(value) {
        selectedClaimId.value = value?.claimId || ''
        expandedExpenseId.value = null
      }
    })

    const visibleRows = computed(() => {
      let filteredRows = rows.value

      // 根据标签筛选
      if (activeTab.value === '高风险') {
        filteredRows = filteredRows.filter((row) => row.riskTone === 'high')
      } else if (activeTab.value === '即将超时') {
        filteredRows = filteredRows.filter((row) => row.statusTone === 'urgent')
      } else if (activeTab.value === '已处理') {
        filteredRows = []
      }

      // 根据搜索关键词筛选
      if (listKeyword.value.trim()) {
        const keyword = listKeyword.value.trim().toLowerCase()
        filteredRows = filteredRows.filter((row) => {
          return (
            String(row.id || '').toLowerCase().includes(keyword) ||
            String(row.applicant || '').toLowerCase().includes(keyword) ||
            String(row.department || '').toLowerCase().includes(keyword) ||
            String(row.type || '').toLowerCase().includes(keyword) ||
            String(row.amount || '').toLowerCase().includes(keyword)
          )
        })
      }

      return filteredRows
    })
    const showTable = computed(() => !loading.value && !error.value && visibleRows.value.length > 0)
    const showEmpty = computed(() => !loading.value && !error.value && visibleRows.value.length === 0)
    const approvalEmptyState = computed(() => {
      if (!rows.value.length) {
        return {
          eyebrow: '审批中心',
          title: '当前没有待审批单据',
          desc: '进入直属领导或财务审批节点的报销单会自动汇总到这里，后续可继续处理或跟踪。',
          icon: 'mdi mdi-clipboard-check-outline',
          actionLabel: null,
          actionIcon: null,
          tone: 'slate',
          artLabel: 'QUEUE',
          tips: ['当前仅展示你有权限处理的单据', '高风险和即将超时单据会优先高亮']
        }
      }

      return {
        eyebrow: '状态列表为空',
        title: `“${activeTab.value}”里暂时没有单据`,
        desc: activeTab.value === '已处理'
          ? '当前视图还没有已处理审批数据，可以先回到全部待审继续处理。'
          : '可以切换到其他状态查看，或返回全部待审列表继续处理。',
        icon: activeTab.value === '已处理' ? 'mdi mdi-archive-clock-outline' : 'mdi mdi-view-list-outline',
        actionLabel: '查看全部待审',
        actionIcon: 'mdi mdi-format-list-bulleted',
        tone: activeTab.value === '已处理' ? 'amber' : 'sky',
        artLabel: activeTab.value === '已处理' ? 'DONE' : 'FILTER',
        tips: ['分页与表格只在有数据时展示', '空态页面会保留当前页签上下文说明']
      }
    })

    const approvalSteps = computed(() => selectedRow.value?.progressSteps || [])
    const summaryItems = computed(() => selectedRow.value?.summaryItems || [])
    const heroSummaryItems = computed(() => selectedRow.value?.heroSummaryItems || [])
    const expenseItems = computed(() => selectedRow.value?.expenseItems || [])
    const expenseTotal = computed(() => selectedRow.value?.amount || formatCurrency(0))
    const uploadedExpenseCount = computed(
      () => expenseItems.value.filter((item) => Array.isArray(item?.attachments) && item.attachments.length).length
    )
    const attachments = computed(() => selectedRow.value?.attachments || [])
    const riskItems = computed(() => selectedRow.value?.riskItems || [])
    const flowItems = computed(() => selectedRow.value?.flowItems || [])

    const currentProgressRingMotion = {
      initial: {
        scale: 1,
        opacity: 0.34
      },
      enter: {
        scale: [1, 1.42, 1.78],
        opacity: [0.34, 0.16, 0],
        transition: {
          duration: 3.2,
          repeat: Infinity,
          repeatType: 'loop',
          repeatDelay: 0.85,
          ease: 'easeOut',
          times: [0, 0.5, 1]
        }
      }
    }

    function showExpenseRisk(item) {
      return ['medium', 'high'].includes(String(item?.riskTone || '').trim())
    }

    function toggleExpenseAttachments(id) {
      expandedExpenseId.value = expandedExpenseId.value === id ? null : id
    }

    function handleEmptyAction() {
      if (!rows.value.length) {
        void reload()
        return
      }

      activeTab.value = '全部待审'
    }

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

      try {
        const payload = await fetchExpenseClaims()
        const mappedRows = Array.isArray(payload)
          ? payload
            .map((item) => mapExpenseClaimToRequest(item))
            .filter((item) => item.approvalKey === 'in_progress')
            .filter((item) => canCurrentUserProcessRequest(item, currentUser.value))
            .map((item) => buildApprovalRow(item))
          : []
        rows.value = mappedRows
        if (!mappedRows.some((item) => item.claimId === selectedClaimId.value)) {
          selectedClaimId.value = ''
        }
      } catch (nextError) {
        rows.value = []
        selectedClaimId.value = ''
        error.value = nextError instanceof Error ? nextError.message : '审批中心加载失败。'
      } finally {
        loading.value = false
      }
    }

    void reload()

    return {
      activeTab,
      selectedRow,
      expandedExpenseId,
      listKeyword,
      tabs,
      filters,
      rows,
      visibleRows,
      showTable,
      showEmpty,
      approvalEmptyState,
      approvalSteps,
      summaryItems,
      heroSummaryItems,
      currentProgressRingMotion,
      expenseItems,
      expenseTotal,
      uploadedExpenseCount,
      showExpenseRisk,
      toggleExpenseAttachments,
      attachments,
      riskItems,
      flowItems,
      handleEmptyAction,
      loading,
      error,
      reload
    }
  }
}