import { computed, onMounted, ref, watch } from 'vue'

import BudgetTrendChart from '../../components/charts/BudgetTrendChart.vue'
import { fetchEmployeeMeta } from '../../services/employees.js'
import {
  BUDGET_CONTROL_ACTION_OPTIONS,
  BUDGET_EXPENSE_TYPE_OPTIONS,
  BUDGET_QUARTER_OPTIONS,
  BUDGET_STATUS_OPTIONS,
  BUDGET_WARNING_OPTIONS,
  BUDGET_YEAR_OPTIONS,
  buildBudgetOntologyContext,
  formatBudgetPeriod,
  resolveBudgetExpenseTypeLabel
} from '../../utils/budgetOntology.js'

const FALLBACK_DEPARTMENTS = [
  { code: 'MARKET-DEPT', name: '市场部', costCenter: 'CC-4100' },
  { code: 'FINANCE-DEPT', name: '财务部', costCenter: 'CC-2100' },
  { code: 'TECH-DEPT', name: '技术部', costCenter: 'CC-6100' },
  { code: 'HR-DEPT', name: '人力资源部', costCenter: 'CC-3200' },
  { code: 'PRODUCTION-DEPT', name: '生产部', costCenter: 'CC-7200' },
  { code: 'PRESIDENT-OFFICE', name: '总裁办', costCenter: 'CC-1000' }
]

const EXPENSE_BUDGET_SEED = {
  travel: { total: 600000, used: 242300, occupied: 150000, warning: 80, action: '提醒' },
  hotel: { total: 360000, used: 139800, occupied: 84000, warning: 80, action: '提醒' },
  transport: { total: 280000, used: 104600, occupied: 56000, warning: 75, action: '提醒' },
  meal: { total: 420000, used: 168200, occupied: 118000, warning: 80, action: '管控' },
  meeting: { total: 260000, used: 84500, occupied: 52000, warning: 75, action: '提醒' },
  marketing: { total: 500000, used: 186400, occupied: 120000, warning: 80, action: '提醒' },
  office: { total: 300000, used: 68500, occupied: 60000, warning: 70, action: '正常' },
  training: { total: 200000, used: 42300, occupied: 20000, warning: 70, action: '正常' },
  software: { total: 600000, used: 249500, occupied: 240800, warning: 80, action: '管控' },
  communication: { total: 120000, used: 38600, occupied: 18000, warning: 70, action: '正常' },
  welfare: { total: 240000, used: 96500, occupied: 42000, warning: 75, action: '提醒' }
}

const DEFAULT_EXPENSE_BUDGET = {
  total: 100000,
  used: 0,
  occupied: 0,
  warning: 70,
  action: '正常'
}

const EXPENSE_BLUEPRINTS = BUDGET_EXPENSE_TYPE_OPTIONS.map((option) => ({
  ...DEFAULT_EXPENSE_BUDGET,
  ...EXPENSE_BUDGET_SEED[option.value],
  budgetSubjectCode: option.value,
  expenseType: option.label
}))

const currency = (value) =>
  Number(value || 0).toLocaleString('zh-CN', {
    minimumFractionDigits: 2,
    maximumFractionDigits: 2
  })

const comparison = (value, direction) => ({
  value,
  tone: direction === 'down' ? 'down' : 'up',
  icon: direction === 'down' ? 'mdi mdi-arrow-down' : 'mdi mdi-arrow-up'
})

const parseBudgetAmount = (value) => Number(String(value || '').replace(/[^\d.-]/g, '')) || 0
const makeBudgetRowId = () => `budget-row-${Date.now()}-${Math.random().toString(16).slice(2)}`
const BUDGET_PAGE_SIZE_OPTIONS = [5, 10]

function buildDepartmentRows(departmentCode) {
  const seed = Array.from(String(departmentCode || '')).reduce(
    (sum, char) => sum + char.charCodeAt(0),
    0
  )
  const factor = 0.88 + (seed % 18) / 100

  return EXPENSE_BLUEPRINTS.map((item, index) => {
    const totalAmount = Math.round(item.total * factor)
    const usedAmount = Math.round(item.used * (0.9 + ((seed + index) % 12) / 100))
    const occupiedAmount = Math.round(
      item.occupied * (0.92 + ((seed + index * 3) % 10) / 100)
    )
    const leftAmount = Math.max(totalAmount - usedAmount - occupiedAmount, 0)
    const rate = Number((((usedAmount + occupiedAmount) / totalAmount) * 100).toFixed(2))

    return {
      ...item,
      totalAmount,
      usedAmount,
      occupiedAmount,
      leftAmount,
      rate,
      rateTone: rate >= item.warning ? 'danger' : rate >= item.warning - 12 ? 'warn' : 'ok',
      warningTone: item.warning >= 80 ? 'budget-warning-red' : 'budget-warning-yellow',
      warningLine: `${item.warning}%`,
      total: currency(totalAmount),
      used: currency(usedAmount),
      occupied: currency(occupiedAmount),
      left: currency(leftAmount)
    }
  })
}

function buildTrendData(rows) {
  const total = rows.reduce((sum, item) => sum + item.totalAmount, 0)
  const used = rows.reduce((sum, item) => sum + item.usedAmount + item.occupiedAmount, 0)

  return {
    labels: ['1月', '2月', '3月', '4月', '5月', '6月', '7月', '8月', '9月', '10月', '11月', '12月'],
    budget: [0.05, 0.18, 0.25, 0.34, 0.45, 0.52, 0.68, 0.76, 0.84, 0.91, 0.96, 1].map((ratio) =>
      Math.round(total * ratio)
    ),
    used: [0.03, 0.1, 0.13, 0.22, 0.3, 0.37, 0.51, 0.59, 0.69, 0.73, 0.86, 0.96].map((ratio) =>
      Math.round(used * ratio)
    )
  }
}

export default {
  name: 'BudgetCenterView',
  components: {
    BudgetTrendChart
  },
  setup() {
    const departments = ref(FALLBACK_DEPARTMENTS)
    const activeDepartmentCode = ref(FALLBACK_DEPARTMENTS[0].code)
    const departmentKeyword = ref('')
    const filters = ref({
      year: '2026',
      quarter: 'Q1',
      expenseType: '全部',
      status: '全部'
    })
    const budgetPage = ref(1)
    const budgetPageSize = ref(5)
    const budgetEditOpen = ref(false)
    const budgetEditForm = ref({
      budgetYear: '2026',
      budgetQuarter: 'Q1',
      budgetPeriod: '2026年Q1',
      departmentCode: FALLBACK_DEPARTMENTS[0].code,
      costCenter: FALLBACK_DEPARTMENTS[0].costCenter,
      budgetOwner: '张晓明',
      budgetVersion: 'V1.0（初始版本）',
      budgetStatus: '编制中',
      budgetDescription: ''
    })
    const budgetEditRows = ref([])

    const activeDepartment = computed(() =>
      departments.value.find((item) => item.code === activeDepartmentCode.value) || departments.value[0]
    )

    const activeDepartmentName = computed(() => activeDepartment.value?.name || '市场部')
    const departmentRows = computed(() =>
      buildDepartmentRows(activeDepartment.value?.code || activeDepartmentCode.value)
    )
    const filteredBudgetRows = computed(() =>
      departmentRows.value
        .filter((row) => filters.value.expenseType === '全部' || row.expenseType === filters.value.expenseType)
        .filter((row) => {
          if (filters.value.status === '全部') return true
          if (filters.value.status === '预警') return row.rateTone === 'warn'
          if (filters.value.status === '管控') return row.rateTone === 'danger'
          return row.rateTone === 'ok'
        })
    )
    const totalBudgetRows = computed(() => filteredBudgetRows.value.length)
    const totalBudgetPages = computed(() =>
      Math.max(1, Math.ceil(totalBudgetRows.value / Number(budgetPageSize.value || 5)))
    )
    const currentBudgetPage = computed(() =>
      Math.min(Math.max(1, budgetPage.value), totalBudgetPages.value)
    )
    const budgetPageNumbers = computed(() =>
      Array.from({ length: totalBudgetPages.value }, (_, index) => index + 1)
    )
    const visibleBudgetRows = computed(() => {
      const pageSize = Number(budgetPageSize.value || 5)
      const start = (currentBudgetPage.value - 1) * pageSize
      return filteredBudgetRows.value.slice(start, start + pageSize)
    })

    const totals = computed(() => {
      const rows = departmentRows.value
      const total = rows.reduce((sum, item) => sum + item.totalAmount, 0)
      const used = rows.reduce((sum, item) => sum + item.usedAmount, 0)
      const occupied = rows.reduce((sum, item) => sum + item.occupiedAmount, 0)
      return {
        total,
        used,
        occupied,
        left: Math.max(total - used - occupied, 0)
      }
    })

    const budgetMetrics = computed(() => [
      {
        label: '预算总额',
        value: `¥${currency(totals.value.total)}`,
        yoy: comparison('+8.42%', 'up'),
        mom: comparison('+2.16%', 'up'),
        tone: 'green',
        icon: 'mdi mdi-wallet-outline'
      },
      {
        label: '已发生',
        value: `¥${currency(totals.value.used)}`,
        yoy: comparison('+12.68%', 'up'),
        mom: comparison('+4.35%', 'up'),
        tone: 'blue',
        icon: 'mdi mdi-chart-line'
      },
      {
        label: '已占用',
        value: `¥${currency(totals.value.occupied)}`,
        yoy: comparison('+6.37%', 'up'),
        mom: comparison('-1.84%', 'down'),
        tone: 'orange',
        icon: 'mdi mdi-briefcase-check-outline'
      },
      {
        label: '剩余可用',
        value: `¥${currency(totals.value.left)}`,
        yoy: comparison('-3.26%', 'down'),
        mom: comparison('-2.08%', 'down'),
        tone: 'green',
        icon: 'mdi mdi-cash'
      }
    ])

    const visibleDepartments = computed(() => {
      const keyword = departmentKeyword.value.trim()
      return departments.value
        .filter((item) => !keyword || item.name.includes(keyword) || item.code.includes(keyword))
        .map((item) => ({
          ...item,
          icon: item.code === activeDepartmentCode.value ? 'mdi mdi-account-group-outline' : 'mdi mdi-domain'
        }))
    })

    const warnings = computed(() =>
      departmentRows.value
        .slice()
        .sort((a, b) => b.rate - a.rate)
        .slice(0, 4)
        .map((row, index) => ({
          title: row.expenseType,
          desc: `使用率已达 ${row.rate}%，${row.rate >= row.warning ? '已超过预警线' : '接近预警线'}（${row.warningLine}）`,
          date: index < 2 ? '2026-05-12' : '2026-05-10',
          tone: row.rate >= row.warning ? 'danger' : row.rate >= row.warning - 12 ? 'warn' : 'ok'
        }))
    )

    const trendData = computed(() => buildTrendData(departmentRows.value))
    const budgetEditTotal = computed(() =>
      currency(
        budgetEditRows.value.reduce(
          (sum, row) => sum + parseBudgetAmount(row.budgetAmount),
          0
        )
      )
    )
    const budgetOntologyContext = computed(() =>
      buildBudgetOntologyContext({
        form: budgetEditForm.value,
        rows: budgetEditRows.value,
        departments: departments.value
      })
    )

    function buildEditableRows() {
      return departmentRows.value.map((row) => ({
        id: makeBudgetRowId(),
        budgetSubject: row.expenseType,
        budgetSubjectCode: row.budgetSubjectCode || '',
        budgetAmount: currency(row.totalAmount),
        warningThreshold: `${row.warning}%`,
        controlAction: row.action,
        budgetRemark: `${row.expenseType}相关费用`
      }))
    }

    function resolveNextExpenseTypeOption() {
      const usedCodes = new Set(budgetEditRows.value.map((row) => row.budgetSubjectCode))
      return (
        BUDGET_EXPENSE_TYPE_OPTIONS.find((item) => !usedCodes.has(item.value)) ||
        BUDGET_EXPENSE_TYPE_OPTIONS[0]
      )
    }

    function syncBudgetRowSubject(row) {
      row.budgetSubject = resolveBudgetExpenseTypeLabel(row.budgetSubjectCode, row.budgetSubject)
    }

    function openBudgetEditDialog() {
      const department = activeDepartment.value
      const budgetPeriod = formatBudgetPeriod(filters.value.year, filters.value.quarter)
      budgetEditForm.value = {
        budgetYear: filters.value.year,
        budgetQuarter: filters.value.quarter,
        budgetPeriod,
        departmentCode: department?.code || activeDepartmentCode.value,
        costCenter: department?.costCenter || '',
        budgetOwner: '张晓明',
        budgetVersion: 'V1.0（初始版本）',
        budgetStatus: '编制中',
        budgetDescription: `${department?.name || '当前部门'}2026年度预算编制，用于指导费用支出及控制成本，确保资源合理使用。`
      }
      budgetEditRows.value = buildEditableRows()
      budgetEditOpen.value = true
    }

    function closeBudgetEditDialog() {
      budgetEditOpen.value = false
    }

    function addBudgetDetailRow() {
      const option = resolveNextExpenseTypeOption()
      budgetEditRows.value.push({
        id: makeBudgetRowId(),
        budgetSubject: option.label,
        budgetSubjectCode: option.value,
        budgetAmount: '0.00',
        warningThreshold: '70%',
        controlAction: '正常',
        budgetRemark: ''
      })
    }

    function removeBudgetDetailRow(rowId) {
      if (budgetEditRows.value.length <= 1) return
      budgetEditRows.value = budgetEditRows.value.filter((row) => row.id !== rowId)
    }

    function goToBudgetPage(page) {
      budgetPage.value = Math.min(Math.max(Number(page) || 1, 1), totalBudgetPages.value)
    }

    function changeBudgetPage(direction) {
      goToBudgetPage(currentBudgetPage.value + direction)
    }

    function saveBudgetDraft() {
      budgetEditForm.value.budgetStatus = '编制中'
      closeBudgetEditDialog()
    }

    function publishBudget() {
      budgetEditForm.value.budgetStatus = '已发布'
      closeBudgetEditDialog()
    }

    async function loadDepartments() {
      try {
        const payload = await fetchEmployeeMeta()
        const options = Array.isArray(payload?.organizationOptions) ? payload.organizationOptions : []
        const nextDepartments = options
          .filter((item) => item?.code && item?.name)
          .map((item) => ({
            code: String(item.code),
            name: String(item.name),
            costCenter: String(item.costCenter || '')
          }))

        if (nextDepartments.length) {
          departments.value = nextDepartments
          if (!nextDepartments.some((item) => item.code === activeDepartmentCode.value)) {
            activeDepartmentCode.value = nextDepartments[0].code
          }
        }
      } catch (error) {
        console.warn('Failed to load budget departments from employee meta:', error)
      }
    }

    onMounted(() => {
      void loadDepartments()
    })

    watch(
      [
        activeDepartmentCode,
        budgetPageSize,
        () => filters.value.year,
        () => filters.value.quarter,
        () => filters.value.expenseType,
        () => filters.value.status
      ],
      () => {
        budgetPage.value = 1
      }
    )

    watch(totalBudgetPages, (pages) => {
      if (budgetPage.value > pages) {
        budgetPage.value = pages
      }
    })

    return {
      activeDepartmentCode,
      activeDepartmentName,
      addBudgetDetailRow,
      budgetEditForm,
      budgetEditOpen,
      budgetEditRows,
      budgetEditTotal,
      budgetMetrics,
      budgetOntologyContext,
      budgetPage: currentBudgetPage,
      budgetPageNumbers,
      budgetPageSize,
      budgetPageSizeOptions: BUDGET_PAGE_SIZE_OPTIONS,
      closeBudgetEditDialog,
      controlActionOptions: BUDGET_CONTROL_ACTION_OPTIONS,
      changeBudgetPage,
      departmentKeyword,
      departments,
      expenseTypeOptions: BUDGET_EXPENSE_TYPE_OPTIONS,
      expenseTypes: ['全部', ...EXPENSE_BLUEPRINTS.map((item) => item.expenseType)],
      filters,
      openBudgetEditDialog,
      quarters: BUDGET_QUARTER_OPTIONS,
      publishBudget,
      removeBudgetDetailRow,
      saveBudgetDraft,
      statusOptions: BUDGET_STATUS_OPTIONS,
      statuses: ['全部', '正常', '预警', '管控'],
      syncBudgetRowSubject,
      goToBudgetPage,
      totalBudgetPages,
      totalBudgetRows,
      trendData,
      visibleBudgetRows,
      visibleDepartments,
      warningOptions: BUDGET_WARNING_OPTIONS,
      warnings,
      years: BUDGET_YEAR_OPTIONS
    }
  }
}