'use client'

/**
 * 구매그룹코드 다중 선택 다이얼로그
 * 
 * @description
 * - 여러 구매그룹코드를 선택할 수 있는 다이얼로그
 * - 체크박스를 통한 다중 선택
 * - 선택된 구매그룹코드들을 상단에 표시
 * - 확인/취소 버튼으로 선택 확정
 * - 선택 시 각 코드에 대한 사용자 정보도 함께 반환
 */

import { useState, useCallback, useMemo, useTransition } from 'react'
import { Button } from '@/components/ui/button'
import { Dialog, DialogContent, DialogHeader, DialogTitle, DialogFooter } from '@/components/ui/dialog'
import { Input } from '@/components/ui/input'
import { Checkbox } from '@/components/ui/checkbox'
import { Badge } from '@/components/ui/badge'
import { Search, Check, X, Trash2 } from 'lucide-react'
import { 
  ColumnDef,
  flexRender,
  getCoreRowModel,
  getFilteredRowModel,
  getPaginationRowModel,
  getSortedRowModel,
  useReactTable,
  SortingState,
  ColumnFiltersState,
  VisibilityState,
  RowSelectionState,
} from '@tanstack/react-table'
import {
  Table,
  TableBody,
  TableCell,
  TableHead,
  TableHeader,
  TableRow,
} from '@/components/ui/table'
import { 
  getPurchaseGroupCodes, 
  addUsersToCodesAsync,
  PurchaseGroupCode, 
  PurchaseGroupCodeWithUser
} from './purchase-group-code-service'
import { toast } from 'sonner'

// 간단한 디바운스 함수
function debounce<T extends (...args: unknown[]) => void>(func: T, delay: number): T {
  let timeoutId: NodeJS.Timeout
  return ((...args: Parameters<T>) => {
    clearTimeout(timeoutId)
    timeoutId = setTimeout(() => func(...args), delay)
  }) as T
}

export interface PurchaseGroupCodeMultiSelectorProps {
  open: boolean
  onOpenChange: (open: boolean) => void
  selectedCodes?: PurchaseGroupCodeWithUser[]
  onCodesSelect: (codes: PurchaseGroupCodeWithUser[]) => void
  onConfirm?: (codes: PurchaseGroupCodeWithUser[]) => void
  onCancel?: () => void
  title?: string
  description?: string
  maxSelection?: number
}

export function PurchaseGroupCodeMultiSelector({ 
  open,
  onOpenChange,
  selectedCodes = [], 
  onCodesSelect, 
  onConfirm,
  onCancel,
  title = "구매그룹코드 다중 선택",
  description = "여러 구매그룹코드를 선택하세요",
  maxSelection
}: PurchaseGroupCodeMultiSelectorProps) {
  const [codes, setCodes] = useState<PurchaseGroupCode[]>([])
  const [sorting, setSorting] = useState<SortingState>([])
  const [columnFilters, setColumnFilters] = useState<ColumnFiltersState>([])
  const [columnVisibility, setColumnVisibility] = useState<VisibilityState>({})
  const [rowSelection, setRowSelection] = useState<RowSelectionState>({})
  const [globalFilter, setGlobalFilter] = useState('')
  const [isPending, startTransition] = useTransition()
  const [tempSelectedCodes, setTempSelectedCodes] = useState<PurchaseGroupCode[]>(
    selectedCodes.map(c => ({
      PURCHASE_GROUP_CODE: c.PURCHASE_GROUP_CODE,
      DISPLAY_NAME: c.DISPLAY_NAME,
      EMPLOYEE_NUMBER: c.EMPLOYEE_NUMBER
    }))
  )

  // 구매그룹코드 선택/해제 핸들러
  const handleCodeToggle = useCallback((code: PurchaseGroupCode, checked: boolean) => {
    setTempSelectedCodes(prev => {
      if (checked) {
        // 최대 선택 수 제한 확인
        if (maxSelection && prev.length >= maxSelection) {
          toast.warning(`최대 ${maxSelection}개까지 선택할 수 있습니다.`)
          return prev
        }
        // 이미 선택된 코드인지 확인
        if (prev.some(c => c.PURCHASE_GROUP_CODE === code.PURCHASE_GROUP_CODE)) {
          return prev
        }
        return [...prev, code]
      } else {
        return prev.filter(c => c.PURCHASE_GROUP_CODE !== code.PURCHASE_GROUP_CODE)
      }
    })
  }, [maxSelection])

  // 개별 코드 제거 핸들러
  const handleRemoveCode = useCallback((purchaseGroupCode: string) => {
    setTempSelectedCodes(prev => prev.filter(c => c.PURCHASE_GROUP_CODE !== purchaseGroupCode))
  }, [])

  // 모든 선택 해제 핸들러
  const handleClearAll = useCallback(() => {
    setTempSelectedCodes([])
  }, [])

  // 확인 버튼 핸들러 (사용자 정보 포함하여 반환)
  const handleConfirm = useCallback(async () => {
    try {
      // 선택된 코드들에 대해 사용자 정보 추가
      const codesWithUsers = await addUsersToCodesAsync(tempSelectedCodes)
      
      onCodesSelect(codesWithUsers)
      onConfirm?.(codesWithUsers)
      onOpenChange(false)
    } catch (error) {
      console.error('구매그룹코드 정보 조회 오류:', error)
      toast.error('구매그룹코드 정보를 가져오는 중 오류가 발생했습니다.')
    }
  }, [tempSelectedCodes, onCodesSelect, onConfirm, onOpenChange])

  // 취소 버튼 핸들러
  const handleCancel = useCallback(() => {
    setTempSelectedCodes(
      selectedCodes.map(c => ({
        PURCHASE_GROUP_CODE: c.PURCHASE_GROUP_CODE,
        DISPLAY_NAME: c.DISPLAY_NAME,
        EMPLOYEE_NUMBER: c.EMPLOYEE_NUMBER
      }))
    )
    onCancel?.()
    onOpenChange(false)
  }, [selectedCodes, onCancel, onOpenChange])

  // 테이블 컬럼 정의
  const columns: ColumnDef<PurchaseGroupCode>[] = useMemo(() => [
    {
      id: 'select',
      header: ({ table }) => (
        <Checkbox
          checked={table.getIsAllPageRowsSelected()}
          onCheckedChange={(value) => {
            if (value) {
              // 페이지의 모든 행을 선택하되, 최대 선택 수 제한 확인
              const currentPageRows = table.getRowModel().rows
              const newSelections = currentPageRows
                .map(row => row.original)
                .filter(code => !tempSelectedCodes.some(c => c.PURCHASE_GROUP_CODE === code.PURCHASE_GROUP_CODE))
              
              if (maxSelection) {
                const remainingSlots = maxSelection - tempSelectedCodes.length
                if (newSelections.length > remainingSlots) {
                  toast.warning(`최대 ${maxSelection}개까지 선택할 수 있습니다.`)
                  return
                }
              }
              
              setTempSelectedCodes(prev => [...prev, ...newSelections])
            } else {
              // 페이지의 모든 행 선택 해제
              const currentPageCodes = table.getRowModel().rows.map(row => row.original.PURCHASE_GROUP_CODE)
              setTempSelectedCodes(prev => prev.filter(c => !currentPageCodes.includes(c.PURCHASE_GROUP_CODE)))
            }
          }}
          aria-label="모든 행 선택"
        />
      ),
      cell: ({ row }) => {
        const isSelected = tempSelectedCodes.some(c => c.PURCHASE_GROUP_CODE === row.original.PURCHASE_GROUP_CODE)
        return (
          <Checkbox
            checked={isSelected}
            onCheckedChange={(value) => handleCodeToggle(row.original, !!value)}
            aria-label="행 선택"
          />
        )
      },
      enableSorting: false,
      enableHiding: false,
    },
    {
      accessorKey: 'PURCHASE_GROUP_CODE',
      header: '구매그룹코드',
      cell: ({ row }) => (
        <div className="font-mono text-sm">{row.getValue('PURCHASE_GROUP_CODE')}</div>
      ),
    },
    {
      accessorKey: 'DISPLAY_NAME',
      header: '이름',
      cell: ({ row }) => (
        <div className="max-w-[400px] truncate">{row.getValue('DISPLAY_NAME')}</div>
      ),
    },
    {
      accessorKey: 'EMPLOYEE_NUMBER',
      header: '사번',
      cell: ({ row }) => (
        <div className="font-mono text-sm">{row.getValue('EMPLOYEE_NUMBER')}</div>
      ),
    },
  ], [handleCodeToggle, tempSelectedCodes, maxSelection])

  // 구매그룹코드 테이블 설정
  const table = useReactTable({
    data: codes,
    columns,
    onSortingChange: setSorting,
    onColumnFiltersChange: setColumnFilters,
    onColumnVisibilityChange: setColumnVisibility,
    onRowSelectionChange: setRowSelection,
    onGlobalFilterChange: setGlobalFilter,
    getCoreRowModel: getCoreRowModel(),
    getPaginationRowModel: getPaginationRowModel(),
    getSortedRowModel: getSortedRowModel(),
    getFilteredRowModel: getFilteredRowModel(),
    state: {
      sorting,
      columnFilters,
      columnVisibility,
      rowSelection,
      globalFilter,
    },
  })

  // 서버에서 구매그룹코드 전체 목록 로드 (한 번만)
  const loadCodes = useCallback(async () => {
    startTransition(async () => {
      try {
        const result = await getPurchaseGroupCodes()
        
        if (result.success) {
          setCodes(result.data)
        } else {
          toast.error(result.error || '구매그룹코드를 불러오는데 실패했습니다.')
          setCodes([])
        }
      } catch (error) {
        console.error('구매그룹코드 목록 로드 실패:', error)
        toast.error('구매그룹코드를 불러오는 중 오류가 발생했습니다.')
        setCodes([])
      }
    })
  }, [])

  // 다이얼로그 열기/닫기 핸들러
  const handleDialogOpenChange = useCallback((newOpen: boolean) => {
    onOpenChange(newOpen)
    if (newOpen) {
      setTempSelectedCodes(
        selectedCodes.map(c => ({
          PURCHASE_GROUP_CODE: c.PURCHASE_GROUP_CODE,
          DISPLAY_NAME: c.DISPLAY_NAME,
          EMPLOYEE_NUMBER: c.EMPLOYEE_NUMBER
        }))
      )
      if (codes.length === 0) {
        loadCodes()
      }
    }
  }, [onOpenChange, selectedCodes, loadCodes, codes.length])

  // 검색어 변경 핸들러 (클라이언트 사이드 필터링)
  const handleSearchChange = useCallback((value: string) => {
    setGlobalFilter(value)
  }, [])

  return (
    <Dialog open={open} onOpenChange={handleDialogOpenChange}>
      <DialogContent className="max-w-6xl max-h-[85vh]">
        <DialogHeader>
          <DialogTitle>{title}</DialogTitle>
          <div className="text-sm text-muted-foreground">
            {description}
            {maxSelection && ` (최대 ${maxSelection}개)`}
          </div>
        </DialogHeader>
        
        <div className="space-y-4">
          {/* 선택된 구매그룹코드들 표시 */}
          {tempSelectedCodes.length > 0 && (
            <div className="space-y-2">
              <div className="flex items-center justify-between">
                <div className="text-sm font-medium">
                  선택된 구매그룹코드 ({tempSelectedCodes.length}개)
                  {maxSelection && ` / ${maxSelection}`}
                </div>
                <Button
                  variant="outline"
                  size="sm"
                  onClick={handleClearAll}
                  disabled={tempSelectedCodes.length === 0}
                >
                  <Trash2 className="h-4 w-4 mr-2" />
                  모두 제거
                </Button>
              </div>
              <div className="flex flex-wrap gap-2 max-h-24 overflow-y-auto p-2 border rounded-md bg-muted/30">
                {tempSelectedCodes.map((code) => (
                  <Badge
                    key={code.PURCHASE_GROUP_CODE}
                    variant="secondary"
                    className="text-xs"
                  >
                    [{code.PURCHASE_GROUP_CODE}] {code.DISPLAY_NAME}
                    <button
                      onClick={() => handleRemoveCode(code.PURCHASE_GROUP_CODE)}
                      className="ml-1 hover:text-destructive"
                    >
                      <X className="h-3 w-3" />
                    </button>
                  </Badge>
                ))}
              </div>
            </div>
          )}

          <div className="flex items-center space-x-2">
            <Search className="h-4 w-4" />
            <Input
              placeholder="구매그룹코드, 이름, 사번으로 검색..."
              value={globalFilter}
              onChange={(e) => handleSearchChange(e.target.value)}
              className="flex-1"
            />
          </div>

          {isPending ? (
            <div className="flex justify-center py-8">
              <div className="text-sm text-muted-foreground">구매그룹코드를 불러오는 중...</div>
            </div>
          ) : (
            <div className="border rounded-md">
              <Table>
                <TableHeader>
                  {table.getHeaderGroups().map((headerGroup) => (
                    <TableRow key={headerGroup.id}>
                      {headerGroup.headers.map((header) => (
                        <TableHead key={header.id}>
                          {header.isPlaceholder
                            ? null
                            : flexRender(
                                header.column.columnDef.header,
                                header.getContext()
                              )}
                        </TableHead>
                      ))}
                    </TableRow>
                  ))}
                </TableHeader>
                <TableBody>
                  {table.getRowModel().rows?.length ? (
                    table.getRowModel().rows.map((row) => {
                      const isSelected = tempSelectedCodes.some(c => c.PURCHASE_GROUP_CODE === row.original.PURCHASE_GROUP_CODE)
                      return (
                        <TableRow
                          key={row.id}
                          data-state={isSelected && "selected"}
                          className={`cursor-pointer hover:bg-muted/50 ${
                            isSelected ? 'bg-muted/30' : ''
                          }`}
                          onClick={() => {
                            const isCurrentlySelected = tempSelectedCodes.some(c => c.PURCHASE_GROUP_CODE === row.original.PURCHASE_GROUP_CODE)
                            handleCodeToggle(row.original, !isCurrentlySelected)
                          }}
                        >
                          {row.getVisibleCells().map((cell) => (
                            <TableCell key={cell.id}>
                              {flexRender(
                                cell.column.columnDef.cell,
                                cell.getContext()
                              )}
                            </TableCell>
                          ))}
                        </TableRow>
                      )
                    })
                  ) : (
                    <TableRow>
                      <TableCell
                        colSpan={columns.length}
                        className="h-24 text-center"
                      >
                        검색 결과가 없습니다.
                      </TableCell>
                    </TableRow>
                  )}
                </TableBody>
              </Table>
            </div>
          )}

          <div className="flex items-center justify-between">
            <div className="text-sm text-muted-foreground">
              총 {table.getFilteredRowModel().rows.length}개 구매그룹코드
            </div>
            <div className="flex items-center space-x-2">
              <Button
                variant="outline"
                size="sm"
                onClick={() => table.previousPage()}
                disabled={!table.getCanPreviousPage()}
              >
                이전
              </Button>
              <div className="text-sm">
                {table.getState().pagination.pageIndex + 1} / {table.getPageCount()}
              </div>
              <Button
                variant="outline"
                size="sm"
                onClick={() => table.nextPage()}
                disabled={!table.getCanNextPage()}
              >
                다음
              </Button>
            </div>
          </div>
        </div>

        <DialogFooter>
          <Button variant="outline" onClick={handleCancel}>
            <X className="h-4 w-4 mr-2" />
            취소
          </Button>
          <Button onClick={handleConfirm}>
            <Check className="h-4 w-4 mr-2" />
            확인 ({tempSelectedCodes.length}개 선택)
          </Button>
        </DialogFooter>
      </DialogContent>
    </Dialog>
  )
}

