'use client'

/**
 * 국가 선택기
 * 
 * @description
 * - 오라클에서 CMCTB_CD 테이블에 대해, CD_CLF = 'LE0010' 인 건들을 조회
 * - CD 컬럼이 대문자 알파벳 2글자 국가코드
 * - CD2 컬럼이 대문자 알파벳 3글자 국가코드
 * - CD3 컬럼이 3글자 숫자로 표현되는 국가코드 (0으로 시작할 수 있음)
 * - CDNM 컬럼이 한국어 국가명
 * - GRP_DSC 컬럼이 영문 국가명
 */

import { useState, useCallback, useMemo, useTransition } from 'react'
import { Button } from '@/components/ui/button'
import { Dialog, DialogContent, DialogHeader, DialogTitle, DialogTrigger } from '@/components/ui/dialog'
import { Input } from '@/components/ui/input'
import { Search, Check } 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 { getNationCodes, NationCode, NationSearchOptions } from './nation-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 NationSelectorProps {
  selectedNation?: NationCode
  onNationSelect: (nation: NationCode) => void
  disabled?: boolean
  searchOptions?: Partial<NationSearchOptions>
  placeholder?: string
  className?: string
}

export function NationSelector({ 
  selectedNation, 
  onNationSelect, 
  disabled,
  searchOptions = {},
  placeholder = "국가를 선택하세요",
  className
}: NationSelectorProps) {
  const [open, setOpen] = useState(false)
  const [nations, setNations] = useState<NationCode[]>([])
  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()

  // searchOptions 안정화
  const stableSearchOptions = useMemo(() => ({
    limit: 100,
    ...searchOptions
  }), [searchOptions])

  // 국가 선택 핸들러
  const handleNationSelect = useCallback((nation: NationCode) => {
    onNationSelect(nation)
    setOpen(false)
  }, [onNationSelect])

  // 테이블 컬럼 정의
  const columns: ColumnDef<NationCode>[] = useMemo(() => [
    {
      accessorKey: 'CD',
      header: '2글자코드',
      cell: ({ row }) => (
        <div className="font-mono text-sm">{row.getValue('CD')}</div>
      ),
    },
    {
      accessorKey: 'CD2',
      header: '3글자코드',
      cell: ({ row }) => (
        <div className="font-mono text-sm">{row.getValue('CD2')}</div>
      ),
    },
    {
      accessorKey: 'CD3',
      header: '숫자코드',
      cell: ({ row }) => (
        <div className="font-mono text-sm">{row.getValue('CD3')}</div>
      ),
    },
    {
      accessorKey: 'CDNM',
      header: '한국어명',
      cell: ({ row }) => (
        <div className="max-w-[120px] truncate">{row.getValue('CDNM')}</div>
      ),
    },
    {
      accessorKey: 'GRP_DSC',
      header: '영문명',
      cell: ({ row }) => (
        <div className="max-w-[150px] truncate">{row.getValue('GRP_DSC')}</div>
      ),
    },
    {
      id: 'actions',
      header: '선택',
      cell: ({ row }) => (
        <Button
          variant="ghost"
          size="sm"
          onClick={(e) => {
            e.stopPropagation()
            handleNationSelect(row.original)
          }}
        >
          <Check className="h-4 w-4" />
        </Button>
      ),
    },
  ], [handleNationSelect])

  // 국가 테이블 설정
  const table = useReactTable({
    data: nations,
    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,
    },
  })

  // 서버 액션을 사용한 국가 목록 로드
  const loadNations = useCallback(async (searchTerm?: string) => {
    startTransition(async () => {
      try {
        const result = await getNationCodes({
          ...stableSearchOptions,
          searchTerm: searchTerm
        })
        
        if (result.success) {
          setNations(result.data)
        } else {
          toast.error(result.error || '국가코드를 불러오는데 실패했습니다.')
          setNations([])
        }
      } catch (error) {
        console.error('국가코드 목록 로드 실패:', error)
        toast.error('국가코드를 불러오는 중 오류가 발생했습니다.')
        setNations([])
      }
    })
  }, [stableSearchOptions])

  // 디바운스된 검색 (클라이언트 로직만)
  const debouncedSearch = useMemo(
    () => debounce((searchTerm: string) => {
      loadNations(searchTerm)
    }, 300),
    [loadNations]
  )

  // 다이얼로그 열기 핸들러
  const handleDialogOpenChange = useCallback((newOpen: boolean) => {
    setOpen(newOpen)
    if (newOpen && nations.length === 0) {
      loadNations()
    }
  }, [loadNations, nations.length])

  // 검색어 변경 핸들러
  const handleSearchChange = useCallback((value: string) => {
    setGlobalFilter(value)
    if (open) {
      debouncedSearch(value)
    }
  }, [open, debouncedSearch])

  return (
    <Dialog open={open} onOpenChange={handleDialogOpenChange}>
      <DialogTrigger asChild>
        <Button 
          variant="outline" 
          disabled={disabled} 
          className={`w-full justify-start ${className || ''}`}
        >
          {selectedNation ? (
            <div className="flex items-center gap-2 w-full">
              <span className="font-mono text-sm">[{selectedNation.CD}]</span>
              <span className="truncate flex-1 text-left">{selectedNation.CDNM}</span>
            </div>
          ) : (
            <span className="text-muted-foreground">{placeholder}</span>
          )}
        </Button>
      </DialogTrigger>
      <DialogContent className="max-w-5xl max-h-[80vh]">
        <DialogHeader>
          <DialogTitle>국가 선택</DialogTitle>
          <div className="text-sm text-muted-foreground">
            국가코드(CD_CLF=LE0010) 조회
          </div>
        </DialogHeader>
        
        <div className="space-y-4">
          <div className="flex items-center space-x-2">
            <Search className="h-4 w-4" />
            <Input
              placeholder="국가코드, 국가명으로 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">국가코드를 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) => (
                      <TableRow
                        key={row.id}
                        data-state={row.getIsSelected() && "selected"}
                        className="cursor-pointer hover:bg-muted/50"
                        onClick={() => handleNationSelect(row.original)}
                      >
                        {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 국가
            </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>
      </DialogContent>
    </Dialog>
  )
}
