'use client'

import * as React from 'react'
import { Card, CardContent, CardHeader, CardTitle } from '@/components/ui/card'
import { Button } from '@/components/ui/button'
import { Input } from '@/components/ui/input'
import { Label } from '@/components/ui/label'
import { Badge } from '@/components/ui/badge'
import {
  Table,
  TableBody,
  TableCell,
  TableHead,
  TableHeader,
  TableRow,
} from '@/components/ui/table'
import {
  Upload,
  FileText,
  Download,
  Trash2
} from 'lucide-react'
import { useToast } from '@/hooks/use-toast'
import { useTransition } from 'react'
import { 
  uploadAwardDocument, 
  getAwardDocuments,
  getAwardDocumentForDownload,
  deleteAwardDocument
} from '../../service'
import { downloadFile } from '@/lib/file-download'

interface UploadedDocument {
  id: number
  fileName: string
  originalFileName: string
  fileSize: number | null
  filePath: string
  title: string | null
  description: string | null
  uploadedAt: Date
  uploadedBy: string
}

interface AwardSimpleFileUploadProps {
  biddingId: number
  userId: string
  readOnly?: boolean
}

export function AwardSimpleFileUpload({
  biddingId,
  userId,
  readOnly = false
}: AwardSimpleFileUploadProps) {
  const { toast } = useToast()
  const [isPending, startTransition] = useTransition()
  const [documents, setDocuments] = React.useState<UploadedDocument[]>([])
  const [isLoading, setIsLoading] = React.useState(true)

  // 업로드된 문서 목록 로드
  const loadDocuments = React.useCallback(async () => {
    try {
      setIsLoading(true)
      const docs = await getAwardDocuments(biddingId)
      setDocuments(docs as UploadedDocument[])
    } catch (error) {
      console.error('Failed to load documents:', error)
      toast({
        title: '오류',
        description: '업로드된 문서 목록을 불러오는데 실패했습니다.',
        variant: 'destructive',
      })
    } finally {
      setIsLoading(false)
    }
  }, [biddingId, toast])

  React.useEffect(() => {
    loadDocuments()
  }, [loadDocuments])

  // 파일 업로드 처리
  const handleFileUpload = (event: React.ChangeEvent<HTMLInputElement>) => {
    const files = event.target.files
    if (!files || files.length === 0) return

    const file = files[0]
    
    // 파일 크기 체크 (50MB 제한)
    if (file.size > 50 * 1024 * 1024) {
      toast({
        title: '파일 크기 초과',
        description: '파일 크기가 50MB를 초과합니다.',
        variant: 'destructive',
      })
      return
    }

    // 파일 타입 체크
    const allowedTypes = [
      'application/pdf',
      'application/msword',
      'application/vnd.openxmlformats-officedocument.wordprocessingml.document',
      'application/vnd.ms-excel',
      'application/vnd.openxmlformats-officedocument.spreadsheetml.sheet',
      'image/jpeg',
      'image/png',
      'application/zip'
    ]
    
    if (!allowedTypes.includes(file.type)) {
      toast({
        title: '지원하지 않는 파일 형식',
        description: 'PDF, Word, Excel, 이미지, ZIP 파일만 업로드 가능합니다.',
        variant: 'destructive',
      })
      return
    }

    startTransition(async () => {
      const result = await uploadAwardDocument(biddingId, file, userId)
      
      if (result.success) {
        toast({
          title: '업로드 완료',
          description: result.message,
        })
        await loadDocuments() // 문서 목록 새로고침
      } else {
        toast({
          title: '업로드 실패',
          description: result.error,
          variant: 'destructive',
        })
      }
    })

    // input 초기화
    event.target.value = ''
  }

  // 파일 다운로드
  const handleDownload = (document: UploadedDocument) => {
    startTransition(async () => {
      const result = await getAwardDocumentForDownload(document.id, biddingId)
      
      if (result.success) {
        try {
          await downloadFile(result.document?.filePath, result.document?.originalFileName, {
            showToast: true
          })
        } catch (error) {
          toast({
            title: '다운로드 실패',
            description: '파일 다운로드에 실패했습니다.',
            variant: 'destructive',
          })
        }
      } else {
        toast({
          title: '다운로드 실패',
          description: result.error,
          variant: 'destructive',
        })
      }
    })
  }

  // 파일 삭제
  const handleDelete = (document: UploadedDocument) => {
    if (!confirm(`"${document.originalFileName}" 파일을 삭제하시겠습니까?`)) {
      return
    }

    startTransition(async () => {
      const result = await deleteAwardDocument(document.id, biddingId, userId)
      
      if (result.success) {
        toast({
          title: '삭제 완료',
          description: result.message,
        })
        await loadDocuments() // 문서 목록 새로고침
      } else {
        toast({
          title: '삭제 실패',
          description: result.error,
          variant: 'destructive',
        })
      }
    })
  }

  // 파일 크기 포맷팅
  const formatFileSize = (bytes: number | null) => {
    if (!bytes) return '-'
    if (bytes === 0) return '0 Bytes'
    const k = 1024
    const sizes = ['Bytes', 'KB', 'MB', 'GB']
    const i = Math.floor(Math.log(bytes) / Math.log(k))
    return parseFloat((bytes / Math.pow(k, i)).toFixed(2)) + ' ' + sizes[i]
  }

  return (
    <Card>
      <CardHeader>
        <CardTitle className="flex items-center gap-2">
          <FileText className="w-5 h-5" />
          낙찰 관련 문서 업로드
        </CardTitle>
      </CardHeader>
      <CardContent className="space-y-4">
        {!readOnly && (
          <div className="space-y-2">
            <Label htmlFor="award-file-upload">낙찰 관련 파일</Label>
            <Input
              id="award-file-upload"
              type="file"
              accept=".pdf,.doc,.docx,.xls,.xlsx,.jpg,.jpeg,.png,.zip"
              onChange={handleFileUpload}
              disabled={isPending}
            />
            <p className="text-xs text-muted-foreground">
              지원 형식: PDF, Word, Excel, 이미지, ZIP (최대 50MB)
            </p>
          </div>
        )}

        {/* 업로드된 문서 목록 */}
        {isLoading ? (
          <div className="text-center py-4">
            <p className="text-muted-foreground">문서 목록을 불러오는 중...</p>
          </div>
        ) : documents.length > 0 ? (
          <div className="space-y-2">
            <Label className="text-sm font-medium">업로드된 문서</Label>
            <Table>
              <TableHeader>
                <TableRow>
                  <TableHead>파일명</TableHead>
                  <TableHead>크기</TableHead>
                  <TableHead>업로드일</TableHead>
                  <TableHead>작성자</TableHead>
                  <TableHead className="w-24">작업</TableHead>
                </TableRow>
              </TableHeader>
              <TableBody>
                {documents.map((doc) => (
                  <TableRow key={doc.id}>
                    <TableCell>
                      <div className="flex items-center gap-2">
                        <FileText className="w-4 h-4 text-gray-500" />
                        <span className="truncate max-w-48" title={doc.originalFileName}>
                          {doc.originalFileName}
                        </span>
                      </div>
                    </TableCell>
                    <TableCell className="text-sm text-gray-500">
                      {formatFileSize(doc.fileSize)}
                    </TableCell>
                    <TableCell className="text-sm text-gray-500">
                      {new Date(doc.uploadedAt).toLocaleDateString('ko-KR')}
                    </TableCell>
                    <TableCell className="text-sm text-gray-500">
                      {doc.uploadedBy}
                    </TableCell>
                    <TableCell>
                      <div className="flex items-center gap-1">
                        <Button
                          variant="outline"
                          size="sm"
                          onClick={() => handleDownload(doc)}
                          disabled={isPending}
                          title="다운로드"
                        >
                          <Download className="w-3 h-3" />
                        </Button>
                        {!readOnly && doc.uploadedBy === userId && (
                          <Button
                            variant="outline"
                            size="sm"
                            onClick={() => handleDelete(doc)}
                            disabled={isPending}
                            title="삭제"
                            className="text-red-600 hover:text-red-700"
                          >
                            <Trash2 className="w-3 h-3" />
                          </Button>
                        )}
                      </div>
                    </TableCell>
                  </TableRow>
                ))}
              </TableBody>
            </Table>
          </div>
        ) : (
          <div className="text-center py-4 text-gray-500">
            <FileText className="w-8 h-8 mx-auto mb-2 opacity-50" />
            <p className="text-sm">업로드된 문서가 없습니다</p>
          </div>
        )}
      </CardContent>
    </Card>
  )
}