"use client"

import { useState, useRef } from "react"
import { useSession } from "next-auth/react"
import { Card, CardContent, CardDescription, CardHeader, CardTitle } from "@/components/ui/card"
import { Button } from "@/components/ui/button"
import { Badge } from "@/components/ui/badge"
import { Alert, AlertDescription } from "@/components/ui/alert"
import {
  Dialog,
  DialogContent,
  DialogDescription,
  DialogFooter,
  DialogHeader,
  DialogTitle,
} from "@/components/ui/dialog"
import {
  Table,
  TableBody,
  TableCell,
  TableHead,
  TableHeader,
  TableRow,
} from "@/components/ui/table"
import {
  Upload,
  FileText,
  File,
  Trash2,
  Download,
  AlertCircle,
  Paperclip,
  FileCheck,
  Calculator,
  Wrench,
  X,
  CheckCircle
} from "lucide-react"
import { formatBytes } from "@/lib/utils"
import { cn } from "@/lib/utils"
import { toast } from "sonner"
import { deleteVendorResponseAttachment } from "../../service"

interface FileWithType extends File {
  attachmentType?: "구매" | "설계"
  description?: string
}

interface AttachmentsUploadProps {
  attachments: FileWithType[]
  onAttachmentsChange: (files: FileWithType[]) => void
  existingAttachments?: any[]
  onExistingAttachmentsChange?: (files: any[]) => void
  responseId?: number
  userId?: number
  isSubmitted?: boolean
}

const acceptedFileTypes = {
  documents: ".pdf,.doc,.docx,.xls,.xlsx,.ppt,.pptx",
  images: ".jpg,.jpeg,.png,.gif,.bmp",
  compressed: ".zip,.rar,.7z",
  all: ".pdf,.doc,.docx,.xls,.xlsx,.ppt,.pptx,.jpg,.jpeg,.png,.gif,.bmp,.zip,.rar,.7z"
}

export default function AttachmentsUpload({
  attachments,
  onAttachmentsChange,
  existingAttachments = [],
  onExistingAttachmentsChange,
  responseId,
  userId,
  isSubmitted = false
}: AttachmentsUploadProps) {
  const purchaseInputRef = useRef<HTMLInputElement>(null)
  const designInputRef = useRef<HTMLInputElement>(null)
  const [purchaseDragActive, setPurchaseDragActive] = useState(false)
  const [designDragActive, setDesignDragActive] = useState(false)
  const [uploadErrors, setUploadErrors] = useState<string[]>([])
  const [deleteDialogOpen, setDeleteDialogOpen] = useState(false)
  const [fileToDelete, setFileToDelete] = useState<{file: any, isExisting: boolean, index: number} | null>(null)
  
  // 파일 유효성 검사
  const validateFile = (file: File): string | null => {
    const maxSize = 1024 * 1024 * 1024 // 10MB
    const allowedExtensions = acceptedFileTypes.all.split(',')
    const fileExtension = `.${file.name.split('.').pop()?.toLowerCase()}`
    
    if (file.size > maxSize) {
      return `${file.name}: 파일 크기가 1GB를 초과합니다`
    }
    
    if (!allowedExtensions.includes(fileExtension)) {
      return `${file.name}: 허용되지 않은 파일 형식입니다`
    }
    
    return null
  }
  
  // 파일 추가
  const handleFileAdd = (files: FileList | null, type: "구매" | "설계") => {
    if (!files) return

    const newFiles: FileWithType[] = []
    const errors: string[] = []

    Array.from(files).forEach(file => {
      const error = validateFile(file)
      if (error) {
        errors.push(error)
      } else {
        const fileWithType = Object.assign(file, {
          attachmentType: type,
          description: ""
        })
        // 디버그 로그 추가
        console.log(`파일 추가됨: ${file.name}, 타입: ${type}`)
        newFiles.push(fileWithType)
      }
    })

    if (errors.length > 0) {
      setUploadErrors(errors)
      setTimeout(() => setUploadErrors([]), 5000)
    }

    if (newFiles.length > 0) {
      const updatedFiles = [...attachments, ...newFiles]
      onAttachmentsChange(updatedFiles)

      // 추가된 파일들의 타입 확인 로그
      console.log('업데이트된 파일 목록:', updatedFiles.map(f => ({
        name: f.name,
        attachmentType: f.attachmentType
      })))

      // 각 파일의 타입이 제대로 설정되었는지 검증
      newFiles.forEach(file => {
        console.log(`새 파일 타입 검증: ${file.name} = ${file.attachmentType}`)
      })
    }
  }
  
  // 구매 드래그 앤 드롭 핸들러
  const handlePurchaseDrag = (e: React.DragEvent) => {
    e.preventDefault()
    e.stopPropagation()
    if (e.type === "dragenter" || e.type === "dragover") {
      setPurchaseDragActive(true)
    } else if (e.type === "dragleave") {
      setPurchaseDragActive(false)
    }
  }
  
  const handlePurchaseDrop = (e: React.DragEvent) => {
    e.preventDefault()
    e.stopPropagation()
    setPurchaseDragActive(false)
    
    if (e.dataTransfer.files && e.dataTransfer.files[0]) {
      handleFileAdd(e.dataTransfer.files, "구매")
    }
  }
  
  // 설계 드래그 앤 드롭 핸들러
  const handleDesignDrag = (e: React.DragEvent) => {
    e.preventDefault()
    e.stopPropagation()
    if (e.type === "dragenter" || e.type === "dragover") {
      setDesignDragActive(true)
    } else if (e.type === "dragleave") {
      setDesignDragActive(false)
    }
  }
  
  const handleDesignDrop = (e: React.DragEvent) => {
    e.preventDefault()
    e.stopPropagation()
    setDesignDragActive(false)
    
    if (e.dataTransfer.files && e.dataTransfer.files[0]) {
      handleFileAdd(e.dataTransfer.files, "설계")
    }
  }
  
  // 파일 삭제
  const handleFileRemove = (index: number) => {
    const newFiles = attachments.filter((_, i) => i !== index)
    onAttachmentsChange(newFiles)
  }
  
  // 파일 타입 변경
  const handleTypeChange = (index: number, newType: "구매" | "설계") => {
    const newFiles = [...attachments]
    const oldType = newFiles[index].attachmentType
    newFiles[index].attachmentType = newType

    console.log(`파일 타입 변경: ${newFiles[index].name} (${oldType} -> ${newType})`)
    console.log('변경 후 파일 목록:', newFiles.map(f => ({
      name: f.name,
      attachmentType: f.attachmentType
    })))

    onAttachmentsChange(newFiles)
  }

  // 파일 삭제 확인
  const handleDeleteClick = (file: any, isExisting: boolean, index: number) => {
    setFileToDelete({ file, isExisting, index })
    setDeleteDialogOpen(true)
  }

  // 파일 삭제 실행
  const handleDeleteConfirm = async () => {
    if (!fileToDelete) return

    const { isExisting, index } = fileToDelete

    if (isExisting) {
      // 기존 첨부파일 삭제 - 서버액션 호출
      if (responseId && userId && fileToDelete.file.id) {
        try {
          const result = await deleteVendorResponseAttachment({
            attachmentId: fileToDelete.file.id,
            responseId,
            userId
          })
          if (result.success) {
            // 클라이언트 상태 업데이트
            const newExistingAttachments = existingAttachments.filter((_, i) => i !== index)
            onExistingAttachmentsChange?.(newExistingAttachments)
          } else {
            toast.error(`삭제 실패: ${result.error}`)
            return
          }
        } catch (error) {
          console.error('삭제 API 호출 실패:', error)
          toast.error('삭제 중 오류가 발생했습니다.')
          return
        }
      }
    } else {
      // 새 첨부파일 삭제 (클라이언트에서만)
      const newFiles = attachments.filter((_, i) => i !== index)
      onAttachmentsChange(newFiles)
    }

    setDeleteDialogOpen(false)
    setFileToDelete(null)
  }

  // 파일 삭제 취소
  const handleDeleteCancel = () => {
    setDeleteDialogOpen(false)
    setFileToDelete(null)
  }
  
  // 파일 아이콘 가져오기
  const getFileIcon = (fileName: string) => {
    const extension = fileName.split('.').pop()?.toLowerCase()
    const imageExtensions = ['jpg', 'jpeg', 'png', 'gif', 'bmp']
    
    if (imageExtensions.includes(extension || '')) {
      return <File className="h-4 w-4 text-blue-500" />
    }
    return <FileText className="h-4 w-4 text-gray-500" />
  }
  
  // 구매/설계 문서 개수 계산
  const purchaseCount = attachments.filter(f => f.attachmentType === "구매").length + 
                        existingAttachments.filter(f => f.attachmentType === "구매").length
  const designCount = attachments.filter(f => f.attachmentType === "설계").length + 
                      existingAttachments.filter(f => f.attachmentType === "설계").length
  
  return (
    <div className="space-y-4">
      {/* 제출완료 상태 알림 */}
      {isSubmitted && (
        <Alert>
          <CheckCircle className="h-4 w-4" />
          <AlertDescription>
            <strong>제출완료:</strong> 견적서가 이미 제출되어 추가 파일 업로드가 제한됩니다.
          </AlertDescription>
        </Alert>
      )}

      {/* 필수 파일 안내 */}
      <Alert>
        <AlertCircle className="h-4 w-4" />
        <AlertDescription>
          <strong>문서 분류:</strong> 구매 문서(견적서, 상업조건 등)와 설계 문서(기술문서, 성적서, 인증서 등)를 구분하여 업로드하세요.
          <br />
          <strong>허용 파일:</strong> PDF, Word, Excel, PowerPoint, 이미지 파일, 압축 파일(ZIP, RAR, 7Z) (최대 1GB)
        </AlertDescription>
      </Alert>
      
      {/* 업로드 오류 표시 */}
      {uploadErrors.length > 0 && (
        <Alert variant="destructive">
          <AlertCircle className="h-4 w-4" />
          <AlertDescription>
            <ul className="list-disc list-inside">
              {uploadErrors.map((error, index) => (
                <li key={index}>{error}</li>
              ))}
            </ul>
          </AlertDescription>
        </Alert>
      )}
      
      {/* 두 개의 드래그존 */}
      <div className="grid grid-cols-1 lg:grid-cols-2 gap-4">
        {/* 구매 문서 업로드 영역 */}
        <Card>
          <CardHeader>
            <CardTitle className="flex items-center gap-2">
              <Calculator className="h-5 w-5" />
              구매 문서
            </CardTitle>
            <CardDescription>
              견적서, 금액, 상업조건 관련 문서
            </CardDescription>
          </CardHeader>
          <CardContent>
            <div
              className={cn(
                "border-2 border-dashed rounded-lg p-6 text-center transition-colors",
                purchaseDragActive && !isSubmitted ? "border-blue-500 bg-blue-50" : "border-gray-300",
                !isSubmitted && "hover:border-blue-400 hover:bg-blue-50/50",
                isSubmitted && "opacity-50 cursor-not-allowed bg-gray-50"
              )}
              onDragEnter={!isSubmitted ? handlePurchaseDrag : undefined}
              onDragLeave={!isSubmitted ? handlePurchaseDrag : undefined}
              onDragOver={!isSubmitted ? handlePurchaseDrag : undefined}
              onDrop={!isSubmitted ? handlePurchaseDrop : undefined}
            >
              <Calculator className="mx-auto h-10 w-10 text-blue-500 mb-3" />
              <p className="text-sm text-gray-600 mb-2">
                구매 문서를 드래그하여 업로드
              </p>
              <Button
                type="button"
                variant="outline"
                size="sm"
                onClick={() => !isSubmitted && purchaseInputRef.current?.click()}
                className={cn(
                  "border-blue-500 text-blue-600 hover:bg-blue-50",
                  isSubmitted && "opacity-50 cursor-not-allowed"
                )}
                disabled={isSubmitted}
              >
                <Paperclip className="h-4 w-4 mr-2" />
                {isSubmitted ? "제출완료" : "구매 문서 선택"}
              </Button>
              <input
                ref={purchaseInputRef}
                type="file"
                multiple
                accept={acceptedFileTypes.all}
                onChange={(e) => handleFileAdd(e.target.files, "구매")}
                className="hidden"
              />
              {purchaseCount > 0 && (
                <div className="mt-2">
                  <Badge variant="secondary">{purchaseCount}개 업로드됨</Badge>
                </div>
              )}
            </div>
          </CardContent>
        </Card>
        
        {/* 설계 문서 업로드 영역 */}
        <Card>
          <CardHeader>
            <CardTitle className="flex items-center gap-2">
              <Wrench className="h-5 w-5" />
              설계 문서
            </CardTitle>
            <CardDescription>
              기술문서, 성적서, 인증서, 도면 등
            </CardDescription>
          </CardHeader>
          <CardContent>
            <div
              className={cn(
                "border-2 border-dashed rounded-lg p-6 text-center transition-colors",
                designDragActive && !isSubmitted ? "border-green-500 bg-green-50" : "border-gray-300",
                !isSubmitted && "hover:border-green-400 hover:bg-green-50/50",
                isSubmitted && "opacity-50 cursor-not-allowed bg-gray-50"
              )}
              onDragEnter={!isSubmitted ? handleDesignDrag : undefined}
              onDragLeave={!isSubmitted ? handleDesignDrag : undefined}
              onDragOver={!isSubmitted ? handleDesignDrag : undefined}
              onDrop={!isSubmitted ? handleDesignDrop : undefined}
            >
              <Wrench className="mx-auto h-10 w-10 text-green-500 mb-3" />
              <p className="text-sm text-gray-600 mb-2">
                설계 문서를 드래그하여 업로드
              </p>
              <Button
                type="button"
                variant="outline"
                size="sm"
                onClick={() => !isSubmitted && designInputRef.current?.click()}
                className={cn(
                  "border-green-500 text-green-600 hover:bg-green-50",
                  isSubmitted && "opacity-50 cursor-not-allowed"
                )}
                disabled={isSubmitted}
              >
                <Paperclip className="h-4 w-4 mr-2" />
                {isSubmitted ? "제출완료" : "설계 문서 선택"}
              </Button>
              <input
                ref={designInputRef}
                type="file"
                multiple
                accept={acceptedFileTypes.all}
                onChange={(e) => handleFileAdd(e.target.files, "설계")}
                className="hidden"
              />
              {designCount > 0 && (
                <div className="mt-2">
                  <Badge variant="secondary">{designCount}개 업로드됨</Badge>
                </div>
              )}
              {/* <p className="text-xs text-gray-500 mt-2">
                최대 1GB, 여러 파일 선택 가능
              </p> */}
            </div>
          </CardContent>
        </Card>
      </div>
      
      {/* 첨부파일 목록 */}
      {(attachments.length > 0 || existingAttachments.length > 0) && (
        <Card>
          <CardHeader>
            <div className="flex items-center justify-between">
              <CardTitle>첨부파일 목록</CardTitle>
              <div className="flex items-center gap-2">
                <Badge variant="outline" className="gap-1">
                  <Calculator className="h-3 w-3" />
                  구매 {purchaseCount}
                </Badge>
                <Badge variant="outline" className="gap-1">
                  <Wrench className="h-3 w-3" />
                  설계 {designCount}
                </Badge>
                <Badge variant="secondary">
                  총 {attachments.length + existingAttachments.length}개
                </Badge>
              </div>
            </div>
          </CardHeader>
          <CardContent>
            <Table>
              <TableHeader>
                <TableRow>
                  <TableHead className="w-[50px]">유형</TableHead>
                  <TableHead>파일명</TableHead>
                  <TableHead className="w-[100px]">크기</TableHead>
                  <TableHead className="w-[120px]">문서 구분</TableHead>
                  <TableHead className="w-[100px]">상태</TableHead>
                  <TableHead className="w-[80px]">작업</TableHead>
                </TableRow>
              </TableHeader>
              <TableBody>
                {/* 기존 첨부파일 */}
                {existingAttachments.map((file, index) => (
                  <TableRow key={`existing-${index}`}>
                    <TableCell>
                      {getFileIcon(file.originalFileName)}
                    </TableCell>
                    <TableCell>
                      <div>
                        <p className="font-medium">{file.originalFileName}</p>
                        {file.description && (
                          <p className="text-xs text-muted-foreground">
                            {file.description}
                          </p>
                        )}
                      </div>
                    </TableCell>
                    <TableCell className="text-sm text-muted-foreground">
                      {formatBytes(file.fileSize || 0)}
                    </TableCell>
                    <TableCell>
                      <Badge 
                        variant={file.attachmentType === "구매" ? "default" : "secondary"}
                        className="gap-1"
                      >
                        {file.attachmentType === "구매" ? 
                          <Calculator className="h-3 w-3" /> : 
                          <Wrench className="h-3 w-3" />
                        }
                        {file.attachmentType}
                      </Badge>
                    </TableCell>
                    <TableCell>
                      <Badge variant="secondary">
                        <FileCheck className="h-3 w-3 mr-1" />
                        기존
                      </Badge>
                    </TableCell>
                    <TableCell>
                      <div className="flex items-center gap-1">
                        <Button
                          type="button"
                          variant="ghost"
                          size="sm"
                          onClick={() => window.open(file.filePath, '_blank')}
                        >
                          <Download className="h-4 w-4" />
                        </Button>
                        <Button
                          type="button"
                          variant="ghost"
                          size="sm"
                          onClick={() => !isSubmitted && handleDeleteClick(file, true, index)}
                          className={isSubmitted ? "opacity-50 cursor-not-allowed" : ""}
                          disabled={isSubmitted}
                        >
                          <Trash2 className="h-4 w-4 text-red-500" />
                        </Button>
                      </div>
                    </TableCell>
                  </TableRow>
                ))}
                
                {/* 새로 추가된 파일 */}
                {attachments.map((file, index) => (
                  <TableRow key={`new-${index}`}>
                    <TableCell>
                      {getFileIcon(file.name)}
                    </TableCell>
                    <TableCell>
                      <div>
                        <p className="font-medium">{file.name}</p>
                      </div>
                    </TableCell>
                    <TableCell className="text-sm text-muted-foreground">
                      {formatBytes(file.size)}
                    </TableCell>
                    <TableCell>
                      <div className="flex items-center gap-1">
                        <Button
                          type="button"
                          variant={file.attachmentType === "구매" ? "default" : "ghost"}
                          size="sm"
                          className={cn(
                            "h-7 px-2 text-xs",
                            isSubmitted && "opacity-50 cursor-not-allowed"
                          )}
                          onClick={() => !isSubmitted && handleTypeChange(index, "구매")}
                          disabled={isSubmitted}
                        >
                          <Calculator className="h-3 w-3 mr-1" />
                          구매
                        </Button>
                        <Button
                          type="button"
                          variant={file.attachmentType === "설계" ? "default" : "ghost"}
                          size="sm"
                          className={cn(
                            "h-7 px-2 text-xs",
                            isSubmitted && "opacity-50 cursor-not-allowed"
                          )}
                          onClick={() => !isSubmitted && handleTypeChange(index, "설계")}
                          disabled={isSubmitted}
                        >
                          <Wrench className="h-3 w-3 mr-1" />
                          설계
                        </Button>
                      </div>
                    </TableCell>
                    <TableCell>
                      <Badge variant="default">
                        <Upload className="h-3 w-3 mr-1" />
                        신규
                      </Badge>
                    </TableCell>
                    <TableCell>
                      <Button
                        type="button"
                        variant="ghost"
                        size="sm"
                        onClick={() => !isSubmitted && handleDeleteClick(file, false, index)}
                        className={isSubmitted ? "opacity-50 cursor-not-allowed" : ""}
                        disabled={isSubmitted}
                      >
                        <Trash2 className="h-4 w-4 text-red-500" />
                      </Button>
                    </TableCell>
                  </TableRow>
                ))}
              </TableBody>
            </Table>
          </CardContent>
        </Card>
      )}

      {/* 파일 삭제 확인 다이얼로그 */}
      <Dialog open={deleteDialogOpen} onOpenChange={setDeleteDialogOpen}>
        <DialogContent>
          <DialogHeader>
            <DialogTitle>파일 삭제</DialogTitle>
            <DialogDescription>
              {fileToDelete?.isExisting ? '기존 첨부파일' : '새로 업로드한 파일'} "{fileToDelete?.file.originalFileName || fileToDelete?.file.name}"을(를) 삭제하시겠습니까?
              <br />
              <strong>삭제된 파일은 복구할 수 없습니다.</strong>
            </DialogDescription>
          </DialogHeader>
          <DialogFooter>
            <Button
              type="button"
              variant="outline"
              onClick={handleDeleteCancel}
            >
              취소
            </Button>
            <Button
              type="button"
              variant="destructive"
              onClick={handleDeleteConfirm}
            >
              <Trash2 className="h-4 w-4 mr-2" />
              삭제
            </Button>
          </DialogFooter>
        </DialogContent>
      </Dialog>
    </div>
  )
}