"use client"

import * as React from "react"
import { useForm } from "react-hook-form"
import { zodResolver } from "@hookform/resolvers/zod"
import { z } from "zod"
import { toast } from "sonner"
import { useRouter } from "next/navigation"

import {
  Dialog,
  DialogContent,
  DialogDescription,
  DialogFooter,
  DialogHeader,
  DialogTitle,
} from "@/components/ui/dialog"
import {
  AlertDialog,
  AlertDialogAction,
  AlertDialogCancel,
  AlertDialogContent,
  AlertDialogDescription,
  AlertDialogFooter,
  AlertDialogHeader,
  AlertDialogTitle,
} from "@/components/ui/alert-dialog"
import { Button } from "@/components/ui/button"
import {
  Form,
  FormControl,
  FormField,
  FormItem,
  FormLabel,
  FormMessage,
} from "@/components/ui/form"
import {
  Select,
  SelectContent,
  SelectItem,
  SelectTrigger,
  SelectValue,
} from "@/components/ui/select"
import { Badge } from "@/components/ui/badge"
import {
  Upload,
  X,
  Loader2,
  CheckCircle2,
  AlertCircle,
  AlertTriangle,
  FileText,
} from "lucide-react"

import { bulkUploadB4Documents } from "../enhanced-document-service"

// 파일명 파싱 유틸리티
function parseFileName(fileName: string): { docNumber: string | null; revision: string | null } {
  // 공백으로 단어 분리 (첫 번째는 파일명으로 무시)
  const words = fileName.trim().split(/\s+/).filter(word => word.length > 0)

  if (words.length < 2) {
    return { docNumber: null, revision: null }
  }

  // 마지막 단어에서 확장자와 리비전을 분리
  const lastWord = words[words.length - 1]
  const lastDotIndex = lastWord.lastIndexOf('.')

  let revision: string | null = null

  if (lastDotIndex !== -1) {
    // 마지막 '.' 기준으로 확장자 앞부분만 사용
    const beforeExt = lastWord.substring(0, lastDotIndex)

    // revision 패턴 찾기 (R01, r01, REV01, rev01 등)
    const revisionMatch = beforeExt.match(/[Rr](?:EV)?(\d+)/)
    revision = revisionMatch ? revisionMatch[0].toUpperCase() : null
  }

  // 문서번호: 첫 번째(파일명)와 마지막(REV.ext)을 제외한 모든 단어들을 '-'로 연결
  const docWords = words.slice(1, -1) // 첫 번째와 마지막 제외
  const docNumber = docWords.length > 0
    ? docWords.join('-').toUpperCase()
    : null

  return { docNumber, revision }
}

// Form schema
const formSchema = z.object({
  projectId: z.string().min(1, "Please select a project"),
  files: z.array(z.instanceof(File)).min(1, "Please select files"),
})

export interface ProjectOption {
  id: string
  code: string
}

interface BulkB4UploadDialogProps {
  open: boolean
  onOpenChange: (open: boolean) => void
  projectOptions: ProjectOption[]
}

interface ParsedFile {
  file: File
  docNumber: string | null
  revision: string | null
  status: 'pending' | 'uploading' | 'success' | 'error' | 'ignored'
  message?: string
}

export function BulkB4UploadDialog({ 
  open, 
  onOpenChange,
  projectOptions
}: BulkB4UploadDialogProps) {
  const [isUploading, setIsUploading] = React.useState(false)
  const [parsedFiles, setParsedFiles] = React.useState<ParsedFile[]>([])
  const [isDragging, setIsDragging] = React.useState(false)
  const [currentProjectId, setCurrentProjectId] = React.useState<string>("")
  const [showProjectChangeWarning, setShowProjectChangeWarning] = React.useState(false)
  const [pendingProjectId, setPendingProjectId] = React.useState<string>("")
  const router = useRouter()
  
  const form = useForm<z.infer<typeof formSchema>>({
    resolver: zodResolver(formSchema),
    defaultValues: {
      projectId: "",
      files: [],
    },
  })
  
  // 프로젝트 변경 핸들러
  const handleProjectChange = (newProjectId: string) => {
    // 기존 파일 목록이 있고, 다른 프로젝트로 변경하는 경우 경고 표시
    if (parsedFiles.length > 0 && currentProjectId && currentProjectId !== newProjectId) {
      setPendingProjectId(newProjectId)
      setShowProjectChangeWarning(true)
    } else {
      // 파일 목록이 비어있거나 첫 선택인 경우 바로 변경
      setCurrentProjectId(newProjectId)
      form.setValue("projectId", newProjectId)
    }
  }
  
  // 프로젝트 변경 확인 처리
  const confirmProjectChange = () => {
    // 파일 목록 초기화하고 프로젝트 변경
    setParsedFiles([])
    form.setValue("files", [])
    setCurrentProjectId(pendingProjectId)
    form.setValue("projectId", pendingProjectId)
    setShowProjectChangeWarning(false)
    setPendingProjectId("")
  }
  
  // 프로젝트 변경 취소 처리
  const cancelProjectChange = () => {
    setShowProjectChangeWarning(false)
    setPendingProjectId("")
  }
  
  // 파일 검증 함수
  const validateFile = (file: File): { valid: boolean; error?: string } => {
    const MAX_FILE_SIZE = 1024 * 1024 * 1024 // 1GB
    const FORBIDDEN_EXTENSIONS = ['exe', 'com', 'dll', 'vbs', 'js', 'asp', 'aspx', 'bat', 'cmd']
    
    // 파일 크기 검증
    if (file.size > MAX_FILE_SIZE) {
      return {
        valid: false,
        error: `파일 크기가 1GB를 초과합니다 (${(file.size / (1024 * 1024 * 1024)).toFixed(2)}GB)`
      }
    }
    
    // 파일 확장자 검증
    const extension = file.name.split('.').pop()?.toLowerCase()
    if (extension && FORBIDDEN_EXTENSIONS.includes(extension)) {
      return {
        valid: false,
        error: `금지된 파일 형식입니다 (.${extension})`
      }
    }
    
    return { valid: true }
  }

  // 파일 선택 시 파싱
  const handleFilesChange = (files: File[]) => {
    const validFiles: File[] = []
    const invalidFiles: string[] = []
    
    // 파일 검증
    files.forEach(file => {
      const validation = validateFile(file)
      if (validation.valid) {
        validFiles.push(file)
      } else {
        invalidFiles.push(`${file.name}: ${validation.error}`)
      }
    })
    
    // 유효하지 않은 파일이 있으면 토스트 표시
    if (invalidFiles.length > 0) {
      invalidFiles.forEach(msg => toast.error(msg))
    }
    
    // 유효한 파일만 파싱
    const parsed = validFiles.map(file => {
      const { docNumber, revision } = parseFileName(file.name)
      return {
        file,
        docNumber,
        revision,
        status: docNumber ? 'pending' as const : 'ignored' as const,
        message: !docNumber ? 'docNumber를 찾을 수 없음' : undefined
      }
    })

    // 기존 파일들과 새 파일들을 합침 (중복 파일명은 제외)
    const existingFileNames = new Set(parsedFiles.map(pf => pf.file.name))
    const newFiles = parsed.filter(pf => !existingFileNames.has(pf.file.name))
    const combinedParsed = [...parsedFiles, ...newFiles]
    const combinedFiles = [...parsedFiles.map(pf => pf.file), ...newFiles.map(pf => pf.file)]

    setParsedFiles(combinedParsed)
    form.setValue("files", combinedFiles)
  }
  
  // 파일 제거
  const removeFile = (index: number) => {
    const newParsedFiles = parsedFiles.filter((_, i) => i !== index)
    setParsedFiles(newParsedFiles)
    form.setValue("files", newParsedFiles.map(pf => pf.file))
  }
  
  // Drag & Drop 핸들러
  const handleDragEnter = (e: React.DragEvent) => {
    e.preventDefault()
    e.stopPropagation()
    setIsDragging(true)
  }
  
  const handleDragLeave = (e: React.DragEvent) => {
    e.preventDefault()
    e.stopPropagation()
    // 자식 요소로 이동할 때도 leave가 발생하므로 실제로 영역을 벗어날 때만 처리
    if (e.currentTarget === e.target) {
      setIsDragging(false)
    }
  }
  
  const handleDragOver = (e: React.DragEvent) => {
    e.preventDefault()
    e.stopPropagation()
    // 드롭 가능하도록 설정
    e.dataTransfer.dropEffect = 'copy'
  }
  
  const handleDrop = (e: React.DragEvent) => {
    e.preventDefault()
    e.stopPropagation()
    setIsDragging(false)
    
    const droppedFiles = Array.from(e.dataTransfer.files)
    if (droppedFiles.length > 0) {
      handleFilesChange(droppedFiles)
    }
  }
  
  // 업로드 처리
  async function onSubmit(values: z.infer<typeof formSchema>) {
    setIsUploading(true)
    
    try {
      // 유효한 파일만 필터링
      const validFiles = parsedFiles.filter(pf => pf.docNumber && pf.status === 'pending')
      
      if (validFiles.length === 0) {
        toast.error("업로드 가능한 파일이 없습니다")
        return
      }
      
      // 파일별로 상태 업데이트
      setParsedFiles(prev => prev.map(pf => 
        pf.docNumber && pf.status === 'pending' 
          ? { ...pf, status: 'uploading' as const }
          : pf
      ))
      
      // FormData 생성
      const formData = new FormData()
      formData.append("projectId", values.projectId)
      
      validFiles.forEach((pf, index) => {
        formData.append(`file_${index}`, pf.file)
        formData.append(`docNumber_${index}`, pf.docNumber!)
        formData.append(`revision_${index}`, pf.revision || "00")
      })
      
      formData.append("fileCount", String(validFiles.length))
      
      // 서버 액션 호출
      const result = await bulkUploadB4Documents(formData)
      
      if (result.success) {
        // 성공한 파일들 표시
        setParsedFiles(prev => prev.map(pf => {
          const uploadResult = result.results?.find(r => 
            r.docNumber === pf.docNumber && r.revision === (pf.revision || "00")
          )
          
          if (uploadResult?.success) {
            return { ...pf, status: 'success' as const, message: uploadResult.message }
          } else if (uploadResult) {
            return { ...pf, status: 'error' as const, message: uploadResult.error }
          }
          return pf
        }))
        
        toast.success(`${result.successCount}/${validFiles.length} 파일 업로드 완료`)
        
        // 모두 성공하면 닫기
        if (result.successCount === validFiles.length) {
          setTimeout(() => {
            onOpenChange(false)
            router.refresh()
          }, 1500)
        }
      } else {
        toast.error(result.error || "업로드 실패")
        setParsedFiles(prev => prev.map(pf => 
          pf.status === 'uploading' 
            ? { ...pf, status: 'error' as const, message: result.error }
            : pf
        ))
      }
    } catch {
      toast.error("업로드 중 오류가 발생했습니다")
      setParsedFiles(prev => prev.map(pf => 
        pf.status === 'uploading' 
          ? { ...pf, status: 'error' as const, message: '업로드 실패' }
          : pf
      ))
    } finally {
      setIsUploading(false)
    }
  }
  
  // 다이얼로그 닫을 때 초기화
  React.useEffect(() => {
    if (!open) {
      form.reset()
      setParsedFiles([])
      setIsDragging(false)
      setCurrentProjectId("")
      setShowProjectChangeWarning(false)
      setPendingProjectId("")
    }
  }, [open, form])
  
  const validFileCount = parsedFiles.filter(pf => pf.docNumber).length
  const ignoredFileCount = parsedFiles.filter(pf => !pf.docNumber).length
  
  return (
    <>
      {/* 프로젝트 변경 경고 다이얼로그 */}
      <AlertDialog open={showProjectChangeWarning} onOpenChange={setShowProjectChangeWarning}>
        <AlertDialogContent>
          <AlertDialogHeader>
            <AlertDialogTitle>프로젝트 변경 확인</AlertDialogTitle>
            <AlertDialogDescription>
              프로젝트를 변경하면 현재 선택된 {parsedFiles.length}개의 파일이 모두 제거됩니다.
              계속하시겠습니까?
            </AlertDialogDescription>
          </AlertDialogHeader>
          <AlertDialogFooter>
            <AlertDialogCancel onClick={cancelProjectChange}>취소</AlertDialogCancel>
            <AlertDialogAction onClick={confirmProjectChange}>확인</AlertDialogAction>
          </AlertDialogFooter>
        </AlertDialogContent>
      </AlertDialog>

      {/* 메인 업로드 다이얼로그 */}
      <Dialog open={open} onOpenChange={onOpenChange}>
      <DialogContent className="max-w-3xl">
        <DialogHeader>
          <DialogTitle>B4 Document Bulk Upload</DialogTitle>
          <DialogDescription>
            Document numbers and revisions will be automatically extracted from file names.
            Format: [filename] [DOC1] [DOC2] ... [DOCN] [REV].[ext]
            Examples:
            &quot;testfile TANK ANA R01.pdf&quot; → Document Number: TANK-ANA, Revision: R01
            &quot;drawing ABC DEF GHI JKL R02.pdf&quot; → Document Number: ABC-DEF-GHI-JKL, Revision: R02
          </DialogDescription>
        </DialogHeader>
        
        <Form {...form}>
          <form onSubmit={form.handleSubmit(onSubmit)} className="space-y-4">
            <FormField
              control={form.control}
              name="projectId"
              render={({ field }) => (
                <FormItem>
                  <FormLabel>Select Project *</FormLabel>
                  <Select 
                    onValueChange={handleProjectChange} 
                    value={field.value}
                    disabled={isUploading}
                  >
                    <FormControl>
                      <SelectTrigger>
                        <SelectValue placeholder="Please select a project" />
                      </SelectTrigger>
                    </FormControl>
                    <SelectContent>
                      {projectOptions.map(project => (
                        <SelectItem key={project.id} value={project.id}>
                          {project.code}
                        </SelectItem>
                      ))}
                    </SelectContent>
                  </Select>
                  <FormMessage />
                </FormItem>
              )}
            />
            
            <div className="space-y-2">
              <FormLabel>Select Files</FormLabel>
              <div 
                className={`border-2 border-dashed rounded-lg p-6 transition-all duration-200 ${
                  !currentProjectId || isUploading
                    ? 'border-muted-foreground/20 opacity-50 cursor-not-allowed'
                    : isDragging 
                      ? 'border-primary bg-primary/5 scale-[1.02]' 
                      : 'border-muted-foreground/30 hover:border-muted-foreground/50'
                }`}
                onDragEnter={!currentProjectId || isUploading ? undefined : handleDragEnter}
                onDragLeave={!currentProjectId || isUploading ? undefined : handleDragLeave}
                onDragOver={!currentProjectId || isUploading ? undefined : handleDragOver}
                onDrop={!currentProjectId || isUploading ? undefined : handleDrop}
              >
                <input
                  type="file"
                  multiple
                  accept=".pdf,.doc,.docx,.xls,.xlsx,.dwg,.dxf"
                  onChange={(e) => handleFilesChange(Array.from(e.target.files || []))}
                  className="hidden"
                  id="file-upload"
                  disabled={!currentProjectId || isUploading}
                />
                <label
                  htmlFor="file-upload"
                  className={`flex flex-col items-center justify-center ${
                    !currentProjectId || isUploading ? 'cursor-not-allowed' : 'cursor-pointer'
                  }`}
                >
                  <Upload className={`h-10 w-10 mb-2 transition-colors ${
                    isDragging ? 'text-primary' : 'text-muted-foreground'
                  }`} />
                  <p className={`text-sm transition-colors ${
                    isDragging ? 'text-primary font-medium' : 'text-muted-foreground'
                  }`}>
                    {!currentProjectId 
                      ? '먼저 프로젝트를 선택해주세요' 
                      : isDragging 
                        ? '파일을 여기에 놓으세요' 
                        : '클릭하거나 파일을 드래그하여 업로드'
                    }
                  </p>
                  <p className="text-xs text-muted-foreground mt-1">
                    PDF, DOC, DOCX, XLS, XLSX, DWG, DXF (max 1GB per file)
                  </p>
                  <p className="text-xs text-red-600 mt-1 font-medium">
                    Forbidden: .exe, .com, .dll, .vbs, .js, .asp, .aspx, .bat, .cmd
                  </p>
                </label>
              </div>
            </div>
            
            {parsedFiles.length > 0 && (
              <div className="space-y-2">
                <div className="flex items-center justify-between">
                  <FormLabel>Selected Files</FormLabel>
                  <div className="flex gap-2">
                    <Badge variant="default">
                      Valid: {validFileCount}
                    </Badge>
                    {ignoredFileCount > 0 && (
                      <Badge variant="secondary">
                        Ignored: {ignoredFileCount}
                      </Badge>
                    )}
                  </div>
                </div>
                
                <div className="max-h-[250px] border rounded-lg p-2 overflow-y-auto">
                  <div className="space-y-2">
                    {parsedFiles.map((pf, index) => (
                      <div
                        key={index}
                        className="flex items-center justify-between p-2 rounded-lg bg-muted/30"
                      >
                        <div className="flex items-center gap-3 flex-1">
                          <FileText className="h-4 w-4 text-muted-foreground" />
                          <div className="flex-1 min-w-0">
                            <p className="text-sm font-medium truncate">
                              {pf.file.name}
                            </p>
                            <div className="flex items-center gap-2 mt-1">
                              {pf.docNumber ? (
                                <>
                                  <Badge variant="outline" className="text-xs">
                                    Doc: {pf.docNumber}
                                  </Badge>
                                  {pf.revision && (
                                    <Badge variant="outline" className="text-xs">
                                      Rev: {pf.revision}
                                    </Badge>
                                  )}
                                </>
                              ) : (
                                <span className="text-xs text-muted-foreground">
                                  {pf.message}
                                </span>
                              )}
                            </div>
                          </div>
                          
                          <div className="flex items-center gap-2">
                            {pf.status === 'uploading' && (
                              <Loader2 className="h-4 w-4 animate-spin" />
                            )}
                            {pf.status === 'success' && (
                              <CheckCircle2 className="h-4 w-4 text-emerald-500 dark:text-emerald-400" />
                            )}
                            {pf.status === 'error' && (
                              <AlertCircle className="h-4 w-4 text-destructive" />
                            )}
                            {pf.status === 'ignored' && (
                              <AlertTriangle className="h-4 w-4 text-yellow-500" />
                            )}
                            
                            {!isUploading && (
                              <Button
                                type="button"
                                variant="ghost"
                                size="sm"
                                onClick={() => removeFile(index)}
                              >
                                <X className="h-4 w-4" />
                              </Button>
                            )}
                          </div>
                        </div>
                      </div>
                    ))}
                  </div>
                </div>
              </div>
            )}
            
            <DialogFooter>
              <Button
                type="button"
                variant="outline"
                onClick={() => onOpenChange(false)}
                disabled={isUploading}
              >
                Cancel
              </Button>
              <Button
                type="submit"
                disabled={isUploading || validFileCount === 0 || !form.watch("projectId")}
              >
                {isUploading ? (
                  <>
                    <Loader2 className="mr-2 h-4 w-4 animate-spin" />
                    Uploading...
                  </>
                ) : (
                  <>
                    <Upload className="mr-2 h-4 w-4" />
                    Upload ({validFileCount} files)
                  </>
                )}
              </Button>
            </DialogFooter>
          </form>
        </Form>
      </DialogContent>
    </Dialog>
    </>
  )
}