// components/file-manager/SharedFileViewer.tsx
'use client';

import { useState, useEffect } from 'react';
import { 
  Download, 
  Eye, 
  EyeOff,
  FileText,
  Image,
  Film,
  Music,
  Archive,
  Code,
  File,
  Lock,
  AlertCircle,
  Calendar,
  Clock,
  User
} from 'lucide-react';
import { Card, CardContent, CardDescription, 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 { Alert, AlertDescription } from '@/components/ui/alert';
import { Badge } from '@/components/ui/badge';
import { Separator } from '@/components/ui/separator';
import { useToast } from '@/hooks/use-toast';
import { cn } from '@/lib/utils';

interface SharedFile {
  id: string;
  name: string;
  type: 'file' | 'folder';
  size: number;
  mimeType?: string;
  category: string;
  createdAt: string;
  updatedAt: string;
}

interface SharedFileViewerProps {
  token: string;
}

export function SharedFileViewer({ token }: SharedFileViewerProps) {
  const [file, setFile] = useState<SharedFile | null>(null);
  const [accessLevel, setAccessLevel] = useState<string>('');
  const [passwordRequired, setPasswordRequired] = useState(false);
  const [password, setPassword] = useState('');
  const [loading, setLoading] = useState(true);
  const [error, setError] = useState<string | null>(null);
  const [showContent, setShowContent] = useState(false);
  const [downloading, setDownloading] = useState(false);
  
  const { toast } = useToast();

  useEffect(() => {
    // 초기 접근 시도
    checkAccess();
  }, [token]);

  const checkAccess = async (pwd?: string) => {
    setLoading(true);
    setError(null);
    
    try {
      const params = new URLSearchParams();
      if (pwd) params.append('password', pwd);
      
      const response = await fetch(`/api/shared/${token}?${params}`);
      const data = await response.json();

      if (!response.ok) {
        if (data.error?.includes('비밀번호')) {
          setPasswordRequired(true);
          setError('비밀번호가 필요합니다');
        } else if (data.error?.includes('만료')) {
          setError('이 공유 링크는 만료되었습니다');
        } else if (data.error?.includes('최대 다운로드')) {
          setError('최대 다운로드 횟수를 초과했습니다');
        } else {
          setError(data.error || '파일에 접근할 수 없습니다');
        }
        return;
      }

      setFile(data.file);
      setAccessLevel(data.accessLevel);
      setShowContent(true);
      setPasswordRequired(false);
    } catch (err) {
      setError('파일을 불러오는 중 오류가 발생했습니다');
    } finally {
      setLoading(false);
    }
  };

  const handlePasswordSubmit = (e: React.FormEvent) => {
    e.preventDefault();
    checkAccess(password);
  };

  const handleDownload = async () => {
    if (!file || accessLevel !== 'view_download') return;
    
    setDownloading(true);
    try {
      const response = await fetch(`/api/shared/${token}/download`, {
        method: 'POST',
        headers: password ? { 'X-Share-Password': password } : {},
      });

      if (!response.ok) {
        throw new Error('다운로드 실패');
      }

      const blob = await response.blob();
      const url = window.URL.createObjectURL(blob);
      
      const a = document.createElement('a');
      a.href = url;
      a.download = file.name;
      document.body.appendChild(a);
      a.click();
      
      window.URL.revokeObjectURL(url);
      document.body.removeChild(a);
      
      toast({
        title: '다운로드 완료',
        description: `${file.name} 파일이 다운로드되었습니다.`,
      });
    } catch (error) {
      toast({
        title: '다운로드 실패',
        description: '파일 다운로드 중 오류가 발생했습니다.',
        variant: 'destructive',
      });
    } finally {
      setDownloading(false);
    }
  };

  const getFileIcon = (mimeType?: string, name?: string) => {
    if (!mimeType && name) {
      const ext = name.split('.').pop()?.toLowerCase();
      if (['jpg', 'jpeg', 'png', 'gif', 'webp'].includes(ext || '')) return Image;
      if (['mp4', 'avi', 'mov', 'wmv'].includes(ext || '')) return Film;
      if (['mp3', 'wav', 'flac'].includes(ext || '')) return Music;
      if (['zip', 'rar', '7z', 'tar'].includes(ext || '')) return Archive;
      if (['js', 'ts', 'py', 'java', 'cpp'].includes(ext || '')) return Code;
      if (['pdf', 'doc', 'docx', 'txt'].includes(ext || '')) return FileText;
    }
    
    if (mimeType?.startsWith('image/')) return Image;
    if (mimeType?.startsWith('video/')) return Film;
    if (mimeType?.startsWith('audio/')) return Music;
    if (mimeType?.includes('zip') || mimeType?.includes('compressed')) return Archive;
    if (mimeType?.includes('pdf')) return FileText;
    
    return File;
  };

  const formatFileSize = (bytes: number) => {
    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];
  };

  if (loading) {
    return (
      <div className="min-h-screen flex items-center justify-center">
        <div className="text-center">
          <div className="animate-spin rounded-full h-12 w-12 border-b-2 border-primary mx-auto mb-4" />
          <p className="text-muted-foreground">파일 정보를 불러오는 중...</p>
        </div>
      </div>
    );
  }

  if (error && !passwordRequired) {
    return (
      <div className="min-h-screen flex items-center justify-center p-4">
        <Card className="max-w-md w-full">
          <CardHeader>
            <div className="h-12 w-12 bg-red-100 rounded-full flex items-center justify-center mx-auto mb-4">
              <AlertCircle className="h-6 w-6 text-red-600" />
            </div>
            <CardTitle className="text-center">접근할 수 없습니다</CardTitle>
          </CardHeader>
          <CardContent>
            <Alert variant="destructive">
              <AlertDescription>{error}</AlertDescription>
            </Alert>
          </CardContent>
        </Card>
      </div>
    );
  }

  if (passwordRequired && !showContent) {
    return (
      <div className="min-h-screen flex items-center justify-center p-4">
        <Card className="max-w-md w-full">
          <CardHeader>
            <div className="h-12 w-12 bg-blue-100 rounded-full flex items-center justify-center mx-auto mb-4">
              <Lock className="h-6 w-6 text-blue-600" />
            </div>
            <CardTitle className="text-center">비밀번호 입력</CardTitle>
            <CardDescription className="text-center">
              이 파일은 비밀번호로 보호되어 있습니다
            </CardDescription>
          </CardHeader>
          <CardContent>
            <form onSubmit={handlePasswordSubmit} className="space-y-4">
              <div>
                <Label htmlFor="password">비밀번호</Label>
                <Input
                  id="password"
                  type="password"
                  value={password}
                  onChange={(e) => setPassword(e.target.value)}
                  placeholder="비밀번호를 입력하세요"
                  autoFocus
                />
              </div>
              {error && (
                <Alert variant="destructive">
                  <AlertDescription>{error}</AlertDescription>
                </Alert>
              )}
              <Button type="submit" className="w-full">
                <Lock className="h-4 w-4 mr-2" />
                확인
              </Button>
            </form>
          </CardContent>
        </Card>
      </div>
    );
  }

  if (!file) return null;

  const FileIcon = getFileIcon(file.mimeType, file.name);

  return (
    <div className="min-h-screen bg-gray-50">
      {/* 헤더 */}
      <div className="bg-white border-b">
        <div className="container mx-auto px-4 py-4">
          <div className="flex items-center gap-3">
            <div className="h-10 w-10 bg-blue-600 rounded-lg flex items-center justify-center">
              <span className="text-white font-bold">FM</span>
            </div>
            <div>
              <h1 className="text-lg font-semibold">공유된 파일</h1>
              <p className="text-sm text-muted-foreground">File Manager Shared</p>
            </div>
          </div>
        </div>
      </div>

      {/* 메인 컨텐츠 */}
      <div className="container mx-auto px-4 py-8 max-w-4xl">
        <Card>
          <CardHeader>
            <div className="flex items-start justify-between">
              <div className="flex items-start gap-4">
                <div className={cn(
                  "h-16 w-16 rounded-lg flex items-center justify-center",
                  "bg-gradient-to-br from-blue-50 to-blue-100"
                )}>
                  <FileIcon className="h-8 w-8 text-blue-600" />
                </div>
                <div>
                  <CardTitle className="text-2xl">{file.name}</CardTitle>
                  <CardDescription className="mt-1">
                    {file.type === 'folder' ? '폴더' : formatFileSize(file.size)}
                  </CardDescription>
                </div>
              </div>
              
              <div className="flex items-center gap-2">
                {accessLevel === 'view_only' && (
                  <Badge variant="secondary">
                    <Eye className="h-3 w-3 mr-1" />
                    보기 전용
                  </Badge>
                )}
                {accessLevel === 'view_download' && (
                  <Badge variant="default">
                    <Download className="h-3 w-3 mr-1" />
                    다운로드 가능
                  </Badge>
                )}
              </div>
            </div>
          </CardHeader>

          <CardContent>
            <div className="space-y-6">
              {/* 파일 정보 */}
              <div className="grid grid-cols-2 gap-4">
                <div className="space-y-3">
                  <div>
                    <p className="text-sm text-muted-foreground mb-1">파일 유형</p>
                    <p className="font-medium">{file.mimeType || '알 수 없음'}</p>
                  </div>
                  <div>
                    <p className="text-sm text-muted-foreground mb-1">생성일</p>
                    <p className="font-medium flex items-center gap-1">
                      <Calendar className="h-4 w-4" />
                      {new Date(file.createdAt).toLocaleDateString()}
                    </p>
                  </div>
                </div>
                
                <div className="space-y-3">
                  <div>
                    <p className="text-sm text-muted-foreground mb-1">카테고리</p>
                    <Badge variant="outline">{file.category}</Badge>
                  </div>
                  <div>
                    <p className="text-sm text-muted-foreground mb-1">수정일</p>
                    <p className="font-medium flex items-center gap-1">
                      <Clock className="h-4 w-4" />
                      {new Date(file.updatedAt).toLocaleDateString()}
                    </p>
                  </div>
                </div>
              </div>

              <Separator />

              {/* 미리보기 영역 (이미지인 경우) */}
              {file.mimeType?.startsWith('image/') && accessLevel !== 'download_only' && (
                <div className="bg-gray-50 rounded-lg p-4">
                  <p className="text-sm text-muted-foreground mb-3">미리보기</p>
                  <div className="bg-white rounded border p-4">
                    <img 
                      src={`/api/shared/${token}/preview`}
                      alt={file.name}
                      className="max-w-full h-auto rounded"
                    />
                  </div>
                </div>
              )}

              {/* 액션 버튼 */}
              <div className="flex gap-3">
                {accessLevel === 'view_download' && (
                  <Button 
                    onClick={handleDownload}
                    disabled={downloading}
                    className="flex-1"
                  >
                    {downloading ? (
                      <>
                        <div className="animate-spin rounded-full h-4 w-4 border-b-2 border-white mr-2" />
                        다운로드 중...
                      </>
                    ) : (
                      <>
                        <Download className="h-4 w-4 mr-2" />
                        파일 다운로드
                      </>
                    )}
                  </Button>
                )}
                
                {accessLevel === 'view_only' && (
                  <Alert className="flex-1">
                    <Eye className="h-4 w-4" />
                    <AlertDescription>
                      이 파일은 보기 전용입니다. 다운로드할 수 없습니다.
                    </AlertDescription>
                  </Alert>
                )}
              </div>

              {/* 보안 안내 */}
              <Alert>
                <Lock className="h-4 w-4" />
                <AlertDescription>
                  이 링크는 보안을 위해 제한된 시간 동안만 유효합니다.
                  필요한 경우 파일을 다운로드하여 보관하세요.
                </AlertDescription>
              </Alert>
            </div>
          </CardContent>
        </Card>

        {/* 하단 정보 */}
        <div className="mt-6 text-center text-sm text-muted-foreground">
          <p>© 2024 File Manager. All rights reserved.</p>
          <p className="mt-1">
            문제가 있으신가요?{' '}
            <a href="/support" className="text-primary hover:underline">
              고객 지원
            </a>
          </p>
        </div>
      </div>
    </div>
  );
}