'use client'

import { useState, useEffect, useCallback } from 'react'
import { useTheme } from '@/lib/ThemeContext'

interface UploadedFile {
  id: string
  sessionId: string
  name: string
  type: string
  size: number
  uploadedAt: string
  dataUrl: string
}

interface QRCodeUploadProps {
  sessionId?: string
  onClose?: () => void
  onFileUploaded?: (file: UploadedFile) => void
  onFilesChanged?: (files: UploadedFile[]) => void
  className?: string
}

export function QRCodeUpload({
  sessionId,
  onClose,
  onFileUploaded,
  onFilesChanged,
  className = ''
}: QRCodeUploadProps) {
  const { isDark } = useTheme()
  const [qrCodeUrl, setQrCodeUrl] = useState<string | null>(null)
  const [uploadUrl, setUploadUrl] = useState<string>('')
  const [isLoading, setIsLoading] = useState(true)
  const [uploadedFiles, setUploadedFiles] = useState<UploadedFile[]>([])
  const [isPolling, setIsPolling] = useState(false)

  // Format file size
  const formatFileSize = (bytes: number): string => {
    if (bytes === 0) return '0 B'
    const k = 1024
    const sizes = ['B', 'KB', 'MB', 'GB']
    const i = Math.floor(Math.log(bytes) / Math.log(k))
    return parseFloat((bytes / Math.pow(k, i)).toFixed(1)) + ' ' + sizes[i]
  }

  // Fetch uploads for this session
  const fetchUploads = useCallback(async () => {
    if (!sessionId) return

    try {
      const response = await fetch(`/api/uploads?sessionId=${sessionId}`)
      if (response.ok) {
        const data = await response.json()
        const newFiles = data.uploads || []

        // Check if there are new files
        if (newFiles.length > uploadedFiles.length) {
          const newlyAdded = newFiles.slice(uploadedFiles.length)
          newlyAdded.forEach((file: UploadedFile) => {
            if (onFileUploaded) {
              onFileUploaded(file)
            }
          })
        }

        setUploadedFiles(newFiles)

        if (onFilesChanged) {
          onFilesChanged(newFiles)
        }
      }
    } catch (error) {
      console.error('Failed to fetch uploads:', error)
    }
  }, [sessionId, uploadedFiles.length, onFileUploaded, onFilesChanged])

  // Initialize QR code and start polling
  useEffect(() => {
    // Generate Upload-URL
    let baseUrl = typeof window !== 'undefined' ? window.location.origin : ''

    // Hostname to IP mapping for local network
    const hostnameToIP: Record<string, string> = {
      'macmini': '192.168.178.100',
      'macmini.local': '192.168.178.100',
    }

    // Replace known hostnames with IP addresses
    Object.entries(hostnameToIP).forEach(([hostname, ip]) => {
      if (baseUrl.includes(hostname)) {
        baseUrl = baseUrl.replace(hostname, ip)
      }
    })

    const uploadPath = `/upload/${sessionId || 'new'}`
    const fullUrl = `${baseUrl}${uploadPath}`
    setUploadUrl(fullUrl)

    // Generate QR code via external API
    const qrApiUrl = `https://api.qrserver.com/v1/create-qr-code/?size=300x300&data=${encodeURIComponent(fullUrl)}`
    setQrCodeUrl(qrApiUrl)
    setIsLoading(false)

    // Initial fetch
    fetchUploads()

    // Start polling for new uploads every 3 seconds
    setIsPolling(true)
    const pollInterval = setInterval(() => {
      fetchUploads()
    }, 3000)

    return () => {
      clearInterval(pollInterval)
      setIsPolling(false)
    }
  }, [sessionId]) // Note: fetchUploads is intentionally not in deps to avoid re-creating interval

  // Separate effect for fetching when uploadedFiles changes
  useEffect(() => {
    // This is just for the callback effect, actual polling is in the other useEffect
  }, [uploadedFiles, onFilesChanged])

  const copyToClipboard = async () => {
    try {
      await navigator.clipboard.writeText(uploadUrl)
      alert('Link kopiert!')
    } catch (err) {
      console.error('Kopieren fehlgeschlagen:', err)
    }
  }

  const deleteUpload = async (id: string) => {
    try {
      const response = await fetch(`/api/uploads?id=${id}`, { method: 'DELETE' })
      if (response.ok) {
        const newFiles = uploadedFiles.filter(f => f.id !== id)
        setUploadedFiles(newFiles)
        if (onFilesChanged) {
          onFilesChanged(newFiles)
        }
      }
    } catch (error) {
      console.error('Failed to delete upload:', error)
    }
  }

  return (
    <div className={`${className}`}>
      <div className={`rounded-3xl border p-6 ${
        isDark ? 'bg-white/10 border-white/20' : 'bg-white border-slate-200 shadow-lg'
      }`}>
        {/* Header */}
        <div className="flex items-center justify-between mb-6">
          <div className="flex items-center gap-3">
            <div className={`w-10 h-10 rounded-xl flex items-center justify-center ${
              isDark ? 'bg-purple-500/20' : 'bg-purple-100'
            }`}>
              <span className="text-xl">📱</span>
            </div>
            <div>
              <h3 className={`font-semibold ${isDark ? 'text-white' : 'text-slate-900'}`}>
                Mit Mobiltelefon hochladen
              </h3>
              <p className={`text-sm ${isDark ? 'text-white/50' : 'text-slate-500'}`}>
                QR-Code scannen oder Link teilen
              </p>
            </div>
          </div>
          {onClose && (
            <button
              onClick={onClose}
              className={`p-2 rounded-lg transition-colors ${
                isDark ? 'hover:bg-white/10 text-white/60' : 'hover:bg-slate-100 text-slate-400'
              }`}
            >
              <svg className="w-5 h-5" fill="none" stroke="currentColor" viewBox="0 0 24 24">
                <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M6 18L18 6M6 6l12 12" />
              </svg>
            </button>
          )}
        </div>

        {/* QR Code */}
        <div className="flex flex-col items-center">
          <div className={`p-4 rounded-2xl ${isDark ? 'bg-white' : 'bg-slate-50'}`}>
            {isLoading ? (
              <div className="w-[200px] h-[200px] flex items-center justify-center">
                <div className="w-8 h-8 border-2 border-purple-500 border-t-transparent rounded-full animate-spin" />
              </div>
            ) : qrCodeUrl ? (
              <img
                src={qrCodeUrl}
                alt="QR Code zum Hochladen"
                className="w-[200px] h-[200px]"
              />
            ) : (
              <div className="w-[200px] h-[200px] flex items-center justify-center text-slate-400">
                QR-Code nicht verfuegbar
              </div>
            )}
          </div>

          <p className={`mt-4 text-center text-sm ${isDark ? 'text-white/60' : 'text-slate-600'}`}>
            Scannen Sie diesen Code mit Ihrem Handy,<br />
            um Dokumente direkt hochzuladen.
          </p>

          {/* Polling indicator */}
          {isPolling && (
            <div className={`mt-2 flex items-center gap-2 text-xs ${isDark ? 'text-white/40' : 'text-slate-400'}`}>
              <div className="w-2 h-2 bg-green-500 rounded-full animate-pulse" />
              Warte auf Uploads...
            </div>
          )}
        </div>

        {/* Uploaded Files List */}
        {uploadedFiles.length > 0 && (
          <div className={`mt-6 p-4 rounded-xl ${
            isDark ? 'bg-green-500/10 border border-green-500/20' : 'bg-green-50 border border-green-200'
          }`}>
            <div className="flex items-center justify-between mb-3">
              <p className={`text-sm font-medium ${isDark ? 'text-green-300' : 'text-green-700'}`}>
                {uploadedFiles.length} Datei{uploadedFiles.length !== 1 ? 'en' : ''} empfangen
              </p>
            </div>
            <div className="space-y-2 max-h-40 overflow-y-auto">
              {uploadedFiles.map((file) => (
                <div
                  key={file.id}
                  className={`flex items-center gap-3 p-2 rounded-lg ${
                    isDark ? 'bg-white/5' : 'bg-white'
                  }`}
                >
                  <span className="text-lg">
                    {file.type.startsWith('image/') ? '🖼️' : '📄'}
                  </span>
                  <div className="flex-1 min-w-0">
                    <p className={`text-sm font-medium truncate ${isDark ? 'text-white' : 'text-slate-900'}`}>
                      {file.name}
                    </p>
                    <p className={`text-xs ${isDark ? 'text-white/50' : 'text-slate-500'}`}>
                      {formatFileSize(file.size)}
                    </p>
                  </div>
                  <button
                    onClick={() => deleteUpload(file.id)}
                    className={`p-1 rounded transition-colors ${
                      isDark ? 'hover:bg-red-500/20 text-red-400' : 'hover:bg-red-100 text-red-500'
                    }`}
                  >
                    <svg className="w-4 h-4" fill="none" stroke="currentColor" viewBox="0 0 24 24">
                      <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M19 7l-.867 12.142A2 2 0 0116.138 21H7.862a2 2 0 01-1.995-1.858L5 7m5 4v6m4-6v6m1-10V4a1 1 0 00-1-1h-4a1 1 0 00-1 1v3M4 7h16" />
                    </svg>
                  </button>
                </div>
              ))}
            </div>
          </div>
        )}

        {/* Link teilen */}
        <div className="mt-6">
          <p className={`text-xs mb-2 ${isDark ? 'text-white/40' : 'text-slate-400'}`}>
            Oder Link teilen:
          </p>
          <div className="flex items-center gap-2">
            <input
              type="text"
              value={uploadUrl}
              readOnly
              className={`flex-1 px-3 py-2 rounded-xl text-sm border ${
                isDark
                  ? 'bg-white/5 border-white/10 text-white/80'
                  : 'bg-slate-50 border-slate-200 text-slate-700'
              }`}
            />
            <button
              onClick={copyToClipboard}
              className={`px-4 py-2 rounded-xl text-sm font-medium transition-colors ${
                isDark
                  ? 'bg-white/10 text-white hover:bg-white/20'
                  : 'bg-slate-200 text-slate-700 hover:bg-slate-300'
              }`}
            >
              Kopieren
            </button>
          </div>
        </div>

        {/* Network hint - only show if no files uploaded yet */}
        {uploadedFiles.length === 0 && (
          <div className={`mt-6 p-4 rounded-xl ${
            isDark ? 'bg-amber-500/10 border border-amber-500/20' : 'bg-amber-50 border border-amber-200'
          }`}>
            <div className="flex items-start gap-3">
              <span className="text-lg">⚠️</span>
              <div>
                <p className={`text-sm font-medium ${isDark ? 'text-amber-300' : 'text-amber-900'}`}>
                  Nur im lokalen Netzwerk
                </p>
                <p className={`text-xs mt-1 ${isDark ? 'text-amber-300/70' : 'text-amber-700'}`}>
                  Ihr Mobiltelefon muss mit dem gleichen Netzwerk verbunden sein.
                </p>
              </div>
            </div>
          </div>
        )}

        {/* Tip */}
        <div className={`mt-4 p-4 rounded-xl ${
          isDark ? 'bg-blue-500/10 border border-blue-500/20' : 'bg-blue-50 border border-blue-200'
        }`}>
          <div className="flex items-start gap-3">
            <span className="text-lg">💡</span>
            <div>
              <p className={`text-sm font-medium ${isDark ? 'text-blue-300' : 'text-blue-900'}`}>
                Tipp: Mehrere Seiten scannen
              </p>
              <p className={`text-xs mt-1 ${isDark ? 'text-blue-300/70' : 'text-blue-700'}`}>
                Sie koennen beliebig viele Fotos hochladen.
              </p>
            </div>
          </div>
        </div>
      </div>
    </div>
  )
}

// Export the UploadedFile type for use in other components
export type { UploadedFile }