'use client'

import { useState, useCallback } from 'react'
import { useTheme } from '@/lib/ThemeContext'
import { useWorksheet } from '@/lib/worksheet-editor/WorksheetContext'
import { UploadStep, PreviewStep, ResultStep } from './CleanupSteps'

interface CleanupPanelProps {
  isOpen: boolean
  onClose: () => void
}

interface CleanupCapabilities {
  opencv_available: boolean
  lama_available: boolean
  paddleocr_available: boolean
}

export interface PreviewResult {
  has_handwriting: boolean
  confidence: number
  handwriting_ratio: number
  image_width: number
  image_height: number
  estimated_times_ms: {
    detection: number
    inpainting: number
    reconstruction: number
    total: number
  }
  capabilities: {
    lama_available: boolean
  }
}

export interface PipelineResult {
  success: boolean
  handwriting_detected: boolean
  handwriting_removed: boolean
  layout_reconstructed: boolean
  cleaned_image_base64?: string
  fabric_json?: any
  metadata: any
}

export function CleanupPanel({ isOpen, onClose }: CleanupPanelProps) {
  const { isDark } = useTheme()
  const { canvas, saveToHistory } = useWorksheet()

  const [file, setFile] = useState<File | null>(null)
  const [previewUrl, setPreviewUrl] = useState<string | null>(null)
  const [cleanedUrl, setCleanedUrl] = useState<string | null>(null)
  const [maskUrl, setMaskUrl] = useState<string | null>(null)

  const [isPreviewing, setIsPreviewing] = useState(false)
  const [isProcessing, setIsProcessing] = useState(false)

  const [error, setError] = useState<string | null>(null)
  const [previewResult, setPreviewResult] = useState<PreviewResult | null>(null)
  const [pipelineResult, setPipelineResult] = useState<PipelineResult | null>(null)
  const [capabilities, setCapabilities] = useState<CleanupCapabilities | null>(null)

  // Options
  const [removeHandwriting, setRemoveHandwriting] = useState(true)
  const [reconstructLayout, setReconstructLayout] = useState(true)
  const [inpaintingMethod, setInpaintingMethod] = useState<string>('auto')

  // Step tracking
  const [currentStep, setCurrentStep] = useState<'upload' | 'preview' | 'result'>('upload')

  const getApiUrl = useCallback(() => {
    if (typeof window === 'undefined') return 'http://localhost:8086'
    const { hostname, protocol } = window.location
    return hostname === 'localhost' ? 'http://localhost:8086' : `${protocol}//${hostname}:8086`
  }, [])

  const loadCapabilities = useCallback(async () => {
    try {
      const response = await fetch(`${getApiUrl()}/api/v1/worksheet/capabilities`)
      if (response.ok) {
        const data = await response.json()
        setCapabilities(data)
      }
    } catch (err) {
      console.error('Failed to load capabilities:', err)
    }
  }, [getApiUrl])

  const handleFileSelect = useCallback((selectedFile: File) => {
    setFile(selectedFile)
    setError(null)
    setPreviewResult(null)
    setPipelineResult(null)
    setCleanedUrl(null)
    setMaskUrl(null)
    const url = URL.createObjectURL(selectedFile)
    setPreviewUrl(url)
    setCurrentStep('upload')
  }, [])

  const handleDrop = useCallback((e: React.DragEvent) => {
    e.preventDefault()
    const droppedFile = e.dataTransfer.files[0]
    if (droppedFile && droppedFile.type.startsWith('image/')) {
      handleFileSelect(droppedFile)
    }
  }, [handleFileSelect])

  const handlePreview = useCallback(async () => {
    if (!file) return
    setIsPreviewing(true)
    setError(null)
    try {
      const formData = new FormData()
      formData.append('image', file)
      const response = await fetch(`${getApiUrl()}/api/v1/worksheet/preview-cleanup`, { method: 'POST', body: formData })
      if (!response.ok) throw new Error(`HTTP ${response.status}`)
      const result = await response.json()
      setPreviewResult(result)
      setCurrentStep('preview')
      await loadCapabilities()
    } catch (err) {
      console.error('Preview failed:', err)
      setError(err instanceof Error ? err.message : 'Vorschau fehlgeschlagen')
    } finally {
      setIsPreviewing(false)
    }
  }, [file, getApiUrl, loadCapabilities])

  const handleCleanup = useCallback(async () => {
    if (!file) return
    setIsProcessing(true)
    setError(null)
    try {
      const formData = new FormData()
      formData.append('image', file)
      formData.append('remove_handwriting', String(removeHandwriting))
      formData.append('reconstruct', String(reconstructLayout))
      formData.append('inpainting_method', inpaintingMethod)
      const response = await fetch(`${getApiUrl()}/api/v1/worksheet/cleanup-pipeline`, { method: 'POST', body: formData })
      if (!response.ok) {
        const errorData = await response.json().catch(() => ({ detail: 'Unknown error' }))
        throw new Error(errorData.detail || `HTTP ${response.status}`)
      }
      const result: PipelineResult = await response.json()
      setPipelineResult(result)
      if (result.cleaned_image_base64) {
        const cleanedBlob = await fetch(`data:image/png;base64,${result.cleaned_image_base64}`).then(r => r.blob())
        setCleanedUrl(URL.createObjectURL(cleanedBlob))
      }
      setCurrentStep('result')
    } catch (err) {
      console.error('Cleanup failed:', err)
      setError(err instanceof Error ? err.message : 'Bereinigung fehlgeschlagen')
    } finally {
      setIsProcessing(false)
    }
  }, [file, removeHandwriting, reconstructLayout, inpaintingMethod, getApiUrl])

  const handleImportToCanvas = useCallback(async () => {
    if (!pipelineResult?.fabric_json || !canvas) return
    try {
      canvas.clear()
      canvas.loadFromJSON(pipelineResult.fabric_json, () => {
        canvas.renderAll()
        saveToHistory('Imported: Cleaned worksheet')
      })
      onClose()
    } catch (err) {
      console.error('Import failed:', err)
      setError('Import in Canvas fehlgeschlagen')
    }
  }, [pipelineResult, canvas, saveToHistory, onClose])

  const handleGetMask = useCallback(async () => {
    if (!file) return
    try {
      const formData = new FormData()
      formData.append('image', file)
      const response = await fetch(`${getApiUrl()}/api/v1/worksheet/detect-handwriting/mask`, { method: 'POST', body: formData })
      if (!response.ok) throw new Error(`HTTP ${response.status}`)
      const blob = await response.blob()
      setMaskUrl(URL.createObjectURL(blob))
    } catch (err) {
      console.error('Mask fetch failed:', err)
    }
  }, [file, getApiUrl])

  if (!isOpen) return null

  const overlayStyle = 'fixed inset-0 bg-black/50 backdrop-blur-sm z-50'
  const modalStyle = isDark
    ? 'backdrop-blur-xl bg-white/10 border border-white/20'
    : 'backdrop-blur-xl bg-white/90 border border-black/10 shadow-2xl'
  const labelStyle = isDark ? 'text-white/70' : 'text-slate-600'
  const cardStyle = isDark
    ? 'bg-white/5 border-white/10 hover:bg-white/10'
    : 'bg-white/50 border-slate-200 hover:bg-slate-50'

  const stepNames = ['upload', 'preview', 'result'] as const
  const stepIndex = stepNames.indexOf(currentStep)

  return (
    <div className={overlayStyle} onClick={onClose}>
      <div
        className={`fixed top-1/2 left-1/2 -translate-x-1/2 -translate-y-1/2 w-full max-w-4xl max-h-[90vh] rounded-3xl p-6 overflow-hidden flex flex-col ${modalStyle}`}
        onClick={(e) => e.stopPropagation()}
      >
        {/* Header */}
        <div className="flex items-center justify-between mb-6">
          <div className="flex items-center gap-3">
            <div className={`w-12 h-12 rounded-xl flex items-center justify-center ${isDark ? 'bg-orange-500/20' : 'bg-orange-100'}`}>
              <svg className={`w-7 h-7 ${isDark ? 'text-orange-300' : 'text-orange-600'}`} fill="none" stroke="currentColor" viewBox="0 0 24 24">
                <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={1.5} d="M19.428 15.428a2 2 0 00-1.022-.547l-2.387-.477a6 6 0 00-3.86.517l-.318.158a6 6 0 01-3.86.517L6.05 15.21a2 2 0 00-1.806.547M8 4h8l-1 1v5.172a2 2 0 00.586 1.414l5 5c1.26 1.26.367 3.414-1.415 3.414H4.828c-1.782 0-2.674-2.154-1.414-3.414l5-5A2 2 0 009 10.172V5L8 4z" />
              </svg>
            </div>
            <div>
              <h2 className={`text-xl font-semibold ${isDark ? 'text-white' : 'text-slate-900'}`}>
                Arbeitsblatt bereinigen
              </h2>
              <p className={`text-sm ${labelStyle}`}>Handschrift entfernen und Layout rekonstruieren</p>
            </div>
          </div>
          <button onClick={onClose} className={`p-2 rounded-xl transition-colors ${isDark ? 'hover:bg-white/10 text-white/70' : 'hover:bg-slate-100 text-slate-500'}`}>
            <svg className="w-6 h-6" 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>

        {/* Step Indicator */}
        <div className="flex items-center gap-2 mb-6">
          {stepNames.map((step, idx) => (
            <div key={step} className="flex items-center">
              <div className={`w-8 h-8 rounded-full flex items-center justify-center font-medium ${
                currentStep === step
                  ? isDark ? 'bg-purple-500 text-white' : 'bg-purple-600 text-white'
                  : idx < stepIndex
                    ? isDark ? 'bg-green-500 text-white' : 'bg-green-600 text-white'
                    : isDark ? 'bg-white/10 text-white/50' : 'bg-slate-200 text-slate-400'
              }`}>
                {idx < stepIndex ? '✓' : idx + 1}
              </div>
              {idx < 2 && (
                <div className={`w-12 h-0.5 ${idx < stepIndex ? isDark ? 'bg-green-500' : 'bg-green-600' : isDark ? 'bg-white/20' : 'bg-slate-200'}`} />
              )}
            </div>
          ))}
        </div>

        {/* Content */}
        <div className="flex-1 overflow-y-auto">
          {error && (
            <div className={`p-4 rounded-xl mb-4 ${isDark ? 'bg-red-500/20 text-red-300' : 'bg-red-50 text-red-700'}`}>
              {error}
            </div>
          )}

          {currentStep === 'upload' && (
            <UploadStep
              isDark={isDark} labelStyle={labelStyle} cardStyle={cardStyle}
              file={file} previewUrl={previewUrl}
              handleDrop={handleDrop} handleFileSelect={handleFileSelect}
              removeHandwriting={removeHandwriting} setRemoveHandwriting={setRemoveHandwriting}
              reconstructLayout={reconstructLayout} setReconstructLayout={setReconstructLayout}
              inpaintingMethod={inpaintingMethod} setInpaintingMethod={setInpaintingMethod}
              lamaAvailable={capabilities?.lama_available ?? false}
            />
          )}

          {currentStep === 'preview' && previewResult && (
            <PreviewStep
              isDark={isDark} labelStyle={labelStyle} cardStyle={cardStyle}
              previewResult={previewResult} previewUrl={previewUrl} maskUrl={maskUrl}
              removeHandwriting={removeHandwriting} reconstructLayout={reconstructLayout}
              handleGetMask={handleGetMask}
            />
          )}

          {currentStep === 'result' && pipelineResult && (
            <ResultStep
              isDark={isDark} labelStyle={labelStyle} cardStyle={cardStyle}
              pipelineResult={pipelineResult} previewUrl={previewUrl} cleanedUrl={cleanedUrl}
            />
          )}
        </div>

        {/* Footer */}
        <div className="mt-6 flex items-center justify-between">
          <div>
            {currentStep !== 'upload' && (
              <button
                onClick={() => setCurrentStep(currentStep === 'result' ? 'preview' : 'upload')}
                className={`px-4 py-2 rounded-xl font-medium transition-colors ${
                  isDark ? 'bg-white/10 text-white hover:bg-white/20' : 'bg-slate-100 text-slate-700 hover:bg-slate-200'
                }`}
              >
                ← Zurück
              </button>
            )}
          </div>

          <div className="flex items-center gap-3">
            <button onClick={onClose} className={`px-5 py-2.5 rounded-xl font-medium transition-colors ${
              isDark ? 'bg-white/10 text-white hover:bg-white/20' : 'bg-slate-100 text-slate-700 hover:bg-slate-200'
            }`}>
              Abbrechen
            </button>

            {currentStep === 'upload' && file && (
              <button onClick={handlePreview} disabled={isPreviewing} className={`px-5 py-2.5 rounded-xl font-medium transition-all flex items-center gap-2 ${
                isDark ? 'bg-purple-500/30 text-purple-300 hover:bg-purple-500/40' : 'bg-purple-600 text-white hover:bg-purple-700'
              } disabled:opacity-50`}>
                {isPreviewing ? (<><div className="w-4 h-4 border-2 border-current border-t-transparent rounded-full animate-spin" />Analysiere...</>) : 'Vorschau'}
              </button>
            )}

            {currentStep === 'preview' && (
              <button onClick={handleCleanup} disabled={isProcessing} className={`px-5 py-2.5 rounded-xl font-medium transition-all flex items-center gap-2 ${
                isDark ? 'bg-gradient-to-r from-orange-500 to-red-500 text-white hover:shadow-lg hover:shadow-orange-500/30' : 'bg-gradient-to-r from-orange-600 to-red-600 text-white hover:shadow-lg hover:shadow-orange-600/30'
              } disabled:opacity-50`}>
                {isProcessing ? (<><div className="w-4 h-4 border-2 border-white border-t-transparent rounded-full animate-spin" />Verarbeite...</>) : (
                  <><svg className="w-5 h-5" fill="none" stroke="currentColor" viewBox="0 0 24 24"><path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M19.428 15.428a2 2 0 00-1.022-.547l-2.387-.477a6 6 0 00-3.86.517l-.318.158a6 6 0 01-3.86.517L6.05 15.21a2 2 0 00-1.806.547M8 4h8l-1 1v5.172a2 2 0 00.586 1.414l5 5c1.26 1.26.367 3.414-1.415 3.414H4.828c-1.782 0-2.674-2.154-1.414-3.414l5-5A2 2 0 009 10.172V5L8 4z" /></svg>Bereinigen</>
                )}
              </button>
            )}

            {currentStep === 'result' && pipelineResult?.success && (
              <button onClick={handleImportToCanvas} className={`px-5 py-2.5 rounded-xl font-medium transition-all flex items-center gap-2 ${
                isDark ? 'bg-gradient-to-r from-green-500 to-emerald-500 text-white hover:shadow-lg hover:shadow-green-500/30' : 'bg-gradient-to-r from-green-600 to-emerald-600 text-white hover:shadow-lg hover:shadow-green-600/30'
              }`}>
                <svg className="w-5 h-5" fill="none" stroke="currentColor" viewBox="0 0 24 24">
                  <path strokeLinecap="round" strokeLinejoin="round" strokeWidth={2} d="M4 16v1a3 3 0 003 3h10a3 3 0 003-3v-1m-4-8l-4-4m0 0L8 8m4-4v12" />
                </svg>
                In Editor übernehmen
              </button>
            )}
          </div>
        </div>
      </div>
    </div>
  )
}
