breakpilot-lehrer/admin-lehrer/components/ocr-pipeline/StepStructureDetection.tsx

'use client'

import { useCallback, useEffect, useRef, useState } from 'react'
import type { ExcludeRegion, StructureResult } from '@/app/(admin)/ai/ocr-pipeline/types'

const KLAUSUR_API = '/klausur-api'

interface StepStructureDetectionProps {
  sessionId: string | null
  onNext: () => void
}

const COLOR_HEX: Record<string, string> = {
  red: '#dc2626',
  orange: '#ea580c',
  yellow: '#ca8a04',
  green: '#16a34a',
  blue: '#2563eb',
  purple: '#9333ea',
}

/**
 * Convert a mouse event on the image container to image-pixel coordinates.
 * The image uses object-contain inside an A4-ratio container, so we need
 * to account for letterboxing.
 */
function mouseToImageCoords(
  e: React.MouseEvent,
  containerEl: HTMLElement,
  imgWidth: number,
  imgHeight: number,
): { x: number; y: number } | null {
  const rect = containerEl.getBoundingClientRect()
  const containerW = rect.width
  const containerH = rect.height

  // object-contain: image is scaled to fit, centered
  const scaleX = containerW / imgWidth
  const scaleY = containerH / imgHeight
  const scale = Math.min(scaleX, scaleY)

  const renderedW = imgWidth * scale
  const renderedH = imgHeight * scale
  const offsetX = (containerW - renderedW) / 2
  const offsetY = (containerH - renderedH) / 2

  const relX = e.clientX - rect.left - offsetX
  const relY = e.clientY - rect.top - offsetY

  if (relX < 0 || relY < 0 || relX > renderedW || relY > renderedH) {
    return null
  }

  return {
    x: Math.round(relX / scale),
    y: Math.round(relY / scale),
  }
}

/**
 * Convert image-pixel coordinates to container-relative percentages
 * for overlay positioning.
 */
function imageToOverlayPct(
  region: { x: number; y: number; w: number; h: number },
  containerW: number,
  containerH: number,
  imgWidth: number,
  imgHeight: number,
): { left: string; top: string; width: string; height: string } {
  const scaleX = containerW / imgWidth
  const scaleY = containerH / imgHeight
  const scale = Math.min(scaleX, scaleY)

  const renderedW = imgWidth * scale
  const renderedH = imgHeight * scale
  const offsetX = (containerW - renderedW) / 2
  const offsetY = (containerH - renderedH) / 2

  const left = offsetX + region.x * scale
  const top = offsetY + region.y * scale
  const width = region.w * scale
  const height = region.h * scale

  return {
    left: `${(left / containerW) * 100}%`,
    top: `${(top / containerH) * 100}%`,
    width: `${(width / containerW) * 100}%`,
    height: `${(height / containerH) * 100}%`,
  }
}

export function StepStructureDetection({ sessionId, onNext }: StepStructureDetectionProps) {
  const [result, setResult] = useState<StructureResult | null>(null)
  const [detecting, setDetecting] = useState(false)
  const [error, setError] = useState<string | null>(null)
  const [hasRun, setHasRun] = useState(false)
  const [overlayTs, setOverlayTs] = useState(0)

  // Exclude region drawing state
  const [excludeRegions, setExcludeRegions] = useState<ExcludeRegion[]>([])
  const [drawing, setDrawing] = useState(false)
  const [drawStart, setDrawStart] = useState<{ x: number; y: number } | null>(null)
  const [drawCurrent, setDrawCurrent] = useState<{ x: number; y: number } | null>(null)
  const [saving, setSaving] = useState(false)
  const [drawMode, setDrawMode] = useState(false)

  const containerRef = useRef<HTMLDivElement>(null)
  const [containerSize, setContainerSize] = useState({ w: 0, h: 0 })

  // Track container size for overlay positioning
  useEffect(() => {
    const el = containerRef.current
    if (!el) return
    const obs = new ResizeObserver((entries) => {
      for (const entry of entries) {
        setContainerSize({ w: entry.contentRect.width, h: entry.contentRect.height })
      }
    })
    obs.observe(el)
    return () => obs.disconnect()
  }, [])

  // Auto-trigger detection on mount
  useEffect(() => {
    if (!sessionId || hasRun) return
    setHasRun(true)

    const runDetection = async () => {
      setDetecting(true)
      setError(null)

      try {
        const res = await fetch(`${KLAUSUR_API}/api/v1/ocr-pipeline/sessions/${sessionId}/detect-structure`, {
          method: 'POST',
        })

        if (!res.ok) {
          throw new Error('Strukturerkennung fehlgeschlagen')
        }

        const data = await res.json()
        setResult(data)
        setExcludeRegions(data.exclude_regions || [])
        setOverlayTs(Date.now())
      } catch (e) {
        setError(e instanceof Error ? e.message : 'Unbekannter Fehler')
      } finally {
        setDetecting(false)
      }
    }

    runDetection()
  }, [sessionId, hasRun])

  const handleRerun = async () => {
    if (!sessionId) return
    setDetecting(true)
    setError(null)
    try {
      const res = await fetch(`${KLAUSUR_API}/api/v1/ocr-pipeline/sessions/${sessionId}/detect-structure`, {
        method: 'POST',
      })
      if (!res.ok) throw new Error('Erneute Erkennung fehlgeschlagen')
      const data = await res.json()
      setResult(data)
      setExcludeRegions(data.exclude_regions || [])
      setOverlayTs(Date.now())
    } catch (e) {
      setError(e instanceof Error ? e.message : 'Unbekannter Fehler')
    } finally {
      setDetecting(false)
    }
  }

  // Save exclude regions to backend
  const saveExcludeRegions = useCallback(async (regions: ExcludeRegion[]) => {
    if (!sessionId) return
    setSaving(true)
    try {
      const res = await fetch(`${KLAUSUR_API}/api/v1/ocr-pipeline/sessions/${sessionId}/exclude-regions`, {
        method: 'PUT',
        headers: { 'Content-Type': 'application/json' },
        body: JSON.stringify({ regions }),
      })
      if (!res.ok) throw new Error('Speichern fehlgeschlagen')
    } catch (e) {
      setError(e instanceof Error ? e.message : 'Speichern fehlgeschlagen')
    } finally {
      setSaving(false)
    }
  }, [sessionId])

  // Mouse handlers for drawing exclude rectangles
  const handleMouseDown = useCallback((e: React.MouseEvent) => {
    if (!drawMode || !containerRef.current || !result) return
    const coords = mouseToImageCoords(e, containerRef.current, result.image_width, result.image_height)
    if (coords) {
      setDrawing(true)
      setDrawStart(coords)
      setDrawCurrent(coords)
    }
  }, [drawMode, result])

  const handleMouseMove = useCallback((e: React.MouseEvent) => {
    if (!drawing || !containerRef.current || !result) return
    const coords = mouseToImageCoords(e, containerRef.current, result.image_width, result.image_height)
    if (coords) {
      setDrawCurrent(coords)
    }
  }, [drawing, result])

  const handleMouseUp = useCallback(() => {
    if (!drawing || !drawStart || !drawCurrent) {
      setDrawing(false)
      return
    }

    const x = Math.min(drawStart.x, drawCurrent.x)
    const y = Math.min(drawStart.y, drawCurrent.y)
    const w = Math.abs(drawCurrent.x - drawStart.x)
    const h = Math.abs(drawCurrent.y - drawStart.y)

    // Minimum size to avoid accidental clicks
    if (w > 10 && h > 10) {
      const newRegion: ExcludeRegion = { x, y, w, h, label: `Bereich ${excludeRegions.length + 1}` }
      const updated = [...excludeRegions, newRegion]
      setExcludeRegions(updated)
      saveExcludeRegions(updated)
    }

    setDrawing(false)
    setDrawStart(null)
    setDrawCurrent(null)
  }, [drawing, drawStart, drawCurrent, excludeRegions, saveExcludeRegions])

  const handleDeleteRegion = useCallback(async (index: number) => {
    if (!sessionId) return
    setSaving(true)
    try {
      const res = await fetch(`${KLAUSUR_API}/api/v1/ocr-pipeline/sessions/${sessionId}/exclude-regions/${index}`, {
        method: 'DELETE',
      })
      if (!res.ok) throw new Error('Loeschen fehlgeschlagen')
      const updated = excludeRegions.filter((_, i) => i !== index)
      setExcludeRegions(updated)
    } catch (e) {
      setError(e instanceof Error ? e.message : 'Loeschen fehlgeschlagen')
    } finally {
      setSaving(false)
    }
  }, [sessionId, excludeRegions])

  if (!sessionId) {
    return <div className="text-sm text-gray-400">Keine Session ausgewaehlt.</div>
  }

  const croppedUrl = `${KLAUSUR_API}/api/v1/ocr-pipeline/sessions/${sessionId}/image/cropped`
  const overlayUrl = `${KLAUSUR_API}/api/v1/ocr-pipeline/sessions/${sessionId}/image/structure-overlay${overlayTs ? `?t=${overlayTs}` : ''}`

  // Current drag rectangle in image coords
  const dragRect = drawing && drawStart && drawCurrent
    ? {
        x: Math.min(drawStart.x, drawCurrent.x),
        y: Math.min(drawStart.y, drawCurrent.y),
        w: Math.abs(drawCurrent.x - drawStart.x),
        h: Math.abs(drawCurrent.y - drawStart.y),
      }
    : null

  return (
    <div className="space-y-4">
      {/* Loading indicator */}
      {detecting && (
        <div className="flex items-center gap-2 text-teal-600 dark:text-teal-400 text-sm">
          <div className="animate-spin w-4 h-4 border-2 border-teal-500 border-t-transparent rounded-full" />
          Dokumentstruktur wird analysiert...
        </div>
      )}

      {/* Draw mode toggle */}
      {result && (
        <div className="flex items-center gap-3">
          <button
            onClick={() => setDrawMode(!drawMode)}
            className={`px-4 py-2 text-sm rounded-lg font-medium transition-colors ${
              drawMode
                ? 'bg-red-600 text-white hover:bg-red-700'
                : 'bg-gray-100 dark:bg-gray-700 text-gray-700 dark:text-gray-300 hover:bg-gray-200 dark:hover:bg-gray-600'
            }`}
          >
            {drawMode ? 'Zeichnen beenden' : 'Ausschlussbereich zeichnen'}
          </button>
          {drawMode && (
            <span className="text-xs text-red-600 dark:text-red-400">
              Rechteck auf dem Bild zeichnen um Bereiche von der OCR-Erkennung auszuschliessen
            </span>
          )}
          {saving && (
            <span className="text-xs text-gray-400">Speichern...</span>
          )}
        </div>
      )}

      {/* Two-column image comparison */}
      <div className="grid grid-cols-1 lg:grid-cols-2 gap-4">
        {/* Left: Original document with exclude region drawing */}
        <div className="space-y-2">
          <div className="text-xs font-medium text-gray-500 dark:text-gray-400 uppercase tracking-wider">
            Original {excludeRegions.length > 0 && `(${excludeRegions.length} Ausschlussbereich${excludeRegions.length !== 1 ? 'e' : ''})`}
          </div>
          <div
            ref={containerRef}
            className={`relative bg-gray-100 dark:bg-gray-800 rounded-lg overflow-hidden ${
              drawMode ? 'cursor-crosshair' : ''
            }`}
            style={{ aspectRatio: '210/297' }}
            onMouseDown={handleMouseDown}
            onMouseMove={handleMouseMove}
            onMouseUp={handleMouseUp}
            onMouseLeave={() => {
              if (drawing) {
                handleMouseUp()
              }
            }}
          >
            {/* eslint-disable-next-line @next/next/no-img-element */}
            <img
              src={croppedUrl}
              alt="Originaldokument"
              className="w-full h-full object-contain pointer-events-none"
              draggable={false}
              onError={(e) => {
                (e.target as HTMLImageElement).style.display = 'none'
              }}
            />

            {/* Saved exclude regions overlay */}
            {result && containerSize.w > 0 && excludeRegions.map((region, i) => {
              const pos = imageToOverlayPct(region, containerSize.w, containerSize.h, result.image_width, result.image_height)
              return (
                <div
                  key={i}
                  className="absolute border-2 border-red-500 bg-red-500/20 group"
                  style={pos}
                >
                  <div className="absolute -top-5 left-0 flex items-center gap-1 opacity-0 group-hover:opacity-100 transition-opacity">
                    <span className="text-[10px] bg-red-600 text-white px-1 rounded whitespace-nowrap">
                      {region.label || `Bereich ${i + 1}`}
                    </span>
                    <button
                      onClick={(e) => { e.stopPropagation(); handleDeleteRegion(i) }}
                      className="w-4 h-4 bg-red-600 text-white rounded-full text-[10px] flex items-center justify-center hover:bg-red-700"
                    >
                      x
                    </button>
                  </div>
                </div>
              )
            })}

            {/* Current drag rectangle */}
            {dragRect && result && containerSize.w > 0 && (() => {
              const pos = imageToOverlayPct(dragRect, containerSize.w, containerSize.h, result.image_width, result.image_height)
              return (
                <div
                  className="absolute border-2 border-red-500 border-dashed bg-red-500/15"
                  style={pos}
                />
              )
            })()}
          </div>
        </div>

        {/* Right: Structure overlay */}
        <div className="space-y-2">
          <div className="text-xs font-medium text-gray-500 dark:text-gray-400 uppercase tracking-wider">
            Erkannte Struktur
          </div>
          <div className="relative bg-gray-100 dark:bg-gray-800 rounded-lg overflow-hidden" style={{ aspectRatio: '210/297' }}>
            {/* eslint-disable-next-line @next/next/no-img-element */}
            <img
              src={overlayUrl}
              alt="Strukturerkennung"
              className="w-full h-full object-contain"
              onError={(e) => {
                (e.target as HTMLImageElement).style.display = 'none'
              }}
            />
          </div>
        </div>
      </div>

      {/* Exclude regions list */}
      {excludeRegions.length > 0 && (
        <div className="bg-red-50 dark:bg-red-900/10 rounded-lg border border-red-200 dark:border-red-800 p-3">
          <h4 className="text-xs font-medium text-red-700 dark:text-red-400 mb-2">
            Ausschlussbereiche ({excludeRegions.length}) — Woerter in diesen Bereichen werden nicht erkannt
          </h4>
          <div className="space-y-1">
            {excludeRegions.map((region, i) => (
              <div key={i} className="flex items-center gap-3 text-xs">
                <span className="w-3 h-3 rounded-sm flex-shrink-0 bg-red-500/30 border border-red-500" />
                <span className="text-red-700 dark:text-red-400 font-medium">
                  {region.label || `Bereich ${i + 1}`}
                </span>
                <span className="font-mono text-red-600/70 dark:text-red-400/70">
                  {region.w}x{region.h}px @ ({region.x}, {region.y})
                </span>
                <button
                  onClick={() => handleDeleteRegion(i)}
                  className="ml-auto text-red-500 hover:text-red-700 dark:hover:text-red-300"
                >
                  Entfernen
                </button>
              </div>
            ))}
          </div>
        </div>
      )}

      {/* Result info */}
      {result && (
        <div className="bg-white dark:bg-gray-800 rounded-lg border border-gray-200 dark:border-gray-700 p-4 space-y-3">
          {/* Summary badges */}
          <div className="flex flex-wrap items-center gap-3 text-sm">
            <span className="inline-flex items-center gap-1.5 px-3 py-1 rounded-full bg-teal-50 dark:bg-teal-900/20 text-teal-700 dark:text-teal-400 text-xs font-medium">
              {result.zones.length} Zone(n)
            </span>
            <span className="inline-flex items-center gap-1.5 px-3 py-1 rounded-full bg-amber-50 dark:bg-amber-900/20 text-amber-700 dark:text-amber-400 text-xs font-medium">
              {result.boxes.length} Box(en)
            </span>
            {result.graphics && result.graphics.length > 0 && (
              <span className="inline-flex items-center gap-1.5 px-3 py-1 rounded-full bg-purple-50 dark:bg-purple-900/20 text-purple-700 dark:text-purple-400 text-xs font-medium">
                {result.graphics.length} Grafik(en)
              </span>
            )}
            {result.has_words && (
              <span className="inline-flex items-center gap-1.5 px-3 py-1 rounded-full bg-blue-50 dark:bg-blue-900/20 text-blue-700 dark:text-blue-400 text-xs font-medium">
                {result.word_count} Woerter
              </span>
            )}
            {excludeRegions.length > 0 && (
              <span className="inline-flex items-center gap-1.5 px-3 py-1 rounded-full bg-red-50 dark:bg-red-900/20 text-red-700 dark:text-red-400 text-xs font-medium">
                {excludeRegions.length} Ausschluss
              </span>
            )}
            {(result.border_ghosts_removed ?? 0) > 0 && (
              <span className="inline-flex items-center gap-1.5 px-3 py-1 rounded-full bg-red-50 dark:bg-red-900/20 text-red-700 dark:text-red-400 text-xs font-medium">
                {result.border_ghosts_removed} Rahmenlinien entfernt
              </span>
            )}
            <span className="text-gray-400 text-xs ml-auto">
              {result.image_width}x{result.image_height}px | {result.duration_seconds}s
            </span>
          </div>

          {/* Boxes detail */}
          {result.boxes.length > 0 && (
            <div>
              <h4 className="text-xs font-medium text-gray-500 dark:text-gray-400 mb-2">Erkannte Boxen</h4>
              <div className="space-y-1.5">
                {result.boxes.map((box, i) => (
                  <div key={i} className="flex items-center gap-3 text-xs">
                    <span
                      className="w-3 h-3 rounded-sm flex-shrink-0 border border-gray-300 dark:border-gray-600"
                      style={{ backgroundColor: box.bg_color_hex || '#6b7280' }}
                    />
                    <span className="text-gray-600 dark:text-gray-400">
                      Box {i + 1}:
                    </span>
                    <span className="font-mono text-gray-500">
                      {box.w}x{box.h}px @ ({box.x}, {box.y})
                    </span>
                    {box.bg_color_name && box.bg_color_name !== 'unknown' && box.bg_color_name !== 'white' && (
                      <span className="px-1.5 py-0.5 rounded bg-gray-100 dark:bg-gray-700 text-gray-500">
                        {box.bg_color_name}
                      </span>
                    )}
                    {box.border_thickness > 0 && (
                      <span className="text-gray-400">
                        Rahmen: {box.border_thickness}px
                      </span>
                    )}
                    <span className="text-gray-400">
                      {Math.round(box.confidence * 100)}%
                    </span>
                  </div>
                ))}
              </div>
            </div>
          )}

          {/* Zones detail */}
          <div>
            <h4 className="text-xs font-medium text-gray-500 dark:text-gray-400 mb-2">Seitenzonen</h4>
            <div className="flex flex-wrap gap-2">
              {result.zones.map((zone) => (
                <span
                  key={zone.index}
                  className={`inline-flex items-center gap-1 px-2 py-1 rounded text-[11px] font-medium ${
                    zone.zone_type === 'box'
                      ? 'bg-amber-50 dark:bg-amber-900/20 text-amber-700 dark:text-amber-300 border border-amber-200 dark:border-amber-800'
                      : 'bg-gray-50 dark:bg-gray-800 text-gray-500 dark:text-gray-400 border border-gray-200 dark:border-gray-700'
                  }`}
                >
                  {zone.zone_type === 'box' ? 'Box' : 'Inhalt'} {zone.index}
                  <span className="text-[10px] font-normal opacity-70">
                    ({zone.w}x{zone.h})
                  </span>
                </span>
              ))}
            </div>
          </div>

          {/* Graphics / visual elements */}
          {result.graphics && result.graphics.length > 0 && (
            <div>
              <h4 className="text-xs font-medium text-gray-500 dark:text-gray-400 mb-2">
                Graphische Elemente ({result.graphics.length})
              </h4>
              {/* Summary by shape */}
              {(() => {
                const shapeCounts: Record<string, number> = {}
                for (const g of result.graphics) {
                  shapeCounts[g.shape] = (shapeCounts[g.shape] || 0) + 1
                }
                return (
                  <div className="flex flex-wrap gap-2 mb-2">
                    {Object.entries(shapeCounts)
                      .sort(([, a], [, b]) => b - a)
                      .map(([shape, count]) => (
                        <span
                          key={shape}
                          className="inline-flex items-center gap-1 px-2 py-1 rounded text-[11px] bg-purple-50 dark:bg-purple-900/20 text-purple-700 dark:text-purple-300 border border-purple-200 dark:border-purple-800"
                        >
                          {shape === 'arrow' ? '→' : shape === 'circle' ? '●' : shape === 'line' ? '─' : shape === 'exclamation' ? '❗' : shape === 'dot' ? '•' : shape === 'illustration' ? '🖼' : '◆'}
                          {' '}{shape} <span className="font-semibold">x{count}</span>
                        </span>
                      ))}
                  </div>
                )
              })()}
              {/* Individual graphics list */}
              <div className="space-y-1.5 max-h-40 overflow-y-auto">
                {result.graphics.map((g, i) => (
                  <div key={i} className="flex items-center gap-3 text-xs">
                    <span
                      className="w-3 h-3 rounded-full flex-shrink-0 border border-gray-300 dark:border-gray-600"
                      style={{ backgroundColor: g.color_hex || '#6b7280' }}
                    />
                    <span className="text-gray-600 dark:text-gray-400 font-medium min-w-[60px]">
                      {g.shape}
                    </span>
                    <span className="font-mono text-gray-500">
                      {g.w}x{g.h}px @ ({g.x}, {g.y})
                    </span>
                    <span className="text-gray-400">
                      {g.color_name}
                    </span>
                    <span className="text-gray-400">
                      {Math.round(g.confidence * 100)}%
                    </span>
                  </div>
                ))}
              </div>
            </div>
          )}

          {/* Color regions */}
          {Object.keys(result.color_pixel_counts).length > 0 && (
            <div>
              <h4 className="text-xs font-medium text-gray-500 dark:text-gray-400 mb-2">Erkannte Farben</h4>
              <div className="flex flex-wrap gap-2">
                {Object.entries(result.color_pixel_counts)
                  .sort(([, a], [, b]) => b - a)
                  .map(([name, count]) => (
                    <span key={name} className="inline-flex items-center gap-1.5 px-2 py-1 rounded text-[11px] bg-gray-50 dark:bg-gray-800 border border-gray-200 dark:border-gray-700">
                      <span
                        className="w-2.5 h-2.5 rounded-full"
                        style={{ backgroundColor: COLOR_HEX[name] || '#6b7280' }}
                      />
                      <span className="text-gray-600 dark:text-gray-400">{name}</span>
                      <span className="text-gray-400 text-[10px]">{count.toLocaleString()}px</span>
                    </span>
                  ))}
              </div>
            </div>
          )}
        </div>
      )}

      {/* Action buttons */}
      {result && (
        <div className="flex justify-between">
          <button
            onClick={handleRerun}
            disabled={detecting}
            className="px-4 py-2 text-sm text-gray-500 hover:text-gray-700 dark:text-gray-400 dark:hover:text-gray-200 transition-colors disabled:opacity-50"
          >
            Erneut erkennen
          </button>
          <button
            onClick={onNext}
            className="px-6 py-2 bg-teal-600 text-white rounded-lg hover:bg-teal-700 font-medium transition-colors"
          >
            Weiter &rarr;
          </button>
        </div>
      )}

      {error && (
        <div className="p-3 bg-red-50 dark:bg-red-900/20 text-red-600 dark:text-red-400 rounded-lg text-sm">
          {error}
        </div>
      )}
    </div>
  )
}