StepAnsicht: split-view with coordinate grid for comparison

Left panel: Original scan + OCR word overlay (red text at exact
word_box positions) + coordinate grid
Right panel: Reconstructed layout + same coordinate grid

Features:
- Coordinate grid toggle with 50/100/200px spacing options
- Grid lines labeled with pixel coordinates in original image space
- Both panels share the same scale for direct visual comparison
- OCR overlay shows detected text in red mono font at original positions

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

admin-lehrer/components/ocr-kombi/StepAnsicht.tsx

@@ -1,13 +1,15 @@
 'use client'
 
 /**
- * StepAnsicht — Read-only page layout preview.
+ * StepAnsicht — Split-view page layout comparison.
  *
- * Shows the reconstructed page with all zones (content grid + embedded boxes)
- * positioned at their original coordinates. Pure CSS positioning, no canvas.
+ * Left:  Original scan with OCR word overlay (red) + coordinate grid
+ * Right: Reconstructed layout with all zones + coordinate grid
+ *
+ * Both sides share the same coordinate system for easy visual comparison.
  */
 
-import { useCallback, useEffect, useRef, useState } from 'react'
+import { useEffect, useRef, useState } from 'react'
 import { useGridEditor } from '@/components/grid-editor/useGridEditor'
 import type { GridZone, GridEditorCell } from '@/components/grid-editor/types'
 
@@ -18,38 +20,30 @@ interface StepAnsichtProps {
   onNext: () => void
 }
 
-/** Get dominant color from a cell's word_boxes or color_override. */
 function getCellColor(cell: GridEditorCell | undefined): string | null {
   if (!cell) return null
-  if ((cell as any).color_override) return (cell as any).color_override
+  if (cell.color_override) return cell.color_override
   const colored = cell.word_boxes?.find((wb) => wb.color_name && wb.color_name !== 'black')
   return colored?.color ?? null
 }
 
 export function StepAnsicht({ sessionId, onNext }: StepAnsichtProps) {
-  const {
-    grid,
-    loading,
-    error,
-    loadGrid,
-  } = useGridEditor(sessionId)
+  const { grid, loading, error, loadGrid } = useGridEditor(sessionId)
 
-  const containerRef = useRef<HTMLDivElement>(null)
-  const [containerWidth, setContainerWidth] = useState(0)
-  const [showOriginal, setShowOriginal] = useState(false)
+  const leftRef = useRef<HTMLDivElement>(null)
+  const [panelWidth, setPanelWidth] = useState(0)
+  const [showGrid, setShowGrid] = useState(true)
+  const [gridSpacing, setGridSpacing] = useState(100) // px in original coordinates
 
-  // Load grid on mount
   useEffect(() => {
     if (sessionId) loadGrid()
   }, [sessionId]) // eslint-disable-line react-hooks/exhaustive-deps
 
-  // Track container width
+  // Track panel width
   useEffect(() => {
-    if (!containerRef.current) return
-    const ro = new ResizeObserver(([entry]) => {
-      setContainerWidth(entry.contentRect.width)
-    })
-    ro.observe(containerRef.current)
+    if (!leftRef.current) return
+    const ro = new ResizeObserver(([entry]) => setPanelWidth(entry.contentRect.width))
+    ro.observe(leftRef.current)
     return () => ro.disconnect()
   }, [])
 
@@ -64,93 +58,158 @@ export function StepAnsicht({ sessionId, onNext }: StepAnsichtProps) {
 
   if (error || !grid) {
     return (
-      <div className="bg-white dark:bg-gray-800 rounded-xl border border-gray-200 dark:border-gray-700 p-8 text-center">
-        <p className="text-red-500 mb-4">{error || 'Keine Grid-Daten vorhanden.'}</p>
-        <button onClick={onNext} className="px-5 py-2 bg-teal-600 text-white rounded-lg hover:bg-teal-700 text-sm font-medium">
-          Weiter →
-        </button>
+      <div className="p-8 text-center">
+        <p className="text-red-500 mb-4">{error || 'Keine Grid-Daten.'}</p>
+        <button onClick={onNext} className="px-5 py-2 bg-teal-600 text-white rounded-lg">Weiter →</button>
       </div>
     )
   }
 
   const imgW = grid.image_width || 1
   const imgH = grid.image_height || 1
-  const scale = containerWidth > 0 ? containerWidth / imgW : 1
-  const containerHeight = imgH * scale
+  const scale = panelWidth > 0 ? panelWidth / imgW : 0.5
+  const panelHeight = imgH * scale
 
-  // Font size: scale from original, with minimum
   const baseFontPx = (grid as any).layout_metrics?.font_size_suggestion_px || 14
   const scaledFont = Math.max(7, baseFontPx * scale * 0.85)
 
+  // Collect all word boxes for OCR overlay
+  const allWordBoxes = grid.zones.flatMap((z) =>
+    z.cells.flatMap((c) => (c.word_boxes || []).map((wb) => ({ ...wb, zone: z })))
+  )
+
   return (
     <div className="space-y-3">
       {/* Header */}
       <div className="flex items-center justify-between">
         <div>
           <h3 className="text-lg font-semibold text-gray-900 dark:text-white">
-            Ansicht — Seitenrekonstruktion
+            Ansicht — Original vs. Rekonstruktion
           </h3>
           <p className="text-sm text-gray-500 dark:text-gray-400">
-            Vorschau der rekonstruierten Seite mit allen Zonen und Boxen an Originalpositionen.
+            Links: Original mit OCR-Overlay. Rechts: Rekonstruierte Seite. Koordinatengitter zum Abgleich.
           </p>
         </div>
         <div className="flex items-center gap-2">
-          <button
-            onClick={() => setShowOriginal(!showOriginal)}
-            className={`px-3 py-1.5 rounded-lg text-xs font-medium transition-colors ${
-              showOriginal
-                ? 'bg-teal-100 text-teal-700 dark:bg-teal-900/40 dark:text-teal-300'
-                : 'bg-gray-100 text-gray-600 dark:bg-gray-700 dark:text-gray-300'
-            }`}
-          >
-            {showOriginal ? 'Original ausblenden' : 'Original einblenden'}
-          </button>
-          <button
-            onClick={onNext}
-            className="px-5 py-2 bg-teal-600 text-white rounded-lg hover:bg-teal-700 text-sm font-medium"
+          <label className="flex items-center gap-1.5 text-xs text-gray-500">
+            <input
+              type="checkbox"
+              checked={showGrid}
+              onChange={(e) => setShowGrid(e.target.checked)}
+              className="w-3.5 h-3.5 rounded border-gray-300"
+            />
+            Gitter
+          </label>
+          <select
+            value={gridSpacing}
+            onChange={(e) => setGridSpacing(Number(e.target.value))}
+            className="text-xs px-1.5 py-1 rounded border border-gray-300 dark:border-gray-600 bg-white dark:bg-gray-700"
           >
+            <option value={50}>50px</option>
+            <option value={100}>100px</option>
+            <option value={200}>200px</option>
+          </select>
+          <button onClick={onNext} className="px-5 py-2 bg-teal-600 text-white rounded-lg hover:bg-teal-700 text-sm font-medium">
             Weiter →
           </button>
         </div>
       </div>
 
-      {/* Page container */}
-      <div
-        ref={containerRef}
-        className="relative bg-white dark:bg-gray-900 border border-gray-300 dark:border-gray-600 rounded-lg overflow-hidden shadow-lg"
-        style={{ height: containerHeight > 0 ? `${containerHeight}px` : 'auto' }}
-      >
-        {/* Original image background (toggleable) */}
-        {showOriginal && sessionId && (
-          <img
-            src={`${KLAUSUR_API}/api/v1/ocr-pipeline/sessions/${sessionId}/image/cropped`}
-            alt="Original"
-            className="absolute inset-0 w-full h-full object-contain opacity-15"
-          />
-        )}
+      {/* Split view */}
+      <div className="flex gap-2" style={{ height: panelHeight > 0 ? `${panelHeight + 40}px` : '600px' }}>
+        {/* LEFT: Original + OCR overlay */}
+        <div ref={leftRef} className="flex-1 relative border border-gray-300 dark:border-gray-600 rounded-lg overflow-hidden bg-white dark:bg-gray-900">
+          <div className="absolute top-0 left-0 px-2 py-0.5 bg-black/60 text-white text-[10px] font-medium rounded-br z-20">
+            Original + OCR
+          </div>
 
-        {/* Render zones */}
-        {grid.zones.map((zone) => (
-          <ZoneRenderer
-            key={zone.zone_index}
-            zone={zone}
-            scale={scale}
-            fontSize={scaledFont}
-          />
-        ))}
+          {/* Scan image */}
+          {sessionId && (
+            <img
+              src={`${KLAUSUR_API}/api/v1/ocr-pipeline/sessions/${sessionId}/image/cropped`}
+              alt="Original"
+              className="absolute inset-0 w-full h-auto"
+              style={{ height: `${panelHeight}px`, objectFit: 'contain' }}
+            />
+          )}
+
+          {/* OCR word overlay (red text) */}
+          {allWordBoxes.map((wb, i) => (
+            <div
+              key={i}
+              className="absolute text-red-500 font-mono leading-none pointer-events-none"
+              style={{
+                left: `${wb.left * scale}px`,
+                top: `${wb.top * scale}px`,
+                fontSize: `${Math.max(6, wb.height * scale * 0.75)}px`,
+                whiteSpace: 'nowrap',
+              }}
+            >
+              {wb.text}
+            </div>
+          ))}
+
+          {/* Coordinate grid */}
+          {showGrid && <CoordinateGrid imgW={imgW} imgH={imgH} scale={scale} spacing={gridSpacing} />}
+        </div>
+
+        {/* RIGHT: Reconstruction */}
+        <div className="flex-1 relative border border-gray-300 dark:border-gray-600 rounded-lg overflow-hidden bg-white dark:bg-gray-900">
+          <div className="absolute top-0 left-0 px-2 py-0.5 bg-teal-600/80 text-white text-[10px] font-medium rounded-br z-20">
+            Rekonstruktion
+          </div>
+
+          {/* Rendered zones */}
+          {grid.zones.map((zone) => (
+            <ZoneRenderer key={zone.zone_index} zone={zone} scale={scale} fontSize={scaledFont} />
+          ))}
+
+          {/* Coordinate grid */}
+          {showGrid && <CoordinateGrid imgW={imgW} imgH={imgH} scale={scale} spacing={gridSpacing} />}
+        </div>
       </div>
     </div>
   )
 }
 
 // ---------------------------------------------------------------------------
-// Zone renderer
+// Coordinate grid overlay
+// ---------------------------------------------------------------------------
+
+function CoordinateGrid({ imgW, imgH, scale, spacing }: {
+  imgW: number; imgH: number; scale: number; spacing: number
+}) {
+  const lines: JSX.Element[] = []
+
+  // Vertical lines
+  for (let x = 0; x <= imgW; x += spacing) {
+    const px = x * scale
+    lines.push(
+      <div key={`v${x}`} className="absolute top-0 bottom-0 pointer-events-none" style={{ left: `${px}px`, width: '1px', background: 'rgba(0,150,255,0.2)' }}>
+        <span className="absolute top-0 left-1 text-[8px] text-blue-400 font-mono">{x}</span>
+      </div>
+    )
+  }
+
+  // Horizontal lines
+  for (let y = 0; y <= imgH; y += spacing) {
+    const px = y * scale
+    lines.push(
+      <div key={`h${y}`} className="absolute left-0 right-0 pointer-events-none" style={{ top: `${px}px`, height: '1px', background: 'rgba(0,150,255,0.2)' }}>
+        <span className="absolute left-1 top-0.5 text-[8px] text-blue-400 font-mono">{y}</span>
+      </div>
+    )
+  }
+
+  return <>{lines}</>
+}
+
+// ---------------------------------------------------------------------------
+// Zone renderer (reconstruction side)
 // ---------------------------------------------------------------------------
 
 function ZoneRenderer({ zone, scale, fontSize }: {
-  zone: GridZone
-  scale: number
-  fontSize: number
+  zone: GridZone; scale: number; fontSize: number
 }) {
   const isBox = zone.zone_type === 'box'
   const boxColor = (zone as any).box_bg_hex || '#6b7280'
@@ -162,23 +221,20 @@ function ZoneRenderer({ zone, scale, fontSize }: {
   const width = zone.bbox_px.w * scale
   const height = zone.bbox_px.h * scale
 
-  // Build cell map
   const cellMap = new Map<string, GridEditorCell>()
   for (const cell of zone.cells) {
     cellMap.set(`${cell.row_index}_${cell.col_index}`, cell)
   }
 
-  // Column widths (relative to zone)
+  // Column widths scaled to zone
   const colWidths = zone.columns.map((col) => {
     const w = (col.x_max_px ?? 0) - (col.x_min_px ?? 0)
-    return Math.max(10, w * scale)
+    return Math.max(5, w * scale)
   })
   const totalColW = colWidths.reduce((s, w) => s + w, 0)
-  // Scale columns to fit zone width
   const colScale = totalColW > 0 ? width / totalColW : 1
   const scaledColWidths = colWidths.map((w) => w * colScale)
 
-  const gridTemplateCols = scaledColWidths.map((w) => `${w.toFixed(1)}px`).join(' ')
   const numCols = zone.columns.length
 
   return (
@@ -189,47 +245,34 @@ function ZoneRenderer({ zone, scale, fontSize }: {
         top: `${top}px`,
         width: `${width}px`,
         minHeight: `${height}px`,
-        border: isBox ? `${Math.max(2, 3 * scale)}px solid ${boxColor}` : undefined,
+        border: isBox ? `${Math.max(1.5, 2.5 * scale)}px solid ${boxColor}` : undefined,
         backgroundColor: isBox ? `${boxColor}08` : undefined,
-        borderRadius: isBox ? `${Math.max(2, 4 * scale)}px` : undefined,
+        borderRadius: isBox ? `${Math.max(1, 3 * scale)}px` : undefined,
         fontSize: `${fontSize}px`,
-        lineHeight: '1.3',
+        lineHeight: '1.25',
       }}
     >
-      <div
-        className="w-full"
-        style={{
-          display: 'grid',
-          gridTemplateColumns: gridTemplateCols,
-        }}
-      >
+      <div style={{ display: 'grid', gridTemplateColumns: scaledColWidths.map((w) => `${w.toFixed(1)}px`).join(' ') }}>
         {zone.rows.map((row) => {
-          const isSpanning = zone.cells.some(
-            (c) => c.row_index === row.index && c.col_type === 'spanning_header',
-          )
-
-          // Row height from measured px
+          const isSpanning = zone.cells.some((c) => c.row_index === row.index && c.col_type === 'spanning_header')
           const measuredH = (row.y_max_px ?? 0) - (row.y_min_px ?? 0)
-          const rowH = Math.max(fontSize * 1.4, measuredH * scale)
+          const rowH = Math.max(fontSize * 1.3, measuredH * scale)
 
           return (
             <div key={row.index} style={{ display: 'contents' }}>
               {isSpanning ? (
-                // Render spanning cells
                 zone.cells
                   .filter((c) => c.row_index === row.index && c.col_type === 'spanning_header')
                   .sort((a, b) => a.col_index - b.col_index)
                   .map((cell) => {
-                    const colspan = (cell as any).colspan || numCols
-                    const gridColStart = cell.col_index + 1
-                    const gridColEnd = gridColStart + colspan
+                    const colspan = cell.colspan || numCols
                     const color = getCellColor(cell)
                     return (
                       <div
                         key={cell.cell_id}
-                        className={`px-1 overflow-hidden ${row.is_header ? 'font-bold' : ''}`}
+                        className={`px-0.5 overflow-hidden ${row.is_header ? 'font-bold' : ''}`}
                         style={{
-                          gridColumn: `${gridColStart} / ${gridColEnd}`,
+                          gridColumn: `${cell.col_index + 1} / ${cell.col_index + 1 + colspan}`,
                           minHeight: `${rowH}px`,
                           color: color || undefined,
                           whiteSpace: 'pre-wrap',
@@ -240,26 +283,22 @@ function ZoneRenderer({ zone, scale, fontSize }: {
                     )
                   })
               ) : (
-                // Render normal columns
                 zone.columns.map((col) => {
                   const cell = cellMap.get(`${row.index}_${col.index}`)
-                  if (!cell) {
-                    return <div key={col.index} style={{ minHeight: `${rowH}px` }} />
-                  }
+                  if (!cell) return <div key={col.index} style={{ minHeight: `${rowH}px` }} />
                   const color = getCellColor(cell)
                   const isBold = col.bold || cell.is_bold || row.is_header
                   const text = cell.text ?? ''
-                  const isMultiLine = text.includes('\n')
 
                   return (
                     <div
                       key={col.index}
-                      className={`px-1 overflow-hidden ${isBold ? 'font-bold' : ''}`}
+                      className={`px-0.5 overflow-hidden ${isBold ? 'font-bold' : ''}`}
                       style={{
                         minHeight: `${rowH}px`,
                         color: color || undefined,
-                        whiteSpace: isMultiLine ? 'pre-wrap' : 'nowrap',
-                        textOverflow: isMultiLine ? undefined : 'ellipsis',
+                        whiteSpace: text.includes('\n') ? 'pre-wrap' : 'nowrap',
+                        textOverflow: text.includes('\n') ? undefined : 'ellipsis',
                       }}
                     >
                       {text}