Complete refactor to clean up project

lib/features/sheet_viewer/widgets/pdf_page_display.dart

@@ -0,0 +1,137 @@
+import 'dart:math';
+
+import 'package:flutter/material.dart';
+import 'package:pdfrx/pdfrx.dart';
+
+import '../../../core/models/config.dart';
+
+/// Displays PDF pages with optional two-page mode.
+class PdfPageDisplay extends StatelessWidget {
+  final PdfDocument document;
+  final int numPages;
+  final int currentPageNumber;
+  final Config config;
+
+  const PdfPageDisplay({
+    super.key,
+    required this.document,
+    required this.numPages,
+    required this.currentPageNumber,
+    required this.config,
+  });
+
+  /// Whether two-page mode is active and we have enough pages.
+  bool get _showTwoPages => config.twoPageMode && numPages >= 2;
+
+  @override
+  Widget build(BuildContext context) {
+    return Row(
+      mainAxisAlignment: MainAxisAlignment.center,
+      crossAxisAlignment: CrossAxisAlignment.center,
+      children: [_buildLeftPage(), if (_showTwoPages) _buildRightPage()],
+    );
+  }
+
+  Widget _buildLeftPage() {
+    return Expanded(
+      child: Stack(
+        children: [
+          PdfPageView(
+            key: ValueKey(currentPageNumber),
+            document: document,
+            pageNumber: currentPageNumber,
+            maximumDpi: 300,
+            alignment: _showTwoPages ? Alignment.centerRight : Alignment.center,
+          ),
+          _buildPageIndicator(currentPageNumber),
+        ],
+      ),
+    );
+  }
+
+  Widget _buildRightPage() {
+    final rightPageNumber = currentPageNumber + 1;
+
+    return Expanded(
+      child: Stack(
+        children: [
+          PdfPageView(
+            key: ValueKey(rightPageNumber),
+            document: document,
+            pageNumber: rightPageNumber,
+            maximumDpi: 300,
+            alignment: Alignment.centerLeft,
+          ),
+          _buildPageIndicator(rightPageNumber),
+        ],
+      ),
+    );
+  }
+
+  Widget _buildPageIndicator(int pageNumber) {
+    return Positioned.fill(
+      child: Container(
+        alignment: Alignment.bottomCenter,
+        padding: const EdgeInsets.only(bottom: 5),
+        child: Text('$pageNumber / $numPages'),
+      ),
+    );
+  }
+
+  // ---------------------------------------------------------------------------
+  // Page Size Calculations
+  // ---------------------------------------------------------------------------
+
+  /// Calculates scaled page sizes for the current view.
+  ///
+  /// Returns a tuple of (leftPageSize, rightPageSize).
+  /// rightPageSize is null when not in two-page mode.
+  (Size, Size?) calculateScaledPageSizes(Size parentSize) {
+    if (config.twoPageMode) {
+      return _calculateTwoPageSizes(parentSize);
+    }
+    return (_calculateSinglePageSize(parentSize), null);
+  }
+
+  (Size, Size?) _calculateTwoPageSizes(Size parentSize) {
+    final leftSize = _getUnscaledPageSize(currentPageNumber);
+    final rightSize = numPages > currentPageNumber
+        ? _getUnscaledPageSize(currentPageNumber + 1)
+        : leftSize;
+
+    // Combine pages for scaling calculation
+    final combinedSize = Size(
+      leftSize.width + rightSize.width,
+      max(leftSize.height, rightSize.height),
+    );
+
+    final scaledCombined = _scaleToFit(parentSize, combinedSize);
+    final scaleFactor = scaledCombined.width / combinedSize.width;
+
+    return (leftSize * scaleFactor, rightSize * scaleFactor);
+  }
+
+  Size _calculateSinglePageSize(Size parentSize) {
+    return _scaleToFit(parentSize, _getUnscaledPageSize(currentPageNumber));
+  }
+
+  Size _getUnscaledPageSize(int pageNumber) {
+    return document.pages.elementAt(pageNumber - 1).size;
+  }
+
+  /// Scales a page size to fit within parent bounds while maintaining aspect ratio.
+  Size _scaleToFit(Size parentSize, Size pageSize) {
+    // Determine if height or width is the limiting factor
+    if (parentSize.aspectRatio > pageSize.aspectRatio) {
+      // Constrained by height
+      final height = parentSize.height;
+      final width = height * pageSize.aspectRatio;
+      return Size(width, height);
+    } else {
+      // Constrained by width
+      final width = parentSize.width;
+      final height = width / pageSize.aspectRatio;
+      return Size(width, height);
+    }
+  }
+}