feat: AtCoderレーティングに基づくテーマ色の適用機能を追加

Author: yuubinnkyoku

lib/main.dart

@@ -103,9 +103,10 @@ class MyApp extends StatelessWidget {
 
     return DynamicColorBuilder(
       builder: (ColorScheme? lightDynamic, ColorScheme? darkDynamic) {
-        // Material Youを使用するかどうかでカラースキームを決定
+        // Material You / Custom theme 基本スキーム決定
         ColorScheme lightColorScheme;
-        ColorScheme darkColorScheme;        if (themeProvider.useMaterialYou) {
+        ColorScheme darkColorScheme;
+        if (themeProvider.useMaterialYou) {
           lightColorScheme = lightDynamic ?? _defaultLightColorScheme;
           darkColorScheme = themeProvider.isPureBlack
               ? _pureBlackColorScheme
@@ -117,6 +118,38 @@ class MyApp extends StatelessWidget {
               : _darkCustomTheme;
         }
 
+        // AtCoderレーティング色をそのままテーマの主色に適用（ハーモナイズなしで忠実に）
+        if (themeProvider.useAtcoderRatingColor &&
+            themeProvider.atcoderAccentColor != null) {
+          final seed = themeProvider.atcoderAccentColor!;
+          final onPrimary = seed.computeLuminance() > 0.5 ? Colors.black : Colors.white;
+
+          lightColorScheme = lightColorScheme.copyWith(
+            primary: seed,
+            onPrimary: onPrimary,
+            primaryContainer: seed,
+            onPrimaryContainer: onPrimary,
+            surfaceTint: Colors.transparent,
+          );
+
+          final baseDark = darkColorScheme;
+          final darkAdjusted = baseDark.copyWith(
+            primary: seed,
+            onPrimary: onPrimary,
+            primaryContainer: seed,
+            onPrimaryContainer: onPrimary,
+            surfaceTint: Colors.transparent,
+          );
+          darkColorScheme = themeProvider.isPureBlack
+              ? darkAdjusted.copyWith(
+                  surface: Colors.black,
+                  surfaceContainerHighest: Colors.black,
+                  onSurface: Colors.white,
+                  surfaceTint: Colors.transparent,
+                )
+              : darkAdjusted;
+        }
+
         // Noto Sans JPフォントをテキストテーマに適用
         final textTheme = TextTheme(
           displayLarge: GoogleFonts.notoSansJp(fontSize: 32, fontWeight: FontWeight.bold),

lib/providers/theme_provider.dart

@@ -1,10 +1,13 @@
 import 'package:flutter/material.dart';
 import 'package:shared_preferences/shared_preferences.dart';
+import '../services/atcoder_service.dart';
+import '../utils/atcoder_colors.dart';
 
 const String _navOpacityKey = 'nav_opacity'; // Key for bottom nav opacity
 const String _useMaterialYouKey = 'use_material_you'; // Key for Material You setting
 const String _codeFontFamilyKey = 'code_font_family'; // Key for code font family
 const String _customCodeFontsKey = 'custom_code_fonts'; // Key for custom code fonts list
+const String _useAtcoderRatingColorKey = 'use_atcoder_rating_color'; // Key for AtCoder accent option
 
 // Built-in supported Google fonts and generic fallback
 const List<String> defaultCodeFontFamilies = [
@@ -32,6 +35,8 @@ class ThemeProvider extends ChangeNotifier {
   String _codeFontFamily = defaultCodeFontFamilies.first; // Default font
   final List<String> _customCodeFonts = []; // User-added font family names (must be declared in pubspec)
   bool _isLoading = true;
+  bool _useAtcoderRatingColor = false; // Default off
+  Color? _atcoderAccentColor; // Resolved accent color based on rating
 
   ThemeProvider() {
     _loadFromPrefs();
@@ -46,6 +51,12 @@ class ThemeProvider extends ChangeNotifier {
   // Material Youを使用するかどうか
   bool get useMaterialYou => _useMaterialYou;
 
+  // AtCoderレート色をアクセントとして使うか
+  bool get useAtcoderRatingColor => _useAtcoderRatingColor;
+
+  // 解決済みのアクセントカラー（nullの場合は未設定/無効）
+  Color? get atcoderAccentColor => _atcoderAccentColor;
+
   // Code block font family
   String get codeFontFamily => _codeFontFamily;
 
@@ -74,6 +85,20 @@ class ThemeProvider extends ChangeNotifier {
     notifyListeners();
   }
 
+  // AtCoderレート色の使用設定を変更
+  Future<void> setUseAtcoderRatingColor(bool use) async {
+    if (_useAtcoderRatingColor == use) return;
+
+    _useAtcoderRatingColor = use;
+    await _saveToPrefs();
+    if (use) {
+      await refreshAtcoderAccentColor();
+    } else {
+      _atcoderAccentColor = null;
+      notifyListeners();
+    }
+  }
+
   // Material Youの使用設定を変更
   Future<void> setUseMaterialYou(bool use) async {
     if (_useMaterialYou == use) return;
@@ -131,6 +156,11 @@ class ThemeProvider extends ChangeNotifier {
     if (savedUseMaterialYou != null) {
       _useMaterialYou = savedUseMaterialYou;
     }
+    // Load AtCoder accent option
+    final savedUseAtcoder = prefs.getBool(_useAtcoderRatingColorKey);
+    if (savedUseAtcoder != null) {
+      _useAtcoderRatingColor = savedUseAtcoder;
+    }
     // Load code font family if exists
     final savedFontFamily = prefs.getString(_codeFontFamilyKey);
     // Load custom fonts list
@@ -150,6 +180,11 @@ class ThemeProvider extends ChangeNotifier {
       _themeMode = ThemeModeOption.values[themeModeIndex];
     }
 
+    // If using AtCoder accent, resolve it now
+    if (_useAtcoderRatingColor) {
+      await refreshAtcoderAccentColor();
+    }
+
     _isLoading = false;
     notifyListeners();
   }
@@ -161,6 +196,7 @@ class ThemeProvider extends ChangeNotifier {
     await prefs.setBool(_useMaterialYouKey, _useMaterialYou); // Save Material You setting
     await prefs.setString(_codeFontFamilyKey, _codeFontFamily); // Save font family
     await prefs.setStringList(_customCodeFontsKey, _customCodeFonts); // Save custom fonts
+    await prefs.setBool(_useAtcoderRatingColorKey, _useAtcoderRatingColor); // Save AtCoder accent option
   }
 
   // Set bottom nav opacity and persist
@@ -170,6 +206,32 @@ class ThemeProvider extends ChangeNotifier {
     await prefs.setDouble(_navOpacityKey, opacity);
     notifyListeners();
   }
+
+  /// Fetch current user's AtCoder rating and resolve accent color.
+  /// Uses 'atcoder_username' from SharedPreferences. If missing or fetch fails,
+  /// falls back to null and leaves theme unchanged.
+  Future<void> refreshAtcoderAccentColor() async {
+    if (!_useAtcoderRatingColor) return;
+    try {
+      final prefs = await SharedPreferences.getInstance();
+      final username = prefs.getString('atcoder_username');
+      if (username == null || username.trim().isEmpty) {
+        _atcoderAccentColor = null;
+        notifyListeners();
+        return;
+      }
+      final service = AtCoderService();
+      final rating = await service.fetchAtCoderRate(username.trim());
+      if (rating == null) {
+        _atcoderAccentColor = null;
+      } else {
+        _atcoderAccentColor = atcoderRatingToColor(rating);
+      }
+    } catch (_) {
+      _atcoderAccentColor = null;
+    }
+    notifyListeners();
+  }
 }
 
 // テーマモードの選択肢

lib/screens/settings_screen.dart

@@ -83,6 +83,15 @@ class _SettingsScreenState extends State<SettingsScreen> {
         'atcoder_username',
         _atcoderUsernameController.text.trim(),
       );
+      // If theme uses AtCoder accent, refresh it
+      try {
+        final themeProvider = Provider.of<ThemeProvider>(context, listen: false);
+        if (themeProvider.useAtcoderRatingColor) {
+          await themeProvider.refreshAtcoderAccentColor();
+        }
+      } catch (_) {
+        // ignore UI refresh errors
+      }
       if (!mounted) return;
       ScaffoldMessenger.of(context).showSnackBar(
         const SnackBar(content: Text('AtCoderユーザー名を保存しました')),
@@ -332,6 +341,18 @@ class _SettingsScreenState extends State<SettingsScreen> {
               onChanged: themeProvider.setUseMaterialYou,
               icon: Icons.color_lens_outlined,
             ),
+            _HapticSwitchListTile(
+              title: 'AtCoderの色をテーマに使う',
+              subtitle: '保存したユーザーのレート色をアクセントに適用します',
+              value: themeProvider.useAtcoderRatingColor,
+              onChanged: (v) async {
+                await themeProvider.setUseAtcoderRatingColor(v);
+                if (v) {
+                  await themeProvider.refreshAtcoderAccentColor();
+                }
+              },
+              icon: Icons.emoji_events_outlined,
+            ),
             const Divider(),
             // Font Family Selector
             Padding(

lib/utils/atcoder_colors.dart

@@ -0,0 +1,14 @@
+import 'package:flutter/material.dart';
+
+/// Map AtCoder rating to its representative color.
+/// Based on typical AtCoder color bands.
+Color atcoderRatingToColor(int rating) {
+  if (rating >= 2800) return const Color(0xFFFF0000); // Red
+  if (rating >= 2400) return const Color(0xFFFF8000); // Orange
+  if (rating >= 2000) return const Color(0xFFC0C000); // Yellow
+  if (rating >= 1600) return const Color(0xFF0000FF); // Blue
+  if (rating >= 1200) return const Color(0xFF00C0C0); // Cyan
+  if (rating >= 800) return const Color(0xFF008000);  // Green
+  if (rating >= 400) return const Color(0xFF804000); // Brown
+  return const Color(0xFF808080); // Gray
+}