Refactoring

package.json

@@ -7,6 +7,7 @@
     "dev": "vite",
     "build": "tsc -b && vite build",
     "lint": "eslint .",
+    "test": "vitest",
     "preview": "vite preview"
   },
   "dependencies": {
@@ -18,6 +19,9 @@
   },
   "devDependencies": {
     "@eslint/js": "^9.39.1",
+    "@testing-library/dom": "^10.4.1",
+    "@testing-library/jest-dom": "^6.9.1",
+    "@testing-library/react": "^16.3.1",
     "@types/node": "^24.10.1",
     "@types/react": "^19.2.5",
     "@types/react-dom": "^19.2.3",
@@ -26,8 +30,10 @@
     "eslint-plugin-react-hooks": "^7.0.1",
     "eslint-plugin-react-refresh": "^0.4.24",
     "globals": "^16.5.0",
+    "jsdom": "^27.4.0",
     "typescript": "~5.9.3",
     "typescript-eslint": "^8.46.4",
-    "vite": "^7.2.4"
+    "vite": "^7.2.4",
+    "vitest": "^4.0.16"
   }
 }

src/App.tsx

@@ -1,24 +1,20 @@
-import { useState, useEffect, useCallback, useMemo, useRef } from 'react';
+import { useState, useEffect, useCallback, useMemo } from 'react';
 import { Logo } from './components/Logo';
 import { LandscapeSuggestion } from './components/LandscapeSuggestion';
 
 
 import { SheetMusic } from './components/SheetMusic';
-import { Controls, type AppSettings } from './components/Controls';
+import { Controls } from './components/Controls';
 import { SettingsModal } from './components/SettingsModal';
 import { OpenSourceModal } from './components/OpenSourceModal';
 import { usePitchDetector } from './hooks/usePitchDetector';
-import { useMetronome } from './hooks/useMetronome';
 import { useAudioPlayer } from './hooks/useAudioPlayer';
-import {
+import { useSettings } from './context/SettingsContext';
-  getRandomNote,
+import { useGameLogic } from './hooks/useGameLogic';
-  getNoteDetails
+import { getNoteDetails } from './music/NoteUtils';
-} from './music/NoteUtils';
 import {
   TUNINGS,
   getFretboardPositions,
-  getOpenStringNotes,
-  getFirstPositionNotes,
 } from './music/Tunings';
 import { INSTRUMENT_DEFINITIONS } from './music/InstrumentConfigs';
 import { Fretboard } from './components/Fretboard';
@@ -28,8 +24,6 @@ import { Mic, MicOff, SkipForward, HelpCircle, Volume2, X, Guitar, Settings, Max
 import './App.css';
 import './styles/skip-button.css';
 
-import { NOTE_MATCH_THRESHOLD_MS } from './AppConfig';
-
 
 
 
@@ -37,47 +31,25 @@ function App() {
   const [listening, setListening] = useState(false);
   const { playNote } = useAudioPlayer();
 
-  const [targetMidi, setTargetMidi] = useState<number>(60); // Start with C4
+  const { settings, updateSettings } = useSettings();
-  const [settings, setSettings] = useState<AppSettings>({
+  // Alias to keep existing code working with minimal changes
-    difficulty: 'first_pos',
+  const setSettings = updateSettings;
-    showHint: false,
-    showFretboard: false,
-    showTuningMeter: false,
-    tuningId: 'standard',
-    keySignature: 'C',
-    instrument: 'guitar',
-    rhythm: {
-      mode: 'bpm',
-      bpm: 60,
-      seconds: 5,
-      active: false,
-      autoAdvance: false,
-      sound: true,
-      volume: 0.5
-    },
-    zenMode: false,
-    gameMode: 'sight_reading',
-    customMinFret: 0,
-    customMaxFret: 12,
-    autoPlaySightReading: false,
-    autoPlayVolume: 0.5,
-    virtualGuitarVolume: 0.5,
-    virtualGuitarMute: false,
-    micSensitivity: 0.5,
-    disableAnimation: false,
-    theme: 'auto'
-  });
 
   const { pitchData, error, audioLevel, debugInfo, isListening } = usePitchDetector(listening, settings.micSensitivity);
 
-  const [matchStartTime, setMatchStartTime] = useState<number | null>(null);
+  // Game Logic Hook
-  const [feedbackMessage, setFeedbackMessage] = useState<string>("");
+  const {
-  const [revealed, setRevealed] = useState(false);
+    targetMidi,
-  const [virtualNote, setVirtualNote] = useState<number | null>(null);
+    feedbackMessage,
+    revealed,
+    virtualNote,
+    generateNewNote,
+    handleVirtualInstrumentPlay
+  } = useGameLogic(pitchData);
+
   const [isSettingsOpen, setIsSettingsOpen] = useState(false);
   const [isOpenSourceModalOpen, setIsOpenSourceModalOpen] = useState(false);
   const [hoveredMidi, setHoveredMidi] = useState<number | null>(null);
-  const feedbackTimeoutRef = useRef<ReturnType<typeof setTimeout> | null>(null);
   const [isFullscreen, setIsFullscreen] = useState(false);
   const [windowWidth, setWindowWidth] = useState(window.innerWidth);
   const [windowHeight, setWindowHeight] = useState(window.innerHeight);
@@ -130,239 +102,10 @@ function App() {
     return currentInstrumentDef.ranges.find(r => r.id === settings.difficulty);
   }, [currentInstrumentDef, settings.difficulty]);
 
+  // Determine active clef/transpose for rendering
   const activeClef = currentRangeDef?.clef ?? currentInstrumentDef.clefMode;
   const activeTranspose = currentRangeDef?.transpose ?? currentInstrumentDef.transpose;
 
-  // Generate valid notes based on difficulty
-  const validNotes = useMemo(() => {
-    // Find range config
-    const rangeConfig = currentInstrumentDef.ranges.find(r => r.id === settings.difficulty);
-
-    const getNotesFromConfig = (config: typeof rangeConfig) => {
-      if (!config) return [];
-
-      // Dynamic logic based on type
-      if (config.type === 'open_strings') {
-        // Use current tuning if applicable (Guitar/Bass)
-        if (currentTuning) {
-          return getOpenStringNotes(currentTuning);
-        }
-        // Fallback for non-fretted if they happen to use this type (unlikely)
-        return config.notes || [];
-      }
-
-      if (config.type === 'first_position') {
-        if (currentTuning) {
-          return getFirstPositionNotes(currentTuning);
-        }
-        return config.notes || [];
-      }
-
-      if (config.type === 'custom_fret') {
-        if (currentTuning) {
-          const minFret = settings.customMinFret ?? config.defaultMinFret ?? 0;
-          const maxFret = settings.customMaxFret ?? config.defaultMaxFret ?? 12;
-
-          const notes = new Set<number>();
-          currentTuning.strings.forEach(stringMidi => {
-            for (let fret = minFret; fret <= maxFret; fret++) {
-              notes.add(stringMidi + fret);
-            }
-          });
-          return Array.from(notes).sort((a, b) => a - b);
-        }
-        return [];
-      }
-
-      if (config.type === 'specific_string') {
-        if (currentTuning && config.stringIndex !== undefined) {
-          const openNote = currentTuning.strings[config.stringIndex];
-          if (openNote === undefined) return [];
-
-          // Generate frets 0 to 12 for this string
-          const notes = [];
-          for (let i = 0; i <= 12; i++) {
-            notes.push(openNote + i);
-          }
-          return notes;
-        }
-        return [];
-      }
-
-      // Static fallback
-      if (config.notes) return config.notes;
-      if (config.min !== undefined && config.max !== undefined) {
-        return Array.from({ length: config.max - config.min + 1 }, (_, i) => config.min! + i);
-      }
-      return [];
-    };
-
-    if (rangeConfig) {
-      return getNotesFromConfig(rangeConfig);
-    }
-
-    // Fallback if difficulty ID doesn't match current instrument (e.g. after switch)
-    // Return first range of current instrument
-    const fallbackRange = currentInstrumentDef.ranges[0];
-    return getNotesFromConfig(fallbackRange);
-
-  }, [settings.difficulty, currentInstrumentDef, currentTuning, settings.customMinFret, settings.customMaxFret]);
-
-  const generateNewNote = useCallback((keepFeedback = false) => {
-    // Determine min/max based on available notes to avoid infinite loops if validNotes empty
-    if (validNotes.length === 0) return;
-    const min = validNotes[0];
-    const max = validNotes[validNotes.length - 1];
-
-    const newNote = getRandomNote(min, max, validNotes);
-    if (newNote === targetMidi && validNotes.length > 1) {
-      // Try once to get a different note
-      const retry = getRandomNote(min, max, validNotes);
-      setTargetMidi(retry);
-    } else {
-      setTargetMidi(newNote);
-    }
-    setMatchStartTime(null);
-    if (!keepFeedback) {
-      setFeedbackMessage("");
-    }
-    setRevealed(false);
-  }, [validNotes, targetMidi]);
-
-  // Audio Playback trigger
-  useEffect(() => {
-    const shouldAutoPlay = settings.gameMode === 'ear_training' || (settings.gameMode === 'sight_reading' && settings.autoPlaySightReading);
-
-    if (shouldAutoPlay && !revealed) {
-      // Add a small delay to ensure state settles or allow UI to update
-      const timer = setTimeout(() => {
-        playNote(targetMidi, 1.0, settings.autoPlayVolume ?? 0.5); // Play for 1 second
-      }, 100);
-      return () => clearTimeout(timer);
-    }
-  }, [targetMidi, settings.gameMode, settings.autoPlaySightReading, revealed, playNote]);
-
-  // Initial note, and whenever difficulty/tuning/gamemode changes
-  useEffect(() => {
-    generateNewNote();
-    // eslint-disable-next-line react-hooks/exhaustive-deps
-  }, [settings.difficulty, settings.tuningId, settings.gameMode]);
-
-
-  // Metronome Logic
-  // Calculate effective BPM based on mode
-  const effectiveBpm = useMemo(() => {
-    if (settings.rhythm.mode === 'bpm') return settings.rhythm.bpm;
-    // In seconds mode, BPM = 60 / seconds
-    return 60 / settings.rhythm.seconds;
-  }, [settings.rhythm.mode, settings.rhythm.bpm, settings.rhythm.seconds]);
-
-  const handleTick = useCallback(() => {
-    if (settings.rhythm.autoAdvance && settings.rhythm.active) {
-      generateNewNote();
-      // Reset feedback message on auto-tick
-      setFeedbackMessage("");
-    }
-  }, [settings.rhythm.autoAdvance, settings.rhythm.active, generateNewNote]);
-
-  const { restart: restartMetronome } = useMetronome({
-    bpm: effectiveBpm,
-    volume: settings.rhythm.sound ? settings.rhythm.volume : 0,
-    playing: settings.rhythm.active,
-    onTick: handleTick
-  });
-
-
-  // Common success handler
-  const handleMatchSuccess = useCallback(() => {
-    // Success!
-    if (feedbackTimeoutRef.current) {
-      clearTimeout(feedbackTimeoutRef.current);
-    }
-
-    const noteDetails = getNoteDetails(targetMidi);
-    setFeedbackMessage(`Good! ${noteDetails.name}`);
-    setRevealed(true);
-    setMatchStartTime(null);
-
-    const isRhythmActive = settings.rhythm.active && settings.rhythm.autoAdvance;
-    const isTimerMode = settings.rhythm.mode === 'seconds';
-
-    if (!isRhythmActive) {
-      // Standard or Rhythm-Manual
-      // Immediate transition
-      generateNewNote(true); // Keep "Good!" message
-
-      if (settings.disableAnimation) {
-        setFeedbackMessage("");
-        setRevealed(false);
-      } else {
-        // Allow visual feedback to persist for a moment before clearing text
-        feedbackTimeoutRef.current = setTimeout(() => {
-          setFeedbackMessage("");
-        }, 1500);
-      }
-
-    } else {
-      // Rhythm Active AND Auto-Advance
-      if (isTimerMode) {
-        // Dynamic Timer Mode: Success triggers advance
-        restartMetronome(); // Reset the countdown
-        // Immediate transition here too?
-        generateNewNote(true);
-        feedbackTimeoutRef.current = setTimeout(() => {
-          setFeedbackMessage("");
-        }, 1500);
-
-        setMatchStartTime(null);
-      } else {
-        // Strict BPM Mode: Consumed success, but wait for tick.
-        // Logic handled by tick
-      }
-    }
-  }, [targetMidi, settings.rhythm, settings.disableAnimation, restartMetronome, generateNewNote]);
-
-  // Virtual Instrument Handler (Guitar or Piano)
-  const handleVirtualInstrumentPlay = useCallback((playedMidi: number) => {
-    if (!settings.virtualGuitarMute) {
-      playNote(playedMidi, 0.5, settings.virtualGuitarVolume ?? 0.5); // Feedback sound
-    }
-    setVirtualNote(playedMidi);
-
-    // Clear the note visualization after a short delay
-    setTimeout(() => {
-      setVirtualNote(null);
-    }, 500);
-
-    if (playedMidi === targetMidi) {
-      // Instant match
-      handleMatchSuccess();
-    }
-  }, [playNote, targetMidi, feedbackMessage, handleMatchSuccess, settings]);
-
-  // Match Logic
-  useEffect(() => {
-    if (!pitchData) {
-      setMatchStartTime(null);
-      return;
-    }
-
-    if (pitchData.midi === targetMidi) {
-
-
-      if (matchStartTime === null) {
-        setMatchStartTime(Date.now());
-      } else {
-        const duration = Date.now() - matchStartTime;
-        if (duration > NOTE_MATCH_THRESHOLD_MS) {
-          handleMatchSuccess();
-        }
-      }
-    } else {
-      setMatchStartTime(null);
-    }
-  }, [pitchData, targetMidi, matchStartTime, feedbackMessage, handleMatchSuccess]);
-
   /* Keyboard Shortcuts */
   const [showHelp, setShowHelp] = useState(false);
 
@@ -659,8 +402,6 @@ function App() {
       {!settings.zenMode && (
         <footer className="settings-footer">
           <Controls
-            settings={settings}
-            onUpdateSettings={setSettings}
             currentPitch={pitchData ? { note: pitchData.note, cents: pitchData.cents } : null}
           />
           <div className="app-subtitle">

src/components/Controls.tsx

@@ -4,47 +4,19 @@ import { INSTRUMENT_DEFINITIONS } from '../music/InstrumentConfigs';
 import { getTempoMarking } from '../music/TempoMarkings';
 import { TuningMeter } from './TuningMeter';
 
-export type Difficulty = string;
+import { useSettings } from '../context/SettingsContext';
+import { type Difficulty, type RhythmSettings } from '../types/SettingsTypes';
 
-export interface RhythmSettings {
-    mode: 'bpm' | 'seconds';
-    bpm: number;
-    seconds: number;
-    active: boolean;
-    autoAdvance: boolean;
-    sound: boolean;
-    volume: number;
-}
 
-export interface AppSettings {
-    difficulty: Difficulty;
-    showHint: boolean;
-    showFretboard: boolean;
-    tuningId: string;
-    keySignature: string;
-    instrument: string;
-    showTuningMeter: boolean;
-    rhythm: RhythmSettings;
-    zenMode: boolean;
-    gameMode: 'sight_reading' | 'ear_training';
-    customMinFret?: number;
-    customMaxFret?: number;
-    autoPlaySightReading?: boolean;
-    autoPlayVolume?: number;
-    virtualGuitarVolume?: number;
-    micSensitivity?: number; // 0.0 to 1.0 (0=least sensitive, 1=most)
-    virtualGuitarMute?: boolean;
-    disableAnimation?: boolean;
-    theme?: 'light' | 'dark' | 'auto';
-}
 
 interface ControlsProps {
-    settings: AppSettings;
-    onUpdateSettings: (s: AppSettings) => void;
     currentPitch: { note: string; cents: number } | null;
 }
 
-export const Controls: React.FC<ControlsProps> = ({ settings, onUpdateSettings, currentPitch }) => {
+export const Controls: React.FC<ControlsProps> = ({ currentPitch }) => {
+    const { settings, updateSettings } = useSettings();
+    // Alias to minimize refactor, or just use updateSettings. 
+    const onUpdateSettings = updateSettings;
     const handleDifficultyChange = (e: React.ChangeEvent<HTMLSelectElement>) => {
         onUpdateSettings({ ...settings, difficulty: e.target.value as Difficulty });
     };

src/components/SettingsModal.tsx

@@ -1,6 +1,6 @@
 import React, { useState } from 'react';
 import { X, Volume2, VolumeX, ChevronDown, ChevronUp, Mic, MicOff, Sun, Moon, Monitor } from 'lucide-react';
-import type { AppSettings } from './Controls';
+import type { AppSettings } from '../types/SettingsTypes';
 import type { MicrophoneDebugInfo } from '../hooks/usePitchDetector';
 
 interface SettingsModalProps {

src/context/SettingsContext.tsx

@@ -0,0 +1,36 @@
+import React, { createContext, useContext, useState, type ReactNode } from 'react';
+import { type AppSettings, DEFAULT_SETTINGS } from '../types/SettingsTypes';
+
+interface SettingsContextType {
+    settings: AppSettings;
+    updateSettings: (newSettings: AppSettings | ((prev: AppSettings) => AppSettings)) => void;
+    updateSetting: <K extends keyof AppSettings>(key: K, value: AppSettings[K]) => void;
+}
+
+const SettingsContext = createContext<SettingsContextType | undefined>(undefined);
+
+export const SettingsProvider: React.FC<{ children: ReactNode }> = ({ children }) => {
+    const [settings, setSettings] = useState<AppSettings>(DEFAULT_SETTINGS);
+
+    const updateSettings = (newSettings: AppSettings | ((prev: AppSettings) => AppSettings)) => {
+        setSettings(newSettings);
+    };
+
+    const updateSetting = <K extends keyof AppSettings>(key: K, value: AppSettings[K]) => {
+        setSettings(prev => ({ ...prev, [key]: value }));
+    };
+
+    return (
+        <SettingsContext.Provider value={{ settings, updateSettings, updateSetting }}>
+            {children}
+        </SettingsContext.Provider>
+    );
+};
+
+export const useSettings = () => {
+    const context = useContext(SettingsContext);
+    if (context === undefined) {
+        throw new Error('useSettings must be used within a SettingsProvider');
+    }
+    return context;
+};

src/hooks/useGameLogic.ts

@@ -0,0 +1,234 @@
+import { useState, useEffect, useCallback, useMemo, useRef } from 'react';
+import { useSettings } from '../context/SettingsContext';
+import { useAudioPlayer } from './useAudioPlayer';
+import { useMetronome } from './useMetronome';
+import {
+    getRandomNote,
+    getNoteDetails
+} from '../music/NoteUtils';
+import {
+    TUNINGS,
+    getOpenStringNotes,
+    getFirstPositionNotes,
+} from '../music/Tunings';
+import { INSTRUMENT_DEFINITIONS } from '../music/InstrumentConfigs';
+import { NOTE_MATCH_THRESHOLD_MS } from '../AppConfig';
+
+export const useGameLogic = (
+    pitchData: { midi: number; note: string; cents: number; frequency: number } | null
+) => {
+    const { settings } = useSettings();
+    const { playNote } = useAudioPlayer();
+
+    const [targetMidi, setTargetMidi] = useState<number>(60);
+    const [matchStartTime, setMatchStartTime] = useState<number | null>(null);
+    const [feedbackMessage, setFeedbackMessage] = useState<string>("");
+    const [revealed, setRevealed] = useState(false);
+    const [virtualNote, setVirtualNote] = useState<number | null>(null);
+    const feedbackTimeoutRef = useRef<ReturnType<typeof setTimeout> | null>(null);
+
+    // --- Valid Notes Calculation ---
+    const currentTuning = TUNINGS[settings.tuningId];
+    const currentInstrumentDef = INSTRUMENT_DEFINITIONS[settings.instrument];
+
+    const validNotes = useMemo(() => {
+        const rangeConfig = currentInstrumentDef.ranges.find(r => r.id === settings.difficulty);
+
+        const getNotesFromConfig = (config: typeof rangeConfig) => {
+            if (!config) return [];
+
+            if (config.type === 'open_strings') {
+                if (currentTuning) return getOpenStringNotes(currentTuning);
+                return config.notes || [];
+            }
+
+            if (config.type === 'first_position') {
+                if (currentTuning) return getFirstPositionNotes(currentTuning);
+                return config.notes || [];
+            }
+
+            if (config.type === 'custom_fret') {
+                if (currentTuning) {
+                    const minFret = settings.customMinFret ?? config.defaultMinFret ?? 0;
+                    const maxFret = settings.customMaxFret ?? config.defaultMaxFret ?? 12;
+                    const notes = new Set<number>();
+                    currentTuning.strings.forEach(stringMidi => {
+                        for (let fret = minFret; fret <= maxFret; fret++) {
+                            notes.add(stringMidi + fret);
+                        }
+                    });
+                    return Array.from(notes).sort((a, b) => a - b);
+                }
+                return [];
+            }
+
+            if (config.type === 'specific_string') {
+                if (currentTuning && config.stringIndex !== undefined) {
+                    const openNote = currentTuning.strings[config.stringIndex];
+                    if (openNote === undefined) return [];
+                    const notes = [];
+                    for (let i = 0; i <= 12; i++) {
+                        notes.push(openNote + i);
+                    }
+                    return notes;
+                }
+                return [];
+            }
+
+            if (config.notes) return config.notes;
+            if (config.min !== undefined && config.max !== undefined) {
+                return Array.from({ length: config.max - config.min + 1 }, (_, i) => config.min! + i);
+            }
+            return [];
+        };
+
+        if (rangeConfig) return getNotesFromConfig(rangeConfig);
+        const fallbackRange = currentInstrumentDef.ranges[0];
+        return getNotesFromConfig(fallbackRange);
+
+    }, [settings.difficulty, currentInstrumentDef, currentTuning, settings.customMinFret, settings.customMaxFret]);
+
+    // --- Note Generation ---
+    const generateNewNote = useCallback((keepFeedback = false) => {
+        if (validNotes.length === 0) return;
+        const min = validNotes[0];
+        const max = validNotes[validNotes.length - 1];
+
+        const newNote = getRandomNote(min, max, validNotes);
+        if (newNote === targetMidi && validNotes.length > 1) {
+            const retry = getRandomNote(min, max, validNotes);
+            setTargetMidi(retry);
+        } else {
+            setTargetMidi(newNote);
+        }
+        setMatchStartTime(null);
+        if (!keepFeedback) {
+            setFeedbackMessage("");
+        }
+        setRevealed(false);
+    }, [validNotes, targetMidi]);
+
+    // --- Metronome Logic ---
+    const effectiveBpm = useMemo(() => {
+        if (settings.rhythm.mode === 'bpm') return settings.rhythm.bpm;
+        return 60 / settings.rhythm.seconds;
+    }, [settings.rhythm.mode, settings.rhythm.bpm, settings.rhythm.seconds]);
+
+    const handleTick = useCallback(() => {
+        if (settings.rhythm.autoAdvance && settings.rhythm.active) {
+            generateNewNote();
+            setFeedbackMessage("");
+        }
+    }, [settings.rhythm.autoAdvance, settings.rhythm.active, generateNewNote]);
+
+    const { restart: restartMetronome } = useMetronome({
+        bpm: effectiveBpm,
+        volume: settings.rhythm.sound ? settings.rhythm.volume : 0,
+        playing: settings.rhythm.active,
+        onTick: handleTick
+    });
+
+    // --- Audio Auto-Play ---
+    useEffect(() => {
+        const shouldAutoPlay = settings.gameMode === 'ear_training' || (settings.gameMode === 'sight_reading' && settings.autoPlaySightReading);
+
+        if (shouldAutoPlay && !revealed) {
+            const timer = setTimeout(() => {
+                playNote(targetMidi, 1.0, settings.autoPlayVolume ?? 0.5);
+            }, 100);
+            return () => clearTimeout(timer);
+        }
+    }, [targetMidi, settings.gameMode, settings.autoPlaySightReading, revealed, playNote, settings.autoPlayVolume]);
+
+    // --- Init / Reset ---
+    useEffect(() => {
+        generateNewNote();
+        // eslint-disable-next-line react-hooks/exhaustive-deps
+    }, [settings.difficulty, settings.tuningId, settings.gameMode]);
+
+
+    // --- Success Handler ---
+    const handleMatchSuccess = useCallback(() => {
+        if (feedbackTimeoutRef.current) {
+            clearTimeout(feedbackTimeoutRef.current);
+        }
+
+        const noteDetails = getNoteDetails(targetMidi);
+        setFeedbackMessage(`Good! ${noteDetails.name}`);
+        setRevealed(true);
+        setMatchStartTime(null);
+
+        const isRhythmActive = settings.rhythm.active && settings.rhythm.autoAdvance;
+        const isTimerMode = settings.rhythm.mode === 'seconds';
+
+        if (!isRhythmActive) {
+            generateNewNote(true);
+            if (settings.disableAnimation) {
+                setFeedbackMessage("");
+                setRevealed(false);
+            } else {
+                feedbackTimeoutRef.current = setTimeout(() => {
+                    setFeedbackMessage("");
+                }, 1500);
+            }
+        } else {
+            if (isTimerMode) {
+                restartMetronome();
+                generateNewNote(true);
+                feedbackTimeoutRef.current = setTimeout(() => {
+                    setFeedbackMessage("");
+                }, 1500);
+                setMatchStartTime(null);
+            }
+        }
+    }, [targetMidi, settings.rhythm, settings.disableAnimation, restartMetronome, generateNewNote]);
+
+    // --- Virtual Instrument Handler ---
+    const handleVirtualInstrumentPlay = useCallback((playedMidi: number) => {
+        if (!settings.virtualGuitarMute) {
+            playNote(playedMidi, 0.5, settings.virtualGuitarVolume ?? 0.5);
+        }
+        setVirtualNote(playedMidi);
+
+        setTimeout(() => {
+            setVirtualNote(null);
+        }, 500);
+
+        if (playedMidi === targetMidi) {
+            handleMatchSuccess();
+        }
+    }, [playNote, targetMidi, handleMatchSuccess, settings.virtualGuitarMute, settings.virtualGuitarVolume]);
+
+
+    // --- Match Checking Loop ---
+    useEffect(() => {
+        if (!pitchData) {
+            setMatchStartTime(null);
+            return;
+        }
+
+        if (pitchData.midi === targetMidi) {
+            if (matchStartTime === null) {
+                setMatchStartTime(Date.now());
+            } else {
+                const duration = Date.now() - matchStartTime;
+                if (duration > NOTE_MATCH_THRESHOLD_MS) {
+                    handleMatchSuccess();
+                }
+            }
+        } else {
+            setMatchStartTime(null);
+        }
+    }, [pitchData, targetMidi, matchStartTime, handleMatchSuccess]);
+
+    return {
+        targetMidi,
+        feedbackMessage,
+        revealed,
+        virtualNote,
+        generateNewNote,
+        handleMatchSuccess,
+        handleVirtualInstrumentPlay,
+        setVirtualNote // Exposed for consistency or additional external control if needed
+    };
+};

src/main.tsx

@@ -1,10 +1,14 @@
+
 import { StrictMode } from 'react'
 import { createRoot } from 'react-dom/client'
 import './styles/variables.css'
 import App from './App.tsx'
+import { SettingsProvider } from './context/SettingsContext.tsx'
 
 createRoot(document.getElementById('root')!).render(
   <StrictMode>
+    <SettingsProvider>
       <App />
+    </SettingsProvider>
   </StrictMode>,
 )

src/music/NoteUtils.test.ts

@@ -0,0 +1,119 @@
+import { describe, it, expect } from 'vitest';
+import {
+    frequencyToMidi,
+    midiToFrequency,
+    getNoteDetails,
+    getRandomNote,
+    getNoteInKey
+} from './NoteUtils';
+
+describe('NoteUtils', () => {
+    describe('frequencyToMidi', () => {
+        it('should correctly convert A4 (440Hz) to MIDI 69', () => {
+            expect(frequencyToMidi(440)).toBe(69);
+        });
+
+        it('should correctly convert C4 (approx 261.63Hz) to MIDI 60', () => {
+            // C4 is 261.625...
+            expect(frequencyToMidi(261.63)).toBe(60);
+        });
+
+        it('should return 0 for 0 or negative frequency', () => {
+            expect(frequencyToMidi(0)).toBe(0);
+            expect(frequencyToMidi(-100)).toBe(0);
+        });
+    });
+
+    describe('midiToFrequency', () => {
+        it('should correctly convert MIDI 69 to 440Hz', () => {
+            expect(midiToFrequency(69)).toBe(440);
+        });
+
+        it('should correctly convert MIDI 60 to C4 frequency', () => {
+            const freq = midiToFrequency(60);
+            expect(freq).toBeCloseTo(261.625565);
+        });
+    });
+
+    describe('getNoteDetails', () => {
+        it('should return correct details for C4 (60)', () => {
+            const details = getNoteDetails(60);
+            expect(details.name).toBe('C');
+            expect(details.octave).toBe(4);
+            expect(details.scientific).toBe('C4');
+        });
+
+        it('should return correct details for A4 (69)', () => {
+            const details = getNoteDetails(69);
+            expect(details.name).toBe('A');
+            expect(details.octave).toBe(4);
+            expect(details.scientific).toBe('A4');
+        });
+
+        it('should return correct details for F#4 (66)', () => {
+            const details = getNoteDetails(66);
+            expect(details.name).toBe('F#');
+            expect(details.octave).toBe(4);
+            expect(details.scientific).toBe('F#4');
+        });
+    });
+
+    describe('getRandomNote', () => {
+        it('should return a note within range', () => {
+            for (let i = 0; i < 100; i++) {
+                const note = getRandomNote(60, 72);
+                expect(note).toBeGreaterThanOrEqual(60);
+                expect(note).toBeLessThanOrEqual(72);
+            }
+        });
+
+        it('should verify min and max bounds are inclusive', () => {
+            // Statistically probable to hit bounds with enough iterations if range is small
+            const results = new Set<number>();
+            for (let i = 0; i < 50; i++) {
+                results.add(getRandomNote(60, 61));
+            }
+            expect(results.has(60)).toBe(true);
+            expect(results.has(61)).toBe(true);
+        });
+
+        it('should return a note from validNotes list if provided', () => {
+            const valid = [60, 64, 67]; // C major triad
+            for (let i = 0; i < 50; i++) {
+                const note = getRandomNote(0, 100, valid);
+                expect(valid).toContain(note);
+            }
+        });
+    });
+
+    describe('getNoteInKey', () => {
+        it('should return simple note for C Major', () => {
+            // C4 in C Major -> c/4
+            const spec = getNoteInKey(60, 'C');
+            expect(spec.keys[0]).toBe('c/4');
+            expect(spec.accidental).toBeUndefined();
+        });
+
+        it('should implies accidental if in key signature (F# in G Major)', () => {
+            // F#4 (66) in G Major (which has F#) -> f#/4, no accidental shown
+            const spec = getNoteInKey(66, 'G');
+            expect(spec.keys[0]).toBe('f#/4');
+            expect(spec.accidental).toBeUndefined();
+        });
+
+        it('should show accidental if outside key signature (F# in C Major)', () => {
+            // F#4 (66) in C Major -> f#/4, show #
+            const spec = getNoteInKey(66, 'C');
+            expect(spec.keys[0]).toBe('f#/4');
+            expect(spec.accidental).toBe('#');
+        });
+
+        it('should show natural if key has accidental but note is natural (F in G Major)', () => {
+            // F4 (65) in G Major (expects F#) -> f/4, show natural
+            const spec = getNoteInKey(65, 'G');
+            // rawName for 65 is F.
+            expect(spec.keys[0]).toBe('f/4'); // "f/4"
+            expect(spec.accidental).toBe('n');
+        });
+    });
+});

src/test/setup.ts

@@ -0,0 +1 @@
+import '@testing-library/jest-dom';

src/types/SettingsTypes.ts

@@ -0,0 +1,63 @@
+export type Difficulty = string;
+
+export interface RhythmSettings {
+    mode: 'bpm' | 'seconds';
+    bpm: number;
+    seconds: number;
+    active: boolean;
+    autoAdvance: boolean;
+    sound: boolean;
+    volume: number;
+}
+
+export interface AppSettings {
+    difficulty: Difficulty;
+    showHint: boolean;
+    showFretboard: boolean;
+    showTuningMeter: boolean;
+    tuningId: string;
+    keySignature: string;
+    instrument: string;
+    rhythm: RhythmSettings;
+    zenMode: boolean;
+    gameMode: 'sight_reading' | 'ear_training';
+    customMinFret?: number;
+    customMaxFret?: number;
+    autoPlaySightReading?: boolean;
+    autoPlayVolume?: number;
+    virtualGuitarVolume?: number;
+    virtualGuitarMute?: boolean;
+    micSensitivity?: number;
+    disableAnimation?: boolean;
+    theme?: 'light' | 'dark' | 'auto';
+}
+
+export const DEFAULT_SETTINGS: AppSettings = {
+    difficulty: 'first_pos',
+    showHint: false,
+    showFretboard: false,
+    showTuningMeter: false,
+    tuningId: 'standard',
+    keySignature: 'C',
+    instrument: 'guitar',
+    rhythm: {
+        mode: 'bpm',
+        bpm: 60,
+        seconds: 5,
+        active: false,
+        autoAdvance: false,
+        sound: true,
+        volume: 0.5
+    },
+    zenMode: false,
+    gameMode: 'sight_reading',
+    customMinFret: 0,
+    customMaxFret: 12,
+    autoPlaySightReading: false,
+    autoPlayVolume: 0.5,
+    virtualGuitarVolume: 0.5,
+    virtualGuitarMute: false,
+    micSensitivity: 0.5,
+    disableAnimation: false,
+    theme: 'auto'
+};

src/vite-env.d.ts

@@ -0,0 +1,2 @@
+/// <reference types="vite/client" />
+/// <reference types="vitest" />

vite.config.ts

@@ -1,4 +1,5 @@
-import { defineConfig } from 'vite'
+/// <reference types="vitest" />
+import { defineConfig } from 'vitest/config'
 import react from '@vitejs/plugin-react'
 
 // https://vite.dev/config/
@@ -6,4 +7,9 @@ export default defineConfig({
   plugins: [react()],
   // IMPORTANT: Replace 'sheet-music-trainer' with your GitHub repository name
   base: '/',
+  test: {
+    globals: true,
+    environment: 'jsdom',
+    setupFiles: './src/test/setup.ts',
+  },
 })