feat(sound): 우하단 빠른 볼륨/3프리셋 및 더미 저장 복원 적용

src/features/sound-preset/model/useSoundPresetSelection.ts

@@ -1,6 +1,6 @@
 'use client';
 
-import { useMemo, useState } from 'react';
+import { useEffect, useMemo, useState } from 'react';
 import { SOUND_PRESETS } from '@/entities/session';
 
 const TRACK_KEYS = ['white', 'rain', 'cafe', 'wave', 'fan'] as const;
@@ -16,24 +16,93 @@ const DEFAULT_TRACK_LEVELS: Record<SoundTrackKey, number> = {
 };
 
 const DEFAULT_MASTER_VOLUME = 68;
+const SOUND_PREF_STORAGE_KEY = 'viberoom:sound-pref:v1';
+
+const clampVolume = (value: number) => {
+  return Math.min(100, Math.max(0, value));
+};
+
+interface StoredSoundPref {
+  selectedPresetId?: string;
+  masterVolume?: number;
+  isMuted?: boolean;
+}
+
+const readStoredSoundPref = (): StoredSoundPref => {
+  if (typeof window === 'undefined') {
+    return {};
+  }
+
+  const raw = window.localStorage.getItem(SOUND_PREF_STORAGE_KEY);
+
+  if (!raw) {
+    return {};
+  }
+
+  try {
+    const parsed = JSON.parse(raw);
+
+    if (!parsed || typeof parsed !== 'object') {
+      return {};
+    }
+
+    return parsed as StoredSoundPref;
+  } catch {
+    return {};
+  }
+};
 
 export const useSoundPresetSelection = (initialPresetId?: string) => {
+  const storedPref = useMemo(() => readStoredSoundPref(), []);
+
   const safeInitialPresetId = useMemo(() => {
-    const hasPreset = SOUND_PRESETS.some((preset) => preset.id === initialPresetId);
-    return hasPreset && initialPresetId ? initialPresetId : SOUND_PRESETS[0].id;
-  }, [initialPresetId]);
+    const candidates = [initialPresetId, storedPref.selectedPresetId];
+
+    for (const candidate of candidates) {
+      if (!candidate) {
+        continue;
+      }
+
+      if (SOUND_PRESETS.some((preset) => preset.id === candidate)) {
+        return candidate;
+      }
+    }
+
+    return SOUND_PRESETS[0].id;
+  }, [initialPresetId, storedPref.selectedPresetId]);
 
   const [selectedPresetId, setSelectedPresetId] = useState(safeInitialPresetId);
   const [isMixerOpen, setMixerOpen] = useState(false);
-  const [isMuted, setMuted] = useState(false);
-  const [masterVolume, setMasterVolume] = useState(DEFAULT_MASTER_VOLUME);
+  const [isMuted, setMuted] = useState(Boolean(storedPref.isMuted));
+  const [masterVolume, setMasterVolume] = useState(
+    clampVolume(storedPref.masterVolume ?? DEFAULT_MASTER_VOLUME),
+  );
   const [trackLevels, setTrackLevels] =
     useState<Record<SoundTrackKey, number>>(DEFAULT_TRACK_LEVELS);
 
+  useEffect(() => {
+    if (typeof window === 'undefined') {
+      return;
+    }
+
+    window.localStorage.setItem(
+      SOUND_PREF_STORAGE_KEY,
+      JSON.stringify({
+        selectedPresetId,
+        masterVolume: clampVolume(masterVolume),
+        isMuted,
+      }),
+    );
+  }, [selectedPresetId, masterVolume, isMuted]);
+
   const setTrackLevel = (track: SoundTrackKey, level: number) => {
     setTrackLevels((current) => ({ ...current, [track]: level }));
   };
 
+  const setMasterVolumeSafe = (nextVolume: number) => {
+    setMasterVolume(clampVolume(nextVolume));
+  };
+
   return {
     selectedPresetId,
     setSelectedPresetId,
@@ -42,7 +111,7 @@ export const useSoundPresetSelection = (initialPresetId?: string) => {
     isMuted,
     setMuted,
     masterVolume,
-    setMasterVolume,
+    setMasterVolume: setMasterVolumeSafe,
     trackLevels,
     setTrackLevel,
     trackKeys: TRACK_KEYS,