refactor(epub): move reader state to route-local hook

src/app/(app)/epub/[id]/layout.tsx

@@ -4,13 +4,12 @@ import type { ReactNode } from 'react';
 
 import { ConfigProvider } from '@/contexts/ConfigContext';
 import { TTSProvider } from '@/contexts/TTSContext';
-import { EPUBProvider } from '@/contexts/EPUBContext';
 
 export default function EpubReaderLayout({ children }: { children: ReactNode }) {
   return (
     <ConfigProvider>
       <TTSProvider>
-        <EPUBProvider>{children}</EPUBProvider>
+        {children}
       </TTSProvider>
     </ConfigProvider>
   );

src/app/(app)/epub/[id]/page.tsx

@@ -3,7 +3,6 @@
 import { useParams, useRouter } from "next/navigation";
 import Link from 'next/link';
 import { useCallback, useEffect, useRef, useState } from 'react';
-import { useEPUB } from '@/contexts/EPUBContext';
 import { DocumentSkeleton } from '@/components/documents/DocumentSkeleton';
 import { EPUBViewer } from '@/components/views/EPUBViewer';
 import { DocumentSettings } from '@/components/documents/DocumentSettings';
@@ -20,12 +19,21 @@ import { resolveDocumentId } from '@/lib/client/dexie';
 import { RateLimitBanner } from '@/components/auth/RateLimitBanner';
 import { useAuthRateLimit } from '@/contexts/AuthRateLimitContext';
 import { useFeatureFlag } from '@/contexts/RuntimeConfigContext';
+import { useEPUB } from './useEpubDocument';
 
 export default function EPUBPage() {
   const canExportAudiobook = useFeatureFlag('enableAudiobookExport');
   const { id } = useParams();
   const router = useRouter();
-  const { setCurrentDocument, currDocName, clearCurrDoc, createFullAudioBook: createEPUBAudioBook, regenerateChapter: regenerateEPUBChapter, bookRef } = useEPUB();
+  const epubState = useEPUB();
+  const {
+    setCurrentDocument,
+    currDocName,
+    clearCurrDoc,
+    createFullAudioBook: createEPUBAudioBook,
+    regenerateChapter: regenerateEPUBChapter,
+    bookRef,
+  } = epubState;
   const { stop } = useTTS();
   const { isAtLimit } = useAuthRateLimit();
   const [error, setError] = useState<string | null>(null);
@@ -209,7 +217,7 @@ export default function EPUBPage() {
           </div>
         ) : (
           <div className="h-full w-full" style={{ paddingLeft: `${Math.round(maxPadPx * ((100 - padPct) / 100))}px`, paddingRight: `${Math.round(maxPadPx * ((100 - padPct) / 100))}px` }}>
-            <EPUBViewer className="h-full" />
+            <EPUBViewer className="h-full" epubState={epubState} />
           </div>
         )}
       </div>

src/app/(app)/epub/[id]/useEpubDocument.ts

@@ -1,10 +1,7 @@
 'use client';
 
 import {
-  createContext,
-  useContext,
   useState,
-  ReactNode,
   useCallback,
   useMemo,
   useRef,
@@ -36,7 +33,7 @@ import {
   type EpubCanonicalWordToken,
 } from '@/lib/client/epub/epub-word-highlight';
 import { useParams } from 'next/navigation';
-import { useConfig } from './ConfigContext';
+import { useConfig } from '@/contexts/ConfigContext';
 import type {
   EpubRenderedLocationWalker,
   TTSSentenceAlignment,
@@ -47,7 +44,7 @@ import type { AudiobookGenerationSettings, TTSSegmentLocator } from '@/types/cli
 import { isStableEpubLocator } from '@/types/client';
 import type { CanonicalTtsSegment } from '@/lib/shared/tts-segment-plan';
 
-interface EPUBContextType {
+export interface EPUBState {
   currDocData: ArrayBuffer | undefined;
   currDocName: string | undefined;
   currDocPages: number | undefined;
@@ -90,8 +87,6 @@ interface EPUBContextType {
   clearWordHighlights: () => void;
 }
 
-const EPUBContext = createContext<EPUBContextType | undefined>(undefined);
-
 const EPUB_CONTINUATION_CHARS = 5000;
 
 const stepToNextNode = (node: Node | null, root: Node): Node | null => {
@@ -526,12 +521,9 @@ const resolveVisibleSegmentRange = (
 
 
 /**
- * Provider component for EPUB functionality
+ * Route-local EPUB reader hook.
- * Manages the state and operations for EPUB document handling
- * @param {Object} props - Component props
- * @param {ReactNode} props.children - Child components to be wrapped by the provider
  */
-export function EPUBProvider({ children }: { children: ReactNode }) {
+export function useEPUB(): EPUBState {
   const { setText: setTTSText, currDocPage, currDocPages, setCurrDocPages, stop, skipToLocation, setIsEPUB } = useTTS();
   const { authEnabled } = useAuthConfig();
   const { id } = useParams();
@@ -1141,8 +1133,7 @@ export function EPUBProvider({ children }: { children: ReactNode }) {
 
 
 
-  // Context value memoization
+  return useMemo(
-  const contextValue = useMemo(
     () => ({
       setCurrentDocument,
       currDocData,
@@ -1190,23 +1181,4 @@ export function EPUBProvider({ children }: { children: ReactNode }) {
       clearWordHighlights,
     ]
   );
-
-  return (
-    <EPUBContext.Provider value={contextValue}>
-      {children}
-    </EPUBContext.Provider>
-  );
-}
-
-/**
- * Custom hook to consume the EPUB context
- * @returns {EPUBContextType} The EPUB context value
- * @throws {Error} When used outside of EPUBProvider
- */
-export function useEPUB() {
-  const context = useContext(EPUBContext);
-  if (context === undefined) {
-    throw new Error('useEPUB must be used within an EPUBProvider');
-  }
-  return context;
 }

src/components/views/EPUBViewer.tsx

@@ -2,13 +2,13 @@
 
 import { useEffect, useRef, useCallback, useState } from 'react';
 import dynamic from 'next/dynamic';
-import { useEPUB } from '@/contexts/EPUBContext';
 import { useTTS } from '@/contexts/TTSContext';
 import { useConfig } from '@/contexts/ConfigContext';
 import { DocumentSkeleton } from '@/components/documents/DocumentSkeleton';
 import { useEPUBTheme, getThemeStyles } from '@/hooks/epub/useEPUBTheme';
 import { useEPUBResize } from '@/hooks/epub/useEPUBResize';
 import { DotsVerticalIcon, ChevronLeftIcon, ChevronRightIcon } from '@/components/icons/Icons';
+import type { EPUBState } from '@/app/(app)/epub/[id]/useEpubDocument';
 
 const ReactReader = dynamic(() => import('react-reader').then(mod => mod.ReactReader), {
   ssr: false,
@@ -17,9 +17,29 @@ const ReactReader = dynamic(() => import('react-reader').then(mod => mod.ReactRe
 
 interface EPUBViewerProps {
   className?: string;
+  epubState: Pick<
+    EPUBState,
+    | 'currDocData'
+    | 'currDocName'
+    | 'currDocPage'
+    | 'currDocPages'
+    | 'locationRef'
+    | 'handleLocationChanged'
+    | 'bookRef'
+    | 'renditionRef'
+    | 'tocRef'
+    | 'setRendition'
+    | 'extractPageText'
+    | 'highlightSegment'
+    | 'clearHighlights'
+    | 'highlightWordIndex'
+    | 'clearWordHighlights'
+    | 'walkUpcomingRenderedLocations'
+    | 'resolveEpubLocator'
+  >;
 }
 
-export function EPUBViewer({ className = '' }: EPUBViewerProps) {
+export function EPUBViewer({ className = '', epubState }: EPUBViewerProps) {
   const [isTocOpen, setIsTocOpen] = useState(false);
   const {
     currDocData,
@@ -39,7 +59,7 @@ export function EPUBViewer({ className = '' }: EPUBViewerProps) {
     clearWordHighlights,
     walkUpcomingRenderedLocations,
     resolveEpubLocator,
-  } = useEPUB();
+  } = epubState;
   const {
     registerLocationChangeHandler,
     registerEpubLocationWalker,