openreader/src/contexts/EPUBContext.tsx

441 lines
No EOL
14 KiB
TypeScript

'use client';
import {
createContext,
useContext,
useState,
ReactNode,
useCallback,
useMemo,
useRef,
RefObject,
} from 'react';
import { indexedDBService } from '@/utils/indexedDB';
import { useTTS } from '@/contexts/TTSContext';
import { Book, Rendition } from 'epubjs';
import { createRangeCfi } from '@/utils/epub';
import type { NavItem } from 'epubjs';
import { setLastDocumentLocation } from '@/utils/indexedDB';
import { SpineItem } from 'epubjs/types/section';
import { useParams } from 'next/navigation';
import { useConfig } from './ConfigContext';
interface EPUBContextType {
currDocData: ArrayBuffer | undefined;
currDocName: string | undefined;
currDocPages: number | undefined;
currDocPage: number | string;
currDocText: string | undefined;
setCurrentDocument: (id: string) => Promise<void>;
clearCurrDoc: () => void;
extractPageText: (book: Book, rendition: Rendition, shouldPause?: boolean) => Promise<string>;
createFullAudioBook: (onProgress: (progress: number) => void, signal?: AbortSignal, format?: 'mp3' | 'm4b') => Promise<ArrayBuffer>;
bookRef: RefObject<Book | null>;
renditionRef: RefObject<Rendition | undefined>;
tocRef: RefObject<NavItem[]>;
locationRef: RefObject<string | number>;
handleLocationChanged: (location: string | number) => void;
setRendition: (rendition: Rendition) => void;
isAudioCombining: boolean;
}
const EPUBContext = createContext<EPUBContextType | undefined>(undefined);
/**
* Provider component for EPUB functionality
* 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 }) {
const { setText: setTTSText, currDocPage, currDocPages, setCurrDocPages, stop, skipToLocation, setIsEPUB } = useTTS();
const { id } = useParams();
// Configuration context to get TTS settings
const {
apiKey,
baseUrl,
voiceSpeed,
voice,
} = useConfig();
// Current document state
const [currDocData, setCurrDocData] = useState<ArrayBuffer>();
const [currDocName, setCurrDocName] = useState<string>();
const [currDocText, setCurrDocText] = useState<string>();
const [isAudioCombining, setIsAudioCombining] = useState(false);
// Add new refs
const bookRef = useRef<Book | null>(null);
const renditionRef = useRef<Rendition | undefined>(undefined);
const tocRef = useRef<NavItem[]>([]);
const locationRef = useRef<string | number>(currDocPage);
const isEPUBSetOnce = useRef(false);
/**
* Clears all current document state and stops any active TTS
*/
const clearCurrDoc = useCallback(() => {
setCurrDocData(undefined);
setCurrDocName(undefined);
setCurrDocText(undefined);
setCurrDocPages(undefined);
stop();
}, [setCurrDocPages, stop]);
/**
* Sets the current document based on its ID by fetching from IndexedDB
* @param {string} id - The unique identifier of the document
* @throws {Error} When document data is empty or retrieval fails
*/
const setCurrentDocument = useCallback(async (id: string): Promise<void> => {
try {
const doc = await indexedDBService.getEPUBDocument(id);
if (doc) {
console.log('Retrieved document size:', doc.size);
console.log('Retrieved ArrayBuffer size:', doc.data.byteLength);
if (doc.data.byteLength === 0) {
console.error('Retrieved ArrayBuffer is empty');
throw new Error('Empty document data');
}
setCurrDocName(doc.name);
setCurrDocData(doc.data); // Store ArrayBuffer directly
} else {
console.error('Document not found in IndexedDB');
}
} catch (error) {
console.error('Failed to get EPUB document:', error);
clearCurrDoc(); // Clean up on error
}
}, [clearCurrDoc]);
/**
* Extracts text content from the current EPUB page/location
* @param {Book} book - The EPUB.js Book instance
* @param {Rendition} rendition - The EPUB.js Rendition instance
* @param {boolean} shouldPause - Whether to pause TTS
* @returns {Promise<string>} The extracted text content
*/
const extractPageText = useCallback(async (book: Book, rendition: Rendition, shouldPause = false): Promise<string> => {
try {
const { start, end } = rendition?.location;
if (!start?.cfi || !end?.cfi || !book || !book.isOpen || !rendition) return '';
const rangeCfi = createRangeCfi(start.cfi, end.cfi);
const range = await book.getRange(rangeCfi);
if (!range) {
console.warn('Failed to get range from CFI:', rangeCfi);
return '';
}
const textContent = range.toString().trim();
setTTSText(textContent, shouldPause);
setCurrDocText(textContent);
return textContent;
} catch (error) {
console.error('Error extracting EPUB text:', error);
return '';
}
}, [setTTSText]);
/**
* Extracts text content from the entire EPUB book
* @returns {Promise<string[]>} Array of text content from each section
*/
const extractBookText = useCallback(async (): Promise<string[]> => {
try {
if (!bookRef.current || !bookRef.current.isOpen) return [''];
const book = bookRef.current;
const spine = book.spine;
const promises: Promise<string>[] = [];
spine.each((item: SpineItem) => {
const url = item.href || '';
if (!url) return;
const promise = book.load(url)
.then((section) => (section as Document))
.then((section) => {
const textContent = section.body.textContent || '';
return textContent;
})
.catch((err) => {
console.error(`Error loading section ${url}:`, err);
return '';
});
promises.push(promise);
});
const textArray = await Promise.all(promises);
const filteredArray = textArray.filter(text => text.trim() !== '');
console.log('Extracted entire EPUB text array:', filteredArray);
return filteredArray;
} catch (error) {
console.error('Error extracting EPUB text:', error);
return [''];
}
}, []);
/**
* Creates a complete audiobook by processing all text through NLP and TTS
*/
const createFullAudioBook = useCallback(async (
onProgress: (progress: number) => void,
signal?: AbortSignal,
format: 'mp3' | 'm4b' = 'mp3'
): Promise<ArrayBuffer> => {
try {
const textArray = await extractBookText();
if (!textArray.length) throw new Error('No text content found in book');
// Calculate total text length for accurate progress tracking
const totalLength = textArray.reduce((sum, text) => sum + text.trim().length, 0);
const audioChunks: { buffer: ArrayBuffer; title?: string; startTime: number }[] = [];
let processedLength = 0;
let currentTime = 0;
// Get TOC for chapter titles if available
const chapters = tocRef.current || [];
const spine = bookRef.current?.spine;
for (const text of textArray) {
if (signal?.aborted) {
const partialBuffer = await combineAudioChunks(audioChunks, format);
return partialBuffer;
}
try {
const trimmedText = text.trim();
if (!trimmedText) continue;
const ttsResponse = await fetch('/api/tts', {
method: 'POST',
headers: {
'x-openai-key': apiKey,
'x-openai-base-url': baseUrl,
},
body: JSON.stringify({
text: trimmedText,
voice: voice,
speed: voiceSpeed,
format: 'audiobook'
}),
signal
});
if (!ttsResponse.ok) {
throw new Error(`TTS processing failed with status ${ttsResponse.status}`);
}
const audioBuffer = await ttsResponse.arrayBuffer();
if (audioBuffer.byteLength === 0) {
throw new Error('Received empty audio buffer from TTS');
}
// Find matching chapter title from TOC if available
let chapterTitle;
if (spine && chapters.length > 0) {
let spineIndex = processedLength;
let currentSpineHref: string | undefined;
spine.each((item: SpineItem) => {
if (spineIndex === 0) {
currentSpineHref = item.href;
}
spineIndex--;
});
const matchingChapter = chapters.find(chapter =>
chapter.href && currentSpineHref?.includes(chapter.href)
);
chapterTitle = matchingChapter?.label || `Section ${processedLength + 1}`;
} else {
chapterTitle = `Section ${processedLength + 1}`;
}
audioChunks.push({
buffer: audioBuffer,
title: chapterTitle,
startTime: currentTime
});
// Add silence between sections
const silenceBuffer = new ArrayBuffer(48000);
audioChunks.push({
buffer: silenceBuffer,
startTime: currentTime + (audioBuffer.byteLength / 48000)
});
currentTime += (audioBuffer.byteLength + 48000) / 48000;
// Update progress based on processed text length
processedLength += trimmedText.length;
onProgress((processedLength / totalLength) * 100);
} catch (error) {
if (error instanceof Error && error.name === 'AbortError') {
console.log('TTS request aborted');
const partialBuffer = await combineAudioChunks(audioChunks, format);
return partialBuffer;
}
console.error('Error processing section:', error);
}
}
if (audioChunks.length === 0) {
throw new Error('No audio was generated from the book content');
}
return combineAudioChunks(audioChunks, format);
} catch (error) {
console.error('Error creating audiobook:', error);
throw error;
}
}, [extractBookText, apiKey, baseUrl, voice, voiceSpeed]);
const combineAudioChunks = async (
audioChunks: { buffer: ArrayBuffer; title?: string; startTime: number }[],
format: 'mp3' | 'm4b'
): Promise<ArrayBuffer> => {
setIsAudioCombining(true);
try {
if (format === 'm4b') {
// Convert to M4B format using the audio conversion API
const response = await fetch('/api/audio/convert', {
method: 'POST',
headers: {
'Content-Type': 'application/json',
},
body: JSON.stringify({
chapters: audioChunks
.filter(chunk => chunk.title) // Only include chunks with titles
.map(chunk => ({
title: chunk.title,
buffer: Array.from(new Uint8Array(chunk.buffer))
}))
}),
});
if (!response.ok) {
throw new Error('Failed to convert audio to M4B format');
}
return response.arrayBuffer();
}
// For MP3, just concatenate the buffers
const totalLength = audioChunks.reduce((acc, chunk) => acc + chunk.buffer.byteLength, 0);
const combinedBuffer = new Uint8Array(totalLength);
let offset = 0;
for (const chunk of audioChunks) {
combinedBuffer.set(new Uint8Array(chunk.buffer), offset);
offset += chunk.buffer.byteLength;
}
return combinedBuffer.buffer;
} finally {
setIsAudioCombining(false);
}
}
const setRendition = useCallback((rendition: Rendition) => {
bookRef.current = rendition.book;
renditionRef.current = rendition;
}, []);
const handleLocationChanged = useCallback((location: string | number) => {
// Set the EPUB flag once the location changes
if (!isEPUBSetOnce.current) {
setIsEPUB(true);
isEPUBSetOnce.current = true;
renditionRef.current?.display(location.toString());
return;
}
if (!bookRef.current?.isOpen || !renditionRef.current) return;
// Handle special 'next' and 'prev' cases
if (location === 'next' && renditionRef.current) {
renditionRef.current.next();
return;
}
if (location === 'prev' && renditionRef.current) {
renditionRef.current.prev();
return;
}
// Save the location to IndexedDB if not initial
if (id && locationRef.current !== 1) {
console.log('Saving location:', location);
setLastDocumentLocation(id as string, location.toString());
}
skipToLocation(location);
locationRef.current = location;
if (bookRef.current && renditionRef.current) {
extractPageText(bookRef.current, renditionRef.current);
}
}, [id, skipToLocation, extractPageText, setIsEPUB]);
// Context value memoization
const contextValue = useMemo(
() => ({
setCurrentDocument,
currDocData,
currDocName,
currDocPages,
currDocPage,
currDocText,
clearCurrDoc,
extractPageText,
createFullAudioBook,
bookRef,
renditionRef,
tocRef,
locationRef,
handleLocationChanged,
setRendition,
isAudioCombining,
}),
[
setCurrentDocument,
currDocData,
currDocName,
currDocPages,
currDocPage,
currDocText,
clearCurrDoc,
extractPageText,
createFullAudioBook,
handleLocationChanged,
setRendition,
isAudioCombining,
]
);
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;
}