forked from akai/readest
Huang Xin
dc788283ad
* security: fix for code scanning alert no. 11: Incomplete multi-character sanitization Co-authored-by: Copilot Autofix powered by AI <62310815+github-advanced-security[bot]@users.noreply.github.com> * fix: use dotAll flag to match multi-line HTML comments Add the 's' flag to the comment-stripping regex so '.' matches newlines, ensuring comments spanning multiple lines are also removed. Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com> --------- Co-authored-by: Copilot Autofix powered by AI <62310815+github-advanced-security[bot]@users.noreply.github.com> Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
987 lines
31 KiB
TypeScript
987 lines
31 KiB
TypeScript
import { partialMD5 } from './md5';
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import { getBaseFilename } from './path';
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import { detectLanguage } from './lang';
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import { configureZip } from './zip';
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interface Metadata {
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bookTitle: string;
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author: string;
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language: string;
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identifier: string;
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}
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interface Chapter {
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title: string;
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content: string;
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isVolume: boolean;
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}
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interface Txt2EpubOptions {
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file: File;
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author?: string;
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language?: string;
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}
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interface ExtractChapterOptions {
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linesBetweenSegments: number;
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fallbackParagraphsPerChapter: number;
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}
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export interface ConversionResult {
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file: File;
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bookTitle: string;
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chapterCount: number;
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language: string;
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}
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const zipWriteOptions = {
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lastAccessDate: new Date(0),
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lastModDate: new Date(0),
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};
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const LARGE_TXT_THRESHOLD_BYTES = 8 * 1024 * 1024;
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const HEADER_TEXT_MAX_CHARS = 1024;
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const HEADER_TEXT_MAX_BYTES = 128 * 1024;
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const ENCODING_HEAD_SAMPLE_BYTES = 64 * 1024;
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const ENCODING_MID_SAMPLE_BYTES = 8192;
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const escapeXml = (str: string) => {
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if (!str) return '';
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return str
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.replace(/&/g, '&')
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.replace(/</g, '<')
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.replace(/>/g, '>')
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.replace(/"/g, '"')
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.replace(/'/g, ''');
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};
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export class TxtToEpubConverter {
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public async convert(options: Txt2EpubOptions): Promise<ConversionResult> {
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if (options.file.size <= LARGE_TXT_THRESHOLD_BYTES) {
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return await this.convertSmallFile(options);
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}
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return await this.convertLargeFile(options);
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}
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private async convertSmallFile(options: Txt2EpubOptions): Promise<ConversionResult> {
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const { file: txtFile, author: providedAuthor, language: providedLanguage } = options;
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const fileContent = await txtFile.arrayBuffer();
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const detectedEncoding = this.detectEncoding(fileContent) || 'utf-8';
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const runtimeEncoding = this.resolveSupportedEncoding(detectedEncoding);
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// console.log(`Detected encoding: ${detectedEncoding}, runtime encoding: ${runtimeEncoding}`);
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const decoder = new TextDecoder(runtimeEncoding);
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const txtContent = decoder.decode(fileContent).trim();
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const bookTitle = this.extractBookTitle(getBaseFilename(txtFile.name));
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const fileName = `${bookTitle}.epub`;
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const fileHeader = txtContent.slice(0, 1024);
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const authorMatch =
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fileHeader.match(/[【\[]?作者[】\]]?[:：\s]\s*(.+)\r?\n/) ||
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fileHeader.match(/[【\[]?\s*(.+)\s+著\s*[】\]]?\r?\n/);
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let matchedAuthor = authorMatch ? authorMatch[1]!.trim() : providedAuthor || '';
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try {
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matchedAuthor = matchedAuthor.replace(/^[\p{P}\p{S}]+|[\p{P}\p{S}]+$/gu, '');
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} catch {}
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const author = matchedAuthor || providedAuthor || '';
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const language = providedLanguage || detectLanguage(fileHeader);
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// console.log(`Detected language: ${language}`);
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const identifier = await partialMD5(txtFile);
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const metadata = { bookTitle, author, language, identifier };
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const fallbackParagraphsPerChapter = 100;
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let chapters = this.extractChapters(txtContent, metadata, {
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linesBetweenSegments: 8,
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fallbackParagraphsPerChapter,
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});
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if (chapters.length === 0) {
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throw new Error('No chapters detected.');
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}
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if (chapters.length <= 1) {
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const probeChapterCount = this.probeChapterCount(txtContent, metadata, {
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linesBetweenSegments: 7,
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fallbackParagraphsPerChapter,
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});
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chapters = this.extractChapters(txtContent, metadata, {
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linesBetweenSegments: probeChapterCount > 1 ? 7 : 6,
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fallbackParagraphsPerChapter,
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});
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}
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const blob = await this.createEpub(chapters, metadata);
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return {
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file: new File([blob], fileName),
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bookTitle,
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chapterCount: chapters.length,
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language,
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};
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}
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private async convertLargeFile(options: Txt2EpubOptions): Promise<ConversionResult> {
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const { file: txtFile, author: providedAuthor, language: providedLanguage } = options;
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const detectedEncoding = (await this.detectEncodingFromFile(txtFile)) || 'utf-8';
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const runtimeEncoding = this.resolveSupportedEncoding(detectedEncoding);
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// console.log(`Detected encoding: ${detectedEncoding}, runtime encoding: ${runtimeEncoding}`);
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const bookTitle = this.extractBookTitle(getBaseFilename(txtFile.name));
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const fileName = `${bookTitle}.epub`;
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const fileHeader = await this.readHeaderTextFromFile(
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txtFile,
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runtimeEncoding,
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HEADER_TEXT_MAX_CHARS,
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HEADER_TEXT_MAX_BYTES,
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);
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const { author, language } = this.extractAuthorAndLanguage(
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fileHeader,
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providedAuthor,
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providedLanguage,
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);
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// console.log(`Detected language: ${language}`);
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const identifier = await partialMD5(txtFile);
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const metadata = { bookTitle, author, language, identifier };
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const fallbackParagraphsPerChapter = 100;
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let chapters = await this.extractChaptersFromFileBySegments(
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txtFile,
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runtimeEncoding,
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metadata,
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{
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linesBetweenSegments: 8,
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fallbackParagraphsPerChapter,
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},
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);
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if (chapters.length === 0) {
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throw new Error('No chapters detected.');
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}
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if (chapters.length <= 1) {
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const probeChapterCount = await this.probeChapterCountFromFileBySegments(
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txtFile,
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runtimeEncoding,
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metadata,
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{
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linesBetweenSegments: 7,
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fallbackParagraphsPerChapter,
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},
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);
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chapters = await this.extractChaptersFromFileBySegments(txtFile, runtimeEncoding, metadata, {
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linesBetweenSegments: probeChapterCount > 1 ? 7 : 6,
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fallbackParagraphsPerChapter,
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});
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}
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const blob = await this.createEpub(chapters, metadata);
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return {
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file: new File([blob], fileName),
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bookTitle,
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chapterCount: chapters.length,
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language,
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};
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}
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private extractChapters(
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txtContent: string,
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metadata: Metadata,
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option: ExtractChapterOptions,
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): Chapter[] {
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const { linesBetweenSegments } = option;
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const segmentRegex = this.createSegmentRegex(linesBetweenSegments);
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const chapters: Chapter[] = [];
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const segments = txtContent.split(segmentRegex);
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for (const segment of segments) {
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const segmentChapters = this.extractChaptersFromSegment(
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segment,
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metadata,
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option,
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chapters.length,
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);
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chapters.push(...segmentChapters);
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}
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return chapters;
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}
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private probeChapterCount(
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txtContent: string,
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metadata: Metadata,
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option: ExtractChapterOptions,
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): number {
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const { linesBetweenSegments } = option;
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const segmentRegex = this.createSegmentRegex(linesBetweenSegments);
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let chapterCount = 0;
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const segments = txtContent.split(segmentRegex);
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for (const segment of segments) {
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chapterCount += this.probeChapterCountFromSegment(segment, metadata, option);
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if (chapterCount > 1) {
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return chapterCount;
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}
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}
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return chapterCount;
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}
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private async extractChaptersFromFileBySegments(
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txtFile: File,
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encoding: string,
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metadata: Metadata,
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option: ExtractChapterOptions,
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): Promise<Chapter[]> {
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const chapters: Chapter[] = [];
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for await (const segment of this.iterateSegmentsFromFile(
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txtFile,
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encoding,
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option.linesBetweenSegments,
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)) {
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const segmentChapters = this.extractChaptersFromSegment(
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segment,
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metadata,
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option,
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chapters.length,
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);
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chapters.push(...segmentChapters);
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}
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return chapters;
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}
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private async probeChapterCountFromFileBySegments(
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txtFile: File,
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encoding: string,
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metadata: Metadata,
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option: ExtractChapterOptions,
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): Promise<number> {
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let chapterCount = 0;
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for await (const segment of this.iterateSegmentsFromFile(
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txtFile,
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encoding,
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option.linesBetweenSegments,
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)) {
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chapterCount += this.probeChapterCountFromSegment(segment, metadata, option);
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if (chapterCount > 1) {
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return chapterCount;
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}
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}
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return chapterCount;
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}
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private async detectEncodingFromFile(file: File): Promise<string | undefined> {
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const headSampleSize = Math.min(file.size, ENCODING_HEAD_SAMPLE_BYTES);
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const headBuffer = await file.slice(0, headSampleSize).arrayBuffer();
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const headSample = new Uint8Array(headBuffer);
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try {
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this.assertStrictUtf8Sample(headSample);
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if (file.size > headSampleSize * 2) {
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const midSampleSize = Math.min(ENCODING_MID_SAMPLE_BYTES, file.size - headSampleSize);
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const midSampleStart = Math.floor((file.size - midSampleSize) / 2);
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const midBuffer = await file
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.slice(midSampleStart, midSampleStart + midSampleSize)
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.arrayBuffer();
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this.assertStrictUtf8Sample(new Uint8Array(midBuffer));
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}
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return 'utf-8';
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} catch {
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let validBytes = 0;
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let checkedBytes = 0;
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const sampleSize = Math.min(headSample.length, 10000);
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for (let i = 0; i < sampleSize; i++) {
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try {
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new TextDecoder('utf-8', { fatal: true }).decode(headSample.slice(i, i + 100));
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validBytes += 100;
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checkedBytes += 100;
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i += 99;
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} catch {
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checkedBytes++;
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}
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}
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const validPercentage = checkedBytes > 0 ? (validBytes / checkedBytes) * 100 : 0;
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console.log(`UTF-8 validity: ${validPercentage.toFixed(2)}%`);
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if (validPercentage > 80) {
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console.log('Treating as UTF-8 despite some invalid sequences');
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return 'utf-8';
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}
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}
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if (headSample[0] === 0xff && headSample[1] === 0xfe) {
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return 'utf-16le';
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}
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if (headSample[0] === 0xfe && headSample[1] === 0xff) {
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return 'utf-16be';
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}
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if (headSample[0] === 0xef && headSample[1] === 0xbb && headSample[2] === 0xbf) {
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return 'utf-8';
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}
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const sample = headSample.slice(0, Math.min(1024, headSample.length));
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let highByteCount = 0;
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for (let i = 0; i < sample.length; i++) {
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if (sample[i]! >= 0x80) {
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highByteCount++;
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}
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}
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const highByteRatio = sample.length > 0 ? highByteCount / sample.length : 0;
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if (highByteRatio > 0.3) {
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return 'gbk';
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}
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if (highByteRatio > 0.1) {
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let sjisPattern = false;
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for (let i = 0; i < sample.length - 1; i++) {
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const b1 = sample[i]!;
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const b2 = sample[i + 1]!;
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if (
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((b1 >= 0x81 && b1 <= 0x9f) || (b1 >= 0xe0 && b1 <= 0xfc)) &&
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((b2 >= 0x40 && b2 <= 0x7e) || (b2 >= 0x80 && b2 <= 0xfc))
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) {
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sjisPattern = true;
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break;
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}
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}
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if (sjisPattern) {
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return 'shift-jis';
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}
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return 'gb18030';
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}
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return 'utf-8';
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}
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private async readHeaderTextFromFile(
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file: File,
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encoding: string,
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maxChars: number,
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maxBytes: number,
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): Promise<string> {
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const decoder = new TextDecoder(encoding);
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const headerBytes = await file.slice(0, Math.min(file.size, maxBytes)).arrayBuffer();
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return decoder.decode(headerBytes).slice(0, maxChars).trim();
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}
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private async *iterateSegmentsFromFile(
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file: File,
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encoding: string,
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linesBetweenSegments: number,
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): AsyncGenerator<string> {
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const reader = file.stream().getReader();
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const decoder = new TextDecoder(encoding);
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const segmentRegex = this.createSegmentRegex(linesBetweenSegments);
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let pending = '';
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let completed = false;
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try {
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while (true) {
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const { value, done } = await reader.read();
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if (done) {
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completed = true;
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break;
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}
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if (!value) continue;
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pending += decoder.decode(value, { stream: true });
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const consumed = this.consumeCompleteSegments(pending, segmentRegex);
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pending = consumed.pending;
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for (const segment of consumed.segments) {
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yield segment;
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}
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}
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pending += decoder.decode();
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const consumed = this.consumeCompleteSegments(pending, segmentRegex);
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for (const segment of consumed.segments) {
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yield segment;
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}
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if (consumed.pending) {
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yield consumed.pending;
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}
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} finally {
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if (!completed) {
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try {
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await reader.cancel();
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} catch {}
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}
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reader.releaseLock();
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}
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}
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*iterateSegmentsFromTextChunks(
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chunks: Iterable<string>,
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linesBetweenSegments: number,
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): Generator<string> {
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const segmentRegex = this.createSegmentRegex(linesBetweenSegments);
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let pending = '';
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for (const chunk of chunks) {
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pending += chunk;
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const consumed = this.consumeCompleteSegments(pending, segmentRegex);
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pending = consumed.pending;
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for (const segment of consumed.segments) {
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yield segment;
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}
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}
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if (pending) {
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yield pending;
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}
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}
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private consumeCompleteSegments(
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pending: string,
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segmentRegex: RegExp,
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): { segments: string[]; pending: string } {
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const segments: string[] = [];
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let match = segmentRegex.exec(pending);
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while (match) {
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segments.push(pending.slice(0, match.index));
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pending = pending.slice(match.index + match[0].length);
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segmentRegex.lastIndex = 0;
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match = segmentRegex.exec(pending);
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}
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return { segments, pending };
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}
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private extractAuthorAndLanguage(
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fileHeader: string,
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providedAuthor?: string,
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providedLanguage?: string,
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): { author: string; language: string } {
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const authorMatch =
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fileHeader.match(/[【\[]?作者[】\]]?[:：\s]\s*(.+)\r?\n/) ||
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fileHeader.match(/[【\[]?\s*(.+)\s+著\s*[】\]]?\r?\n/);
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let matchedAuthor = authorMatch ? authorMatch[1]!.trim() : providedAuthor || '';
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try {
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matchedAuthor = matchedAuthor.replace(/^[\p{P}\p{S}]+|[\p{P}\p{S}]+$/gu, '');
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} catch {}
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const author = matchedAuthor || providedAuthor || '';
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const language = providedLanguage || detectLanguage(fileHeader);
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return { author, language };
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}
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private extractChaptersFromSegment(
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segment: string,
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metadata: Metadata,
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option: ExtractChapterOptions,
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chapterOffset: number,
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): Chapter[] {
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const { language } = metadata;
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const { fallbackParagraphsPerChapter } = option;
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const trimmedSegment = segment.replace(/<!--.*?-->/g, '').trim();
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if (!trimmedSegment) return [];
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const chapterRegexps = this.createChapterRegexps(language);
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let matches: string[] = [];
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for (const chapterRegex of chapterRegexps) {
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const tryMatches = trimmedSegment.split(chapterRegex);
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if (this.isGoodMatches(tryMatches)) {
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matches = this.joinAroundUndefined(tryMatches);
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break;
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}
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}
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if (matches.length === 0 && fallbackParagraphsPerChapter > 0) {
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const chapters: Chapter[] = [];
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const paragraphs = trimmedSegment.split(/\n+/);
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const totalParagraphs = paragraphs.length;
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for (let i = 0; i < totalParagraphs; i += fallbackParagraphsPerChapter) {
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const chunks = paragraphs.slice(i, i + fallbackParagraphsPerChapter);
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const formattedSegment = this.formatSegment(chunks.join('\n'));
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const title = `${chapterOffset + chapters.length + 1}`;
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const content = `<h2>${title}</h2><p>${formattedSegment}</p>`;
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chapters.push({ title, content, isVolume: false });
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}
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return chapters;
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}
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const segmentChapters: Chapter[] = [];
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for (let j = 1; j < matches.length; j += 2) {
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const title = matches[j]?.trim() || '';
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const content = matches[j + 1]?.trim() || '';
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let isVolume = false;
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if (language === 'zh') {
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isVolume = /第[零〇一二三四五六七八九十百千万0-9]+(卷|本|册|部)/.test(title);
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} else {
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isVolume = /\b(Part|Volume|Book)\b/i.test(title);
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}
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const headTitle = isVolume ? `<h1>${title}</h1>` : `<h2>${title}</h2>`;
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const formattedSegment = this.formatSegment(content);
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segmentChapters.push({
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title: escapeXml(title),
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content: `${headTitle}<p>${formattedSegment}</p>`,
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isVolume,
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});
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}
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|
||
if (matches[0] && matches[0].trim()) {
|
||
const initialContent = matches[0].trim();
|
||
const firstLine = initialContent.split('\n')[0]!.trim();
|
||
const segmentTitle =
|
||
(firstLine.length > 16 ? initialContent.split(/[\n\s\p{P}]/u)[0]!.trim() : firstLine) ||
|
||
initialContent.slice(0, 16);
|
||
const formattedSegment = this.formatSegment(initialContent);
|
||
segmentChapters.unshift({
|
||
title: escapeXml(segmentTitle),
|
||
content: `<h3></h3><p>${formattedSegment}</p>`,
|
||
isVolume: false,
|
||
});
|
||
}
|
||
|
||
return segmentChapters;
|
||
}
|
||
|
||
private probeChapterCountFromSegment(
|
||
segment: string,
|
||
metadata: Metadata,
|
||
option: ExtractChapterOptions,
|
||
): number {
|
||
const { language } = metadata;
|
||
const { fallbackParagraphsPerChapter } = option;
|
||
let sanitizedSegment = segment;
|
||
let previousSegment: string;
|
||
do {
|
||
previousSegment = sanitizedSegment;
|
||
sanitizedSegment = sanitizedSegment.replace(/<!--.*?-->/gs, '');
|
||
} while (sanitizedSegment !== previousSegment);
|
||
const trimmedSegment = sanitizedSegment.trim();
|
||
if (!trimmedSegment) return 0;
|
||
|
||
const chapterRegexps = this.createChapterRegexps(language);
|
||
let matches: string[] = [];
|
||
for (const chapterRegex of chapterRegexps) {
|
||
const tryMatches = trimmedSegment.split(chapterRegex);
|
||
if (this.isGoodMatches(tryMatches)) {
|
||
matches = this.joinAroundUndefined(tryMatches);
|
||
break;
|
||
}
|
||
}
|
||
|
||
if (matches.length === 0 && fallbackParagraphsPerChapter > 0) {
|
||
const paragraphs = trimmedSegment.split(/\n+/);
|
||
return Math.ceil(paragraphs.length / fallbackParagraphsPerChapter);
|
||
}
|
||
|
||
let chapterCount = Math.floor(matches.length / 2);
|
||
if (matches[0] && matches[0].trim()) {
|
||
chapterCount++;
|
||
}
|
||
return chapterCount;
|
||
}
|
||
|
||
private createSegmentRegex(linesBetweenSegments: number): RegExp {
|
||
return new RegExp(`(?:\\r?\\n){${linesBetweenSegments},}|-{8,}\r?\n`);
|
||
}
|
||
|
||
private formatSegment(segment: string): string {
|
||
segment = escapeXml(segment);
|
||
return segment
|
||
.replace(/-{8,}|_{8,}/g, '\n')
|
||
.split(/\n+/)
|
||
.map((line) => line.trim())
|
||
.filter((line) => line)
|
||
.join('</p><p>');
|
||
}
|
||
|
||
private joinAroundUndefined(arr: (string | undefined)[]): string[] {
|
||
return arr.reduce<string[]>((acc, curr, i, src) => {
|
||
if (
|
||
curr === undefined &&
|
||
i > 0 &&
|
||
i < src.length - 1 &&
|
||
src[i - 1] !== undefined &&
|
||
src[i + 1] !== undefined
|
||
) {
|
||
acc[acc.length - 1] += src[i + 1]!;
|
||
return acc;
|
||
}
|
||
if (curr !== undefined && (i === 0 || src[i - 1] !== undefined)) {
|
||
acc.push(curr);
|
||
}
|
||
return acc;
|
||
}, []);
|
||
}
|
||
|
||
private isGoodMatches(matches: string[], maxLength: number = 100000): boolean {
|
||
const meaningfulParts = matches.filter((part) => part && part.trim().length > 0);
|
||
if (meaningfulParts.length <= 1) return false;
|
||
|
||
const hasLongParts = meaningfulParts.some((part) => part.length > maxLength);
|
||
return !hasLongParts;
|
||
}
|
||
|
||
private createChapterRegexps(language: string): RegExp[] {
|
||
const chapterRegexps: RegExp[] = [];
|
||
|
||
if (language === 'zh') {
|
||
chapterRegexps.push(
|
||
new RegExp(
|
||
String.raw`(?:^|\n)\s*` +
|
||
'(' +
|
||
[
|
||
String.raw`第[ 零〇一二三四五六七八九十0-9][ 零〇一二三四五六七八九十百千万0-9]*(?:[章卷节回讲篇封本册部话])(?:[：:、 \(\)0-9]*[^\n-]{0,24})(?!\S)`,
|
||
String.raw`(?:楔子|前言|简介|引言|序言|序章|总论|概论|后记)(?:[：: ][^\n-]{0,24})?(?!\S)`,
|
||
String.raw`chapter[\s.]*[0-9]+(?:[：:. ]+[^\n-]{0,50})?(?!\S)`,
|
||
].join('|') +
|
||
')',
|
||
'gui',
|
||
),
|
||
);
|
||
chapterRegexps.push(
|
||
new RegExp(
|
||
String.raw`(?:^|\n)\s*` +
|
||
'(' +
|
||
[
|
||
String.raw`[一二三四五六七八九十][零〇一二三四五六七八九十百千万]?[：:、 ][^\n-]{0,24}(?=\n|$)`,
|
||
String.raw`[0-9]+[^\n]{0,16}(?=\n|$)`,
|
||
].join('|') +
|
||
')',
|
||
'gu',
|
||
),
|
||
);
|
||
return chapterRegexps;
|
||
}
|
||
|
||
const chapterKeywords = ['Chapter', 'Part', 'Section', 'Book', 'Volume', 'Act'];
|
||
const prefaceKeywords = [
|
||
'Prologue',
|
||
'Epilogue',
|
||
'Introduction',
|
||
'Foreword',
|
||
'Preface',
|
||
'Afterword',
|
||
];
|
||
|
||
const numberPattern = String.raw`(?:\d+|(?:[IVXLCDM]{2,}|V|X|L|C|D|M)\b)`;
|
||
const dotNumberPattern = String.raw`\.\d{1,4}`;
|
||
const titlePattern = String.raw`[^\n]{0,50}`;
|
||
|
||
const normalChapterPattern = chapterKeywords
|
||
.map(
|
||
(k) =>
|
||
String.raw`${k}\s*(?:${numberPattern}|${dotNumberPattern})(?:[:.\-–—]?\s*${titlePattern})?`,
|
||
)
|
||
.join('|');
|
||
|
||
const prefacePattern = prefaceKeywords
|
||
.map((k) => String.raw`${k}(?:[:.\-–—]?\s*${titlePattern})?`)
|
||
.join('|');
|
||
|
||
const combinedPattern = String.raw`(?:^|\n)(${normalChapterPattern}|${prefacePattern})(?=\s|$)`;
|
||
chapterRegexps.push(new RegExp(combinedPattern, 'gi'));
|
||
|
||
// Second-tier: bare numbered headings like "1.1The Elements" or "1Building Data"
|
||
// Dotted numbers (1.1, 1.2.3) allow an optional space before the title.
|
||
// Single bare digits (1, 2) require the title to start immediately (no space)
|
||
// to avoid matching footnotes like "1 The Lisp...".
|
||
const numberedHeadingPattern = String.raw`(?:^|\n)(\d+\.\d+(?:\.\d+)* ?[A-Z][^\n]{0,80}|\d+[A-Z][^\n]{0,80})`;
|
||
chapterRegexps.push(new RegExp(numberedHeadingPattern, 'g'));
|
||
|
||
return chapterRegexps;
|
||
}
|
||
|
||
private async createEpub(chapters: Chapter[], metadata: Metadata): Promise<Blob> {
|
||
await configureZip();
|
||
const { BlobWriter, TextReader, ZipWriter } = await import('@zip.js/zip.js');
|
||
const { bookTitle, author, language, identifier } = metadata;
|
||
|
||
const zipWriter = new ZipWriter(new BlobWriter('application/epub+zip'), {
|
||
extendedTimestamp: false,
|
||
});
|
||
await zipWriter.add('mimetype', new TextReader('application/epub+zip'), zipWriteOptions);
|
||
|
||
// Add META-INF/container.xml
|
||
const containerXml = `<?xml version="1.0" encoding="UTF-8"?>
|
||
<container xmlns="urn:oasis:names:tc:opendocument:xmlns:container" version="1.0">
|
||
<rootfiles>
|
||
<rootfile full-path="content.opf" media-type="application/oebps-package+xml"/>
|
||
</rootfiles>
|
||
</container>`.trim();
|
||
|
||
await zipWriter.add('META-INF/container.xml', new TextReader(containerXml), zipWriteOptions);
|
||
|
||
// Create navigation points for TOC
|
||
let isNested = false;
|
||
let navPoints = ``;
|
||
for (let i = 0; i < chapters.length; i++) {
|
||
const id = `chapter${i + 1}`;
|
||
const playOrder = i + 1;
|
||
if (chapters[i]!.isVolume && isNested) {
|
||
navPoints += `</navPoint>\n`;
|
||
isNested = !isNested;
|
||
}
|
||
navPoints +=
|
||
`<navPoint id="navPoint-${id}" playOrder="${playOrder}">\n` +
|
||
`<navLabel><text>${chapters[i]!.title}</text></navLabel>\n` +
|
||
`<content src="./OEBPS/${id}.xhtml" />\n`;
|
||
if (chapters[i]!.isVolume && !isNested) {
|
||
isNested = !isNested;
|
||
} else {
|
||
navPoints += `</navPoint>\n`;
|
||
}
|
||
}
|
||
if (isNested) {
|
||
navPoints += `</navPoint>`;
|
||
}
|
||
|
||
// Add NCX file (table of contents)
|
||
const tocNcx = `<?xml version="1.0" encoding="UTF-8"?>
|
||
<ncx xmlns="http://www.daisy.org/z3986/2005/ncx/" version="2005-1">
|
||
<head>
|
||
<meta name="dtb:uid" content="book-id" />
|
||
<meta name="dtb:depth" content="1" />
|
||
<meta name="dtb:totalPageCount" content="0" />
|
||
<meta name="dtb:maxPageNumber" content="0" />
|
||
</head>
|
||
<docTitle>
|
||
<text>${escapeXml(bookTitle)}</text>
|
||
</docTitle>
|
||
<docAuthor>
|
||
<text>${escapeXml(author)}</text>
|
||
</docAuthor>
|
||
<navMap>
|
||
${navPoints}
|
||
</navMap>
|
||
</ncx>`.trim();
|
||
|
||
await zipWriter.add('toc.ncx', new TextReader(tocNcx), zipWriteOptions);
|
||
|
||
// Create manifest and spine items
|
||
const manifest = chapters
|
||
.map(
|
||
(_, index) => `
|
||
<item id="chap${index + 1}" href="OEBPS/chapter${index + 1}.xhtml" media-type="application/xhtml+xml"/>
|
||
`,
|
||
)
|
||
.join('\n')
|
||
.trim();
|
||
|
||
const spine = chapters
|
||
.map(
|
||
(_, index) => `
|
||
<itemref idref="chap${index + 1}"/>`,
|
||
)
|
||
.join('\n')
|
||
.trim();
|
||
|
||
// Add CSS stylesheet
|
||
const css = `
|
||
body { line-height: 1.6; font-size: 1em; font-family: 'Arial', sans-serif; text-align: justify; }
|
||
p { text-indent: 2em; margin: 0; }
|
||
`;
|
||
|
||
await zipWriter.add('style.css', new TextReader(css), zipWriteOptions);
|
||
|
||
// Add chapter files
|
||
for (let i = 0; i < chapters.length; i++) {
|
||
const chapter = chapters[i]!;
|
||
const lang = language;
|
||
const chapterContent = `<?xml version="1.0" encoding="UTF-8"?>
|
||
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.1//EN" "http://www.w3.org/TR/xhtml11/DTD/xhtml11.dtd">
|
||
<html xmlns="http://www.w3.org/1999/xhtml" lang="${lang}" xml:lang="${lang}">
|
||
<head>
|
||
<title>${chapter.title}</title>
|
||
<link rel="stylesheet" type="text/css" href="../style.css"/>
|
||
</head>
|
||
<body>${chapter.content}</body>
|
||
</html>`.trim();
|
||
|
||
await zipWriter.add(
|
||
`OEBPS/chapter${i + 1}.xhtml`,
|
||
new TextReader(chapterContent),
|
||
zipWriteOptions,
|
||
);
|
||
}
|
||
|
||
const tocManifest = `<item id="ncx" href="toc.ncx" media-type="application/x-dtbncx+xml"/>`;
|
||
const styleManifest = `<item id="css" href="style.css" media-type="text/css"/>`;
|
||
|
||
// Add content.opf file
|
||
const contentOpf = `<?xml version="1.0" encoding="UTF-8"?>
|
||
<package xmlns="http://www.idpf.org/2007/opf" unique-identifier="book-id" version="2.0">
|
||
<metadata xmlns:dc="http://purl.org/dc/elements/1.1/">
|
||
<dc:title>${escapeXml(bookTitle)}</dc:title>
|
||
<dc:language>${language}</dc:language>
|
||
<dc:creator>${escapeXml(author)}</dc:creator>
|
||
<dc:identifier id="book-id">${identifier}</dc:identifier>
|
||
</metadata>
|
||
<manifest>
|
||
${manifest}
|
||
${tocManifest}
|
||
${styleManifest}
|
||
</manifest>
|
||
<spine toc="ncx">
|
||
${spine}
|
||
</spine>
|
||
</package>`.trim();
|
||
|
||
await zipWriter.add('content.opf', new TextReader(contentOpf), zipWriteOptions);
|
||
|
||
return await zipWriter.close();
|
||
}
|
||
|
||
private detectEncoding(buffer: ArrayBuffer): string | undefined {
|
||
const utf8HeadSampleSize = Math.min(buffer.byteLength, 64 * 1024);
|
||
const utf8HeadSample = buffer.slice(0, utf8HeadSampleSize);
|
||
|
||
try {
|
||
this.assertStrictUtf8Sample(new Uint8Array(utf8HeadSample));
|
||
if (buffer.byteLength > utf8HeadSampleSize * 2) {
|
||
const midSampleSize = Math.min(8192, buffer.byteLength - utf8HeadSampleSize);
|
||
const midSampleStart = Math.floor((buffer.byteLength - midSampleSize) / 2);
|
||
const midSample = buffer.slice(midSampleStart, midSampleStart + midSampleSize);
|
||
this.assertStrictUtf8Sample(new Uint8Array(midSample));
|
||
}
|
||
return 'utf-8';
|
||
} catch {
|
||
const uint8Array = new Uint8Array(buffer);
|
||
// Try tolerant UTF-8 detection - check if most of it is valid UTF-8
|
||
let validBytes = 0;
|
||
let checkedBytes = 0;
|
||
const sampleSize = Math.min(uint8Array.length, 10000);
|
||
|
||
for (let i = 0; i < sampleSize; i++) {
|
||
try {
|
||
new TextDecoder('utf-8', { fatal: true }).decode(uint8Array.slice(i, i + 100));
|
||
validBytes += 100;
|
||
checkedBytes += 100;
|
||
i += 99;
|
||
} catch {
|
||
checkedBytes++;
|
||
}
|
||
}
|
||
|
||
const validPercentage = checkedBytes > 0 ? (validBytes / checkedBytes) * 100 : 0;
|
||
console.log(`UTF-8 validity: ${validPercentage.toFixed(2)}%`);
|
||
|
||
// If more than 80% is valid UTF-8, consider it UTF-8 with some corruption
|
||
if (validPercentage > 80) {
|
||
console.log('Treating as UTF-8 despite some invalid sequences');
|
||
return 'utf-8';
|
||
}
|
||
// If UTF-8 decoding fails, try to detect other encodings
|
||
}
|
||
|
||
const headerBytes = new Uint8Array(buffer.slice(0, 4));
|
||
|
||
if (headerBytes[0] === 0xff && headerBytes[1] === 0xfe) {
|
||
return 'utf-16le';
|
||
}
|
||
|
||
if (headerBytes[0] === 0xfe && headerBytes[1] === 0xff) {
|
||
return 'utf-16be';
|
||
}
|
||
|
||
if (headerBytes[0] === 0xef && headerBytes[1] === 0xbb && headerBytes[2] === 0xbf) {
|
||
return 'utf-8';
|
||
}
|
||
|
||
// Analyze a sample of the content to guess between common East Asian encodings
|
||
// If the content has a high ratio of bytes in the 0x80-0xFF range, it's likely GBK/GB18030
|
||
const sample = new Uint8Array(buffer.slice(0, Math.min(1024, buffer.byteLength)));
|
||
let highByteCount = 0;
|
||
|
||
for (let i = 0; i < sample.length; i++) {
|
||
if (sample[i]! >= 0x80) {
|
||
highByteCount++;
|
||
}
|
||
}
|
||
|
||
const highByteRatio = highByteCount / sample.length;
|
||
if (highByteRatio > 0.3) {
|
||
return 'gbk';
|
||
}
|
||
|
||
if (highByteRatio > 0.1) {
|
||
let sjisPattern = false;
|
||
for (let i = 0; i < sample.length - 1; i++) {
|
||
const b1 = sample[i]!;
|
||
const b2 = sample[i + 1]!;
|
||
if (
|
||
((b1 >= 0x81 && b1 <= 0x9f) || (b1 >= 0xe0 && b1 <= 0xfc)) &&
|
||
((b2 >= 0x40 && b2 <= 0x7e) || (b2 >= 0x80 && b2 <= 0xfc))
|
||
) {
|
||
sjisPattern = true;
|
||
break;
|
||
}
|
||
}
|
||
|
||
if (sjisPattern) {
|
||
return 'shift-jis';
|
||
}
|
||
|
||
return 'gb18030';
|
||
}
|
||
|
||
return 'utf-8';
|
||
}
|
||
|
||
private extractBookTitle(filename: string): string {
|
||
const match = filename.match(/《([^》]+)》/);
|
||
return match ? match[1]! : filename.split('.')[0]!;
|
||
}
|
||
|
||
private assertStrictUtf8Sample(sample: Uint8Array): void {
|
||
const decoder = new TextDecoder('utf-8', { fatal: true });
|
||
try {
|
||
decoder.decode(sample);
|
||
return;
|
||
} catch {
|
||
// Sampling may start/end inside a multibyte code point.
|
||
// Retry a few boundary offsets while keeping most bytes untouched.
|
||
const maxOffset = Math.min(3, sample.length - 1);
|
||
for (let startOffset = 0; startOffset <= maxOffset; startOffset++) {
|
||
for (let endOffset = 0; endOffset <= maxOffset; endOffset++) {
|
||
if (startOffset === 0 && endOffset === 0) continue;
|
||
const end = sample.length - endOffset;
|
||
if (end - startOffset < 16) continue;
|
||
try {
|
||
decoder.decode(sample.subarray(startOffset, end));
|
||
return;
|
||
} catch {
|
||
// continue trying other offsets
|
||
}
|
||
}
|
||
}
|
||
throw new Error('invalid utf-8 sample');
|
||
}
|
||
}
|
||
|
||
private isEncodingSupported(encoding: string): boolean {
|
||
try {
|
||
new TextDecoder(encoding);
|
||
return true;
|
||
} catch {
|
||
return false;
|
||
}
|
||
}
|
||
|
||
private resolveSupportedEncoding(detectedEncoding: string): string {
|
||
const normalized = detectedEncoding.toLowerCase();
|
||
const candidates = [
|
||
normalized,
|
||
...(normalized === 'gbk' ? ['gb18030', 'gb2312'] : []),
|
||
...(normalized === 'gb18030' ? ['gbk', 'gb2312'] : []),
|
||
...(normalized === 'shift-jis' ? ['shift_jis', 'sjis'] : []),
|
||
...(normalized === 'utf-16' ? ['utf-16le', 'utf-16be'] : []),
|
||
'utf-8',
|
||
];
|
||
|
||
for (const encoding of candidates) {
|
||
if (this.isEncodingSupported(encoding)) {
|
||
return encoding;
|
||
}
|
||
}
|
||
return 'utf-8';
|
||
}
|
||
}
|