import { Zip, ZipPassThrough } from "fflate";
import { BaseGenerator } from "./baseGenerator";
import report from "./report";
const enc = new TextEncoder();
/**
* Handles epub generation
*/
export class EpubGenerator extends BaseGenerator {
async generate() {
this.writer = this.opts.file.getWriter();
this.zip = new Zip();
this.zip.ondata = (error, data, final) => {
if(error) {
console.error(error);
if(this.opts.onerror) this.opts.onerror(error);
}
if(data) {
this.writer.write(data);
}
if(final) {
this.writer.close();
}
};
this.hashes = [];
for(const chapterI in this.opts.chapters) {
const chapter = this.opts.chapters[chapterI];
if(!chapter.links) {
let data = await this.getURLs(chapter);
chapter.links = data.urls;
chapter.hashes = data.hashes;
chapter.hash = data.hash;
this.hashes.push(...chapter.hashes);
}
}
this.mimetype();
this.container();
this.package();
this.toc();
this.callback(); // signals the template is ready
for(const chapterI in this.opts.chapters) {
const chapter = this.opts.chapters[chapterI];
if(chapter.number == null || chapter.number == undefined) chapter.number = chapterI;
for(const i in chapter.links) {
let url = chapter.links[i];
let hash = chapter.hashes[i];
this.callback(chapterI, i, false);
const start = performance.now();
const res = await this.fetchImage(url, chapter);
const image = new ZipPassThrough("OEBPS/" + hash);
this.zip.add(image);
const data = new Uint8Array(await res.arrayBuffer());
const end = performance.now() - start;
report({
bytes: data.byteLength,
cached: res.headers.get("X-Cache") === "HIT",
duration: end,
success: Math.floor(res.status / 100) === 2,
url: url
});
image.push(data, true);
const textContent = new ZipPassThrough("OEBPS/" + i + ".xhtml");
this.zip.add(textContent);
textContent.push(enc.encode(`
Page ${i + 1}
`), true);
this.callback(chapterI, i, true);
}
}
this.zip.end();
this.callback(-1, -1, true);
}
mimetype() {
const mimetype = new ZipPassThrough("mimetype");
this.zip.add(mimetype);
mimetype.push(enc.encode("application/epub+zip"), true);
}
container() {
const container = new ZipPassThrough("META-INF/container.xml");
this.zip.add(container);
container.push(enc.encode(`
`), true);
}
package() {
const opf = new ZipPassThrough("OEBPS/content.opf");
this.zip.add(opf);
opf.push(enc.encode(`
${this.opts.title}
${this.opts.language || "en"}
${this.opts.author}
${this.opts.id}
Image
${this.opts.updatedAt.toString().split("+")[0]}Z
pre-paginated
portrait
landscape
${this.hashes.map((t, i) => `