gadl/library.ts

import fs from "node:fs/promises";
import { createWriteStream } from "node:fs";
import stream from "node:stream/promises";
import { Zip, ZipPassThrough } from "fflate";
import { Database } from "./database";

export type Book = {
  id: number;
  platform: "dmm-books" | "google-play-books";
  readerUrl: string;
  title: string;
  authors: Array<string>;
};

export function createLibrary(db: Database) {
  return {
    async add(readerUrlOrBook: string | Book) {
      const platform = "dmm-books";

      if (typeof readerUrlOrBook === "string") {
        await db.run(
          `insert into books(platform_id, reader_url) values((select id from platforms where name = ?), ?)`,
          platform,
          readerUrlOrBook,
        );

        return;
      }

      await db.run(
        `\
insert into books(
  platform_id,
  reader_url,
  title,
  authors)
values((select id from platforms where name = ?), ?, ?, ?)
on conflict(reader_url)
  do update set title = excluded.title, authors = excluded.authors
`,
        platform,
        readerUrlOrBook.readerUrl,
        readerUrlOrBook.title,
        JSON.stringify(readerUrlOrBook.authors),
      );
    },
    async delete(id: number) {
      await db.run(`delete from books where id = ?`, id);
    },
    async get(id: number): Promise<Book | undefined> {
      const row = await db.get(
        `select books.id, platforms.name as platform, books.reader_url as readerUrl, books.title, books.authors from books left join platforms on books.platform_id = platforms.id where books.id = ?`,
        id,
      );

      const book: Book | undefined = row && {
        ...row,
        authors: JSON.parse(row.authors),
      };

      return book;
    },
    async getBooks(): Promise<Array<Book>> {
      const rows = await db.all(
        `select books.id, platforms.name as platform, books.reader_url as readerUrl, books.title, books.authors from books left join platforms on books.platform_id = platforms.id`,
      );

      const books: Array<Book> = rows.map((row) => ({
        ...row,
        authors: JSON.parse(row.authors),
      }));

      return books;
    },
    async archive(dir: string) {
      const bookDirs = await fs.readdir(dir, { withFileTypes: true });

      for (const bookDir of bookDirs) {
        if (!bookDir.isDirectory()) {
          continue;
        }

        const path = `${bookDir.path}/${bookDir.name}`;
        const book = await this.get(bookDir.name);
        const title = book
          ? `${book.authors.join("、")}「${book.title}」`.replace(/[/]/g, "%2F")
          : bookDir.name;
        const out = createWriteStream(`${dir}/${title}.cbz`);
        const zip = new Zip(function cb(err, data, final) {
          if (err) {
            out.destroy(err);
            return;
          }

          out[final ? "end" : "write"](data);
        });

        const files = await fs.readdir(path);

        for (const file of files) {
          const data = new ZipPassThrough(file);
          zip.add(data);

          const buffer = await fs.readFile(`${path}/${file}`);
          data.push(buffer, true);
        }

        zip.end();

        await stream.finished(out);
        await fs.rm(path, { recursive: true });
      }
    },
  };
}