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";
import { type TPlatform, site } from "./platform";

export type Book = {
  id: number;
  platform: TPlatform;
  readerUrl: string;
  title: string;
  authors: Array<string>;
};

export function createLibrary(db: Database) {
  return {
    async add(readerUrlOrBook: string | Book) {
      if (typeof readerUrlOrBook === "string") {
        const platform = site(readerUrlOrBook);

        await db.run(
          `\
insert into books(
  platform_id,
  reader_url)
values((select id from platforms where name = ?), ?)
on conflict(reader_url)
  do nothing
`,
          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
`,
        readerUrlOrBook.platform,
        readerUrlOrBook.readerUrl,
        readerUrlOrBook.title,
        JSON.stringify(readerUrlOrBook.authors),
      );
    },
    async delete(id: number) {
      await db.run(`delete from books where id = ?`, id);
    },
    async get(readerUrlOrBookId: string | 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.reader_url = ? or books.id = ?`,
        readerUrlOrBookId,
        Number(readerUrlOrBookId),
      );

      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(
      path: string,
      book: Book,
      opts: {
        outDir: string;
        outAuthorsLimit: number;
      },
    ) {
      const bookDir = await fs.stat(path);

      if (!bookDir.isDirectory()) {
        throw new Error(`Not found: ${path}`);
      }

      if (!book.title) {
        book.title = String(book.id);
      }

      if (book.authors.length > 0) {
        book.title = `[${book.authors
          .slice(0, opts.outAuthorsLimit)
          .join(", ")}] ${book.title}`.replace(/[/]/g, "%2F");
      }

      await fs.mkdir(opts.outDir, {
        recursive: true,
      });

      const files = await fs.readdir(path);

      if (files.every((f) => f.match(/[.](zip|cbz)$/))) {
        const digits = String(files.length).length;

        function pad(n: string) {
          return n.padStart(digits, "0");
        }

        for (const [n, f] of Object.entries(files)) {
          await fs.copyFile(
            `${path}/${f}`,
            `${opts.outDir}/${book.title}${
              files.length > 1 ? ` - ${pad(n)}` : ""
            }.${f.split(".").at(-1)}`,
          );
        }

        await fs.rm(path, { recursive: true });
        return;
      }

      const out = createWriteStream(`${opts.outDir}/${book.title}.cbz`);

      const zip = new Zip(function cb(err, data, final) {
        if (err) {
          out.destroy(err);
          return;
        }

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

      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 });
    },
  };
}