Slideshare downloader

slideshare_bot.ts

import { Bot, InputFile } from "https://deno.land/x/grammy@v1.8.0/mod.ts";
import { DOMParser } from "https://deno.land/x/deno_dom@v0.1.22-alpha/deno-dom-wasm.ts";
import { StatusMessage } from "https://gist.githubusercontent.com/dcdunkan/235859eac749d36f4df7c00b99fbbc8f/raw/status.ts";

const bot = new Bot(Deno.env.get("BOT_TOKEN")!);

bot.command("start", async (ctx) => await ctx.reply("yeah!"));

bot.on("message:text").on("::url", async (ctx) => {
  const url = ctx.message.text;
  const status = new StatusMessage(ctx);
  await status.send("Getting slides...");

  const response = await fetch(url);
  if (!response.ok) return await status.set("Failed to fetch :(");

  const html = await response.text();
  const doc = new DOMParser().parseFromString(html, "text/html")!;
  const imageElements = doc.getElementsByClassName("slide-image");

  await status.set(`Downloading ${imageElements.length} slides...`);

  const files: string[] = [];
  const tempDir = await Deno.makeTempDir({
    dir: Deno.cwd(),
    prefix: "slideshare-dl",
  });

  for (let i = 0; i < imageElements.length; i++) {
    const src = imageElements[i].attributes.srcset.split(", ").at(-1) ??
      imageElements[i].attributes.src;

    const imgResponse = await fetch(src);
    if (!response.ok) continue;
    const img = await imgResponse.arrayBuffer();
    const filename = `${tempDir}/slide-${i}.jpg`;
    files.push(filename);
    await Deno.writeFile(filename, new Uint8Array(img));
  }

  if (!files.length) return await status.set("Failed to fetch images :(");

  await status.set("Creating PDF...");
  const pdfName = `${tempDir}/${url.split("/").at(-1)}.pdf`;
  const convertProcess = Deno.run({
    cmd: ["convert", ...files, pdfName],
  });
  const processStatus = await convertProcess.status();

  if (processStatus.success) {
    await status.set("Sending file...");
    await ctx.replyWithDocument(new InputFile(pdfName), { caption: url });
    await status.set("Here we go!");
  } else {
    await status.clear();
    await status.send("Failed to send PDF!");
  }

  await Deno.remove(tempDir, { recursive: true }); // remove temporary folder
});

bot.catch(console.error);

bot.start({
  onStart: () => console.log("Bot is online"),
});