memorium/lib/telegram.ts

import { Bot } from "https://deno.land/x/grammy@v1.36.1/mod.ts";
import { TELEGRAM_API_KEY } from "@lib/env.ts";
import { transcribe } from "@lib/openai.ts";
import { createDocument } from "@lib/documents.ts";
import { renderMarkdown } from "@lib/documents.ts";

const bot = new Bot(TELEGRAM_API_KEY);

// In-memory task state
const activeTasks: Record<
  string,
  {
    noteName: string;
    entries: Array<
      { type: string; content: string | Uint8Array; fileName?: string }
    >;
  }
> = {};

async function downloadFile(filePath: string): Promise<Uint8Array> {
  const url = `https://api.telegram.org/file/bot${bot.token}/${filePath}`;
  const response = await fetch(url);
  if (!response.ok) {
    throw new Error("Failed to download file: " + response.statusText);
  }
  const buffer = await response.arrayBuffer();
  return new Uint8Array(buffer);
}

bot.command("start", async (ctx) => {
  const [_, noteName] = ctx.message?.text?.split(" ") || [];
  if (!noteName) {
    return ctx.reply("Please provide a note name. Usage: /start NoteName");
  }
  activeTasks[ctx.chat.id.toString()] = { noteName, entries: [] };
  await ctx.reply(`Started note: ${noteName}`);
});

bot.command("end", async (ctx) => {
  const task = activeTasks[ctx.chat.id.toString()];
  if (!task) return ctx.reply("No active note found.");

  console.log("Ending note", task.noteName);

  let finalNote = `# ${task.noteName}\n\n`;

  const photoTasks: { content: Uint8Array; path: string }[] = [];

  let photoIndex = 0;
  for (const entry of task.entries) {
    if (entry.type === "text") {
      finalNote += entry.content + "\n\n";
    } else if (entry.type === "voice") {
      try {
        console.log("Converting OGG to MP3");
        const mp3Data = await convertOggToMp3(entry.content as Uint8Array);
        console.log("Finished converting OGG to MP3, transcribing...");
        const transcript = await transcribe(mp3Data);
        finalNote += `**Voice Transcript:**\n${transcript}\n\n`;
        console.log("Finished transcribing");
      } catch (error) {
        console.log(error);
        finalNote += "**[Voice message could not be transcribed]**\n\n";
      }
    } else if (entry.type === "photo") {
      const photoUrl = `${
        task.noteName.replace(/\.md$/, "")
      }/photo-${photoIndex++}.jpg`;

      finalNote += `**Photo**:\n ${photoUrl}\n\n`;
      photoTasks.push({
        content: entry.content as Uint8Array,
        path: photoUrl,
      });
    }
  }

  try {
    for (const entry of photoTasks) {
      await createDocument(entry.path, entry.content, "image/jpeg");
    }
    await createDocument(task.noteName, finalNote, "text/markdown");
    delete activeTasks[ctx.chat.id.toString()];
    await ctx.reply("Note complete. Here is your markdown:");
    await ctx.reply(renderMarkdown(finalNote), { parse_mode: "HTML" });
  } catch (error) {
    console.error("Error creating document:", error);
    await ctx.reply("Error creating document:");
    if (error instanceof Error) {
      await ctx.reply(error?.toString());
    } else if (error instanceof Response) {
      await ctx.reply(error?.statusText);
    } else if (typeof error === "string") {
      await ctx.reply(error);
    }
  }
});

bot.on("message:text", (ctx) => {
  const task = activeTasks[ctx.chat.id.toString()];
  if (!task) return;
  const entry = { type: "text", content: ctx.message.text };
  console.log("New Entry", entry);
  task.entries.push(entry);
});

bot.on("message:voice", async (ctx) => {
  const task = activeTasks[ctx.chat.id.toString()];
  if (!task) return;
  const file = await ctx.getFile();
  const buffer = await downloadFile(file.file_path!);
  const entry = { type: "voice", content: buffer };
  console.log("New Entry", entry);
  task.entries.push(entry);
});

bot.on("message:photo", async (ctx) => {
  const task = activeTasks[ctx.chat.id.toString()];
  if (!task) return;
  const file = await ctx.getFile();
  const buffer = await downloadFile(file.file_path!);
  const fileName = file.file_path!.split("/").pop()!;
  const entry = { type: "photo", content: buffer, fileName };
  console.log("New Entry", entry);
  task.entries.push(entry);
});

export async function convertOggToMp3(
  oggData: Uint8Array,
): Promise<Uint8Array> {
  const ffmpeg = new Deno.Command("ffmpeg", {
    args: ["-f", "ogg", "-i", "pipe:0", "-f", "mp3", "pipe:1"],
    stdin: "piped",
    stdout: "piped",
    stderr: "null",
  });

  const process = ffmpeg.spawn();
  const writer = process.stdin.getWriter();
  await writer.write(oggData);
  await writer.close();

  const output = await process.output();
  const { code } = await process.status;
  if (code !== 0) throw new Error(`FFmpeg exited with code ${code}`);
  return output.stdout;
}

bot.start();