require("dotenv").config();
const { Telegraf } = require("telegraf");
const fs = require("fs").promises;
const path = require("path");
const stream = require("stream");
const { pipeline } = require("stream/promises");
const BOT_TOKEN = process.env.BOT_TOKEN;
const BASE_DIR = process.env.BASE_DIR || "/srv/files";
const ALLOWED = (process.env.ALLOWED_TELEGRAM_IDS || "")
  .split(",")
  .filter(Boolean)
  .map((x) => Number(x));
if (!BOT_TOKEN) {
  console.error("Missing BOT_TOKEN in .env");
  process.exit(1);
}
const bot = new Telegraf(BOT_TOKEN);
function allowed(ctx) {
  const id = ctx.from && ctx.from.id;
  if (!id) return false;
  if (ALLOWED.length === 0) return true;
  return ALLOWED.includes(id);
}
function safeJoin(base, target) {
  const resolved = path.resolve(base, "." + path.sep + target);
  if (!resolved.startsWith(path.resolve(base)))
    throw new Error("Access denied");
  return resolved;
}
bot.use(async (ctx, next) => {
  try {
    if (!allowed(ctx)) return ctx.reply("Access denied");
    return await next();
  } catch (err) {
    console.error(err);
    try {
      await ctx.reply("Error: " + String(err.message));
    } catch (e) {}
  }
});
bot.start((ctx) =>
  ctx.reply("File manager bot ready. Use /help to list commands"),
);
bot.help((ctx) =>
  ctx.reply(
    "/ls [path]\n/get <path>\n/put (send file with caption: /put <path>)\n/mv <src> <dst>\n/mkdir <path>\n/rm <path>",
  ),
);
bot.command("ls", async (ctx) => {
  const arg = ctx.message.text.split(" ").slice(1).join(" ") || ".";
  const dir = safeJoin(BASE_DIR, arg);
  const entries = await fs.readdir(dir, { withFileTypes: true });
  const lines = entries.map((e) => `${e.isDirectory() ? "d" : "-"}\t${e.name}`);
  await ctx.replyWithMarkdownV2("`" + lines.join("\n") + "`");
});
bot.command("mkdir", async (ctx) => {
  const arg = ctx.message.text.split(" ").slice(1).join(" ");
  if (!arg) return ctx.reply("Usage: /mkdir <path>");
  const target = safeJoin(BASE_DIR, arg);
  await fs.mkdir(target, { recursive: true });
  await ctx.reply("Created " + arg);
});
bot.command("mv", async (ctx) => {
  const parts = ctx.message.text.split(" ").slice(1);
  if (parts.length < 2) return ctx.reply("Usage: /mv <src> <dst>");
  const src = safeJoin(BASE_DIR, parts[0]);
  const dst = safeJoin(BASE_DIR, parts[1]);
  await fs.rename(src, dst);
  await ctx.reply("Moved");
});
bot.command("rm", async (ctx) => {
  const arg = ctx.message.text.split(" ").slice(1).join(" ");
  if (!arg) return ctx.reply("Usage: /rm <path>");
  const target = safeJoin(BASE_DIR, arg);
  const stat = await fs.lstat(target);
  if (stat.isDirectory()) await fs.rmdir(target, { recursive: true });
  else await fs.unlink(target);
  await ctx.reply("Removed " + arg);
});
bot.command("get", async (ctx) => {
  const arg = ctx.message.text.split(" ").slice(1).join(" ");
  if (!arg) return ctx.reply("Usage: /get <path>");
  const target = safeJoin(BASE_DIR, arg);
  await ctx.replyWithDocument({
    source: target,
    filename: path.basename(target),
  });
});
bot.on("document", async (ctx) => {
  const caption = (ctx.message.caption || "").trim();
  let destPath = ".";
  if (caption.startsWith("/put"))
    destPath = caption.split(" ").slice(1).join(" ") || ".";
  const fileId = ctx.message.document.file_id;
  const fileName = ctx.message.document.file_name || "file";
  const filePath = safeJoin(BASE_DIR, path.join(destPath, fileName));
  const fileLink = await ctx.telegram.getFileLink(fileId);
  const res = await fetch(fileLink.href);
  if (!res.ok) throw new Error("download failed");
  await fs.mkdir(path.dirname(filePath), { recursive: true });
  const dest = await fs.open(filePath, "w");
  await pipeline(res.body, dest.createWriteStream());
  await dest.close();
  await ctx.reply("Saved to " + path.relative(BASE_DIR, filePath));
});
bot.launch();
process.once("SIGINT", () => bot.stop("SIGINT"));
process.once("SIGTERM", () => bot.stop("SIGTERM"));