#!/usr/bin/env bun

import { basename, join } from "node:path";
import { homedir } from "node:os";

const configDir = process.env.XDG_CONFIG_HOME || join(homedir(), ".config");
const webhookFile = join(configDir, "discord-send", "webhook");

function usage() {
  console.error(
    "Usage: discord-send [--attach <file>] <message>\n" +
      "\n" +
      "Sends a message to a Discord channel via webhook.\n" +
      `Reads the webhook URL from ${webhookFile}.`,
  );
}

const args = Bun.argv.slice(2);
let attachPath = null;
const messageParts = [];

for (let i = 0; i < args.length; i++) {
  const arg = args[i];
  if (arg === "--attach") {
    attachPath = args[++i];
    if (!attachPath) {
      console.error("Error: --attach requires a file path");
      process.exit(2);
    }
  } else if (arg.startsWith("--attach=")) {
    attachPath = arg.slice("--attach=".length);
  } else if (arg === "-h" || arg === "--help") {
    usage();
    process.exit(0);
  } else {
    messageParts.push(arg);
  }
}

const message = messageParts.join(" ");

const webhookFileHandle = Bun.file(webhookFile);
if (!(await webhookFileHandle.exists())) {
  console.error(
    `Error: webhook file not found: ${webhookFile}\n` +
      "Create it and write your Discord webhook URL inside.",
  );
  process.exit(1);
}
const webhookUrl = (await webhookFileHandle.text()).trim();
if (!webhookUrl) {
  console.error(`Error: webhook file is empty: ${webhookFile}`);
  process.exit(1);
}

if (!message && !attachPath) {
  usage();
  process.exit(2);
}

let body;
const headers = {};

if (attachPath) {
  const file = Bun.file(attachPath);
  if (!(await file.exists())) {
    console.error(`Error: file not found: ${attachPath}`);
    process.exit(1);
  }
  const filename = basename(attachPath);
  const payload = { attachments: [{ id: 0, filename }] };
  if (message) payload.content = message;

  const form = new FormData();
  form.append("payload_json", JSON.stringify(payload));
  form.append("files[0]", file, filename);
  body = form;
} else {
  headers["Content-Type"] = "application/json";
  body = JSON.stringify({ content: message });
}

const response = await fetch(webhookUrl, { method: "POST", headers, body });

if (!response.ok) {
  const text = await response.text();
  console.error(
    `Error: Discord returned ${response.status} ${response.statusText}\n${text}`,
  );
  process.exit(1);
}

console.log("Message sent successfully");