#!/usr/bin/env node
import { load, save, add, has, complete, remove, format } from "./todo.js";

const FILE = process.env.TODO_FILE ?? "todos.json";
const USAGE = "Usage: todo [ls | add <text> | done <id> | rm <id>]";
const [cmd = "ls", ...args] = process.argv.slice(2);

function fail(message) {
  console.error(message);
  process.exit(1);
}

function parseId(todos, arg) {
  if (!/^\d+$/.test(arg ?? "")) fail(`Invalid id: ${arg ?? "(missing)"}\n${USAGE}`);
  const id = Number(arg);
  if (!has(todos, id)) fail(`No todo with id ${id}`);
  return id;
}

if (!["ls", "add", "done", "rm"].includes(cmd)) fail(`Unknown command: ${cmd}\n${USAGE}`);

let todos;
try {
  todos = load(FILE);
} catch (err) {
  fail(err.message);
}

switch (cmd) {
  case "add": {
    const text = args.join(" ").trim();
    if (!text) fail(`Missing todo text\n${USAGE}`);
    todos = add(todos, text);
    break;
  }
  case "done":
    todos = complete(todos, parseId(todos, args[0]));
    break;
  case "rm":
    todos = remove(todos, parseId(todos, args[0]));
    break;
}

if (cmd !== "ls") {
  try {
    save(FILE, todos);
  } catch (err) {
    fail(err.message);
  }
}
console.log(format(todos));