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

const CONFIG_PATH =
  process.env["GMAPS_CONFIG"] ?? join(homedir(), ".gmaps.json");

interface Config {
  lists: Record<string, string>;
}

export async function loadConfig(): Promise<Config> {
  try {
    const file = Bun.file(CONFIG_PATH);
    const text = await file.text();
    const data: unknown = JSON.parse(text);

    if (
      data !== null &&
      typeof data === "object" &&
      "lists" in data &&
      data.lists !== null &&
      typeof data.lists === "object"
    ) {
      return data as Config;
    }
  } catch {
    // File doesn't exist or is invalid
  }

  return { lists: {} };
}

async function saveConfig(config: Config): Promise<void> {
  await Bun.write(CONFIG_PATH, JSON.stringify(config, null, 2) + "\n");
}

export async function addList(alias: string, url: string): Promise<void> {
  const config = await loadConfig();
  config.lists[alias] = url;
  await saveConfig(config);
}

export async function removeList(alias: string): Promise<boolean> {
  const config = await loadConfig();

  if (!(alias in config.lists)) {
    return false;
  }

  delete config.lists[alias];
  await saveConfig(config);
  return true;
}

export async function getLists(): Promise<Record<string, string>> {
  const config = await loadConfig();
  return config.lists;
}

export async function resolveAlias(urlOrAlias: string): Promise<string> {
  if (urlOrAlias.startsWith("http") || urlOrAlias.includes("goo.gl")) {
    return urlOrAlias;
  }

  const config = await loadConfig();
  const url = config.lists[urlOrAlias];

  if (!url) {
    throw new Error(
      `Unknown alias "${urlOrAlias}". Run "gmaps lists ls" to see saved lists.`,
    );
  }

  return url;
}