interface HeadscaleUser {
  id: string;
  name: string;
}

interface HeadscalePreAuthKey {
  key: string;
  expiration: string;
  aclTags: string[];
}

export async function getHeadscaleUserId(
  baseUrl: string,
  apiKey: string,
  userName: string
): Promise<string> {
  const res = await fetch(
    `${baseUrl}/api/v1/user?name=${encodeURIComponent(userName)}`,
    {
      headers: { Authorization: `Bearer ${apiKey}` },
    }
  );
  if (!res.ok) {
    throw new Error(
      `Headscale list users failed: ${res.status} ${await res.text()}`
    );
  }
  const data = (await res.json()) as { users: HeadscaleUser[] };
  const user = data.users.find((u) => u.name === userName);
  if (!user) {
    throw new Error(`Headscale user not found: ${userName}`);
  }
  return user.id;
}

export async function createEphemeralPreAuthKey(
  baseUrl: string,
  apiKey: string,
  userId: string,
  options: {
    expirationMinutes?: number;
    aclTags?: string[];
  } = {}
): Promise<string> {
  const expirationMinutes = options.expirationMinutes ?? 15;
  const aclTags = options.aclTags ?? [];

  const expiration = new Date(
    Date.now() + expirationMinutes * 60 * 1000
  ).toISOString();

  const res = await fetch(`${baseUrl}/api/v1/preauthkey`, {
    method: "POST",
    headers: {
      Authorization: `Bearer ${apiKey}`,
      "Content-Type": "application/json",
    },
    body: JSON.stringify({
      user: userId,
      reusable: false,
      ephemeral: false,
      expiration,
      aclTags,
    }),
  });

  if (!res.ok) {
    throw new Error(
      `Headscale create preauthkey failed: ${res.status} ${await res.text()}`
    );
  }

  const data = (await res.json()) as { preAuthKey: HeadscalePreAuthKey };
  return data.preAuthKey.key;
}