import { authStrings } from "./strings";

export interface AuthActionResult {
  ok: boolean;
  twoFactor?: boolean;
  challenge?: string;
  error?: string;
}

// Mirrors AuthError.userMessage in ios/Mercury/Features/Auth/AuthRepository.swift,
// keyed by the `{error:{code,message}}` envelope the Go backend writes
// (internal/transport/api/respond.go, auth_handlers.go, twofa_handlers.go).
const ERROR_MESSAGE_BY_CODE: Record<string, string> = {
  invalid_credentials: authStrings.errors.invalidCredentials,
  email_taken: authStrings.errors.emailTaken,
  invalid_code: authStrings.errors.invalidCode,
  invalid_challenge: authStrings.errors.invalidCode,
};

function messageForCode(code: string | undefined): string {
  if (code && ERROR_MESSAGE_BY_CODE[code]) return ERROR_MESSAGE_BY_CODE[code];
  return authStrings.errors.unknown;
}

async function postAuth(
  path: "login" | "register" | "forgot" | "2fa",
  body: unknown,
): Promise<AuthActionResult> {
  let res: Response;
  try {
    res = await fetch(`/api/auth/${path}`, {
      method: "POST",
      credentials: "same-origin",
      headers: { "Content-Type": "application/json" },
      body: JSON.stringify(body),
    });
  } catch {
    return { ok: false, error: authStrings.errors.network };
  }

  const data = await res.json().catch(() => ({}));

  if (!res.ok) {
    return { ok: false, error: messageForCode(data?.error?.code) };
  }
  if (data?.twoFactor) {
    return { ok: false, twoFactor: true, challenge: data.challenge };
  }
  return { ok: true };
}

export function submitLogin(
  email: string,
  password: string,
): Promise<AuthActionResult> {
  return postAuth("login", { email, password });
}

export function submitRegister(
  email: string,
  password: string,
): Promise<AuthActionResult> {
  return postAuth("register", { email, password });
}

export function submit2FA(
  challenge: string,
  code: string,
): Promise<AuthActionResult> {
  return postAuth("2fa", { challenge, code });
}

export function submitForgot(email: string): Promise<AuthActionResult> {
  return postAuth("forgot", { email });
}