import type { createAuthClient } from "better-auth/react";

import { authStoragePrefix } from "@/lib/accounts";
import {
  clearAuthStorage,
  GUEST_AUTH_STORAGE_PREFIX,
  prepareForAdditionalSignIn,
} from "@/lib/auth-storage";

type AuthClient = ReturnType<typeof createAuthClient>;

type PerformAuthResetInput = {
  authClient: AuthClient;
  clearActiveAccount: () => Promise<void>;
  activeAccountId?: string | null;
  refetchSession?: () => Promise<unknown>;
};

/** Sign out, wipe local auth storage, and return to guest mode for a clean sign-in screen. */
export async function performAuthReset({
  authClient,
  clearActiveAccount,
  activeAccountId,
  refetchSession,
}: PerformAuthResetInput): Promise<void> {
  const accountPrefix = activeAccountId ? authStoragePrefix(activeAccountId) : null;

  try {
    await authClient.signOut();
  } catch {
    // Continue clearing local state even when the server session is already gone.
  }

  if (accountPrefix) {
    await clearAuthStorage(accountPrefix);
  }
  await clearAuthStorage(GUEST_AUTH_STORAGE_PREFIX);
  await clearActiveAccount();
  await refetchSession?.();
}

/**
 * When the auth stack is shown, discard stale SecureStore sessions so sign-in starts clean.
 * Expired account sessions switch back to guest storage; orphaned guest copies are cleared.
 */
export async function prepareAuthScreenSession(
  authClient: AuthClient,
  activeAccountId: string | null,
  clearActiveAccount: () => Promise<void>,
): Promise<void> {
  const session = await authClient.getSession();
  if (session.data?.user) return;

  if (activeAccountId) {
    await clearAuthStorage(authStoragePrefix(activeAccountId));
    await clearActiveAccount();
  }

  await prepareForAdditionalSignIn();
}