export type AuthRequestMessage =
  | { type: "auth:get-state" }
  | { type: "auth:sign-in" }
  | { type: "auth:sign-out" }
  | { type: "auth:get-access-token" };

export interface AuthStateValue {
  accessTokenExpiresAt?: number | null;
  isAuthenticated: boolean;
  lastError?: string | null;
  resource?: string | null;
  scopes?: string[];
  tokenAvailable?: boolean;
  userInfo?: {
    email?: string;
    name?: string;
    sub?: string;
    username?: string;
  } | null;
}

export type AuthResponseMessage =
  | { ok: true; type: "auth:state"; value: AuthStateValue }
  | { ok: true; type: "auth:token"; value: { accessToken: string } }
  | { ok: true; type: "auth:ack" }
  | { ok: false; type: "auth:error"; error: string };

const authRequestTypes = new Set<AuthRequestMessage["type"]>([
  "auth:get-state",
  "auth:sign-in",
  "auth:sign-out",
  "auth:get-access-token"
]);

export function isAuthRequestMessage(
  value: unknown
): value is AuthRequestMessage {
  if (!value || typeof value !== "object") {
    return false;
  }

  const candidate = value as Partial<AuthRequestMessage>;
  return typeof candidate.type === "string" && authRequestTypes.has(candidate.type);
}

export function isAuthResponseMessage(
  value: unknown
): value is AuthResponseMessage {
  if (!value || typeof value !== "object") {
    return false;
  }

  const candidate = value as Partial<AuthResponseMessage>;
  if (candidate.ok === false) {
    return candidate.type === "auth:error" && typeof candidate.error === "string";
  }

  if (candidate.ok !== true || typeof candidate.type !== "string") {
    return false;
  }

  if (candidate.type === "auth:ack") {
    return true;
  }

  if (candidate.type === "auth:token") {
    return Boolean(
      candidate.value &&
        typeof candidate.value === "object" &&
        typeof (candidate.value as { accessToken?: unknown }).accessToken === "string"
    );
  }

  if (candidate.type === "auth:state") {
    return Boolean(
      candidate.value &&
        typeof candidate.value === "object" &&
        typeof (candidate.value as { isAuthenticated?: unknown }).isAuthenticated ===
          "boolean"
    );
  }

  return false;
}