import { describe, expect, it } from "vitest";
import {
  type ModuleUiHostContext,
  type ModuleUiNavigation,
  ModuleUiNavigationError,
} from "../src/index.js";

/** The navigation capability's public surface (ADR 0063). Its behaviour is the host's: the
 * Dashboard's implementation is proven in `surfaces/shell/tests/module-navigation.test.tsx`. */
describe("module UI navigation contract", () => {
  it("reports a refused path with a stable code and a fixed message that never echoes the path", () => {
    for (const code of [
      "MODULE_NAVIGATION_PATH_INVALID",
      "MODULE_NAVIGATION_PATH_UNKNOWN",
    ] as const) {
      const error = new ModuleUiNavigationError(code);
      expect(error).toBeInstanceOf(Error);
      expect(error.name).toBe("ModuleUiNavigationError");
      expect(error.code).toBe(code);
      expect(error.stack).toBe(`ModuleUiNavigationError: ${error.message}`);
      expect(error.message).not.toMatch(/[/:?#]/u);
    }
  });

  it("makes navigation a context member a host without pages leaves undefined", () => {
    // A type-level contract: a context may say it has no navigation, as the display host does, and
    // a module reads it through an optional check.
    const describe = (context: Pick<ModuleUiHostContext, "navigation">): string =>
      context.navigation?.location().path ?? "no navigation";
    const navigation: ModuleUiNavigation = {
      link: () => ({ href: "/m/x", onClick: () => undefined }),
      location: () => ({ page: "x", path: "x" }),
      navigate: () => undefined,
      settings: undefined,
      subscribe: () => () => undefined,
    };
    expect(describe({ navigation: undefined })).toBe("no navigation");
    expect(describe({ navigation })).toBe("x");
  });
});