import { describe, expect, it } from "vitest";
import {
  EXAMPLE_ECHO_TOOL_NAME,
  EXAMPLE_SUMMARY_PROMPT_NAME,
  type CapabilityRegistration,
  createCapabilityRegistry,
  registerCapabilities,
  registerCoreCapabilities,
} from "../src/capabilities/index.js";

describe("capability registration", () => {
  it("aggregates core registrations through plain function composition", () => {
    const registry = registerCapabilities();

    expect(registry.tools.map((entry) => entry.name)).toEqual([
      EXAMPLE_ECHO_TOOL_NAME,
    ]);
    expect(registry.resources.map((entry) => entry.name)).toEqual([
      "template://status",
    ]);
    expect(registry.prompts.map((entry) => entry.name)).toEqual([
      EXAMPLE_SUMMARY_PROMPT_NAME,
    ]);
  });

  it("supports explicit composition with custom registrations", () => {
    const registerCustom: CapabilityRegistration = (registry) => {
      registry.tools.push({
        name: "custom.tool",
        kind: "tool",
        description: "Custom tool descriptor",
      });
    };

    const registry = registerCapabilities([
      registerCoreCapabilities,
      registerCustom,
    ]);

    expect(registry.tools.map((entry) => entry.name)).toEqual([
      EXAMPLE_ECHO_TOOL_NAME,
      "custom.tool",
    ]);
    expect(registry.resources).toHaveLength(1);
    expect(registry.prompts).toHaveLength(1);
  });

  it("lets callers register into an existing registry", () => {
    const registry = createCapabilityRegistry();

    registerCoreCapabilities(registry);

    expect(registry.tools).toHaveLength(1);
    expect(registry.resources).toHaveLength(1);
    expect(registry.prompts).toHaveLength(1);
  });
});