import { existsSync, mkdirSync, rmSync } from "node:fs";
import { tmpdir } from "node:os";
import { join } from "node:path";
import { getModel } from "@mariozechner/companion-ai";
import { Type } from "@sinclair/typebox";
import { afterEach, beforeEach, describe, expect, it } from "vitest";
import { DefaultResourceLoader } from "../src/core/resource-loader.js";
import { createAgentSession } from "../src/core/sdk.js";
import { SessionManager } from "../src/core/session-manager.js";
import { SettingsManager } from "../src/core/settings-manager.js";

describe("AgentSession dynamic tool registration", () => {
  let tempDir: string;
  let agentDir: string;

  beforeEach(() => {
    tempDir = join(
      tmpdir(),
      `companion-dynamic-tool-test-${Date.now()}-${Math.random().toString(36).slice(2)}`,
    );
    agentDir = join(tempDir, "agent");
    mkdirSync(agentDir, { recursive: true });
  });

  afterEach(() => {
    if (tempDir && existsSync(tempDir)) {
      rmSync(tempDir, { recursive: true, force: true });
    }
  });

  it("refreshes tool registry when tools are registered after initialization", async () => {
    const settingsManager = SettingsManager.create(tempDir, agentDir);
    const sessionManager = SessionManager.inMemory();

    const resourceLoader = new DefaultResourceLoader({
      cwd: tempDir,
      agentDir,
      settingsManager,
      extensionFactories: [
        (companion) => {
          companion.on("session_start", () => {
            companion.registerTool({
              name: "dynamic_tool",
              label: "Dynamic Tool",
              description: "Tool registered from session_start",
              promptSnippet: "Run dynamic test behavior",
              promptGuidelines: [
                "Use dynamic_tool when the user asks for dynamic behavior tests.",
              ],
              parameters: Type.Object({}),
              execute: async () => ({
                content: [{ type: "text", text: "ok" }],
                details: {},
              }),
            });
          });
        },
      ],
    });
    await resourceLoader.reload();

    const { session } = await createAgentSession({
      cwd: tempDir,
      agentDir,
      model: getModel("anthropic", "claude-sonnet-4-5")!,
      settingsManager,
      sessionManager,
      resourceLoader,
    });

    expect(session.getAllTools().map((tool) => tool.name)).not.toContain(
      "dynamic_tool",
    );

    await session.bindExtensions({});

    expect(session.getAllTools().map((tool) => tool.name)).toContain(
      "dynamic_tool",
    );
    expect(session.getActiveToolNames()).toContain("dynamic_tool");
    expect(session.systemPrompt).toContain(
      "- dynamic_tool: Run dynamic test behavior",
    );
    expect(session.systemPrompt).toContain(
      "- Use dynamic_tool when the user asks for dynamic behavior tests.",
    );

    session.dispose();
  });
});