/**
 * @license
 * Copyright 2025 Google LLC
 * SPDX-License-Identifier: Apache-2.0
 */

import { vi, describe, it, expect, beforeEach, Mock } from 'vitest';
import { clearCommand } from './clearCommand.js';
import { type CommandContext } from './types.js';
import { createMockCommandContext } from '../../test-utils/mockCommandContext.js';
import { GeminiClient } from '@google/gemini-cli-core';

describe('clearCommand', () => {
  let mockContext: CommandContext;
  let mockResetChat: ReturnType<typeof vi.fn>;

  beforeEach(() => {
    mockResetChat = vi.fn().mockResolvedValue(undefined);

    mockContext = createMockCommandContext({
      services: {
        config: {
          getGeminiClient: () =>
            ({
              resetChat: mockResetChat,
            }) as unknown as GeminiClient,
        },
      },
    });
  });

  it('should set debug message, reset chat, and clear UI when config is available', async () => {
    if (!clearCommand.action) {
      throw new Error('clearCommand must have an action.');
    }

    await clearCommand.action(mockContext, '');

    expect(mockContext.ui.setDebugMessage).toHaveBeenCalledWith(
      'Clearing terminal and resetting chat.',
    );
    expect(mockContext.ui.setDebugMessage).toHaveBeenCalledTimes(1);

    expect(mockResetChat).toHaveBeenCalledTimes(1);

    expect(mockContext.ui.clear).toHaveBeenCalledTimes(1);

    // Check the order of operations.
    const setDebugMessageOrder = (mockContext.ui.setDebugMessage as Mock).mock
      .invocationCallOrder[0];
    const resetChatOrder = mockResetChat.mock.invocationCallOrder[0];
    const clearOrder = (mockContext.ui.clear as Mock).mock
      .invocationCallOrder[0];

    expect(setDebugMessageOrder).toBeLessThan(resetChatOrder);
    expect(resetChatOrder).toBeLessThan(clearOrder);
  });

  it('should not attempt to reset chat if config service is not available', async () => {
    if (!clearCommand.action) {
      throw new Error('clearCommand must have an action.');
    }

    const nullConfigContext = createMockCommandContext({
      services: {
        config: null,
      },
    });

    await clearCommand.action(nullConfigContext, '');

    expect(nullConfigContext.ui.setDebugMessage).toHaveBeenCalledWith(
      'Clearing terminal and resetting chat.',
    );
    expect(mockResetChat).not.toHaveBeenCalled();
    expect(nullConfigContext.ui.clear).toHaveBeenCalledTimes(1);
  });
});