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

import { describe, it, expect, vi, beforeEach } from 'vitest';
import { Mock } from 'vitest';
import { Config, ConfigParameters, SandboxConfig } from './config.js';
import * as path from 'path';
import { setGeminiMdFilename as mockSetGeminiMdFilename } from '../tools/memoryTool.js';
import {
  DEFAULT_TELEMETRY_TARGET,
  DEFAULT_OTLP_ENDPOINT,
} from '../telemetry/index.js';
import {
  AuthType,
  ContentGeneratorConfig,
  createContentGeneratorConfig,
} from '../core/contentGenerator.js';
import { GeminiClient } from '../core/client.js';
import { GitService } from '../services/gitService.js';
import { ClearcutLogger } from '../telemetry/clearcut-logger/clearcut-logger.js';

vi.mock('fs', async (importOriginal) => {
  const actual = await importOriginal<typeof import('fs')>();
  return {
    ...actual,
    existsSync: vi.fn().mockReturnValue(true),
    statSync: vi.fn().mockReturnValue({
      isDirectory: vi.fn().mockReturnValue(true),
    }),
    realpathSync: vi.fn((path) => path),
  };
});

// Mock dependencies that might be called during Config construction or createServerConfig
vi.mock('../tools/tool-registry', () => {
  const ToolRegistryMock = vi.fn();
  ToolRegistryMock.prototype.registerTool = vi.fn();
  ToolRegistryMock.prototype.discoverAllTools = vi.fn();
  ToolRegistryMock.prototype.getAllTools = vi.fn(() => []); // Mock methods if needed
  ToolRegistryMock.prototype.getTool = vi.fn();
  ToolRegistryMock.prototype.getFunctionDeclarations = vi.fn(() => []);
  return { ToolRegistry: ToolRegistryMock };
});

vi.mock('../utils/memoryDiscovery.js', () => ({
  loadServerHierarchicalMemory: vi.fn(),
}));

// Mock individual tools if their constructors are complex or have side effects
vi.mock('../tools/ls');
vi.mock('../tools/read-file');
vi.mock('../tools/grep');
vi.mock('../tools/glob');
vi.mock('../tools/edit');
vi.mock('../tools/shell');
vi.mock('../tools/write-file');
vi.mock('../tools/web-fetch');
vi.mock('../tools/read-many-files');
vi.mock('../tools/memoryTool', () => ({
  MemoryTool: vi.fn(),
  setGeminiMdFilename: vi.fn(),
  getCurrentGeminiMdFilename: vi.fn(() => 'GEMINI.md'), // Mock the original filename
  DEFAULT_CONTEXT_FILENAME: 'GEMINI.md',
  GEMINI_CONFIG_DIR: '.gemini',
}));

vi.mock('../core/contentGenerator.js', async (importOriginal) => {
  const actual =
    await importOriginal<typeof import('../core/contentGenerator.js')>();
  return {
    ...actual,
    createContentGeneratorConfig: vi.fn(),
  };
});

vi.mock('../core/client.js', () => ({
  GeminiClient: vi.fn().mockImplementation(() => ({
    initialize: vi.fn().mockResolvedValue(undefined),
  })),
}));

vi.mock('../telemetry/index.js', async (importOriginal) => {
  const actual = await importOriginal<typeof import('../telemetry/index.js')>();
  return {
    ...actual,
    initializeTelemetry: vi.fn(),
  };
});

vi.mock('../services/gitService.js', () => {
  const GitServiceMock = vi.fn();
  GitServiceMock.prototype.initialize = vi.fn();
  return { GitService: GitServiceMock };
});

describe('Server Config (config.ts)', () => {
  const MODEL = 'gemini-pro';
  const SANDBOX: SandboxConfig = {
    command: 'docker',
    image: 'gemini-cli-sandbox',
  };
  const TARGET_DIR = '/path/to/target';
  const DEBUG_MODE = false;
  const QUESTION = 'test question';
  const FULL_CONTEXT = false;
  const USER_MEMORY = 'Test User Memory';
  const TELEMETRY_SETTINGS = { enabled: false };
  const EMBEDDING_MODEL = 'gemini-embedding';
  const SESSION_ID = 'test-session-id';
  const baseParams: ConfigParameters = {
    cwd: '/tmp',
    embeddingModel: EMBEDDING_MODEL,
    sandbox: SANDBOX,
    targetDir: TARGET_DIR,
    debugMode: DEBUG_MODE,
    question: QUESTION,
    fullContext: FULL_CONTEXT,
    userMemory: USER_MEMORY,
    telemetry: TELEMETRY_SETTINGS,
    sessionId: SESSION_ID,
    model: MODEL,
    usageStatisticsEnabled: false,
  };

  beforeEach(() => {
    // Reset mocks if necessary
    vi.clearAllMocks();
    vi.spyOn(
      ClearcutLogger.prototype,
      'logStartSessionEvent',
    ).mockImplementation(() => undefined);
  });

  describe('initialize', () => {
    it('should throw an error if checkpointing is enabled and GitService fails', async () => {
      const gitError = new Error('Git is not installed');
      (GitService.prototype.initialize as Mock).mockRejectedValue(gitError);

      const config = new Config({
        ...baseParams,
        checkpointing: true,
      });

      await expect(config.initialize()).rejects.toThrow(gitError);
    });

    it('should not throw an error if checkpointing is disabled and GitService fails', async () => {
      const gitError = new Error('Git is not installed');
      (GitService.prototype.initialize as Mock).mockRejectedValue(gitError);

      const config = new Config({
        ...baseParams,
        checkpointing: false,
      });

      await expect(config.initialize()).resolves.toBeUndefined();
    });

    it('should throw an error if initialized more than once', async () => {
      const config = new Config({
        ...baseParams,
        checkpointing: false,
      });

      await expect(config.initialize()).resolves.toBeUndefined();
      await expect(config.initialize()).rejects.toThrow(
        'Config was already initialized',
      );
    });
  });

  describe('refreshAuth', () => {
    it('should refresh auth and update config', async () => {
      const config = new Config(baseParams);
      const authType = AuthType.USE_GEMINI;
      const newModel = 'gemini-flash';
      const mockContentConfig = {
        model: newModel,
        apiKey: 'test-key',
      };

      (createContentGeneratorConfig as Mock).mockReturnValue(mockContentConfig);

      // Set fallback mode to true to ensure it gets reset
      config.setFallbackMode(true);
      expect(config.isInFallbackMode()).toBe(true);

      await config.refreshAuth(authType);

      expect(createContentGeneratorConfig).toHaveBeenCalledWith(
        config,
        authType,
      );
      // Verify that contentGeneratorConfig is updated with the new model
      expect(config.getContentGeneratorConfig()).toEqual(mockContentConfig);
      expect(config.getContentGeneratorConfig().model).toBe(newModel);
      expect(config.getModel()).toBe(newModel); // getModel() should return the updated model
      expect(GeminiClient).toHaveBeenCalledWith(config);
      // Verify that fallback mode is reset
      expect(config.isInFallbackMode()).toBe(false);
    });

    it('should preserve conversation history when refreshing auth', async () => {
      const config = new Config(baseParams);
      const authType = AuthType.USE_GEMINI;
      const mockContentConfig = {
        model: 'gemini-pro',
        apiKey: 'test-key',
      };

      (createContentGeneratorConfig as Mock).mockReturnValue(mockContentConfig);

      // Mock the existing client with some history
      const mockExistingHistory = [
        { role: 'user', parts: [{ text: 'Hello' }] },
        { role: 'model', parts: [{ text: 'Hi there!' }] },
        { role: 'user', parts: [{ text: 'How are you?' }] },
      ];

      const mockExistingClient = {
        isInitialized: vi.fn().mockReturnValue(true),
        getHistory: vi.fn().mockReturnValue(mockExistingHistory),
      };

      const mockNewClient = {
        isInitialized: vi.fn().mockReturnValue(true),
        getHistory: vi.fn().mockReturnValue([]),
        setHistory: vi.fn(),
        initialize: vi.fn().mockResolvedValue(undefined),
      };

      // Set the existing client
      (
        config as unknown as { geminiClient: typeof mockExistingClient }
      ).geminiClient = mockExistingClient;
      (GeminiClient as Mock).mockImplementation(() => mockNewClient);

      await config.refreshAuth(authType);

      // Verify that existing history was retrieved
      expect(mockExistingClient.getHistory).toHaveBeenCalled();

      // Verify that new client was created and initialized
      expect(GeminiClient).toHaveBeenCalledWith(config);
      expect(mockNewClient.initialize).toHaveBeenCalledWith(mockContentConfig);

      // Verify that history was restored to the new client
      expect(mockNewClient.setHistory).toHaveBeenCalledWith(
        mockExistingHistory,
        { stripThoughts: false },
      );
    });

    it('should handle case when no existing client is initialized', async () => {
      const config = new Config(baseParams);
      const authType = AuthType.USE_GEMINI;
      const mockContentConfig = {
        model: 'gemini-pro',
        apiKey: 'test-key',
      };

      (createContentGeneratorConfig as Mock).mockReturnValue(mockContentConfig);

      const mockNewClient = {
        isInitialized: vi.fn().mockReturnValue(true),
        getHistory: vi.fn().mockReturnValue([]),
        setHistory: vi.fn(),
        initialize: vi.fn().mockResolvedValue(undefined),
      };

      // No existing client
      (config as unknown as { geminiClient: null }).geminiClient = null;
      (GeminiClient as Mock).mockImplementation(() => mockNewClient);

      await config.refreshAuth(authType);

      // Verify that new client was created and initialized
      expect(GeminiClient).toHaveBeenCalledWith(config);
      expect(mockNewClient.initialize).toHaveBeenCalledWith(mockContentConfig);

      // Verify that setHistory was not called since there was no existing history
      expect(mockNewClient.setHistory).not.toHaveBeenCalled();
    });

    it('should strip thoughts when switching from GenAI to Vertex', async () => {
      const config = new Config(baseParams);
      const mockContentConfig = {
        model: 'gemini-pro',
        apiKey: 'test-key',
        authType: AuthType.USE_GEMINI,
      };
      (
        config as unknown as { contentGeneratorConfig: ContentGeneratorConfig }
      ).contentGeneratorConfig = mockContentConfig;

      (createContentGeneratorConfig as Mock).mockReturnValue({
        ...mockContentConfig,
        authType: AuthType.LOGIN_WITH_GOOGLE,
      });

      const mockExistingHistory = [
        { role: 'user', parts: [{ text: 'Hello' }] },
      ];
      const mockExistingClient = {
        isInitialized: vi.fn().mockReturnValue(true),
        getHistory: vi.fn().mockReturnValue(mockExistingHistory),
      };
      const mockNewClient = {
        isInitialized: vi.fn().mockReturnValue(true),
        getHistory: vi.fn().mockReturnValue([]),
        setHistory: vi.fn(),
        initialize: vi.fn().mockResolvedValue(undefined),
      };

      (
        config as unknown as { geminiClient: typeof mockExistingClient }
      ).geminiClient = mockExistingClient;
      (GeminiClient as Mock).mockImplementation(() => mockNewClient);

      await config.refreshAuth(AuthType.LOGIN_WITH_GOOGLE);

      expect(mockNewClient.setHistory).toHaveBeenCalledWith(
        mockExistingHistory,
        { stripThoughts: true },
      );
    });

    it('should not strip thoughts when switching from Vertex to GenAI', async () => {
      const config = new Config(baseParams);
      const mockContentConfig = {
        model: 'gemini-pro',
        apiKey: 'test-key',
        authType: AuthType.LOGIN_WITH_GOOGLE,
      };
      (
        config as unknown as { contentGeneratorConfig: ContentGeneratorConfig }
      ).contentGeneratorConfig = mockContentConfig;

      (createContentGeneratorConfig as Mock).mockReturnValue({
        ...mockContentConfig,
        authType: AuthType.USE_GEMINI,
      });

      const mockExistingHistory = [
        { role: 'user', parts: [{ text: 'Hello' }] },
      ];
      const mockExistingClient = {
        isInitialized: vi.fn().mockReturnValue(true),
        getHistory: vi.fn().mockReturnValue(mockExistingHistory),
      };
      const mockNewClient = {
        isInitialized: vi.fn().mockReturnValue(true),
        getHistory: vi.fn().mockReturnValue([]),
        setHistory: vi.fn(),
        initialize: vi.fn().mockResolvedValue(undefined),
      };

      (
        config as unknown as { geminiClient: typeof mockExistingClient }
      ).geminiClient = mockExistingClient;
      (GeminiClient as Mock).mockImplementation(() => mockNewClient);

      await config.refreshAuth(AuthType.USE_GEMINI);

      expect(mockNewClient.setHistory).toHaveBeenCalledWith(
        mockExistingHistory,
        { stripThoughts: false },
      );
    });
  });

  it('Config constructor should store userMemory correctly', () => {
    const config = new Config(baseParams);

    expect(config.getUserMemory()).toBe(USER_MEMORY);
    // Verify other getters if needed
    expect(config.getTargetDir()).toBe(path.resolve(TARGET_DIR)); // Check resolved path
  });

  it('Config constructor should default userMemory to empty string if not provided', () => {
    const paramsWithoutMemory: ConfigParameters = { ...baseParams };
    delete paramsWithoutMemory.userMemory;
    const config = new Config(paramsWithoutMemory);

    expect(config.getUserMemory()).toBe('');
  });

  it('Config constructor should call setGeminiMdFilename with contextFileName if provided', () => {
    const contextFileName = 'CUSTOM_AGENTS.md';
    const paramsWithContextFile: ConfigParameters = {
      ...baseParams,
      contextFileName,
    };
    new Config(paramsWithContextFile);
    expect(mockSetGeminiMdFilename).toHaveBeenCalledWith(contextFileName);
  });

  it('Config constructor should not call setGeminiMdFilename if contextFileName is not provided', () => {
    new Config(baseParams); // baseParams does not have contextFileName
    expect(mockSetGeminiMdFilename).not.toHaveBeenCalled();
  });

  it('should set default file filtering settings when not provided', () => {
    const config = new Config(baseParams);
    expect(config.getFileFilteringRespectGitIgnore()).toBe(true);
  });

  it('should set custom file filtering settings when provided', () => {
    const paramsWithFileFiltering: ConfigParameters = {
      ...baseParams,
      fileFiltering: {
        respectGitIgnore: false,
      },
    };
    const config = new Config(paramsWithFileFiltering);
    expect(config.getFileFilteringRespectGitIgnore()).toBe(false);
  });

  it('should initialize WorkspaceContext with includeDirectories', () => {
    const includeDirectories = ['/path/to/dir1', '/path/to/dir2'];
    const paramsWithIncludeDirs: ConfigParameters = {
      ...baseParams,
      includeDirectories,
    };
    const config = new Config(paramsWithIncludeDirs);
    const workspaceContext = config.getWorkspaceContext();
    const directories = workspaceContext.getDirectories();

    // Should include the target directory plus the included directories
    expect(directories).toHaveLength(3);
    expect(directories).toContain(path.resolve(baseParams.targetDir));
    expect(directories).toContain('/path/to/dir1');
    expect(directories).toContain('/path/to/dir2');
  });

  it('Config constructor should set telemetry to true when provided as true', () => {
    const paramsWithTelemetry: ConfigParameters = {
      ...baseParams,
      telemetry: { enabled: true },
    };
    const config = new Config(paramsWithTelemetry);
    expect(config.getTelemetryEnabled()).toBe(true);
  });

  it('Config constructor should set telemetry to false when provided as false', () => {
    const paramsWithTelemetry: ConfigParameters = {
      ...baseParams,
      telemetry: { enabled: false },
    };
    const config = new Config(paramsWithTelemetry);
    expect(config.getTelemetryEnabled()).toBe(false);
  });

  it('Config constructor should default telemetry to default value if not provided', () => {
    const paramsWithoutTelemetry: ConfigParameters = { ...baseParams };
    delete paramsWithoutTelemetry.telemetry;
    const config = new Config(paramsWithoutTelemetry);
    expect(config.getTelemetryEnabled()).toBe(TELEMETRY_SETTINGS.enabled);
  });

  it('should have a getFileService method that returns FileDiscoveryService', () => {
    const config = new Config(baseParams);
    const fileService = config.getFileService();
    expect(fileService).toBeDefined();
  });

  describe('Usage Statistics', () => {
    it('defaults usage statistics to enabled if not specified', () => {
      const config = new Config({
        ...baseParams,
        usageStatisticsEnabled: undefined,
      });

      expect(config.getUsageStatisticsEnabled()).toBe(true);
    });

    it.each([{ enabled: true }, { enabled: false }])(
      'sets usage statistics based on the provided value (enabled: $enabled)',
      ({ enabled }) => {
        const config = new Config({
          ...baseParams,
          usageStatisticsEnabled: enabled,
        });
        expect(config.getUsageStatisticsEnabled()).toBe(enabled);
      },
    );

    it('logs the session start event', () => {
      new Config({
        ...baseParams,
        usageStatisticsEnabled: true,
      });

      expect(
        ClearcutLogger.prototype.logStartSessionEvent,
      ).toHaveBeenCalledOnce();
    });
  });

  describe('Telemetry Settings', () => {
    it('should return default telemetry target if not provided', () => {
      const params: ConfigParameters = {
        ...baseParams,
        telemetry: { enabled: true },
      };
      const config = new Config(params);
      expect(config.getTelemetryTarget()).toBe(DEFAULT_TELEMETRY_TARGET);
    });

    it('should return provided OTLP endpoint', () => {
      const endpoint = 'http://custom.otel.collector:4317';
      const params: ConfigParameters = {
        ...baseParams,
        telemetry: { enabled: true, otlpEndpoint: endpoint },
      };
      const config = new Config(params);
      expect(config.getTelemetryOtlpEndpoint()).toBe(endpoint);
    });

    it('should return default OTLP endpoint if not provided', () => {
      const params: ConfigParameters = {
        ...baseParams,
        telemetry: { enabled: true },
      };
      const config = new Config(params);
      expect(config.getTelemetryOtlpEndpoint()).toBe(DEFAULT_OTLP_ENDPOINT);
    });

    it('should return provided logPrompts setting', () => {
      const params: ConfigParameters = {
        ...baseParams,
        telemetry: { enabled: true, logPrompts: false },
      };
      const config = new Config(params);
      expect(config.getTelemetryLogPromptsEnabled()).toBe(false);
    });

    it('should return default logPrompts setting (true) if not provided', () => {
      const params: ConfigParameters = {
        ...baseParams,
        telemetry: { enabled: true },
      };
      const config = new Config(params);
      expect(config.getTelemetryLogPromptsEnabled()).toBe(true);
    });

    it('should return default logPrompts setting (true) if telemetry object is not provided', () => {
      const paramsWithoutTelemetry: ConfigParameters = { ...baseParams };
      delete paramsWithoutTelemetry.telemetry;
      const config = new Config(paramsWithoutTelemetry);
      expect(config.getTelemetryLogPromptsEnabled()).toBe(true);
    });

    it('should return default telemetry target if telemetry object is not provided', () => {
      const paramsWithoutTelemetry: ConfigParameters = { ...baseParams };
      delete paramsWithoutTelemetry.telemetry;
      const config = new Config(paramsWithoutTelemetry);
      expect(config.getTelemetryTarget()).toBe(DEFAULT_TELEMETRY_TARGET);
    });

    it('should return default OTLP endpoint if telemetry object is not provided', () => {
      const paramsWithoutTelemetry: ConfigParameters = { ...baseParams };
      delete paramsWithoutTelemetry.telemetry;
      const config = new Config(paramsWithoutTelemetry);
      expect(config.getTelemetryOtlpEndpoint()).toBe(DEFAULT_OTLP_ENDPOINT);
    });

    it('should return provided OTLP protocol', () => {
      const params: ConfigParameters = {
        ...baseParams,
        telemetry: { enabled: true, otlpProtocol: 'http' },
      };
      const config = new Config(params);
      expect(config.getTelemetryOtlpProtocol()).toBe('http');
    });

    it('should return default OTLP protocol if not provided', () => {
      const params: ConfigParameters = {
        ...baseParams,
        telemetry: { enabled: true },
      };
      const config = new Config(params);
      expect(config.getTelemetryOtlpProtocol()).toBe('grpc');
    });

    it('should return default OTLP protocol if telemetry object is not provided', () => {
      const paramsWithoutTelemetry: ConfigParameters = { ...baseParams };
      delete paramsWithoutTelemetry.telemetry;
      const config = new Config(paramsWithoutTelemetry);
      expect(config.getTelemetryOtlpProtocol()).toBe('grpc');
    });
  });
});