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

import {
  expect,
  it,
  describe,
  vi,
  beforeEach,
  afterEach,
  MockInstance,
} from 'vitest';
import fs from 'node:fs';
import path from 'node:path';
import { randomUUID } from 'node:crypto';
import {
  ChatRecordingService,
  ConversationRecord,
  ToolCallRecord,
} from './chatRecordingService.js';
import { Config } from '../config/config.js';
import { getProjectHash } from '../utils/paths.js';

vi.mock('node:fs');
vi.mock('node:path');
vi.mock('node:crypto');
vi.mock('../utils/paths.js');

describe('ChatRecordingService', () => {
  let chatRecordingService: ChatRecordingService;
  let mockConfig: Config;

  let mkdirSyncSpy: MockInstance<typeof fs.mkdirSync>;
  let writeFileSyncSpy: MockInstance<typeof fs.writeFileSync>;

  beforeEach(() => {
    mockConfig = {
      getSessionId: vi.fn().mockReturnValue('test-session-id'),
      getProjectRoot: vi.fn().mockReturnValue('/test/project/root'),
      storage: {
        getProjectTempDir: vi
          .fn()
          .mockReturnValue('/test/project/root/.gemini/tmp'),
      },
      getModel: vi.fn().mockReturnValue('gemini-pro'),
      getDebugMode: vi.fn().mockReturnValue(false),
    } as unknown as Config;

    vi.mocked(getProjectHash).mockReturnValue('test-project-hash');
    vi.mocked(randomUUID).mockReturnValue('this-is-a-test-uuid');
    vi.mocked(path.join).mockImplementation((...args) => args.join('/'));

    chatRecordingService = new ChatRecordingService(mockConfig);

    mkdirSyncSpy = vi
      .spyOn(fs, 'mkdirSync')
      .mockImplementation(() => undefined);

    writeFileSyncSpy = vi
      .spyOn(fs, 'writeFileSync')
      .mockImplementation(() => undefined);
  });

  afterEach(() => {
    vi.restoreAllMocks();
  });

  describe('initialize', () => {
    it('should create a new session if none is provided', () => {
      chatRecordingService.initialize();

      expect(mkdirSyncSpy).toHaveBeenCalledWith(
        '/test/project/root/.gemini/tmp/chats',
        { recursive: true },
      );
      expect(writeFileSyncSpy).not.toHaveBeenCalled();
    });

    it('should resume from an existing session if provided', () => {
      const readFileSyncSpy = vi.spyOn(fs, 'readFileSync').mockReturnValue(
        JSON.stringify({
          sessionId: 'old-session-id',
          projectHash: 'test-project-hash',
          messages: [],
        }),
      );
      const writeFileSyncSpy = vi
        .spyOn(fs, 'writeFileSync')
        .mockImplementation(() => undefined);

      chatRecordingService.initialize({
        filePath: '/test/project/root/.gemini/tmp/chats/session.json',
        conversation: {
          sessionId: 'old-session-id',
        } as ConversationRecord,
      });

      expect(mkdirSyncSpy).not.toHaveBeenCalled();
      expect(readFileSyncSpy).toHaveBeenCalled();
      expect(writeFileSyncSpy).not.toHaveBeenCalled();
    });
  });

  describe('recordMessage', () => {
    beforeEach(() => {
      chatRecordingService.initialize();
      vi.spyOn(fs, 'readFileSync').mockReturnValue(
        JSON.stringify({
          sessionId: 'test-session-id',
          projectHash: 'test-project-hash',
          messages: [],
        }),
      );
    });

    it('should record a new message', () => {
      const writeFileSyncSpy = vi
        .spyOn(fs, 'writeFileSync')
        .mockImplementation(() => undefined);
      chatRecordingService.recordMessage({ type: 'user', content: 'Hello' });
      expect(mkdirSyncSpy).toHaveBeenCalled();
      expect(writeFileSyncSpy).toHaveBeenCalled();
      const conversation = JSON.parse(
        writeFileSyncSpy.mock.calls[0][1] as string,
      ) as ConversationRecord;
      expect(conversation.messages).toHaveLength(1);
      expect(conversation.messages[0].content).toBe('Hello');
      expect(conversation.messages[0].type).toBe('user');
    });

    it('should append to the last message if append is true and types match', () => {
      const writeFileSyncSpy = vi
        .spyOn(fs, 'writeFileSync')
        .mockImplementation(() => undefined);
      const initialConversation = {
        sessionId: 'test-session-id',
        projectHash: 'test-project-hash',
        messages: [
          {
            id: '1',
            type: 'user',
            content: 'Hello',
            timestamp: new Date().toISOString(),
          },
        ],
      };
      vi.spyOn(fs, 'readFileSync').mockReturnValue(
        JSON.stringify(initialConversation),
      );

      chatRecordingService.recordMessage({
        type: 'user',
        content: ' World',
        append: true,
      });

      expect(mkdirSyncSpy).toHaveBeenCalled();
      expect(writeFileSyncSpy).toHaveBeenCalled();
      const conversation = JSON.parse(
        writeFileSyncSpy.mock.calls[0][1] as string,
      ) as ConversationRecord;
      expect(conversation.messages).toHaveLength(1);
      expect(conversation.messages[0].content).toBe('Hello World');
    });
  });

  describe('recordThought', () => {
    it('should queue a thought', () => {
      chatRecordingService.initialize();
      chatRecordingService.recordThought({
        subject: 'Thinking',
        description: 'Thinking...',
      });
      // @ts-expect-error private property
      expect(chatRecordingService.queuedThoughts).toHaveLength(1);
      // @ts-expect-error private property
      expect(chatRecordingService.queuedThoughts[0].subject).toBe('Thinking');
      // @ts-expect-error private property
      expect(chatRecordingService.queuedThoughts[0].description).toBe(
        'Thinking...',
      );
    });
  });

  describe('recordMessageTokens', () => {
    beforeEach(() => {
      chatRecordingService.initialize();
    });

    it('should update the last message with token info', () => {
      const writeFileSyncSpy = vi
        .spyOn(fs, 'writeFileSync')
        .mockImplementation(() => undefined);
      const initialConversation = {
        sessionId: 'test-session-id',
        projectHash: 'test-project-hash',
        messages: [
          {
            id: '1',
            type: 'gemini',
            content: 'Response',
            timestamp: new Date().toISOString(),
          },
        ],
      };
      vi.spyOn(fs, 'readFileSync').mockReturnValue(
        JSON.stringify(initialConversation),
      );

      chatRecordingService.recordMessageTokens({
        input: 1,
        output: 2,
        total: 3,
        cached: 0,
      });

      expect(mkdirSyncSpy).toHaveBeenCalled();
      expect(writeFileSyncSpy).toHaveBeenCalled();
      const conversation = JSON.parse(
        writeFileSyncSpy.mock.calls[0][1] as string,
      ) as ConversationRecord;
      expect(conversation.messages[0]).toEqual({
        ...initialConversation.messages[0],
        tokens: { input: 1, output: 2, total: 3, cached: 0 },
      });
    });

    it('should queue token info if the last message already has tokens', () => {
      const initialConversation = {
        sessionId: 'test-session-id',
        projectHash: 'test-project-hash',
        messages: [
          {
            id: '1',
            type: 'gemini',
            content: 'Response',
            timestamp: new Date().toISOString(),
            tokens: { input: 1, output: 1, total: 2, cached: 0 },
          },
        ],
      };
      vi.spyOn(fs, 'readFileSync').mockReturnValue(
        JSON.stringify(initialConversation),
      );

      chatRecordingService.recordMessageTokens({
        input: 2,
        output: 2,
        total: 4,
        cached: 0,
      });

      // @ts-expect-error private property
      expect(chatRecordingService.queuedTokens).toEqual({
        input: 2,
        output: 2,
        total: 4,
        cached: 0,
      });
    });
  });

  describe('recordToolCalls', () => {
    beforeEach(() => {
      chatRecordingService.initialize();
    });

    it('should add new tool calls to the last message', () => {
      const writeFileSyncSpy = vi
        .spyOn(fs, 'writeFileSync')
        .mockImplementation(() => undefined);
      const initialConversation = {
        sessionId: 'test-session-id',
        projectHash: 'test-project-hash',
        messages: [
          {
            id: '1',
            type: 'gemini',
            content: '',
            timestamp: new Date().toISOString(),
          },
        ],
      };
      vi.spyOn(fs, 'readFileSync').mockReturnValue(
        JSON.stringify(initialConversation),
      );

      const toolCall: ToolCallRecord = {
        id: 'tool-1',
        name: 'testTool',
        args: {},
        status: 'awaiting_approval',
        timestamp: new Date().toISOString(),
      };
      chatRecordingService.recordToolCalls([toolCall]);

      expect(mkdirSyncSpy).toHaveBeenCalled();
      expect(writeFileSyncSpy).toHaveBeenCalled();
      const conversation = JSON.parse(
        writeFileSyncSpy.mock.calls[0][1] as string,
      ) as ConversationRecord;
      expect(conversation.messages[0]).toEqual({
        ...initialConversation.messages[0],
        toolCalls: [toolCall],
      });
    });

    it('should create a new message if the last message is not from gemini', () => {
      const writeFileSyncSpy = vi
        .spyOn(fs, 'writeFileSync')
        .mockImplementation(() => undefined);
      const initialConversation = {
        sessionId: 'test-session-id',
        projectHash: 'test-project-hash',
        messages: [
          {
            id: 'a-uuid',
            type: 'user',
            content: 'call a tool',
            timestamp: new Date().toISOString(),
          },
        ],
      };
      vi.spyOn(fs, 'readFileSync').mockReturnValue(
        JSON.stringify(initialConversation),
      );

      const toolCall: ToolCallRecord = {
        id: 'tool-1',
        name: 'testTool',
        args: {},
        status: 'awaiting_approval',
        timestamp: new Date().toISOString(),
      };
      chatRecordingService.recordToolCalls([toolCall]);

      expect(mkdirSyncSpy).toHaveBeenCalled();
      expect(writeFileSyncSpy).toHaveBeenCalled();
      const conversation = JSON.parse(
        writeFileSyncSpy.mock.calls[0][1] as string,
      ) as ConversationRecord;
      expect(conversation.messages).toHaveLength(2);
      expect(conversation.messages[1]).toEqual({
        ...conversation.messages[1],
        id: 'this-is-a-test-uuid',
        model: 'gemini-pro',
        type: 'gemini',
        thoughts: [],
        content: '',
        toolCalls: [toolCall],
      });
    });
  });

  describe('deleteSession', () => {
    it('should delete the session file', () => {
      const unlinkSyncSpy = vi
        .spyOn(fs, 'unlinkSync')
        .mockImplementation(() => undefined);
      chatRecordingService.deleteSession('test-session-id');
      expect(unlinkSyncSpy).toHaveBeenCalledWith(
        '/test/project/root/.gemini/tmp/chats/test-session-id.json',
      );
    });
  });
});