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

import { describe, it, expect, beforeEach, vi, afterEach } from 'vitest';
import { GitIgnoreParser } from './gitIgnoreParser.js';
import * as fs from 'fs/promises';
import * as path from 'path';

// Mock fs module
vi.mock('fs/promises');

// Mock gitUtils module
vi.mock('./gitUtils.js', () => ({
  isGitRepository: vi.fn(() => true),
}));

describe('GitIgnoreParser', () => {
  let parser: GitIgnoreParser;
  const mockProjectRoot = '/test/project';

  beforeEach(() => {
    parser = new GitIgnoreParser(mockProjectRoot);
    // Reset mocks before each test
    vi.mocked(fs.readFile).mockClear();
    vi.mocked(fs.readFile).mockRejectedValue(new Error('ENOENT')); // Default to no file
  });

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

  describe('initialization', () => {
    it('should initialize without errors when no .gitignore exists', async () => {
      await expect(parser.initialize()).resolves.not.toThrow();
    });

    it('should load .gitignore patterns when file exists', async () => {
      const gitignoreContent = `
# Comment
node_modules/
*.log
/dist
.env
`;
      vi.mocked(fs.readFile)
        .mockResolvedValueOnce(gitignoreContent)
        .mockRejectedValue(new Error('ENOENT'));

      await parser.initialize();

      expect(parser.isIgnored('node_modules/some-lib')).toBe(true);
      expect(parser.isIgnored('src/app.log')).toBe(true);
      expect(parser.isIgnored('dist/index.js')).toBe(true);
      expect(parser.isIgnored('.env')).toBe(true);
    });

    it('should handle git exclude file', async () => {
      vi.mocked(fs.readFile).mockImplementation(async (filePath) => {
        if (
          filePath === path.join(mockProjectRoot, '.git', 'info', 'exclude')
        ) {
          return 'temp/\n*.tmp';
        }
        throw new Error('ENOENT');
      });

      await parser.initialize();

      expect(parser.isIgnored('temp/file.txt')).toBe(true);
      expect(parser.isIgnored('src/file.tmp')).toBe(true);
    });
  });

  describe('isIgnored', () => {
    beforeEach(async () => {
      const gitignoreContent = `
node_modules/
*.log
/dist
/.env
src/*.tmp
!src/important.tmp
`;
      vi.mocked(fs.readFile)
        .mockResolvedValueOnce(gitignoreContent)
        .mockRejectedValue(new Error('ENOENT'));
      await parser.initialize();
    });

    it('should always ignore .git directory', () => {
      expect(parser.isIgnored('.git')).toBe(true);
      expect(parser.isIgnored('.git/config')).toBe(true);
      expect(parser.isIgnored(path.join(mockProjectRoot, '.git', 'HEAD'))).toBe(
        true,
      );
    });

    it('should ignore files matching patterns', () => {
      expect(parser.isIgnored('node_modules/package/index.js')).toBe(true);
      expect(parser.isIgnored('app.log')).toBe(true);
      expect(parser.isIgnored('logs/app.log')).toBe(true);
      expect(parser.isIgnored('dist/bundle.js')).toBe(true);
      expect(parser.isIgnored('.env')).toBe(true);
      expect(parser.isIgnored('config/.env')).toBe(false); // .env is anchored to root
    });

    it('should ignore files with path-specific patterns', () => {
      expect(parser.isIgnored('src/temp.tmp')).toBe(true);
      expect(parser.isIgnored('other/temp.tmp')).toBe(false);
    });

    it('should handle negation patterns', () => {
      expect(parser.isIgnored('src/important.tmp')).toBe(false);
    });

    it('should not ignore files that do not match patterns', () => {
      expect(parser.isIgnored('src/index.ts')).toBe(false);
      expect(parser.isIgnored('README.md')).toBe(false);
    });

    it('should handle absolute paths correctly', () => {
      const absolutePath = path.join(mockProjectRoot, 'node_modules', 'lib');
      expect(parser.isIgnored(absolutePath)).toBe(true);
    });

    it('should handle paths outside project root by not ignoring them', () => {
      const outsidePath = path.resolve(mockProjectRoot, '../other/file.txt');
      expect(parser.isIgnored(outsidePath)).toBe(false);
    });

    it('should handle relative paths correctly', () => {
      expect(parser.isIgnored('node_modules/some-package')).toBe(true);
      expect(parser.isIgnored('../some/other/file.txt')).toBe(false);
    });

    it('should normalize path separators on Windows', () => {
      expect(parser.isIgnored('node_modules\\package')).toBe(true);
      expect(parser.isIgnored('src\\temp.tmp')).toBe(true);
    });
  });

  describe('getIgnoredPatterns', () => {
    it('should return the raw patterns added', async () => {
      const gitignoreContent = '*.log\n!important.log';
      vi.mocked(fs.readFile).mockResolvedValueOnce(gitignoreContent);

      await parser.initialize();
    });
  });
});