import { execSync } from 'child_process';
import fs from 'fs/promises';
import { lintAgent, LintAgentResult } from '../src/services/qualimetrie/lintAgent';

jest.mock('child_process', () => ({ execSync: jest.fn() }));
jest.mock('fs/promises');

describe('lintAgent', () => {
  beforeEach(() => jest.resetAllMocks());

  it('returns metrics on successful ESLint run', async () => {
    const results = [
      { messages: [{ severity: 2 }, { severity: 1 }, { severity: 2 }] },
      { messages: [] },
    ];
    const stdout = JSON.stringify(results);
    (execSync as jest.Mock).mockReturnValue(stdout);
    (fs.writeFile as jest.Mock).mockResolvedValue(undefined);

    const res: LintAgentResult = await lintAgent();
    expect(execSync).toHaveBeenCalledWith(
      'npx eslint . --ext .ts,.js --format json',
      { encoding: 'utf-8' }
    );
    expect(fs.writeFile).toHaveBeenCalledWith(
      'eslint-report.json', stdout, 'utf-8'
    );
    expect(res.passed).toBe(false);
    expect(res.metrics).toMatchObject({ errors: 2, warnings: 1 });
    expect(res.metrics?.files).toBe(2);
    expect(res.metrics?.total).toBe(3);
    expect(res.metrics?.fixable).toBe(0);
    expect(res.detailPath).toBe('eslint-report.json');
  });

  it('handles execSync throwing with stderr output', async () => {
    const results = [{ messages: [{ severity: 2 }] }];
    const raw = JSON.stringify(results);
    const error: any = new Error('fail');
    error.stdout = raw;
    (execSync as jest.Mock).mockImplementation(() => { throw error; });
    (fs.writeFile as jest.Mock).mockResolvedValue(undefined);

    const res: LintAgentResult = await lintAgent();
    expect(fs.writeFile).toHaveBeenCalledWith(
      'eslint-report.json', raw, 'utf-8'
    );
    expect(res.passed).toBe(false);
    expect(res.metrics).toMatchObject({ errors: 1, warnings: 0 });
    expect(res.metrics?.files).toBe(1);
    expect(res.metrics?.total).toBe(1);
    expect(res.metrics?.fixable).toBe(0);
    expect(res.detailPath).toBe('eslint-report.json');
    expect(res.output).toBe(raw);
  });
});