/// <reference types="jest" />
import * as fs from 'fs';
import * as path from 'path';
import * as os from 'os';
import { TransactionManager } from '../src/core/transaction';

describe('TransactionManager', () => {
    let tm: TransactionManager;
    let testDir: string;

    beforeEach(() => {
        tm = new TransactionManager();
        testDir = path.join(os.tmpdir(), `g1-test-${Date.now()}`);
        if (!fs.existsSync(testDir)) {
            fs.mkdirSync(testDir, { recursive: true });
        }
    });

    afterEach(() => {
        if (fs.existsSync(testDir)) {
            fs.rmSync(testDir, { recursive: true, force: true });
        }
    });

    test('should record and rollback file creation', () => {
        const testFile = path.join(testDir, 'test.txt');
        
        tm.begin();
        tm.record(testFile);
        fs.writeFileSync(testFile, 'hello world');
        
        expect(fs.existsSync(testFile)).toBe(true);
        
        tm.rollback();
        
        expect(fs.existsSync(testFile)).toBe(false);
    });

    test('should record and rollback file modification', () => {
        const testFile = path.join(testDir, 'edit.txt');
        fs.writeFileSync(testFile, 'original');
        
        tm.begin();
        tm.record(testFile);
        fs.writeFileSync(testFile, 'modified');
        
        expect(fs.readFileSync(testFile, 'utf8')).toBe('modified');
        
        tm.rollback();
        
        expect(fs.readFileSync(testFile, 'utf8')).toBe('original');
    });

    test('should delete backup files after commit', () => {
        const testFile = path.join(testDir, 'commit.txt');
        fs.writeFileSync(testFile, 'data');
        
        tm.begin();
        tm.record(testFile);
        fs.writeFileSync(testFile, 'new data');
        
        tm.commit();
        
        expect(fs.readFileSync(testFile, 'utf8')).toBe('new data');
        // Backups are in ~/.g1nation-backups (hardcoded in TM, but let's assume it cleans up internal state)
        expect(tm.isActive()).toBe(false);
    });
});