/**
 * Unit Tests für hostGate Middleware
 * Testet Host-basierte Zugriffskontrolle
 */

// Setup ENV VOR dem Require
process.env.ENABLE_HOST_RESTRICTION = 'true';
process.env.PUBLIC_HOST = 'public.example.com';
process.env.INTERNAL_HOST = 'internal.example.com';
process.env.NODE_ENV = 'development';

const hostGate = require('../../../src/middlewares/hostGate');

describe('Host Gate Middleware', () => {
    let req, res, next;
    let originalEnv;

    beforeAll(() => {
        // Sichere Original-Env
        originalEnv = { ...process.env };
    });

    beforeEach(() => {
        // Mock Request
        req = {
            get: jest.fn(),
            path: '/api/admin/test'
        };

        // Mock Response
        res = {
            status: jest.fn().mockReturnThis(),
            json: jest.fn()
        };

        // Mock Next
        next = jest.fn();

        // Setup Environment
        process.env.ENABLE_HOST_RESTRICTION = 'true';
        process.env.PUBLIC_HOST = 'public.example.com';
        process.env.INTERNAL_HOST = 'internal.example.com';
        process.env.NODE_ENV = 'development'; // NOT 'test' to enable restrictions
    });

    afterEach(() => {
        jest.clearAllMocks();
    });

    afterAll(() => {
        // Restore Original-Env
        process.env = originalEnv;
    });

    describe('Host Detection', () => {
        test('should detect public host from X-Forwarded-Host header', () => {
            req.get.mockImplementation((header) => {
                if (header === 'x-forwarded-host') return 'public.example.com';
                return null;
            });

            hostGate(req, res, next);

            expect(req.isPublicHost).toBe(true);
            expect(req.isInternalHost).toBe(false);
            expect(req.requestSource).toBe('public');
        });

        test('should detect internal host from X-Forwarded-Host header', () => {
            req.get.mockImplementation((header) => {
                if (header === 'x-forwarded-host') return 'internal.example.com';
                return null;
            });

            hostGate(req, res, next);

            expect(req.isPublicHost).toBe(false);
            expect(req.isInternalHost).toBe(true);
            expect(req.requestSource).toBe('internal');
        });

        test('should fallback to Host header if X-Forwarded-Host not present', () => {
            req.get.mockImplementation((header) => {
                if (header === 'x-forwarded-host') return null;
                if (header === 'host') return 'public.example.com';
                return null;
            });

            hostGate(req, res, next);

            expect(req.isPublicHost).toBe(true);
        });

        test('should handle localhost as internal host', () => {
            req.get.mockImplementation((header) => {
                if (header === 'x-forwarded-host') return null;
                if (header === 'host') return 'localhost:3000';
                return null;
            });

            hostGate(req, res, next);

            expect(req.isInternalHost).toBe(true);
            expect(req.isPublicHost).toBe(false);
        });

        test('should strip port from hostname', () => {
            req.get.mockReturnValue('public.example.com:8080');

            hostGate(req, res, next);

            expect(req.isPublicHost).toBe(true);
        });
    });

    describe('Route Protection', () => {
        test('should block admin routes on public host', () => {
            req.get.mockReturnValue('public.example.com');
            req.path = '/api/admin/deletion-log';

            hostGate(req, res, next);

            expect(res.status).toHaveBeenCalledWith(403);
            expect(res.json).toHaveBeenCalledWith({
                error: 'Not available on public host',
                message: 'This endpoint is only available on the internal network'
            });
            expect(next).not.toHaveBeenCalled();
        });

        test('should block groups routes on public host', () => {
            req.get.mockReturnValue('public.example.com');
            req.path = '/api/groups';

            hostGate(req, res, next);

            expect(res.status).toHaveBeenCalledWith(403);
        });

        test('should block slideshow routes on public host', () => {
            req.get.mockReturnValue('public.example.com');
            req.path = '/api/slideshow';

            hostGate(req, res, next);

            expect(res.status).toHaveBeenCalledWith(403);
        });

        test('should block migration routes on public host', () => {
            req.get.mockReturnValue('public.example.com');
            req.path = '/api/migration/start';

            hostGate(req, res, next);

            expect(res.status).toHaveBeenCalledWith(403);
        });

        test('should block auth login on public host', () => {
            req.get.mockReturnValue('public.example.com');
            req.path = '/api/auth/login';

            hostGate(req, res, next);

            expect(res.status).toHaveBeenCalledWith(403);
        });
    });

    describe('Allowed Routes', () => {
        test('should allow upload route on public host', () => {
            req.get.mockReturnValue('public.example.com');
            req.path = '/api/upload';

            hostGate(req, res, next);

            expect(next).toHaveBeenCalled();
            expect(res.status).not.toHaveBeenCalled();
        });

        test('should allow manage routes on public host', () => {
            req.get.mockReturnValue('public.example.com');
            req.path = '/api/manage/abc-123';

            hostGate(req, res, next);

            expect(next).toHaveBeenCalled();
        });

        test('should allow preview routes on public host', () => {
            req.get.mockReturnValue('public.example.com');
            req.path = '/api/previews/image.jpg';

            hostGate(req, res, next);

            expect(next).toHaveBeenCalled();
        });

        test('should allow consent routes on public host', () => {
            req.get.mockReturnValue('public.example.com');
            req.path = '/api/consent';

            hostGate(req, res, next);

            expect(next).toHaveBeenCalled();
        });

        test('should allow all routes on internal host', () => {
            req.get.mockReturnValue('internal.example.com');
            req.path = '/api/admin/deletion-log';

            hostGate(req, res, next);

            expect(next).toHaveBeenCalled();
            expect(res.status).not.toHaveBeenCalled();
        });
    });

    describe('Feature Flags', () => {
        test('should bypass restriction when NODE_ENV is test and not explicitly enabled', () => {
            // Reload module with test environment
            delete require.cache[require.resolve('../../../src/middlewares/hostGate')];
            process.env.NODE_ENV = 'test';
            process.env.ENABLE_HOST_RESTRICTION = 'false'; // Not explicitly enabled
            const hostGateTest = require('../../../src/middlewares/hostGate');
            
            req.get.mockReturnValue('public.example.com');
            req.path = '/api/admin/test';

            hostGateTest(req, res, next);

            expect(next).toHaveBeenCalled();
            expect(res.status).not.toHaveBeenCalled();
            expect(req.isInternalHost).toBe(true);
            
            // Restore
            delete require.cache[require.resolve('../../../src/middlewares/hostGate')];
            process.env.NODE_ENV = 'development';
            process.env.ENABLE_HOST_RESTRICTION = 'true';
        });

        test('should work in test environment when explicitly enabled', () => {
            // Already set up correctly
            process.env.NODE_ENV = 'development';
            expect(req.isInternalHost).toBeUndefined(); // Not processed yet, just checking setup
        });
    });

    describe('Request Source Tracking', () => {
        test('should set requestSource to "public" for public host', () => {
            req.get.mockReturnValue('public.example.com');
            req.path = '/api/upload';

            hostGate(req, res, next);

            expect(req.requestSource).toBe('public');
        });

        test('should set requestSource to "internal" for internal host', () => {
            req.get.mockReturnValue('internal.example.com');
            req.path = '/api/admin/test';

            hostGate(req, res, next);

            expect(req.requestSource).toBe('internal');
        });

        test('should set requestSource to "internal" when restrictions disabled', () => {
            process.env.ENABLE_HOST_RESTRICTION = 'false';
            req.get.mockReturnValue('anything.example.com');
            req.path = '/api/test';

            hostGate(req, res, next);

            expect(req.requestSource).toBe('internal');
        });
    });
});