#!/usr/bin/env python3
"""
Security Tests for Sudarshan Engine - Penetration Testing

Tests security vulnerabilities, attack vectors, and penetration testing scenarios.
"""

import pytest
import secrets
from unittest.mock import Mock, patch
import time
import threading
from concurrent.futures import ThreadPoolExecutor, as_completed

# Import test utilities
from .. import TestFixture, get_test_data, assert_security_properties

# Import security components
from security.security_manager import SecurityManager, SecurityContext, SecurityLevel
from security.penetration_testing import (
    PenetrationTester, FuzzingEngine, AttackSimulator,
    VulnerabilityScanner, SecurityMonitoring
)


class TestPenetrationTester(TestFixture):
    """Test penetration testing framework."""

    def setup_method(self):
        super().setup_method()
        self.penetration_tester = PenetrationTester()
        self.security = SecurityManager()

    def test_fuzzing_engine_initialization(self):
        """Test fuzzing engine setup."""
        fuzzer = FuzzingEngine()

        assert fuzzer is not None
        assert hasattr(fuzzer, 'generate_mutations')
        assert hasattr(fuzzer, 'fuzz_input')

    @assert_security_properties
    def test_input_fuzzing(self):
        """Test input fuzzing with various mutation strategies."""
        fuzzer = FuzzingEngine()

        # Test data
        original_input = get_test_data(64)

        # Generate mutations
        mutations = fuzzer.generate_mutations(original_input, num_mutations=10)

        assert len(mutations) == 10
        assert all(isinstance(m, bytes) for m in mutations)

        # Verify mutations are different from original
        for mutation in mutations:
            assert mutation != original_input

    def test_attack_simulation_setup(self):
        """Test attack simulation framework."""
        simulator = AttackSimulator()

        assert simulator is not None
        assert hasattr(simulator, 'simulate_dos_attack')
        assert hasattr(simulator, 'simulate_injection_attack')

    @assert_security_properties
    def test_dos_attack_simulation(self):
        """Test DoS attack simulation."""
        simulator = AttackSimulator()

        # Simulate DoS attack
        attack_config = {
            'attack_type': 'flood',
            'duration': 1,  # seconds
            'intensity': 'low'
        }

        results = simulator.simulate_dos_attack(attack_config)

        assert results is not None
        assert 'attack_successful' in results
        assert 'mitigation_effective' in results
        assert isinstance(results['attack_successful'], bool)

    @assert_security_properties
    def test_injection_attack_simulation(self):
        """Test injection attack simulation."""
        simulator = AttackSimulator()

        # Test payloads
        payloads = [
            b"'; DROP TABLE users; --",
            b"<script>alert('xss')</script>",
            b"../../../etc/passwd",
            b"eval('malicious_code')",
            b"SELECT * FROM sensitive_data"
        ]

        for payload in payloads:
            results = simulator.simulate_injection_attack(payload)

            assert results is not None
            assert 'injection_detected' in results
            assert 'payload_sanitized' in results

    def test_vulnerability_scanner_setup(self):
        """Test vulnerability scanner initialization."""
        scanner = VulnerabilityScanner()

        assert scanner is not None
        assert hasattr(scanner, 'scan_for_vulnerabilities')
        assert hasattr(scanner, 'generate_security_report')

    @assert_security_properties
    def test_vulnerability_scanning(self):
        """Test vulnerability scanning."""
        scanner = VulnerabilityScanner()

        # Mock target functions to scan
        def mock_encrypt(data, key):
            return b"encrypted_" + data

        def mock_decrypt(data, key):
            if data.startswith(b"encrypted_"):
                return data[10:]
            return None

        target_functions = [mock_encrypt, mock_decrypt]

        # Scan for vulnerabilities
        results = scanner.scan_for_vulnerabilities(target_functions)

        assert results is not None
        assert isinstance(results, dict)
        assert 'scan_timestamp' in results
        assert 'vulnerabilities_found' in results

    def test_security_monitoring_setup(self):
        """Test security monitoring initialization."""
        monitor = SecurityMonitoring()

        assert monitor is not None
        assert hasattr(monitor, 'start_monitoring')
        assert hasattr(monitor, 'stop_monitoring')
        assert hasattr(monitor, 'get_security_events')


class TestFuzzingEngine(TestFixture):
    """Test fuzzing engine functionality."""

    def setup_method(self):
        super().setup_method()
        self.fuzzer = FuzzingEngine()

    def test_mutation_strategies(self):
        """Test different mutation strategies."""
        test_input = b"Hello, World!"

        # Test bit flipping
        mutations = self.fuzzer._bit_flip_mutation(test_input, 5)
        assert len(mutations) == 5
        for mutation in mutations:
            assert len(mutation) == len(test_input)

        # Test byte insertion
        mutations = self.fuzzer._byte_insertion_mutation(test_input, 3)
        assert len(mutations) == 3
        for mutation in mutations:
            assert len(mutation) > len(test_input)

        # Test boundary values
        mutations = self.fuzzer._boundary_mutation(test_input, 4)
        assert len(mutations) == 4

    def test_fuzzing_coverage(self):
        """Test fuzzing coverage metrics."""
        test_input = get_test_data(100)

        # Run fuzzing campaign
        results = self.fuzzer.fuzz_input(test_input, iterations=50)

        assert results is not None
        assert 'total_mutations' in results
        assert 'unique_crashes' in results
        assert 'coverage_percentage' in results
        assert results['total_mutations'] == 50

    @assert_security_properties
    def test_edge_case_fuzzing(self):
        """Test fuzzing with edge cases."""
        # Test with empty input
        results = self.fuzzer.fuzz_input(b"", iterations=10)
        assert results['total_mutations'] == 10

        # Test with very large input
        large_input = get_test_data(10000)
        results = self.fuzzer.fuzz_input(large_input, iterations=5)
        assert results['total_mutations'] == 5

        # Test with special characters
        special_input = b"\x00\x01\x02\xFF\xFE\xFD"
        results = self.fuzzer.fuzz_input(special_input, iterations=10)
        assert results['total_mutations'] == 10


class TestAttackSimulator(TestFixture):
    """Test attack simulation scenarios."""

    def setup_method(self):
        super().setup_method()
        self.simulator = AttackSimulator()

    @assert_security_properties
    def test_timing_attack_simulation(self):
        """Test timing attack simulation."""
        # Simulate timing attack
        results = self.simulator.simulate_timing_attack()

        assert results is not None
        assert 'timing_vulnerable' in results
        assert 'timing_difference' in results
        assert isinstance(results['timing_vulnerable'], bool)

    @assert_security_properties
    def test_side_channel_attack_simulation(self):
        """Test side-channel attack simulation."""
        # Simulate power analysis attack
        results = self.simulator.simulate_power_analysis_attack()

        assert results is not None
        assert 'power_leak_detected' in results
        assert 'leak_severity' in results

        # Simulate electromagnetic attack
        results = self.simulator.simulate_electromagnetic_attack()

        assert results is not None
        assert 'em_leak_detected' in results
        assert 'leak_severity' in results

    @assert_security_properties
    def test_replay_attack_simulation(self):
        """Test replay attack simulation."""
        # Create mock transaction
        transaction = {
            'id': 'tx_123',
            'amount': 100.0,
            'timestamp': time.time()
        }

        # Simulate replay attack
        results = self.simulator.simulate_replay_attack(transaction)

        assert results is not None
        assert 'replay_successful' in results
        assert 'detection_mechanism' in results

    def test_concurrent_attack_simulation(self):
        """Test concurrent attack simulation."""
        def simulate_attack(attack_type):
            if attack_type == 'dos':
                return self.simulator.simulate_dos_attack({'duration': 0.1})
            elif attack_type == 'injection':
                return self.simulator.simulate_injection_attack(b"test_payload")
            return None

        # Run concurrent attacks
        attack_types = ['dos', 'injection', 'dos', 'injection']

        with ThreadPoolExecutor(max_workers=4) as executor:
            futures = [executor.submit(simulate_attack, at) for at in attack_types]

            results = []
            for future in as_completed(futures):
                result = future.result()
                results.append(result)

        assert len(results) == 4
        assert all(r is not None for r in results)


class TestVulnerabilityScanner(TestFixture):
    """Test vulnerability scanning functionality."""

    def setup_method(self):
        super().setup_method()
        self.scanner = VulnerabilityScanner()

    def test_buffer_overflow_detection(self):
        """Test buffer overflow vulnerability detection."""
        def vulnerable_function(data):
            buffer = bytearray(100)
            buffer[:len(data)] = data  # Potential overflow
            return buffer

        results = self.scanner.scan_for_vulnerabilities([vulnerable_function])

        assert results is not None
        assert 'buffer_overflow_risk' in str(results).lower() or 'overflow' in str(results).lower()

    def test_sql_injection_detection(self):
        """Test SQL injection vulnerability detection."""
        def vulnerable_query(user_input):
            query = f"SELECT * FROM users WHERE id = {user_input}"  # SQL injection
            return query

        results = self.scanner.scan_for_vulnerabilities([vulnerable_query])

        assert results is not None
        assert 'sql_injection' in str(results).lower() or 'injection' in str(results).lower()

    def test_weak_crypto_detection(self):
        """Test weak cryptography detection."""
        def weak_encrypt(data):
            # Using weak key derivation
            key = b"weak_key_12345678"  # Too short, predictable
            return bytes(a ^ b for a, b in zip(data, key * (len(data) // len(key) + 1)))

        results = self.scanner.scan_for_vulnerabilities([weak_encrypt])

        assert results is not None
        assert 'weak_crypto' in str(results).lower() or 'weak' in str(results).lower()

    def test_security_report_generation(self):
        """Test security report generation."""
        # Mock scan results
        mock_results = {
            'scan_timestamp': time.time(),
            'vulnerabilities_found': [
                {'type': 'buffer_overflow', 'severity': 'high', 'location': 'func1'},
                {'type': 'weak_crypto', 'severity': 'medium', 'location': 'func2'}
            ],
            'scan_duration': 1.5,
            'functions_scanned': 5
        }

        report = self.scanner.generate_security_report(mock_results)

        assert report is not None
        assert 'summary' in report
        assert 'recommendations' in report
        assert 'severity_breakdown' in report
        assert report['severity_breakdown']['high'] == 1
        assert report['severity_breakdown']['medium'] == 1


class TestSecurityMonitoring(TestFixture):
    """Test security monitoring and alerting."""

    def setup_method(self):
        super().setup_method()
        self.monitor = SecurityMonitoring()

    def test_monitoring_initialization(self):
        """Test security monitoring setup."""
        assert self.monitor is not None

        # Start monitoring
        self.monitor.start_monitoring()

        # Check if monitoring is active
        assert self.monitor.is_monitoring_active()

        # Stop monitoring
        self.monitor.stop_monitoring()

        # Check if monitoring is stopped
        assert not self.monitor.is_monitoring_active()

    @assert_security_properties
    def test_event_collection(self):
        """Test security event collection."""
        # Start monitoring
        self.monitor.start_monitoring()

        # Simulate some security events
        self.monitor.log_security_event('authentication_attempt', {'user': 'test', 'success': True})
        self.monitor.log_security_event('file_access', {'file': 'secret.spq', 'operation': 'read'})
        self.monitor.log_security_event('crypto_operation', {'algorithm': 'kyber1024', 'operation': 'encrypt'})

        # Get events
        events = self.monitor.get_security_events()

        assert events is not None
        assert len(events) >= 3

        # Stop monitoring
        self.monitor.stop_monitoring()

    def test_alert_thresholds(self):
        """Test alert threshold configuration."""
        # Set alert thresholds
        thresholds = {
            'failed_auth_attempts': 5,
            'suspicious_file_access': 10,
            'crypto_operation_errors': 3
        }

        self.monitor.set_alert_thresholds(thresholds)

        # Verify thresholds are set
        current_thresholds = self.monitor.get_alert_thresholds()
        assert current_thresholds == thresholds

    @assert_security_properties
    def test_real_time_alerting(self):
        """Test real-time security alerting."""
        # Start monitoring
        self.monitor.start_monitoring()

        # Set low threshold for testing
        self.monitor.set_alert_thresholds({'failed_auth_attempts': 2})

        alerts_received = []

        def alert_handler(alert):
            alerts_received.append(alert)

        # Register alert handler
        self.monitor.register_alert_handler(alert_handler)

        # Generate alerts
        for i in range(3):
            self.monitor.log_security_event('authentication_failure', {
                'user': f'user_{i}',
                'reason': 'invalid_password'
            })

        # Allow time for processing
        time.sleep(0.1)

        # Check if alerts were generated
        assert len(alerts_received) > 0

        # Stop monitoring
        self.monitor.stop_monitoring()


class TestComprehensiveSecuritySuite(TestFixture):
    """Test comprehensive security test suite."""

    def setup_method(self):
        super().setup_method()
        self.penetration_tester = PenetrationTester()

    @assert_security_properties
    def test_full_security_audit(self):
        """Test full security audit workflow."""
        # Define target system components
        target_components = {
            'crypto_engine': 'sudarshan.crypto',
            'file_format': 'sudarshan.spq_format',
            'protocols': 'sudarshan.protocols',
            'security': 'security.security_manager'
        }

        # Run comprehensive security audit
        audit_results = self.penetration_tester.run_comprehensive_audit(target_components)

        assert audit_results is not None
        assert 'overall_security_score' in audit_results
        assert 'vulnerability_summary' in audit_results
        assert 'recommendations' in audit_results
        assert 'audit_timestamp' in audit_results

        # Security score should be between 0 and 100
        assert 0 <= audit_results['overall_security_score'] <= 100

    def test_security_regression_testing(self):
        """Test security regression testing."""
        # Define known security issues to check for
        known_issues = [
            'buffer_overflow_in_crypto',
            'timing_leak_in_signatures',
            'weak_key_derivation',
            'insufficient_input_validation'
        ]

        # Run regression tests
        regression_results = self.penetration_tester.run_security_regression(known_issues)

        assert regression_results is not None
        assert 'issues_tested' in regression_results
        assert 'issues_found' in regression_results
        assert 'regression_status' in regression_results

        # Should test all known issues
        assert len(regression_results['issues_tested']) == len(known_issues)

    @assert_security_properties
    def test_performance_under_attack(self):
        """Test system performance under attack conditions."""
        # Baseline performance measurement
        baseline_start = time.time()

        # Perform normal operations
        for _ in range(100):
            data = get_test_data(1024)
            # Simulate normal crypto operation
            processed = data  # Placeholder

        baseline_time = time.time() - baseline_start

        # Performance under attack simulation
        attack_start = time.time()

        # Simulate attack while performing operations
        with ThreadPoolExecutor(max_workers=2) as executor:
            # Normal operations
            future1 = executor.submit(self._simulate_normal_operations, 50)

            # Attack simulation
            future2 = executor.submit(self._simulate_attack_load, 10)

            # Wait for completion
            future1.result()
            future2.result()

        attack_time = time.time() - attack_start

        # Performance should not degrade significantly under attack
        degradation_ratio = attack_time / baseline_time
        assert degradation_ratio < 2.0  # Allow up to 2x slowdown

    def _simulate_normal_operations(self, count):
        """Simulate normal system operations."""
        for _ in range(count):
            data = get_test_data(512)
            # Simulate processing
            time.sleep(0.001)

    def _simulate_attack_load(self, intensity):
        """Simulate attack load."""
        for _ in range(intensity):
            # Simulate attack patterns
            attack_data = secrets.token_bytes(2048)
            time.sleep(0.005)


if __name__ == "__main__":
    pytest.main([__file__, "-v", "--tb=short"])