"""
Load Testing Engine for Project Starlight
High-performance load testing for steganography detection systems
"""

import json
import math
import base64
import hashlib
import datetime
import re
import string
import itertools
import collections
import dataclasses
from typing import Dict, List, Optional, Any, Union, Tuple
from dataclasses import dataclass
from enum import Enum


class LoadTestType(Enum):
    SPIKE = "spike"
    STRESS = "stress"
    VOLUME = "volume"
    ENDURANCE = "endurance"
    PEAK = "peak"


class TestStatus(Enum):
    PENDING = "pending"
    RUNNING = "running"
    COMPLETED = "completed"
    FAILED = "failed"
    CANCELLED = "cancelled"


@dataclass
class LoadTestScenario:
    name: str
    test_type: LoadTestType
    concurrent_users: int
    requests_per_second: int
    duration_seconds: int
    ramp_up_time: int
    data_payload_size: int


@dataclass
class LoadTestResult:
    scenario: LoadTestScenario
    status: TestStatus
    total_requests: int
    successful_requests: int
    failed_requests: int
    avg_response_time: float
    min_response_time: float
    max_response_time: float
    p95_response_time: float
    p99_response_time: float
    throughput: float
    error_rate: float
    cpu_utilization: float
    memory_utilization: float


class MockSteganographyService:
    """Mock steganography detection service for load testing"""
    
    def __init__(self):
        self.request_count = 0
        self.processing_times = []
    
    def process_image(self, image_data: bytes) -> Dict[str, Any]:
        """Mock image processing with variable latency"""
        self.request_count += 1
        
        # Simulate variable processing time (10ms to 500ms)
        base_time = 0.01
        variation = 0.49
        processing_time = base_time + (variation * (hash(image_data) % 1000) / 1000)
        
        # Simulate CPU/memory intensive operations
        hash_value = hashlib.sha256(image_data).hexdigest()
        
        # Simulate steganography detection algorithm
        for _ in range(100):  # Simulate processing loops
            _ = hashlib.md5(image_data + str(_).encode()).hexdigest()
        
        result = {
            "request_id": self.request_count,
            "image_hash": hash_value,
            "steganography_detected": len(image_data) % 1000 < 500,  # Mock detection logic
            "confidence": 0.5 + (hash(hash_value) % 100) / 200.0,
            "processing_time": processing_time,
            "timestamp": datetime.datetime.now().isoformat()
        }
        
        self.processing_times.append(processing_time)
        return result
    
    def get_metrics(self) -> Dict[str, float]:
        """Get service performance metrics"""
        if not self.processing_times:
            return {"avg_processing_time": 0, "max_processing_time": 0}
        
        return {
            "avg_processing_time": sum(self.processing_times) / len(self.processing_times),
            "max_processing_time": max(self.processing_times),
            "min_processing_time": min(self.processing_times)
        }


class LoadTestEngine:
    """Enterprise-grade load testing engine"""
    
    def __init__(self):
        self.service = MockSteganographyService()
        self.test_results: List[LoadTestResult] = []
        
    def generate_test_data(self, size_bytes: int) -> bytes:
        """Generate test image data of specified size"""
        base_pattern = b"steganography_test_data_"
        repeat_count = max(1, size_bytes // len(base_pattern))
        data = base_pattern * repeat_count
        
        # Add some randomness
        random_suffix = str(hash(datetime.datetime.now().microsecond)).encode()
        return (data + random_suffix)[:size_bytes]
    
    def execute_load_test(self, scenario: LoadTestScenario) -> LoadTestResult:
        """Execute load test scenario"""
        print(f"🚀 Starting Load Test: {scenario.name}")
        print(f"📊 {scenario.concurrent_users} concurrent users, {scenario.requests_per_second} RPS")
        print(f"⏱️ Duration: {scenario.duration_seconds}s, Ramp-up: {scenario.ramp_up_time}s")
        
        start_time = datetime.datetime.now()
        total_requests = 0
        successful_requests = 0
        failed_requests = 0
        response_times = []
        
        # Simulate user ramp-up
        users_active = 0
        ramp_up_increment = scenario.concurrent_users / max(1, scenario.ramp_up_time)
        
        try:
            # Main test execution loop
            elapsed_seconds = 0
            
            while elapsed_seconds < scenario.duration_seconds:
                current_time = datetime.datetime.now()
                
                # Handle user ramp-up
                if elapsed_seconds < scenario.ramp_up_time:
                    users_active = min(scenario.concurrent_users, 
                                     int(ramp_up_increment * elapsed_seconds))
                else:
                    users_active = scenario.concurrent_users
                
                # Calculate requests for this second
                requests_this_second = min(users_active, scenario.requests_per_second)
                
                # Execute requests
                second_response_times = []
                for i in range(requests_this_second):
                    try:
                        # Generate test data
                        test_data = self.generate_test_data(scenario.data_payload_size)
                        
                        # Process request
                        request_start = datetime.datetime.now()
                        result = self.service.process_image(test_data)
                        request_time = (datetime.datetime.now() - request_start).total_seconds()
                        
                        response_times.append(request_time)
                        second_response_times.append(request_time)
                        successful_requests += 1
                        
                    except Exception as e:
                        failed_requests += 1
                        print(f"Request failed: {str(e)}")
                    
                    total_requests += 1
                
                # Simulate 1-second intervals
                elapsed_seconds = (datetime.datetime.now() - start_time).total_seconds()
                
                # Progress reporting
                if int(elapsed_seconds) % 10 == 0 and int(elapsed_seconds) > 0:
                    print(f"⏳ Progress: {int(elapsed_seconds)}s / {scenario.duration_seconds}s")
            
            # Calculate performance metrics
            if response_times:
                avg_response_time = sum(response_times) / len(response_times)
                min_response_time = min(response_times)
                max_response_time = max(response_times)
                
                # Calculate percentiles
                sorted_times = sorted(response_times)
                p95_index = int(len(sorted_times) * 0.95)
                p99_index = int(len(sorted_times) * 0.99)
                p95_response_time = sorted_times[p95_index] if p95_index < len(sorted_times) else max_response_time
                p99_response_time = sorted_times[p99_index] if p99_index < len(sorted_times) else max_response_time
            else:
                avg_response_time = min_response_time = max_response_time = 0
                p95_response_time = p99_response_time = 0
            
            # Calculate throughput and error rate
            actual_duration = (datetime.datetime.now() - start_time).total_seconds()
            throughput = successful_requests / actual_duration if actual_duration > 0 else 0
            error_rate = (failed_requests / total_requests * 100) if total_requests > 0 else 0
            
            # Mock resource utilization
            cpu_utilization = min(95, 30 + (users_active * 2) + (successful_requests * 0.01))
            memory_utilization = min(90, 40 + (users_active * 1.5))
            
            result = LoadTestResult(
                scenario=scenario,
                status=TestStatus.COMPLETED,
                total_requests=total_requests,
                successful_requests=successful_requests,
                failed_requests=failed_requests,
                avg_response_time=avg_response_time,
                min_response_time=min_response_time,
                max_response_time=max_response_time,
                p95_response_time=p95_response_time,
                p99_response_time=p99_response_time,
                throughput=throughput,
                error_rate=error_rate,
                cpu_utilization=cpu_utilization,
                memory_utilization=memory_utilization
            )
            
            self.test_results.append(result)
            
            print(f"✅ Load Test Completed: {scenario.name}")
            print(f"📈 Throughput: {throughput:.2f} RPS, Error Rate: {error_rate:.2f}%")
            print(f"⚡ Avg Response: {avg_response_time:.3f}s, P95: {p95_response_time:.3f}s")
            
            return result
            
        except Exception as e:
            error_result = LoadTestResult(
                scenario=scenario,
                status=TestStatus.FAILED,
                total_requests=total_requests,
                successful_requests=successful_requests,
                failed_requests=failed_requests,
                avg_response_time=0,
                min_response_time=0,
                max_response_time=0,
                p95_response_time=0,
                p99_response_time=0,
                throughput=0,
                error_rate=100.0,
                cpu_utilization=0,
                memory_utilization=0
            )
            
            print(f"❌ Load Test Failed: {scenario.name} - {str(e)}")
            return error_result
    
    def create_enterprise_scenarios(self) -> List[LoadTestScenario]:
        """Create enterprise-grade load testing scenarios"""
        scenarios = [
            # Volume Test: Normal traffic load
            LoadTestScenario(
                name="enterprise_volume_normal",
                test_type=LoadTestType.VOLUME,
                concurrent_users=50,
                requests_per_second=100,
                duration_seconds=300,  # 5 minutes
                ramp_up_time=60,       # 1 minute ramp-up
                data_payload_size=1024  # 1KB images
            ),
            
            # Peak Load Test: Maximum expected traffic
            LoadTestScenario(
                name="enterprise_peak_traffic",
                test_type=LoadTestType.PEAK,
                concurrent_users=200,
                requests_per_second=500,
                duration_seconds=180,  # 3 minutes
                ramp_up_time=30,       # 30 second ramp-up
                data_payload_size=2048  # 2KB images
            ),
            
            # Stress Test: Beyond normal capacity
            LoadTestScenario(
                name="enterprise_stress_test",
                test_type=LoadTestType.STRESS,
                concurrent_users=500,
                requests_per_second=1000,
                duration_seconds=120,  # 2 minutes
                ramp_up_time=20,       # 20 second ramp-up
                data_payload_size=4096  # 4KB images
            ),
            
            # Spike Test: Sudden traffic spikes
            LoadTestScenario(
                name="enterprise_spike_test",
                test_type=LoadTestType.SPIKE,
                concurrent_users=1000,
                requests_per_second=2000,
                duration_seconds=60,   # 1 minute
                ramp_up_time=5,        # 5 second ramp-up
                data_payload_size=512   # 512B images
            ),
            
            # Endurance Test: Sustained load
            LoadTestScenario(
                name="enterprise_endurance_test",
                test_type=LoadTestType.ENDURANCE,
                concurrent_users=100,
                requests_per_second=200,
                duration_seconds=1800,  # 30 minutes
                ramp_up_time=120,       # 2 minute ramp-up
                data_payload_size=1536  # 1.5KB images
            )
        ]
        
        return scenarios
    
    def run_enterprise_load_tests(self) -> List[LoadTestResult]:
        """Run complete enterprise load test suite"""
        scenarios = self.create_enterprise_scenarios()
        results = []
        
        print("🏗️ Starting Enterprise Load Testing Suite")
        print("=" * 60)
        
        for i, scenario in enumerate(scenarios, 1):
            print(f"\n[{i}/{len(scenarios)}] Executing: {scenario.name}")
            result = self.execute_load_test(scenario)
            results.append(result)
            
            # Brief pause between tests
            if i < len(scenarios):
                print("⏸️ Pausing between tests...")
        
        return results
    
    def generate_load_test_report(self) -> Dict[str, Any]:
        """Generate comprehensive load testing report"""
        if not self.test_results:
            return {"message": "No load test results available"}
        
        report = {
            "summary": {
                "total_scenarios": len(self.test_results),
                "total_requests": sum(r.total_requests for r in self.test_results),
                "total_successful_requests": sum(r.successful_requests for r in self.test_results),
                "total_failed_requests": sum(r.failed_requests for r in self.test_results),
                "overall_success_rate": 0,
                "average_throughput": 0,
                "average_response_time": 0,
                "generated_at": datetime.datetime.now().isoformat()
            },
            "performance_benchmarks": {
                "max_throughput": 0,
                "min_response_time": float('inf'),
                "max_response_time": 0,
                "max_cpu_utilization": 0,
                "max_memory_utilization": 0
            },
            "scenario_results": []
        }
        
        # Calculate summary metrics
        total_requests = report["summary"]["total_requests"]
        total_successful = report["summary"]["total_successful_requests"]
        report["summary"]["overall_success_rate"] = (total_successful / total_requests * 100) if total_requests > 0 else 0
        
        throughputs = [r.throughput for r in self.test_results if r.throughput > 0]
        response_times = [r.avg_response_time for r in self.test_results if r.avg_response_time > 0]
        
        report["summary"]["average_throughput"] = sum(throughputs) / len(throughputs) if throughputs else 0
        report["summary"]["average_response_time"] = sum(response_times) / len(response_times) if response_times else 0
        
        # Process individual scenario results
        for result in self.test_results:
            # Update benchmarks
            report["performance_benchmarks"]["max_throughput"] = max(
                report["performance_benchmarks"]["max_throughput"], result.throughput
            )
            report["performance_benchmarks"]["min_response_time"] = min(
                report["performance_benchmarks"]["min_response_time"], result.avg_response_time
            ) if result.avg_response_time > 0 else report["performance_benchmarks"]["min_response_time"]
            report["performance_benchmarks"]["max_response_time"] = max(
                report["performance_benchmarks"]["max_response_time"], result.max_response_time
            )
            report["performance_benchmarks"]["max_cpu_utilization"] = max(
                report["performance_benchmarks"]["max_cpu_utilization"], result.cpu_utilization
            )
            report["performance_benchmarks"]["max_memory_utilization"] = max(
                report["performance_benchmarks"]["max_memory_utilization"], result.memory_utilization
            )
            
            # Add scenario details
            scenario_report = {
                "scenario_name": result.scenario.name,
                "test_type": result.scenario.test_type.value,
                "status": result.status.value,
                "configuration": {
                    "concurrent_users": result.scenario.concurrent_users,
                    "requests_per_second": result.scenario.requests_per_second,
                    "duration_seconds": result.scenario.duration_seconds,
                    "data_payload_size": result.scenario.data_payload_size
                },
                "results": {
                    "total_requests": result.total_requests,
                    "successful_requests": result.successful_requests,
                    "failed_requests": result.failed_requests,
                    "success_rate": ((result.successful_requests / result.total_requests) * 100) if result.total_requests > 0 else 0,
                    "throughput_rps": result.throughput,
                    "error_rate": result.error_rate,
                    "response_times": {
                        "average": result.avg_response_time,
                        "minimum": result.min_response_time,
                        "maximum": result.max_response_time,
                        "p95": result.p95_response_time,
                        "p99": result.p99_response_time
                    },
                    "resource_utilization": {
                        "cpu_percentage": result.cpu_utilization,
                        "memory_percentage": result.memory_utilization
                    }
                }
            }
            report["scenario_results"].append(scenario_report)
        
        return report


def main():
    """Main load testing runner"""
    engine = LoadTestEngine()
    
    # Run enterprise load tests
    results = engine.run_enterprise_load_tests()
    
    # Generate report
    report = engine.generate_load_test_report()
    
    print(f"\n📊 Load Testing Summary:")
    print(f"Total Requests: {report['summary']['total_requests']}")
    print(f"Overall Success Rate: {report['summary']['overall_success_rate']:.2f}%")
    print(f"Average Throughput: {report['summary']['average_throughput']:.2f} RPS")
    print(f"Max Throughput: {report['performance_benchmarks']['max_throughput']:.2f} RPS")
    
    return report


if __name__ == "__main__":
    main()