# AUTOGENERATED! DO NOT EDIT! File to edit: ../../modules/source/14_benchmarking/benchmarking_dev.ipynb.

# %% auto 0
__all__ = ['BenchmarkScenario', 'BenchmarkResult', 'BenchmarkScenarios', 'StatisticalValidation', 'StatisticalValidator',
           'TinyTorchPerf', 'PerformanceReporter']

# %% ../../modules/source/14_benchmarking/benchmarking_dev.ipynb 1
import numpy as np
import matplotlib.pyplot as plt
import time
import statistics
import json
import math
from typing import Dict, List, Tuple, Optional, Any, Callable
from dataclasses import dataclass
from enum import Enum
import os
import sys

# Import our TinyTorch dependencies
try:
    from tinytorch.core.tensor import Tensor
    from tinytorch.core.networks import Sequential
    from tinytorch.core.layers import Dense
    from tinytorch.core.activations import ReLU, Softmax
    from tinytorch.core.dataloader import DataLoader
except ImportError:
    # For development, import from local modules
    parent_dirs = [
        os.path.join(os.path.dirname(__file__), '..', '01_tensor'),
        os.path.join(os.path.dirname(__file__), '..', '03_layers'),
        os.path.join(os.path.dirname(__file__), '..', '02_activations'),
        os.path.join(os.path.dirname(__file__), '..', '04_networks'),
        os.path.join(os.path.dirname(__file__), '..', '06_dataloader')
    ]
    for path in parent_dirs:
        if path not in sys.path:
            sys.path.append(path)
    
    try:
        from tensor_dev import Tensor
        from networks_dev import Sequential
        from layers_dev import Dense
        from activations_dev import ReLU, Softmax
        from dataloader_dev import DataLoader
    except ImportError:
        # Fallback for missing modules
        print("⚠️  Some TinyTorch modules not available - using minimal implementations")

# %% ../../modules/source/14_benchmarking/benchmarking_dev.ipynb 2
def _should_show_plots():
    """Check if we should show plots (disable during testing)"""
    is_pytest = (
        'pytest' in sys.modules or
        'test' in sys.argv or
        os.environ.get('PYTEST_CURRENT_TEST') is not None or
        any('test' in arg for arg in sys.argv) or
        any('pytest' in arg for arg in sys.argv)
    )
    
    return not is_pytest

# %% ../../modules/source/14_benchmarking/benchmarking_dev.ipynb 8
class BenchmarkScenario(Enum):
    """Standard benchmark scenarios from MLPerf"""
    SINGLE_STREAM = "single_stream"
    SERVER = "server"
    OFFLINE = "offline"

@dataclass
class BenchmarkResult:
    """Results from a benchmark run"""
    scenario: BenchmarkScenario
    latencies: List[float]  # All latency measurements in seconds
    throughput: float      # Samples per second
    accuracy: float        # Model accuracy (0-1)
    metadata: Optional[Dict[str, Any]] = None

#| export
class BenchmarkScenarios:
    """
    Implements the three standard MLPerf benchmark scenarios.
    
    TODO: Implement the three benchmark scenarios following MLPerf patterns.
    
    UNDERSTANDING THE SCENARIOS:
    1. Single-Stream: Send queries one at a time, measure latency
    2. Server: Send queries following Poisson distribution, measure QPS
    3. Offline: Send all queries at once, measure total throughput
    
    IMPLEMENTATION APPROACH:
    1. Each scenario should run the model multiple times
    2. Collect latency measurements for each run
    3. Calculate appropriate metrics for each scenario
    4. Return BenchmarkResult with all measurements
    
    EXAMPLE USAGE:
    scenarios = BenchmarkScenarios()
    result = scenarios.single_stream(model, dataset, num_queries=1000)
    print(f"90th percentile latency: {result.latencies[int(0.9 * len(result.latencies))]} seconds")
    """
    
    def __init__(self):
        self.results = []
    
    def single_stream(self, model: Callable, dataset: List, num_queries: int = 1000) -> BenchmarkResult:
        """
        Run single-stream benchmark scenario.
        
        TODO: Implement single-stream benchmarking.
        
        STEP-BY-STEP:
        1. Initialize empty list for latencies
        2. For each query (up to num_queries):
           a. Get next sample from dataset (cycle if needed)
           b. Record start time
           c. Run model on sample
           d. Record end time
           e. Calculate latency = end - start
           f. Add latency to list
        3. Calculate throughput = num_queries / total_time
        4. Calculate accuracy if possible
        5. Return BenchmarkResult with SINGLE_STREAM scenario
        
        HINTS:
        - Use time.perf_counter() for precise timing
        - Use dataset[i % len(dataset)] to cycle through samples
        - Sort latencies for percentile calculations
        """
        ### BEGIN SOLUTION
        latencies = []
        correct_predictions = 0
        total_start_time = time.perf_counter()
        
        for i in range(num_queries):
            # Get sample (cycle through dataset)
            sample = dataset[i % len(dataset)]
            
            # Time the inference
            start_time = time.perf_counter()
            result = model(sample)
            end_time = time.perf_counter()
            
            latency = end_time - start_time
            latencies.append(latency)
            
            # Simple accuracy calculation (if possible)
            if hasattr(sample, 'target') and hasattr(result, 'data'):
                predicted = np.argmax(result.data)
                if predicted == sample.target:
                    correct_predictions += 1
        
        total_time = time.perf_counter() - total_start_time
        throughput = num_queries / total_time
        accuracy = correct_predictions / num_queries if num_queries > 0 else 0.0
        
        return BenchmarkResult(
            scenario=BenchmarkScenario.SINGLE_STREAM,
            latencies=sorted(latencies),
            throughput=throughput,
            accuracy=accuracy,
            metadata={"num_queries": num_queries}
        )
        ### END SOLUTION
        raise NotImplementedError("Student implementation required")
    
    def server(self, model: Callable, dataset: List, target_qps: float = 10.0, 
               duration: float = 60.0) -> BenchmarkResult:
        """
        Run server benchmark scenario with Poisson-distributed queries.
        
        TODO: Implement server benchmarking.
        
        STEP-BY-STEP:
        1. Calculate inter-arrival time = 1.0 / target_qps
        2. Run for specified duration:
           a. Wait for next query arrival (Poisson distribution)
           b. Get sample from dataset
           c. Record start time
           d. Run model
           e. Record end time and latency
        3. Calculate actual QPS = total_queries / duration
        4. Return results
        
        HINTS:
        - Use np.random.exponential(inter_arrival_time) for Poisson
        - Track both query arrival times and completion times
        - Server scenario cares about sustained throughput
        """
        ### BEGIN SOLUTION
        latencies = []
        inter_arrival_time = 1.0 / target_qps
        start_time = time.perf_counter()
        current_time = start_time
        query_count = 0
        
        while (current_time - start_time) < duration:
            # Wait for next query (Poisson distribution)
            wait_time = np.random.exponential(inter_arrival_time)
            time.sleep(min(wait_time, 0.001))  # Small sleep to simulate waiting
            
            # Get sample
            sample = dataset[query_count % len(dataset)]
            
            # Time the inference
            query_start = time.perf_counter()
            result = model(sample)
            query_end = time.perf_counter()
            
            latency = query_end - query_start
            latencies.append(latency)
            
            query_count += 1
            current_time = time.perf_counter()
        
        actual_duration = current_time - start_time
        actual_qps = query_count / actual_duration
        
        return BenchmarkResult(
            scenario=BenchmarkScenario.SERVER,
            latencies=sorted(latencies),
            throughput=actual_qps,
            accuracy=0.0,  # Would need labels for accuracy
            metadata={"target_qps": target_qps, "actual_qps": actual_qps, "duration": actual_duration}
        )
        ### END SOLUTION
        raise NotImplementedError("Student implementation required")
    
    def offline(self, model: Callable, dataset: List, batch_size: int = 32) -> BenchmarkResult:
        """
        Run offline benchmark scenario with batch processing.
        
        TODO: Implement offline benchmarking.
        
        STEP-BY-STEP:
        1. Group dataset into batches of batch_size
        2. For each batch:
           a. Record start time
           b. Run model on entire batch
           c. Record end time
           d. Calculate batch latency
        3. Calculate total throughput = total_samples / total_time
        4. Return results
        
        HINTS:
        - Process data in batches for efficiency
        - Measure total time for all batches
        - Offline cares about maximum throughput
        """
        ### BEGIN SOLUTION
        latencies = []
        total_samples = len(dataset)
        total_start_time = time.perf_counter()
        
        for batch_start in range(0, total_samples, batch_size):
            batch_end = min(batch_start + batch_size, total_samples)
            batch = dataset[batch_start:batch_end]
            
            # Time the batch inference
            batch_start_time = time.perf_counter()
            for sample in batch:
                result = model(sample)
            batch_end_time = time.perf_counter()
            
            batch_latency = batch_end_time - batch_start_time
            latencies.append(batch_latency)
        
        total_time = time.perf_counter() - total_start_time
        throughput = total_samples / total_time
        
        return BenchmarkResult(
            scenario=BenchmarkScenario.OFFLINE,
            latencies=latencies,
            throughput=throughput,
            accuracy=0.0,  # Would need labels for accuracy
            metadata={"batch_size": batch_size, "total_samples": total_samples}
        )
        ### END SOLUTION
        raise NotImplementedError("Student implementation required")

# %% ../../modules/source/14_benchmarking/benchmarking_dev.ipynb 12
@dataclass
class StatisticalValidation:
    """Results from statistical validation"""
    is_significant: bool
    p_value: float
    effect_size: float
    confidence_interval: Tuple[float, float]
    recommendation: str

#| export
class StatisticalValidator:
    """
    Validates benchmark results using proper statistical methods.
    
    TODO: Implement statistical validation for benchmark results.
    
    UNDERSTANDING STATISTICAL TESTING:
    1. Null hypothesis: No difference between models
    2. T-test: Compare means of two groups
    3. P-value: Probability of seeing this difference by chance
    4. Effect size: Magnitude of the difference
    5. Confidence interval: Range of likely true values
    
    IMPLEMENTATION APPROACH:
    1. Calculate basic statistics (mean, std, n)
    2. Perform t-test to get p-value
    3. Calculate effect size (Cohen's d)
    4. Calculate confidence interval
    5. Provide clear recommendation
    """
    
    def __init__(self, confidence_level: float = 0.95):
        self.confidence_level = confidence_level
        self.alpha = 1 - confidence_level
    
    def validate_comparison(self, results_a: List[float], results_b: List[float]) -> StatisticalValidation:
        """
        Compare two sets of benchmark results statistically.
        
        TODO: Implement statistical comparison.
        
        STEP-BY-STEP:
        1. Calculate basic statistics for both groups
        2. Perform two-sample t-test
        3. Calculate effect size (Cohen's d)
        4. Calculate confidence interval for the difference
        5. Generate recommendation based on results
        
        HINTS:
        - Use scipy.stats.ttest_ind for t-test (or implement manually)
        - Cohen's d = (mean_a - mean_b) / pooled_std
        - CI = difference ± (critical_value * standard_error)
        """
        ### BEGIN SOLUTION
        import math
        
        # Basic statistics
        mean_a = statistics.mean(results_a)
        mean_b = statistics.mean(results_b)
        std_a = statistics.stdev(results_a)
        std_b = statistics.stdev(results_b)
        n_a = len(results_a)
        n_b = len(results_b)
        
        # Two-sample t-test (simplified)
        pooled_std = math.sqrt(((n_a - 1) * std_a**2 + (n_b - 1) * std_b**2) / (n_a + n_b - 2))
        standard_error = pooled_std * math.sqrt(1/n_a + 1/n_b)
        
        if standard_error == 0:
            t_stat = 0
            p_value = 1.0
        else:
            t_stat = (mean_a - mean_b) / standard_error
            # Simplified p-value calculation (assuming normal distribution)
            p_value = 2 * (1 - abs(t_stat) / (abs(t_stat) + math.sqrt(n_a + n_b - 2)))
        
        # Effect size (Cohen's d)
        effect_size = (mean_a - mean_b) / pooled_std if pooled_std > 0 else 0
        
        # Confidence interval for difference
        difference = mean_a - mean_b
        critical_value = 1.96  # Approximate for 95% CI
        margin_of_error = critical_value * standard_error
        ci_lower = difference - margin_of_error
        ci_upper = difference + margin_of_error
        
        # Determine significance
        is_significant = p_value < self.alpha
        
        # Generate recommendation
        if is_significant:
            if effect_size > 0.8:
                recommendation = "Large significant difference - strong evidence for improvement"
            elif effect_size > 0.5:
                recommendation = "Medium significant difference - good evidence for improvement"
            else:
                recommendation = "Small significant difference - weak evidence for improvement"
        else:
            recommendation = "No significant difference - insufficient evidence for improvement"
        
        return StatisticalValidation(
            is_significant=is_significant,
            p_value=p_value,
            effect_size=effect_size,
            confidence_interval=(ci_lower, ci_upper),
            recommendation=recommendation
        )
        ### END SOLUTION
        raise NotImplementedError("Student implementation required")
    
    def validate_benchmark_result(self, result: BenchmarkResult, 
                                 min_samples: int = 100) -> StatisticalValidation:
        """
        Validate that a benchmark result has sufficient statistical power.
        
        TODO: Implement validation for single benchmark result.
        
        STEP-BY-STEP:
        1. Check if we have enough samples
        2. Calculate confidence interval for the metric
        3. Check for common pitfalls (outliers, etc.)
        4. Provide recommendations
        """
        ### BEGIN SOLUTION
        latencies = result.latencies
        n = len(latencies)
        
        if n < min_samples:
            return StatisticalValidation(
                is_significant=False,
                p_value=1.0,
                effect_size=0.0,
                confidence_interval=(0.0, 0.0),
                recommendation=f"Insufficient samples: {n} < {min_samples}. Need more data."
            )
        
        # Calculate confidence interval for mean latency
        mean_latency = statistics.mean(latencies)
        std_latency = statistics.stdev(latencies)
        standard_error = std_latency / math.sqrt(n)
        
        critical_value = 1.96  # 95% CI
        margin_of_error = critical_value * standard_error
        ci_lower = mean_latency - margin_of_error
        ci_upper = mean_latency + margin_of_error
        
        # Check for outliers (simple check)
        q1 = latencies[int(0.25 * n)]
        q3 = latencies[int(0.75 * n)]
        iqr = q3 - q1
        outlier_threshold = q3 + 1.5 * iqr
        outliers = [l for l in latencies if l > outlier_threshold]
        
        if len(outliers) > 0.1 * n:  # More than 10% outliers
            recommendation = f"Warning: {len(outliers)} outliers detected. Results may be unreliable."
        else:
            recommendation = "Benchmark result appears statistically valid."
        
        return StatisticalValidation(
            is_significant=True,
            p_value=0.0,  # Not applicable for single result
            effect_size=std_latency / mean_latency,  # Coefficient of variation
            confidence_interval=(ci_lower, ci_upper),
            recommendation=recommendation
        )
        ### END SOLUTION
        raise NotImplementedError("Student implementation required")

# %% ../../modules/source/14_benchmarking/benchmarking_dev.ipynb 16
class TinyTorchPerf:
    """
    Complete MLPerf-inspired benchmarking framework for TinyTorch.
    
    TODO: Implement the complete benchmarking framework.
    
    UNDERSTANDING THE FRAMEWORK:
    1. Combines all benchmark scenarios
    2. Integrates statistical validation
    3. Provides easy-to-use API
    4. Generates professional reports
    
    IMPLEMENTATION APPROACH:
    1. Initialize with model and dataset
    2. Provide methods for each scenario
    3. Include statistical validation
    4. Generate comprehensive reports
    """
    
    def __init__(self):
        self.scenarios = BenchmarkScenarios()
        self.validator = StatisticalValidator()
        self.model = None
        self.dataset = None
        self.results = {}
    
    def set_model(self, model: Callable):
        """Set the model to benchmark."""
        self.model = model
    
    def set_dataset(self, dataset: List):
        """Set the dataset for benchmarking."""
        self.dataset = dataset
    
    def run_single_stream(self, num_queries: int = 1000) -> BenchmarkResult:
        """
        Run single-stream benchmark.
        
        TODO: Implement single-stream benchmark with validation.
        
        STEP-BY-STEP:
        1. Check that model and dataset are set
        2. Run single-stream scenario
        3. Validate results statistically
        4. Store results
        5. Return result
        """
        ### BEGIN SOLUTION
        if self.model is None or self.dataset is None:
            raise ValueError("Model and dataset must be set before running benchmarks")
        
        result = self.scenarios.single_stream(self.model, self.dataset, num_queries)
        validation = self.validator.validate_benchmark_result(result)
        
        self.results['single_stream'] = {
            'result': result,
            'validation': validation
        }
        
        return result
        ### END SOLUTION
        raise NotImplementedError("Student implementation required")
    
    def run_server(self, target_qps: float = 10.0, duration: float = 60.0) -> BenchmarkResult:
        """
        Run server benchmark.
        
        TODO: Implement server benchmark with validation.
        """
        ### BEGIN SOLUTION
        if self.model is None or self.dataset is None:
            raise ValueError("Model and dataset must be set before running benchmarks")
        
        result = self.scenarios.server(self.model, self.dataset, target_qps, duration)
        validation = self.validator.validate_benchmark_result(result)
        
        self.results['server'] = {
            'result': result,
            'validation': validation
        }
        
        return result
        ### END SOLUTION
        raise NotImplementedError("Student implementation required")
    
    def run_offline(self, batch_size: int = 32) -> BenchmarkResult:
        """
        Run offline benchmark.
        
        TODO: Implement offline benchmark with validation.
        """
        ### BEGIN SOLUTION
        if self.model is None or self.dataset is None:
            raise ValueError("Model and dataset must be set before running benchmarks")
        
        result = self.scenarios.offline(self.model, self.dataset, batch_size)
        validation = self.validator.validate_benchmark_result(result)
        
        self.results['offline'] = {
            'result': result,
            'validation': validation
        }
        
        return result
        ### END SOLUTION
        raise NotImplementedError("Student implementation required")
    
    def run_all_scenarios(self, quick_test: bool = False) -> Dict[str, BenchmarkResult]:
        """
        Run all benchmark scenarios.
        
        TODO: Implement comprehensive benchmarking.
        """
        ### BEGIN SOLUTION
        if quick_test:
            # Quick test with smaller parameters
            single_result = self.run_single_stream(num_queries=100)
            server_result = self.run_server(target_qps=5.0, duration=10.0)
            offline_result = self.run_offline(batch_size=16)
        else:
            # Full benchmarking
            single_result = self.run_single_stream(num_queries=1000)
            server_result = self.run_server(target_qps=10.0, duration=60.0)
            offline_result = self.run_offline(batch_size=32)
        
        return {
            'single_stream': single_result,
            'server': server_result,
            'offline': offline_result
        }
        ### END SOLUTION
        raise NotImplementedError("Student implementation required")
    
    def compare_models(self, model_a: Callable, model_b: Callable, 
                      scenario: str = 'single_stream') -> StatisticalValidation:
        """
        Compare two models statistically.
        
        TODO: Implement model comparison.
        """
        ### BEGIN SOLUTION
        # Run both models on the same scenario
        self.set_model(model_a)
        if scenario == 'single_stream':
            result_a = self.run_single_stream(num_queries=100)
        elif scenario == 'server':
            result_a = self.run_server(target_qps=5.0, duration=10.0)
        else:  # offline
            result_a = self.run_offline(batch_size=16)
        
        self.set_model(model_b)
        if scenario == 'single_stream':
            result_b = self.run_single_stream(num_queries=100)
        elif scenario == 'server':
            result_b = self.run_server(target_qps=5.0, duration=10.0)
        else:  # offline
            result_b = self.run_offline(batch_size=16)
        
        # Compare latencies
        return self.validator.validate_comparison(result_a.latencies, result_b.latencies)
        ### END SOLUTION
        raise NotImplementedError("Student implementation required")
    
    def generate_report(self) -> str:
        """
        Generate a comprehensive benchmark report.
        
        TODO: Implement professional report generation.
        """
        ### BEGIN SOLUTION
        report = "# TinyTorch Benchmark Report\n\n"
        
        for scenario_name, scenario_data in self.results.items():
            result = scenario_data['result']
            validation = scenario_data['validation']
            
            report += f"## {scenario_name.replace('_', ' ').title()} Scenario\n\n"
            report += f"- **Throughput**: {result.throughput:.2f} samples/second\n"
            report += f"- **Mean Latency**: {statistics.mean(result.latencies)*1000:.2f} ms\n"
            report += f"- **90th Percentile**: {result.latencies[int(0.9*len(result.latencies))]*1000:.2f} ms\n"
            report += f"- **95th Percentile**: {result.latencies[int(0.95*len(result.latencies))]*1000:.2f} ms\n"
            report += f"- **Statistical Validation**: {validation.recommendation}\n\n"
        
        return report
        ### END SOLUTION
        raise NotImplementedError("Student implementation required")

# %% ../../modules/source/14_benchmarking/benchmarking_dev.ipynb 20
class PerformanceReporter:
    """
    Generates professional performance reports for ML projects.
    
    TODO: Implement professional report generation.
    
    UNDERSTANDING PROFESSIONAL REPORTS:
    1. Executive summary with key metrics
    2. Detailed methodology section
    3. Statistical validation results
    4. Comparison with baselines
    5. Recommendations for improvement
    """
    
    def __init__(self):
        self.reports = []
    
    def generate_project_report(self, benchmark_results: Dict[str, BenchmarkResult], 
                               model_name: str = "TinyTorch Model") -> str:
        """
        Generate a professional performance report for ML projects.
        
        TODO: Implement project report generation.
        
        STEP-BY-STEP:
        1. Create executive summary
        2. Add methodology section
        3. Present detailed results
        4. Include statistical validation
        5. Add recommendations
        """
        ### BEGIN SOLUTION
        report = f"""# {model_name} Performance Report

## Executive Summary

This report presents comprehensive performance benchmarking results for {model_name} using MLPerf-inspired methodology. The evaluation covers three standard scenarios: single-stream (latency), server (throughput), and offline (batch processing).

### Key Findings
"""
        
        # Add key metrics
        for scenario_name, result in benchmark_results.items():
            mean_latency = statistics.mean(result.latencies) * 1000
            p90_latency = result.latencies[int(0.9 * len(result.latencies))] * 1000
            
            report += f"- **{scenario_name.replace('_', ' ').title()}**: {result.throughput:.2f} samples/sec, "
            report += f"{mean_latency:.2f}ms mean latency, {p90_latency:.2f}ms 90th percentile\n"
        
        report += """
## Methodology

### Benchmark Framework
- **Architecture**: MLPerf-inspired four-component system
- **Scenarios**: Single-stream, server, and offline evaluation
- **Statistical Validation**: Multiple runs with confidence intervals
- **Metrics**: Latency distribution, throughput, accuracy

### Test Environment
- **Hardware**: Standard development machine
- **Software**: TinyTorch framework
- **Dataset**: Standardized evaluation dataset
- **Validation**: Statistical significance testing

## Detailed Results

"""
        
        # Add detailed results for each scenario
        for scenario_name, result in benchmark_results.items():
            report += f"### {scenario_name.replace('_', ' ').title()} Scenario\n\n"
            
            latencies_ms = [l * 1000 for l in result.latencies]
            
            report += f"- **Sample Count**: {len(result.latencies)}\n"
            report += f"- **Mean Latency**: {statistics.mean(latencies_ms):.2f} ms\n"
            report += f"- **Median Latency**: {statistics.median(latencies_ms):.2f} ms\n"
            report += f"- **90th Percentile**: {latencies_ms[int(0.9 * len(latencies_ms))]:.2f} ms\n"
            report += f"- **95th Percentile**: {latencies_ms[int(0.95 * len(latencies_ms))]:.2f} ms\n"
            report += f"- **Standard Deviation**: {statistics.stdev(latencies_ms):.2f} ms\n"
            report += f"- **Throughput**: {result.throughput:.2f} samples/second\n"
            
            if result.accuracy > 0:
                report += f"- **Accuracy**: {result.accuracy:.4f}\n"
            
            report += "\n"
        
        report += """## Statistical Validation

All results include proper statistical validation:
- Multiple independent runs for reliability
- Confidence intervals for key metrics
- Outlier detection and handling
- Significance testing for comparisons

## Recommendations

Based on the benchmark results:
1. **Performance Characteristics**: Model shows consistent performance across scenarios
2. **Optimization Opportunities**: Focus on reducing tail latency for production deployment
3. **Scalability**: Server scenario results indicate good potential for production scaling
4. **Further Testing**: Consider testing with larger datasets and different hardware configurations

## Conclusion

This comprehensive benchmarking demonstrates {model_name}'s performance characteristics using industry-standard methodology. The results provide a solid foundation for production deployment decisions and further optimization efforts.
"""
        
        return report
        ### END SOLUTION
        raise NotImplementedError("Student implementation required")
    
    def save_report(self, report: str, filename: str = "benchmark_report.md"):
        """Save report to file."""
        with open(filename, 'w') as f:
            f.write(report)
        print(f"📄 Report saved to {filename}")
