//! Comprehensive End-to-End ML Training Workflow Tests
//! 
//! Tests the complete integration pipeline:
//! TLI → MLTrainingService → Trading Service
//! 
//! Validates:
//! - Model training → deployment → inference pipeline
//! - Training data ingestion → processing → model update
//! - Failure scenarios and recovery testing
//! - Performance requirements and regression detection

use anyhow::Result;
use std::time::Duration;
use tokio::time::{sleep, timeout};
use uuid::Uuid;

use crate::harness::{TestHarness, TestResult};
use crate::harness::grpc_clients::*;
use crate::harness::test_data::{TestDataGenerator, ModelArtifact};
use crate::harness::performance::RegressionResult;

/// Complete ML training workflow integration tests
pub struct MLTrainingWorkflowTests {
    harness: TestHarness,
}

impl MLTrainingWorkflowTests {
    pub async fn new() -> Result<Self> {
        let harness = TestHarness::new().await?;
        Ok(Self { harness })
    }

    /// Execute all comprehensive workflow tests
    pub async fn run_all_tests(&mut self) -> Result<Vec<TestResult>> {
        let mut results = Vec::new();

        // Setup test environment
        self.harness.setup().await?;

        // Layer 1: Foundation Tests
        results.push(self.test_service_connectivity().await?);
        results.push(self.test_health_checks().await?);

        // Layer 2: Integration Tests
        results.push(self.test_tli_to_ml_training_integration().await?);
        results.push(self.test_ml_training_to_trading_integration().await?);

        // Layer 3: End-to-End Workflow Tests
        results.push(self.test_complete_training_pipeline().await?);
        results.push(self.test_model_deployment_workflow().await?);
        results.push(self.test_live_trading_with_ml_workflow().await?);
        results.push(self.test_model_update_and_rollback_workflow().await?);

        // Layer 4: Performance Tests
        results.push(self.test_training_performance_requirements().await?);
        results.push(self.test_inference_latency_requirements().await?);

        // Layer 5: Failure and Recovery Tests
        results.push(self.test_training_failure_recovery().await?);
        results.push(self.test_deployment_failure_recovery().await?);
        results.push(self.test_service_restart_recovery().await?);

        // Cleanup
        self.harness.cleanup().await?;

        Ok(results)
    }

    /// Test basic service connectivity
    async fn test_service_connectivity(&mut self) -> Result<TestResult> {
        self.harness.execute_scenario("service_connectivity", |harness| async move {
            // Test all service endpoints are reachable
            let endpoints = harness.grpc_clients.get_endpoints();
            
            for (service_name, endpoint) in endpoints {
                println!("Testing connectivity to {}: {}", service_name, endpoint);
                
                // This would test actual connectivity
                // For now, simulate the test
                sleep(Duration::from_millis(100)).await;
            }

            assert!(harness.grpc_clients.are_all_healthy().await?, 
                   "All services should be healthy and reachable");

            Ok(())
        }).await
    }

    /// Test service health checks
    async fn test_health_checks(&mut self) -> Result<TestResult> {
        self.harness.execute_scenario("health_checks", |harness| async move {
            let start_time = std::time::Instant::now();

            // Test TLI health
            harness.grpc_clients.tli_client.health_check().await?;
            harness.performance.record_latency("health_checks", "tli_health_check", start_time.elapsed());

            let start_time = std::time::Instant::now();
            // Test ML Training Service health
            let _resource_response = harness.grpc_clients.ml_training_client.clone()
                .get_resource_utilization(foxhunt_ml::ResourceRequest {}).await?;
            harness.performance.record_latency("health_checks", "ml_training_health_check", start_time.elapsed());

            let start_time = std::time::Instant::now();
            // Test Trading Service health
            harness.grpc_clients.trading_client.health_check().await?;
            harness.performance.record_latency("health_checks", "trading_health_check", start_time.elapsed());

            println!("All health checks passed");
            Ok(())
        }).await
    }

    /// Test TLI to ML Training Service integration
    async fn test_tli_to_ml_training_integration(&mut self) -> Result<TestResult> {
        self.harness.execute_scenario("tli_ml_training_integration", |harness| async move {
            let start_time = std::time::Instant::now();

            // Start training via TLI
            let training_request = StartMLTrainingRequest {
                model_name: "test_dqn_aapl".to_string(),
                dataset_id: "synthetic_aapl_dataset".to_string(),
                hyperparameters: vec![
                    ("learning_rate".to_string(), "0.001".to_string()),
                    ("batch_size".to_string(), "32".to_string()),
                    ("epochs".to_string(), "10".to_string()),
                ].into_iter().collect(),
                auto_deploy: false,
            };

            let response = harness.grpc_clients.tli_client
                .start_ml_training(training_request).await?;

            harness.performance.record_latency("tli_ml_training_integration", "start_training_command", start_time.elapsed());

            assert!(response.success, "Training should start successfully");
            assert!(!response.job_id.is_empty(), "Job ID should be provided");

            // Monitor training progress
            let job_id = response.job_id.clone();
            let mut progress_checks = 0;
            const MAX_PROGRESS_CHECKS: u32 = 30;

            while progress_checks < MAX_PROGRESS_CHECKS {
                let start_time = std::time::Instant::now();
                
                let status = harness.grpc_clients.tli_client
                    .get_ml_training_status(job_id.clone()).await?;

                harness.performance.record_latency("tli_ml_training_integration", "status_check", start_time.elapsed());

                println!("Training progress: {}% (epoch {}/{})", 
                        status.progress_percentage, status.current_epoch, status.total_epochs);

                if status.status == "COMPLETED" || status.status == "FAILED" {
                    break;
                }

                progress_checks += 1;
                sleep(Duration::from_secs(2)).await;
            }

            // Stop training (test the stop functionality)
            let start_time = std::time::Instant::now();
            let stop_response = harness.grpc_clients.tli_client
                .stop_ml_training(job_id).await?;
            harness.performance.record_latency("tli_ml_training_integration", "stop_training_command", start_time.elapsed());

            assert!(stop_response.success, "Training should stop successfully");

            Ok(())
        }).await
    }

    /// Test ML Training Service to Trading Service integration
    async fn test_ml_training_to_trading_integration(&mut self) -> Result<TestResult> {
        self.harness.execute_scenario("ml_training_trading_integration", |harness| async move {
            // First, simulate a completed training job with model artifact
            let model_artifact = harness.test_data.test_data.create_model_artifact("DQN", "AAPL").await?;
            
            let start_time = std::time::Instant::now();

            // Deploy model to trading service
            let deploy_request = DeployModelRequest {
                model_id: model_artifact.model_id.clone(),
                model_path: model_artifact.model_path.clone(),
                target_symbols: vec!["AAPL".to_string()],
            };

            let deploy_response = harness.grpc_clients.trading_client
                .deploy_model(deploy_request).await?;

            harness.performance.record_latency("ml_training_trading_integration", "model_deployment", start_time.elapsed());

            assert!(deploy_response.success, "Model deployment should succeed");
            assert_eq!(deploy_response.model_id, model_artifact.model_id);

            // Test model inference
            let start_time = std::time::Instant::now();
            
            let prediction_request = PredictionRequest {
                model_id: model_artifact.model_id.clone(),
                symbol: "AAPL".to_string(),
                features: vec![1.0, 2.0, 3.0, 4.0, 5.0], // Mock features
            };

            let prediction_response = harness.grpc_clients.trading_client
                .get_model_predictions(prediction_request).await?;

            harness.performance.record_latency("ml_training_trading_integration", "model_inference", start_time.elapsed());

            assert_eq!(prediction_response.symbol, "AAPL");
            assert!(prediction_response.confidence > 0.0 && prediction_response.confidence <= 1.0);
            assert!(!prediction_response.prediction.is_empty());

            println!("Model inference result: {} with confidence {}", 
                    prediction_response.prediction, prediction_response.confidence);

            Ok(())
        }).await
    }

    /// Test complete training pipeline: Data → Training → Validation → Storage
    async fn test_complete_training_pipeline(&mut self) -> Result<TestResult> {
        self.harness.execute_scenario("complete_training_pipeline", |harness| async move {
            let start_time = std::time::Instant::now();

            // 1. Data Ingestion Phase
            println!("Phase 1: Data Ingestion");
            let market_data = harness.test_data.generate_market_data("AAPL", 1000).await?;
            assert!(!market_data.is_empty(), "Market data should be generated");

            // 2. Feature Engineering Phase
            println!("Phase 2: Feature Engineering");
            let training_dataset = harness.test_data.create_training_dataset("AAPL").await?;
            assert!(!training_dataset.features.is_empty(), "Features should be extracted");
            assert!(!training_dataset.labels.is_empty(), "Labels should be generated");

            harness.performance.record_latency("complete_training_pipeline", "data_preparation", start_time.elapsed());

            // 3. Model Training Phase
            println!("Phase 3: Model Training");
            let start_time = std::time::Instant::now();

            let training_request = StartMLTrainingRequest {
                model_name: "pipeline_test_model".to_string(),
                dataset_id: "aapl_pipeline_dataset".to_string(),
                hyperparameters: vec![
                    ("learning_rate".to_string(), "0.001".to_string()),
                    ("batch_size".to_string(), "64".to_string()),
                    ("epochs".to_string(), "20".to_string()),
                ].into_iter().collect(),
                auto_deploy: true, // Enable auto-deployment for full pipeline test
            };

            let training_response = harness.grpc_clients.tli_client
                .start_ml_training(training_request).await?;

            assert!(training_response.success, "Training should start successfully");

            // 4. Training Monitoring Phase
            println!("Phase 4: Training Monitoring");
            let job_id = training_response.job_id;
            let training_completion = timeout(Duration::from_secs(300), async {
                loop {
                    let status = harness.grpc_clients.tli_client
                        .get_ml_training_status(job_id.clone()).await?;

                    println!("Training status: {} ({}%)", status.status, status.progress_percentage);

                    if status.status == "COMPLETED" {
                        return Ok::<(), anyhow::Error>(());
                    } else if status.status == "FAILED" {
                        return Err(anyhow::anyhow!("Training failed"));
                    }

                    sleep(Duration::from_secs(5)).await;
                }
            }).await;

            match training_completion {
                Ok(_) => {
                    harness.performance.record_latency("complete_training_pipeline", "model_training", start_time.elapsed());
                    println!("Training completed successfully");
                },
                Err(_) => {
                    println!("Training timeout - this is acceptable for integration testing");
                    // Stop the training job
                    harness.grpc_clients.tli_client.stop_ml_training(job_id).await?;
                }
            }

            // 5. Model Validation Phase
            println!("Phase 5: Model Validation");
            let model_artifact = harness.test_data.create_model_artifact("DQN", "AAPL").await?;
            
            // Validate model performance metrics
            assert!(model_artifact.metadata.validation_accuracy > 0.5, 
                   "Model should have reasonable validation accuracy");

            // 6. Model Storage Phase
            println!("Phase 6: Model Storage");
            harness.test_data.save_model_artifact(&model_artifact).await?;

            println!("Complete training pipeline test passed");
            Ok(())
        }).await
    }

    /// Test model deployment workflow: Retrieval → Deployment → Activation
    async fn test_model_deployment_workflow(&mut self) -> Result<TestResult> {
        self.harness.execute_scenario("model_deployment_workflow", |harness| async move {
            // Create a test model artifact
            let model_artifact = harness.test_data.create_model_artifact("MAMBA", "TSLA").await?;
            harness.test_data.save_model_artifact(&model_artifact).await?;

            let start_time = std::time::Instant::now();

            // Phase 1: Model Retrieval
            println!("Phase 1: Model Retrieval");
            // In a real implementation, this would retrieve from model registry
            assert!(tokio::fs::metadata(&model_artifact.model_path).await.is_ok(), 
                   "Model artifact should exist");

            // Phase 2: Model Deployment
            println!("Phase 2: Model Deployment");
            let deploy_request = DeployModelRequest {
                model_id: model_artifact.model_id.clone(),
                model_path: model_artifact.model_path.clone(),
                target_symbols: vec!["TSLA".to_string(), "AAPL".to_string()],
            };

            let deploy_response = harness.grpc_clients.trading_client
                .deploy_model(deploy_request).await?;

            harness.performance.record_latency("model_deployment_workflow", "model_deployment", start_time.elapsed());

            assert!(deploy_response.success, "Model deployment should succeed");
            assert!(!deploy_response.deployment_id.is_empty(), "Deployment ID should be provided");

            // Phase 3: Model Activation
            println!("Phase 3: Model Activation");
            let start_time = std::time::Instant::now();

            // Test that the model is active and can make predictions
            for symbol in &["TSLA", "AAPL"] {
                let prediction_request = PredictionRequest {
                    model_id: model_artifact.model_id.clone(),
                    symbol: symbol.to_string(),
                    features: vec![1.5, 2.8, 3.2, 4.1, 5.0], // Mock features
                };

                let prediction_response = harness.grpc_clients.trading_client
                    .get_model_predictions(prediction_request).await?;

                assert_eq!(prediction_response.symbol, *symbol);
                assert!(prediction_response.confidence > 0.0);

                println!("Model prediction for {}: {} (confidence: {:.3})", 
                        symbol, prediction_response.prediction, prediction_response.confidence);
            }

            harness.performance.record_latency("model_deployment_workflow", "model_activation", start_time.elapsed());

            println!("Model deployment workflow completed successfully");
            Ok(())
        }).await
    }

    /// Test live trading workflow: Signal → Risk → Execution → Reporting
    async fn test_live_trading_with_ml_workflow(&mut self) -> Result<TestResult> {
        self.harness.execute_scenario("live_trading_ml_workflow", |harness| async move {
            // Setup: Deploy a model for trading
            let model_artifact = harness.test_data.create_model_artifact("TFT", "SPY").await?;
            
            let deploy_request = DeployModelRequest {
                model_id: model_artifact.model_id.clone(),
                model_path: model_artifact.model_path.clone(),
                target_symbols: vec!["SPY".to_string()],
            };

            harness.grpc_clients.trading_client.deploy_model(deploy_request).await?;

            let start_time = std::time::Instant::now();

            // Phase 1: Signal Generation
            println!("Phase 1: ML Signal Generation");
            let prediction_request = PredictionRequest {
                model_id: model_artifact.model_id.clone(),
                symbol: "SPY".to_string(),
                features: vec![450.5, 451.2, 449.8, 452.1, 450.9], // Mock SPY price features
            };

            let prediction_response = harness.grpc_clients.trading_client
                .get_model_predictions(prediction_request).await?;

            harness.performance.record_latency("live_trading_ml_workflow", "signal_generation", start_time.elapsed());

            assert!(!prediction_response.prediction.is_empty(), "Model should generate a signal");
            assert!(prediction_response.confidence > 0.0, "Signal should have confidence");

            // Phase 2: Risk Management Check
            println!("Phase 2: Risk Management Validation");
            let start_time = std::time::Instant::now();

            // This would integrate with the risk management service
            // For now, simulate risk checks
            let risk_approved = prediction_response.confidence > 0.7 && 
                               prediction_response.signal_strength.abs() > 0.5;

            harness.performance.record_latency("live_trading_ml_workflow", "risk_validation", start_time.elapsed());

            if !risk_approved {
                println!("Trade rejected by risk management");
                return Ok(());
            }

            // Phase 3: Order Execution
            println!("Phase 3: Order Execution");
            let start_time = std::time::Instant::now();

            // Simulate order execution based on ML signal
            let order_side = match prediction_response.prediction.as_str() {
                "BUY" | "STRONG_BUY" => "BUY",
                "SELL" | "STRONG_SELL" => "SELL",
                _ => "HOLD",
            };

            if order_side != "HOLD" {
                println!("Executing {} order for SPY based on ML signal", order_side);
                // In practice, this would call the actual trading service
                sleep(Duration::from_millis(10)).await; // Simulate execution latency
            }

            harness.performance.record_latency("live_trading_ml_workflow", "order_execution", start_time.elapsed());

            // Phase 4: Trade Reporting
            println!("Phase 4: Trade Reporting");
            let start_time = std::time::Instant::now();

            // Report trade execution and model performance
            println!("Trade executed: {} SPY @ market price, signal confidence: {:.3}", 
                    order_side, prediction_response.confidence);

            harness.performance.record_latency("live_trading_ml_workflow", "trade_reporting", start_time.elapsed());

            println!("Live trading with ML workflow completed successfully");
            Ok(())
        }).await
    }

    /// Test model update and rollback workflow
    async fn test_model_update_and_rollback_workflow(&mut self) -> Result<TestResult> {
        self.harness.execute_scenario("model_update_rollback_workflow", |harness| async move {
            // Setup: Deploy initial model version
            let initial_model = harness.test_data.create_model_artifact("ENSEMBLE", "QQQ").await?;
            
            let deploy_request = DeployModelRequest {
                model_id: initial_model.model_id.clone(),
                model_path: initial_model.model_path.clone(),
                target_symbols: vec!["QQQ".to_string()],
            };

            harness.grpc_clients.trading_client.deploy_model(deploy_request).await?;

            // Phase 1: Model Update
            println!("Phase 1: Model Update");
            let start_time = std::time::Instant::now();

            // Create new model version
            let mut updated_model = initial_model.clone();
            updated_model.version = "2.0.0".to_string();
            updated_model.model_id = format!("ensemble_qqq_v2.0");
            updated_model.model_path = format!("/tmp/test_models/ensemble_qqq_v2.pkl");

            let update_request = UpdateModelRequest {
                model_id: initial_model.model_id.clone(),
                new_model_path: updated_model.model_path.clone(),
            };

            let update_response = harness.grpc_clients.trading_client
                .update_model(update_request).await?;

            harness.performance.record_latency("model_update_rollback_workflow", "model_update", start_time.elapsed());

            assert!(update_response.success, "Model update should succeed");
            assert_eq!(update_response.previous_version, "v1.0.0");
            assert_eq!(update_response.new_version, "v1.1.0");

            // Phase 2: Validation of Updated Model
            println!("Phase 2: Updated Model Validation");
            let start_time = std::time::Instant::now();

            let prediction_request = PredictionRequest {
                model_id: update_response.model_id.clone(),
                symbol: "QQQ".to_string(),
                features: vec![350.0, 351.5, 349.2, 352.8, 350.5],
            };

            let prediction_response = harness.grpc_clients.trading_client
                .get_model_predictions(prediction_request).await?;

            harness.performance.record_latency("model_update_rollback_workflow", "updated_model_validation", start_time.elapsed());

            assert!(!prediction_response.prediction.is_empty(), "Updated model should work");

            // Phase 3: Rollback Scenario (simulate performance degradation)
            println!("Phase 3: Model Rollback");
            let start_time = std::time::Instant::now();

            // Simulate detecting performance issues with new model
            let performance_degraded = prediction_response.confidence < 0.5; // Simulate poor performance

            if performance_degraded {
                println!("Performance degradation detected, rolling back to previous version");
                
                let rollback_request = UpdateModelRequest {
                    model_id: update_response.model_id.clone(),
                    new_model_path: initial_model.model_path.clone(),
                };

                let rollback_response = harness.grpc_clients.trading_client
                    .update_model(rollback_request).await?;

                assert!(rollback_response.success, "Model rollback should succeed");
                
                harness.performance.record_latency("model_update_rollback_workflow", "model_rollback", start_time.elapsed());

                println!("Successfully rolled back to version {}", rollback_response.new_version);
            } else {
                println!("New model performing well, no rollback needed");
            }

            println!("Model update and rollback workflow completed successfully");
            Ok(())
        }).await
    }

    /// Test training performance requirements
    async fn test_training_performance_requirements(&mut self) -> Result<TestResult> {
        self.harness.execute_scenario("training_performance_requirements", |harness| async move {
            println!("Testing ML training performance requirements");

            // Test concurrent training jobs
            let mut training_jobs = Vec::new();
            let start_time = std::time::Instant::now();

            for i in 0..3 {
                let training_request = StartMLTrainingRequest {
                    model_name: format!("perf_test_model_{}", i),
                    dataset_id: "performance_test_dataset".to_string(),
                    hyperparameters: vec![
                        ("learning_rate".to_string(), "0.001".to_string()),
                        ("batch_size".to_string(), "32".to_string()),
                        ("epochs".to_string(), "5".to_string()), // Short training for performance test
                    ].into_iter().collect(),
                    auto_deploy: false,
                };

                let response = harness.grpc_clients.tli_client
                    .start_ml_training(training_request).await?;

                assert!(response.success, "Training job {} should start", i);
                training_jobs.push(response.job_id);
            }

            harness.performance.record_latency("training_performance_requirements", "concurrent_job_startup", start_time.elapsed());

            // Monitor resource utilization during training
            let start_time = std::time::Instant::now();
            for _ in 0..10 {
                // Simulate resource monitoring
                harness.performance.record_resource_usage(
                    "training_performance_requirements",
                    75.0, // CPU %
                    8192.0, // Memory MB
                    Some(85.0), // GPU %
                );
                
                sleep(Duration::from_millis(500)).await;
            }

            harness.performance.record_latency("training_performance_requirements", "resource_monitoring", start_time.elapsed());

            // Test training throughput
            let start_time = std::time::Instant::now();
            let samples_processed = 10000; // Simulate processed samples
            let processing_duration = Duration::from_secs(30);
            
            harness.performance.record_throughput(
                "training_performance_requirements",
                "samples_per_second",
                samples_processed,
                processing_duration,
            );

            // Stop all training jobs
            for job_id in training_jobs {
                harness.grpc_clients.tli_client.stop_ml_training(job_id).await?;
            }

            // Check performance regression
            let regression_result = harness.performance.check_regression("training_performance_requirements");
            match regression_result {
                RegressionResult::NoRegression => println!("No performance regression detected"),
                RegressionResult::LatencyRegression { operation, increase_percent } => {
                    println!("WARNING: Latency regression in {}: {:.2}% increase", operation, increase_percent);
                },
                RegressionResult::ThroughputRegression { operation, decrease_percent } => {
                    println!("WARNING: Throughput regression in {}: {:.2}% decrease", operation, decrease_percent);
                },
                RegressionResult::NoBaseline => println!("No baseline available for comparison"),
                _ => {},
            }

            println!("Training performance requirements test completed");
            Ok(())
        }).await
    }

    /// Test inference latency requirements
    async fn test_inference_latency_requirements(&mut self) -> Result<TestResult> {
        self.harness.execute_scenario("inference_latency_requirements", |harness| async move {
            println!("Testing ML inference latency requirements");

            // Deploy a model for latency testing
            let model_artifact = harness.test_data.create_model_artifact("LIQUID", "NVDA").await?;
            let deploy_request = DeployModelRequest {
                model_id: model_artifact.model_id.clone(),
                model_path: model_artifact.model_path.clone(),
                target_symbols: vec!["NVDA".to_string()],
            };

            harness.grpc_clients.trading_client.deploy_model(deploy_request).await?;

            // Test inference latency under load
            const INFERENCE_COUNT: usize = 1000;
            let mut latencies = Vec::with_capacity(INFERENCE_COUNT);

            println!("Running {} inference requests to measure latency", INFERENCE_COUNT);

            for i in 0..INFERENCE_COUNT {
                let start_time = std::time::Instant::now();

                let prediction_request = PredictionRequest {
                    model_id: model_artifact.model_id.clone(),
                    symbol: "NVDA".to_string(),
                    features: vec![400.0 + i as f64, 401.0, 399.5, 402.1, 400.8],
                };

                let prediction_response = harness.grpc_clients.trading_client
                    .get_model_predictions(prediction_request).await?;

                let latency = start_time.elapsed();
                latencies.push(latency);

                harness.performance.record_latency("inference_latency_requirements", "single_inference", latency);

                assert!(!prediction_response.prediction.is_empty(), "Inference should return prediction");

                // Add small delay to avoid overwhelming the system
                if i % 100 == 0 {
                    sleep(Duration::from_millis(10)).await;
                }
            }

            // Analyze latency statistics
            latencies.sort();
            let p50 = latencies[INFERENCE_COUNT / 2];
            let p95 = latencies[(INFERENCE_COUNT * 95) / 100];
            let p99 = latencies[(INFERENCE_COUNT * 99) / 100];

            println!("Inference latency statistics:");
            println!("  P50: {:?}", p50);
            println!("  P95: {:?}", p95);
            println!("  P99: {:?}", p99);

            // Verify HFT latency requirements
            const MAX_P95_LATENCY_US: u64 = 1000; // 1ms for P95
            const MAX_P99_LATENCY_US: u64 = 5000; // 5ms for P99

            assert!(p95.as_micros() <= MAX_P95_LATENCY_US as u128, 
                   "P95 latency should be under {}μs, got {}μs", 
                   MAX_P95_LATENCY_US, p95.as_micros());

            assert!(p99.as_micros() <= MAX_P99_LATENCY_US as u128,
                   "P99 latency should be under {}μs, got {}μs",
                   MAX_P99_LATENCY_US, p99.as_micros());

            println!("Inference latency requirements test passed");
            Ok(())
        }).await
    }

    /// Test training failure recovery
    async fn test_training_failure_recovery(&mut self) -> Result<TestResult> {
        self.harness.execute_scenario("training_failure_recovery", |harness| async move {
            println!("Testing training failure recovery scenarios");

            // Scenario 1: Invalid hyperparameters
            let invalid_request = StartMLTrainingRequest {
                model_name: "failure_test_model".to_string(),
                dataset_id: "invalid_dataset".to_string(),
                hyperparameters: vec![
                    ("learning_rate".to_string(), "invalid_value".to_string()), // Invalid value
                    ("batch_size".to_string(), "-1".to_string()), // Invalid value
                ].into_iter().collect(),
                auto_deploy: false,
            };

            let response = harness.grpc_clients.tli_client
                .start_ml_training(invalid_request).await;

            // Should either fail immediately or handle gracefully
            match response {
                Ok(resp) => {
                    if resp.success {
                        // If it started, it should fail quickly
                        sleep(Duration::from_secs(5)).await;
                        let status = harness.grpc_clients.tli_client
                            .get_ml_training_status(resp.job_id.clone()).await?;
                        assert_eq!(status.status, "FAILED", "Job with invalid params should fail");
                    }
                },
                Err(_) => {
                    println!("Training correctly rejected invalid parameters");
                }
            }

            // Scenario 2: Resource exhaustion simulation
            println!("Testing resource exhaustion recovery");
            let resource_test_request = StartMLTrainingRequest {
                model_name: "resource_test_model".to_string(),
                dataset_id: "large_dataset".to_string(),
                hyperparameters: vec![
                    ("learning_rate".to_string(), "0.001".to_string()),
                    ("batch_size".to_string(), "1000000".to_string()), // Very large batch
                ].into_iter().collect(),
                auto_deploy: false,
            };

            let response = harness.grpc_clients.tli_client
                .start_ml_training(resource_test_request).await?;

            if response.success {
                // Monitor for resource-related failure
                let mut checks = 0;
                while checks < 10 {
                    let status = harness.grpc_clients.tli_client
                        .get_ml_training_status(response.job_id.clone()).await?;

                    if status.status == "FAILED" {
                        println!("Training failed due to resource constraints (expected)");
                        break;
                    }

                    checks += 1;
                    sleep(Duration::from_secs(2)).await;
                }

                // Clean up
                harness.grpc_clients.tli_client.stop_ml_training(response.job_id).await.ok();
            }

            println!("Training failure recovery test completed");
            Ok(())
        }).await
    }

    /// Test deployment failure recovery
    async fn test_deployment_failure_recovery(&mut self) -> Result<TestResult> {
        self.harness.execute_scenario("deployment_failure_recovery", |harness| async move {
            println!("Testing deployment failure recovery scenarios");

            // Scenario 1: Invalid model path
            let invalid_deploy_request = DeployModelRequest {
                model_id: "nonexistent_model".to_string(),
                model_path: "/invalid/path/to/model.pkl".to_string(),
                target_symbols: vec!["TEST".to_string()],
            };

            let response = harness.grpc_clients.trading_client
                .deploy_model(invalid_deploy_request).await;

            match response {
                Ok(resp) => {
                    assert!(!resp.success, "Deployment with invalid path should fail");
                    println!("Deployment correctly rejected invalid model path");
                },
                Err(_) => {
                    println!("Deployment correctly failed with invalid model path");
                }
            }

            // Scenario 2: Model corruption simulation
            let corrupt_model = harness.test_data.create_model_artifact("CORRUPT", "TEST").await?;
            
            // Create a corrupt model file
            tokio::fs::write(&corrupt_model.model_path, b"invalid model data").await?;

            let corrupt_deploy_request = DeployModelRequest {
                model_id: corrupt_model.model_id.clone(),
                model_path: corrupt_model.model_path.clone(),
                target_symbols: vec!["TEST".to_string()],
            };

            let response = harness.grpc_clients.trading_client
                .deploy_model(corrupt_deploy_request).await;

            match response {
                Ok(resp) => {
                    if resp.success {
                        // If deployment succeeded, inference should fail
                        let prediction_request = PredictionRequest {
                            model_id: corrupt_model.model_id.clone(),
                            symbol: "TEST".to_string(),
                            features: vec![1.0, 2.0, 3.0],
                        };

                        let inference_result = harness.grpc_clients.trading_client
                            .get_model_predictions(prediction_request).await;

                        assert!(inference_result.is_err(), "Inference with corrupt model should fail");
                    }
                },
                Err(_) => {
                    println!("Deployment correctly rejected corrupt model");
                }
            }

            println!("Deployment failure recovery test completed");
            Ok(())
        }).await
    }

    /// Test service restart recovery
    async fn test_service_restart_recovery(&mut self) -> Result<TestResult> {
        self.harness.execute_scenario("service_restart_recovery", |harness| async move {
            println!("Testing service restart recovery scenarios");

            // Start a training job
            let training_request = StartMLTrainingRequest {
                model_name: "restart_test_model".to_string(),
                dataset_id: "restart_test_dataset".to_string(),
                hyperparameters: vec![
                    ("learning_rate".to_string(), "0.001".to_string()),
                    ("batch_size".to_string(), "32".to_string()),
                    ("epochs".to_string(), "50".to_string()), // Long training
                ].into_iter().collect(),
                auto_deploy: false,
            };

            let response = harness.grpc_clients.tli_client
                .start_ml_training(training_request).await?;

            assert!(response.success, "Training should start successfully");
            let job_id = response.job_id;

            // Wait for training to get started
            sleep(Duration::from_secs(5)).await;

            // Simulate service restart by checking if training state is recoverable
            println!("Simulating service restart scenario");
            
            // In a real test, we would restart the ML training service here
            // For now, we'll test that the job status is still queryable
            let status_after_restart = harness.grpc_clients.tli_client
                .get_ml_training_status(job_id.clone()).await;

            match status_after_restart {
                Ok(status) => {
                    println!("Training status after simulated restart: {}", status.status);
                    // The service should either:
                    // 1. Continue the training from checkpoint
                    // 2. Mark the job as failed and allow restart
                    // 3. Provide clear status about recovery
                    assert!(!status.status.is_empty(), "Status should be available after restart");
                },
                Err(_) => {
                    println!("Training status unavailable after restart - this may be expected");
                }
            }

            // Test recovery by stopping and potentially restarting
            let stop_response = harness.grpc_clients.tli_client
                .stop_ml_training(job_id).await?;

            assert!(stop_response.success, "Should be able to stop training after restart");

            // Test starting a new training job after restart
            let recovery_request = StartMLTrainingRequest {
                model_name: "recovery_test_model".to_string(),
                dataset_id: "recovery_test_dataset".to_string(),
                hyperparameters: vec![
                    ("learning_rate".to_string(), "0.001".to_string()),
                ].into_iter().collect(),
                auto_deploy: false,
            };

            let recovery_response = harness.grpc_clients.tli_client
                .start_ml_training(recovery_request).await?;

            assert!(recovery_response.success, "Should be able to start new training after restart");

            // Clean up
            harness.grpc_clients.tli_client.stop_ml_training(recovery_response.job_id).await.ok();

            println!("Service restart recovery test completed");
            Ok(())
        }).await
    }
}

// Module-level test runner function
#[tokio::test]
async fn run_comprehensive_ml_training_workflow_tests() -> Result<()> {
    let mut test_suite = MLTrainingWorkflowTests::new().await?;
    let results = test_suite.run_all_tests().await?;

    // Print test summary
    let total_tests = results.len();
    let passed_tests = results.iter().filter(|r| r.is_success()).count();
    let failed_tests = total_tests - passed_tests;

    println!("\n=== TEST SUMMARY ===");
    println!("Total tests: {}", total_tests);
    println!("Passed: {}", passed_tests);
    println!("Failed: {}", failed_tests);

    // Print detailed results
    for (i, result) in results.into_iter().enumerate() {
        match result {
            TestResult::Success { duration, metrics } => {
                println!("✅ Test {}: PASSED ({:?})", i + 1, duration);
            },
            TestResult::Failure { duration, error, metrics } => {
                println!("❌ Test {}: FAILED ({:?}) - {}", i + 1, duration, error);
            },
        }
    }

    assert_eq!(failed_tests, 0, "All tests should pass");
    println!("\n🎉 All comprehensive ML training workflow tests passed!");

    Ok(())
}