/// Module de tests de production
/// 
/// Implémente load testing, stress testing et chaos testing
/// pour valider la scalabilité et résilience production

pub mod load_testing;
pub mod chaos_testing;
pub mod benchmarks;
pub mod stress_testing;

pub use load_testing::*;
pub use chaos_testing::*;
pub use benchmarks::*;
pub use stress_testing::*;

use std::sync::Arc;
use std::time::{Duration, Instant};
use tokio::sync::RwLock;
// Note: Use tracing::info! macro directly instead of importing
use serde::{Serialize, Deserialize};
use uuid::Uuid;

use crate::error::AppError;
use crate::core::StreamManager;

/// Configuration des tests de production
#[derive(Debug, Clone)]
pub struct ProductionTestConfig {
    /// Nombre maximum de connexions simultanées
    pub max_concurrent_connections: u32,
    /// Durée du test
    pub test_duration: Duration,
    /// Montée en charge progressive
    pub ramp_up_duration: Duration,
    /// Descente en charge
    pub ramp_down_duration: Duration,
    /// Métriques cibles
    pub target_metrics: TargetMetrics,
    /// Configuration du chaos testing
    pub chaos_config: ChaosConfig,
}

/// Métriques cibles pour validation
#[derive(Debug, Clone)]
pub struct TargetMetrics {
    /// Latence P99 maximale acceptable (ms)
    pub max_p99_latency_ms: f64,
    /// Throughput minimum (requêtes/sec)
    pub min_throughput_rps: f64,
    /// Taux d'erreur maximum acceptable (%)
    pub max_error_rate_percent: f64,
    /// Utilisation CPU maximale (%)
    pub max_cpu_usage_percent: f64,
    /// Utilisation mémoire maximale (GB)
    pub max_memory_usage_gb: f64,
}

/// Configuration du chaos testing
#[derive(Debug, Clone)]
pub struct ChaosConfig {
    /// Taux de panne réseau (%)
    pub network_failure_rate: f64,
    /// Latence réseau artificielle (ms)
    pub artificial_latency_ms: u64,
    /// Taux de perte de paquets (%)
    pub packet_loss_rate: f64,
    /// Redémarrages de services
    pub service_restart_interval: Duration,
}

/// Gestionnaire principal des tests de production
#[derive(Debug)]
pub struct ProductionTestRunner {
    config: ProductionTestConfig,
    stream_manager: Arc<StreamManager>,
    test_results: Arc<RwLock<TestResults>>,
    active_connections: Arc<RwLock<Vec<TestConnection>>>,
}

/// Résultats des tests de production
#[derive(Debug, Clone, Default)]
pub struct TestResults {
    /// Métriques de performance
    pub performance_metrics: PerformanceMetrics,
    /// Métriques de résilience
    pub resilience_metrics: ResilienceMetrics,
    /// Événements détectés
    pub events: Vec<TestEvent>,
    /// Status final
    pub final_status: TestStatus,
}

/// Métriques de performance mesurées
#[derive(Debug, Clone, Default)]
pub struct PerformanceMetrics {
    /// Latence P50, P95, P99 (ms)
    pub latency_p50: f64,
    pub latency_p95: f64,
    pub latency_p99: f64,
    /// Throughput (requêtes/sec)
    pub throughput_rps: f64,
    /// Taux d'erreur (%)
    pub error_rate: f64,
    /// Connexions simultanées maximum atteint
    pub max_concurrent_connections: u32,
    /// Utilisation des ressources
    pub cpu_usage_percent: f64,
    pub memory_usage_gb: f64,
    pub network_io_mbps: f64,
}

/// Métriques de résilience
#[derive(Debug, Clone, Default)]
pub struct ResilienceMetrics {
    /// Temps de récupération après panne (s)
    pub recovery_time_seconds: f64,
    /// Pourcentage de requêtes perdues durant panne
    pub lost_requests_percent: f64,
    /// Nombre de redémarrages survivis
    pub survived_restarts: u32,
    /// Stabilité sous charge
    pub stability_score: f64,
}

/// Événement de test
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct TestEvent {
    pub timestamp: std::time::SystemTime,
    pub event_type: TestEventType,
    pub description: String,
    pub severity: EventSeverity,
}

/// Types d'événements de test
#[derive(Debug, Clone, Serialize, Deserialize)]
pub enum TestEventType {
    LoadThresholdReached,
    LatencySpike,
    ErrorRateHigh,
    ResourceExhaustion,
    ServiceFailure,
    RecoveryCompleted,
    TestCompleted,
}

/// Sévérité des événements
#[derive(Debug, Clone, Serialize, Deserialize)]
pub enum EventSeverity {
    Info,
    Warning,
    Error,
    Critical,
}

/// Status final du test
#[derive(Debug, Clone, Serialize, Deserialize)]
pub enum TestStatus {
    Passed,
    Failed { reason: String },
    PartiallyPassed { warnings: Vec<String> },
}

/// Connexion de test simulée
#[derive(Debug, Clone)]
pub struct TestConnection {
    pub id: Uuid,
    pub created_at: Instant,
    pub last_activity: Instant,
    pub status: ConnectionStatus,
    pub metrics: ConnectionMetrics,
}

/// Status d'une connexion de test
#[derive(Debug, Clone)]
pub enum ConnectionStatus {
    Connecting,
    Connected,
    Active,
    Idle,
    Disconnected,
    Error { message: String },
}

/// Métriques par connexion
#[derive(Debug, Clone, Default)]
pub struct ConnectionMetrics {
    pub requests_sent: u64,
    pub responses_received: u64,
    pub bytes_sent: u64,
    pub bytes_received: u64,
    pub errors: u64,
}

impl Default for ProductionTestConfig {
    fn default() -> Self {
        Self {
            max_concurrent_connections: 100_000,
            test_duration: Duration::from_secs(3600), // 1 heure
            ramp_up_duration: Duration::from_secs(300), // 5 minutes
            ramp_down_duration: Duration::from_secs(120), // 2 minutes
            target_metrics: TargetMetrics {
                max_p99_latency_ms: 50.0,
                min_throughput_rps: 10_000.0,
                max_error_rate_percent: 0.1,
                max_cpu_usage_percent: 80.0,
                max_memory_usage_gb: 16.0,
            },
            chaos_config: ChaosConfig {
                network_failure_rate: 0.1,
                artificial_latency_ms: 100,
                packet_loss_rate: 0.01,
                service_restart_interval: Duration::from_secs(600),
            },
        }
    }
}

impl ProductionTestRunner {
    /// Crée un nouveau runner de tests
    pub fn new(
        config: ProductionTestConfig,
        stream_manager: Arc<StreamManager>,
    ) -> Self {
        Self {
            config,
            stream_manager,
            test_results: Arc::new(RwLock::new(TestResults::default())),
            active_connections: Arc::new(RwLock::new(Vec::new())),
        }
    }

    /// Lance la suite complète de tests de production
    pub async fn run_production_tests(&self) -> Result<TestResults, AppError> {
        tracing::info!("🚀 Démarrage tests de production - 100k+ connexions");
        
        let start_time = Instant::now();
        
        // Phase 1: Load Testing
        self.run_load_test().await?;
        
        // Phase 2: Stress Testing
        self.run_stress_test().await?;
        
        // Phase 3: Chaos Testing
        self.run_chaos_test().await?;
        
        // Phase 4: Validation des résultats
        let results = self.validate_results().await?;
        
        let total_duration = start_time.elapsed();
        tracing::info!("✅ Tests de production terminés en {:?}", total_duration);
        
        Ok(results)
    }

    /// Execute le load testing
    async fn run_load_test(&self) -> Result<(), AppError> {
        tracing::info!("📈 Phase 1: Load Testing - Montée en charge progressive");
        
        let load_tester = LoadTester::new(
            self.config.max_concurrent_connections,
            self.config.ramp_up_duration,
            self.config.test_duration,
        );
        
        load_tester.execute(
            self.stream_manager.clone(),
            self.active_connections.clone(),
        ).await?;
        
        Ok(())
    }

    /// Execute le stress testing
    async fn run_stress_test(&self) -> Result<(), AppError> {
        tracing::info!("🔥 Phase 2: Stress Testing - Limites système");
        
        let stress_tester = StressTester::new(
            self.config.max_concurrent_connections * 2, // 200k connexions
            Duration::from_secs(600), // 10 minutes de stress
        );
        
        stress_tester.execute().await?;
        
        Ok(())
    }

    /// Execute le chaos testing
    async fn run_chaos_test(&self) -> Result<(), AppError> {
        tracing::info!("🌪️  Phase 3: Chaos Testing - Résilience");
        
        let chaos_tester = ChaosTester::new(self.config.chaos_config.clone());
        
        chaos_tester.execute(
            self.stream_manager.clone(),
            Duration::from_secs(900), // 15 minutes de chaos
        ).await?;
        
        Ok(())
    }

    /// Valide les résultats par rapport aux métriques cibles
    async fn validate_results(&self) -> Result<TestResults, AppError> {
        tracing::info!("📊 Validation des résultats contre métriques cibles");
        
        let results = self.test_results.read().await.clone();
        
        // Validation des métriques
        let mut warnings = Vec::new();
        let mut failed = false;
        
        if results.performance_metrics.latency_p99 > self.config.target_metrics.max_p99_latency_ms {
            failed = true;
            warnings.push(format!(
                "Latence P99 trop élevée: {:.1}ms > {:.1}ms",
                results.performance_metrics.latency_p99,
                self.config.target_metrics.max_p99_latency_ms
            ));
        }
        
        if results.performance_metrics.throughput_rps < self.config.target_metrics.min_throughput_rps {
            failed = true;
            warnings.push(format!(
                "Throughput insuffisant: {:.1} < {:.1} req/s",
                results.performance_metrics.throughput_rps,
                self.config.target_metrics.min_throughput_rps
            ));
        }
        
        if results.performance_metrics.error_rate > self.config.target_metrics.max_error_rate_percent {
            failed = true;
            warnings.push(format!(
                "Taux d'erreur trop élevé: {:.2}% > {:.2}%",
                results.performance_metrics.error_rate,
                self.config.target_metrics.max_error_rate_percent
            ));
        }
        
        let mut final_results = results.clone();
        final_results.final_status = if failed {
            TestStatus::Failed { reason: warnings.join(", ") }
        } else if !warnings.is_empty() {
            TestStatus::PartiallyPassed { warnings }
        } else {
            TestStatus::Passed
        };
        
        Ok(final_results)
    }

    /// Obtient un snapshot des métriques actuelles
    pub async fn get_current_metrics(&self) -> PerformanceMetrics {
        // Simulation de métriques en temps réel
        PerformanceMetrics {
            latency_p50: 12.5,
            latency_p95: 28.3,
            latency_p99: 45.7,
            throughput_rps: 12_500.0,
            error_rate: 0.05,
            max_concurrent_connections: 95_000,
            cpu_usage_percent: 72.8,
            memory_usage_gb: 12.4,
            network_io_mbps: 890.3,
        }
    }
}
