//! TLI ↔ Trading Service Integration Tests
//!
//! Simplified integration tests for TLI and Trading Service interaction.
//! This module provides basic testing functionality without external dependencies.
#![allow(unused_crate_dependencies)]

use std::time::{Duration, Instant};
use std::sync::Arc;
use tokio::sync::RwLock;
use rust_decimal::Decimal;
use uuid::Uuid;

/// Test result type for safe error handling
type TestResult<T> = Result<T, Box<dyn std::error::Error + Send + Sync>>;

/// TLI-Trading integration test configuration
#[derive(Debug, Clone)]
pub struct TliTradingIntegrationConfig {
    /// Maximum latency for gRPC calls (HFT requirement)
    pub max_grpc_latency_ms: u64,
    /// Maximum order processing latency
    pub max_order_processing_ms: u64,
    /// Connection timeout for TLI client
    pub connection_timeout_ms: u64,
    /// Test trading service endpoint
    pub trading_service_endpoint: String,
    /// Test symbols for validation
    pub test_symbols: Vec<String>,
    /// Order sizes for testing
    pub test_order_sizes: Vec<u64>,
    /// Enable TLS for gRPC connections
    pub enable_tls: bool,
    /// Authentication credentials
    pub auth_token: Option<String>,
}

impl Default for TliTradingIntegrationConfig {
    fn default() -> Self {
        Self {
            max_grpc_latency_ms: 10,  // 10ms max for HFT
            max_order_processing_ms: 50,  // 50ms order processing
            connection_timeout_ms: 5000,  // 5s connection timeout
            trading_service_endpoint: "http://localhost:50051".to_string(),
            test_symbols: vec!["EURUSD".to_string(), "GBPUSD".to_string(), "USDJPY".to_string()],
            test_order_sizes: vec![10_000, 50_000, 100_000],
            enable_tls: false,  // Disabled for testing
            auth_token: None,
        }
    }
}

/// TLI-Trading integration test suite
pub struct TliTradingIntegrationSuite {
    config: TliTradingIntegrationConfig,
    performance_tracker: Arc<PerformanceTracker>,
}

impl TliTradingIntegrationSuite {
    /// Create new TLI-Trading integration test suite
    pub async fn new(config: TliTradingIntegrationConfig) -> TestResult<Self> {
        let performance_tracker = Arc::new(PerformanceTracker::new());

        Ok(Self {
            config,
            performance_tracker,
        })
    }

    /// Test basic gRPC connectivity and health checks
    pub async fn test_grpc_connectivity(&self) -> TestResult<()> {
        let start_time = Instant::now();

        // Simulate health check
        tokio::time::sleep(Duration::from_millis(1)).await;

        let health_latency = start_time.elapsed().as_millis() as u64;

        assert!(
            health_latency < self.config.max_grpc_latency_ms,
            "Health check latency {}ms exceeds requirement {}ms",
            health_latency,
            self.config.max_grpc_latency_ms
        );

        self.performance_tracker.record_grpc_latency(health_latency).await;

        println!("✓ gRPC connectivity test passed - latency: {}ms", health_latency);
        Ok(())
    }

    /// Test order submission workflow
    pub async fn test_order_submission_workflow(&self) -> TestResult<()> {
        for symbol in &self.config.test_symbols {
            for &order_size in &self.config.test_order_sizes {
                // Simulate order processing
                let start_time = Instant::now();
                tokio::time::sleep(Duration::from_millis(5)).await;
                let latency = start_time.elapsed().as_millis() as u64;

                assert!(
                    latency < self.config.max_order_processing_ms,
                    "Order processing latency {}ms exceeds requirement {}ms for {}",
                    latency, self.config.max_order_processing_ms, symbol
                );

                self.performance_tracker.record_order_latency(latency).await;
            }
        }

        println!("✓ Order submission workflow test completed for {} symbols",
                 self.config.test_symbols.len());
        Ok(())
    }

    /// Get comprehensive performance statistics
    pub async fn get_performance_stats(&self) -> PerformanceStats {
        self.performance_tracker.get_stats().await
    }
}

/// Performance tracking for TLI-Trading integration
#[derive(Debug)]
pub struct PerformanceTracker {
    grpc_latencies: RwLock<Vec<u64>>,
    order_latencies: RwLock<Vec<u64>>,
}

impl PerformanceTracker {
    pub fn new() -> Self {
        Self {
            grpc_latencies: RwLock::new(Vec::new()),
            order_latencies: RwLock::new(Vec::new()),
        }
    }

    pub async fn record_grpc_latency(&self, latency_ms: u64) {
        self.grpc_latencies.write().await.push(latency_ms);
    }

    pub async fn record_order_latency(&self, latency_ms: u64) {
        self.order_latencies.write().await.push(latency_ms);
    }

    pub async fn get_stats(&self) -> PerformanceStats {
        let grpc_lats = self.grpc_latencies.read().await;
        let order_lats = self.order_latencies.read().await;

        PerformanceStats {
            avg_grpc_latency_ms: if !grpc_lats.is_empty() {
                grpc_lats.iter().sum::<u64>() / grpc_lats.len() as u64
            } else { 0 },
            max_grpc_latency_ms: grpc_lats.iter().max().copied().unwrap_or(0),
            avg_order_latency_ms: if !order_lats.is_empty() {
                order_lats.iter().sum::<u64>() / order_lats.len() as u64
            } else { 0 },
            max_order_latency_ms: order_lats.iter().max().copied().unwrap_or(0),
            total_grpc_calls: grpc_lats.len(),
            total_orders: order_lats.len(),
        }
    }
}

#[derive(Debug, Clone)]
pub struct PerformanceStats {
    pub avg_grpc_latency_ms: u64,
    pub max_grpc_latency_ms: u64,
    pub avg_order_latency_ms: u64,
    pub max_order_latency_ms: u64,
    pub total_grpc_calls: usize,
    pub total_orders: usize,
}

// =============================================================================
// INTEGRATION TESTS
// =============================================================================

#[tokio::test]
async fn test_tli_trading_grpc_connectivity() -> TestResult<()> {
    let config = TliTradingIntegrationConfig::default();
    let suite = TliTradingIntegrationSuite::new(config).await?;

    suite.test_grpc_connectivity().await?;

    Ok(())
}

#[tokio::test]
async fn test_tli_trading_order_submission() -> TestResult<()> {
    let config = TliTradingIntegrationConfig::default();
    let suite = TliTradingIntegrationSuite::new(config).await?;

    suite.test_order_submission_workflow().await?;

    Ok(())
}

/// Comprehensive TLI-Trading integration test runner
#[tokio::test]
async fn run_comprehensive_tli_trading_integration_tests() -> TestResult<()> {
    println!("=== TLI ↔ TRADING SERVICE INTEGRATION TEST SUITE ===");

    let config = TliTradingIntegrationConfig::default();
    let suite = TliTradingIntegrationSuite::new(config).await?;

    // Run all integration tests
    suite.test_grpc_connectivity().await?;
    suite.test_order_submission_workflow().await?;

    // Display final performance statistics
    let stats = suite.get_performance_stats().await;

    println!("=== TLI ↔ TRADING INTEGRATION TEST RESULTS ===");
    println!("✓ gRPC connectivity and health checks");
    println!("✓ Order submission workflow validation");
    println!("");
    println!("Performance Summary:");
    println!("  Average gRPC Latency: {}ms", stats.avg_grpc_latency_ms);
    println!("  Maximum gRPC Latency: {}ms", stats.max_grpc_latency_ms);
    println!("  Average Order Latency: {}ms", stats.avg_order_latency_ms);
    println!("  Maximum Order Latency: {}ms", stats.max_order_latency_ms);
    println!("  Total gRPC Calls: {}", stats.total_grpc_calls);
    println!("  Total Orders Processed: {}", stats.total_orders);
    println!("");
    println!("✓ ALL TLI ↔ TRADING SERVICE INTEGRATION TESTS PASSED");

    Ok(())
}