//! Wave D: Regime Tracking Database Tests
//!
//! Tests cover:
//! - Regime state insertion and retrieval
//! - Regime transitions tracking
//! - Adaptive strategy metrics recording
//! - Database constraints and validations
//! - Helper function correctness

use common::database::{DatabasePool, LocalDatabaseConfig};
use sqlx::PgPool;
use std::time::Duration;

// ============================================================================
// Helper Functions
// ============================================================================

/// Create a test database pool for Wave D regime tracking tests
async fn create_test_pool() -> DatabasePool {
    let config = LocalDatabaseConfig {
        url: "postgresql://foxhunt:foxhunt_dev_password@localhost:5432/foxhunt".to_string(),
        pool: common::database::PoolConfig {
            max_connections: 5,
            min_connections: 2,
            connect_timeout_ms: 5000,
            acquire_timeout_ms: 5000,
            max_lifetime_seconds: 3600,
            idle_timeout_seconds: 300,
        },
        performance: common::database::PerformanceConfig {
            query_timeout_micros: 10000,
            enable_prewarming: false,
            enable_prepared_statements: true,
            enable_slow_query_logging: false,
            slow_query_threshold_micros: 10000,
        },
    };

    DatabasePool::new(config)
        .await
        .expect("Failed to create test database pool")
}

/// Clean up test data for a symbol
async fn cleanup_test_data(pool: &PgPool, symbol: &str) {
    let _ = sqlx::query!("DELETE FROM regime_states WHERE symbol = $1", symbol)
        .execute(pool)
        .await;
    let _ = sqlx::query!("DELETE FROM regime_transitions WHERE symbol = $1", symbol)
        .execute(pool)
        .await;
    let _ = sqlx::query!(
        "DELETE FROM adaptive_strategy_metrics WHERE symbol = $1",
        symbol
    )
    .execute(pool)
    .await;
}

// ============================================================================
// Regime State Tests
// ============================================================================

#[tokio::test]
async fn test_insert_regime_state() {
    let pool = create_test_pool().await;
    let symbol = "TEST.REGIME.STATE";
    cleanup_test_data(pool.pool(), symbol).await;

    let event_timestamp = chrono::Utc::now();

    // Insert regime state
    let result = pool
        .insert_regime_state(
            symbol,
            "Trending",
            0.85,
            event_timestamp,
            Some(2.5),
            Some(-1.2),
            Some(45.0),
            Some(0.92),
        )
        .await;

    assert!(
        result.is_ok(),
        "Failed to insert regime state: {:?}",
        result
    );
    cleanup_test_data(pool.pool(), symbol).await;
}

#[tokio::test]
async fn test_get_latest_regime() {
    let pool = create_test_pool().await;
    let symbol = "TEST.LATEST.REGIME";
    cleanup_test_data(pool.pool(), symbol).await;

    let event_timestamp = chrono::Utc::now();

    // Insert regime state
    pool.insert_regime_state(
        symbol,
        "Volatile",
        0.78,
        event_timestamp,
        Some(1.8),
        Some(-2.1),
        Some(32.5),
        Some(0.65),
    )
    .await
    .expect("Failed to insert regime state");

    // Retrieve latest regime
    let regime = pool
        .get_latest_regime(symbol)
        .await
        .expect("Failed to get latest regime");

    assert_eq!(regime.symbol, symbol);
    assert_eq!(regime.regime, "Volatile");
    assert!((regime.confidence - 0.78).abs() < 1e-6);
    assert!(regime.cusum_s_plus.is_some());
    assert!((regime.cusum_s_plus.unwrap() - 1.8).abs() < 1e-6);
    assert!(regime.adx.is_some());
    assert!((regime.adx.unwrap() - 32.5).abs() < 1e-6);

    cleanup_test_data(pool.pool(), symbol).await;
}

#[tokio::test]
async fn test_upsert_regime_state() {
    let pool = create_test_pool().await;
    let symbol = "TEST.UPSERT.REGIME";
    cleanup_test_data(pool.pool(), symbol).await;

    let event_timestamp = chrono::Utc::now();

    // Insert initial regime state
    pool.insert_regime_state(
        symbol,
        "Normal",
        0.90,
        event_timestamp,
        Some(0.5),
        Some(-0.3),
        Some(25.0),
        Some(0.95),
    )
    .await
    .expect("Failed to insert regime state");

    // Upsert with different values (same timestamp)
    pool.insert_regime_state(
        symbol,
        "Trending",
        0.92,
        event_timestamp,
        Some(3.2),
        Some(-0.8),
        Some(55.0),
        Some(0.88),
    )
    .await
    .expect("Failed to upsert regime state");

    // Retrieve and verify update
    let regime = pool
        .get_latest_regime(symbol)
        .await
        .expect("Failed to get latest regime");

    assert_eq!(regime.regime, "Trending");
    assert!((regime.confidence - 0.92).abs() < 1e-6);
    assert!((regime.cusum_s_plus.unwrap() - 3.2).abs() < 1e-6);
    assert!((regime.adx.unwrap() - 55.0).abs() < 1e-6);

    cleanup_test_data(pool.pool(), symbol).await;
}

#[tokio::test]
async fn test_regime_state_constraints() {
    let pool = create_test_pool().await;
    let symbol = "TEST.CONSTRAINTS";
    cleanup_test_data(pool.pool(), symbol).await;

    let event_timestamp = chrono::Utc::now();

    // Test valid regimes
    let valid_regimes = vec![
        "Normal", "Trending", "Ranging", "Volatile", "Crisis", "Illiquid", "Momentum",
    ];

    for (idx, regime) in valid_regimes.iter().enumerate() {
        let result = pool
            .insert_regime_state(
                symbol,
                regime,
                0.80,
                event_timestamp + chrono::Duration::seconds(i64::try_from(idx).unwrap()), // Unique timestamp
                None,
                None,
                None,
                None,
            )
            .await;
        assert!(result.is_ok(), "Failed for valid regime: {}", regime);
    }

    cleanup_test_data(pool.pool(), symbol).await;
}

// ============================================================================
// Regime Transition Tests
// ============================================================================

#[tokio::test]
async fn test_insert_regime_transition() {
    let pool = create_test_pool().await;
    let symbol = "TEST.TRANSITION";
    cleanup_test_data(pool.pool(), symbol).await;

    let event_timestamp = chrono::Utc::now();

    // Insert transition
    let result = pool
        .insert_regime_transition(
            symbol,
            "Normal",
            "Trending",
            event_timestamp,
            Some(120),
            Some(0.35),
            Some(48.5),
            true,
        )
        .await;

    assert!(
        result.is_ok(),
        "Failed to insert regime transition: {:?}",
        result
    );

    cleanup_test_data(pool.pool(), symbol).await;
}

#[tokio::test]
async fn test_regime_transition_invalid_same_regime() {
    let pool = create_test_pool().await;
    let symbol = "TEST.INVALID.TRANSITION";
    cleanup_test_data(pool.pool(), symbol).await;

    let event_timestamp = chrono::Utc::now();

    // Attempt invalid transition (same from and to regime)
    let result = pool
        .insert_regime_transition(
            symbol,
            "Normal",
            "Normal", // Invalid: same regime
            event_timestamp,
            Some(50),
            Some(0.0),
            None,
            false,
        )
        .await;

    // Should fail due to CHECK constraint
    assert!(
        result.is_err(),
        "Should fail for same-regime transition, but succeeded"
    );

    cleanup_test_data(pool.pool(), symbol).await;
}

#[tokio::test]
async fn test_multiple_regime_transitions() {
    let pool = create_test_pool().await;
    let symbol = "TEST.MULTIPLE.TRANSITIONS";
    cleanup_test_data(pool.pool(), symbol).await;

    let base_time = chrono::Utc::now();

    // Insert multiple transitions
    let transitions = vec![
        ("Normal", "Trending", 100, 0.40),
        ("Trending", "Volatile", 50, 0.25),
        ("Volatile", "Normal", 80, 0.35),
    ];

    for (idx, (from, to, duration, prob)) in transitions.iter().enumerate() {
        let result = pool
            .insert_regime_transition(
                symbol,
                from,
                to,
                base_time + chrono::Duration::seconds(i64::try_from(idx).unwrap() * 60),
                Some(*duration),
                Some(*prob),
                None,
                false,
            )
            .await;
        assert!(
            result.is_ok(),
            "Failed to insert transition {}->{}",
            from,
            to
        );
    }

    cleanup_test_data(pool.pool(), symbol).await;
}

// ============================================================================
// Adaptive Strategy Metrics Tests
// ============================================================================

#[tokio::test]
async fn test_upsert_adaptive_strategy_metrics() {
    let pool = create_test_pool().await;
    let symbol = "TEST.ADAPTIVE.METRICS";
    cleanup_test_data(pool.pool(), symbol).await;

    let event_timestamp = chrono::Utc::now();

    // Insert initial metrics
    let result = pool
        .upsert_adaptive_strategy_metrics(
            symbol,
            "Trending",
            event_timestamp,
            1.5,        // position_multiplier
            2.5,        // stop_loss_multiplier
            Some(1.8),  // regime_sharpe
            Some(0.75), // risk_budget_utilization
            10,         // total_trades
            7,          // winning_trades
            15000,      // total_pnl
        )
        .await;

    assert!(
        result.is_ok(),
        "Failed to insert adaptive strategy metrics: {:?}",
        result
    );

    // Upsert with additional trades (same timestamp and regime)
    let result = pool
        .upsert_adaptive_strategy_metrics(
            symbol,
            "Trending",
            event_timestamp,
            1.6,        // Updated multiplier
            2.6,        // Updated stop-loss
            Some(1.9),  // Updated Sharpe
            Some(0.80), // Updated utilization
            5,          // Additional trades
            3,          // Additional wins
            7500,       // Additional PnL
        )
        .await;

    assert!(result.is_ok(), "Failed to upsert metrics: {:?}", result);

    cleanup_test_data(pool.pool(), symbol).await;
}

#[tokio::test]
async fn test_adaptive_strategy_metrics_constraints() {
    let pool = create_test_pool().await;
    let symbol = "TEST.METRICS.CONSTRAINTS";
    cleanup_test_data(pool.pool(), symbol).await;

    let event_timestamp = chrono::Utc::now();

    // Test valid position multipliers (0.0-2.0)
    let valid_result = pool
        .upsert_adaptive_strategy_metrics(
            symbol,
            "Normal",
            event_timestamp,
            1.0, // Valid
            2.0, // Valid
            None,
            None,
            0,
            0,
            0,
        )
        .await;
    assert!(valid_result.is_ok(), "Valid multipliers should succeed");

    cleanup_test_data(pool.pool(), symbol).await;
}

#[tokio::test]
async fn test_get_regime_performance() {
    let pool = create_test_pool().await;
    let symbol = "TEST.PERFORMANCE";
    cleanup_test_data(pool.pool(), symbol).await;

    let event_timestamp = chrono::Utc::now();

    // Insert metrics for different regimes
    pool.upsert_adaptive_strategy_metrics(
        symbol,
        "Trending",
        event_timestamp,
        1.5,
        2.5,
        Some(2.1),
        Some(0.80),
        20,
        15,
        30000,
    )
    .await
    .expect("Failed to insert Trending metrics");

    pool.upsert_adaptive_strategy_metrics(
        symbol,
        "Ranging",
        event_timestamp + chrono::Duration::seconds(1),
        0.8,
        3.0,
        Some(1.2),
        Some(0.50),
        15,
        8,
        12000,
    )
    .await
    .expect("Failed to insert Ranging metrics");

    // Retrieve performance metrics
    let performance = pool
        .get_regime_performance(Some(symbol), 24)
        .await
        .expect("Failed to get regime performance");

    assert!(!performance.is_empty(), "Should have performance data");
    assert!(
        performance.len() >= 2,
        "Should have metrics for at least 2 regimes"
    );

    cleanup_test_data(pool.pool(), symbol).await;
}

// ============================================================================
// Integration Tests
// ============================================================================

#[tokio::test]
async fn test_end_to_end_regime_workflow() {
    let pool = create_test_pool().await;
    let symbol = "TEST.E2E.WORKFLOW";
    cleanup_test_data(pool.pool(), symbol).await;

    let base_time = chrono::Utc::now();

    // Step 1: Insert initial regime state
    pool.insert_regime_state(
        symbol,
        "Normal",
        0.95,
        base_time,
        Some(0.2),
        Some(-0.1),
        Some(22.0),
        Some(0.98),
    )
    .await
    .expect("Failed to insert initial regime");

    // Step 2: Insert adaptive strategy metrics for Normal regime
    pool.upsert_adaptive_strategy_metrics(
        symbol,
        "Normal",
        base_time,
        1.0,
        2.0,
        Some(1.5),
        Some(0.60),
        10,
        6,
        10000,
    )
    .await
    .expect("Failed to insert Normal metrics");

    // Step 3: Transition to Trending regime
    tokio::time::sleep(Duration::from_millis(100)).await;
    let transition_time = base_time + chrono::Duration::seconds(60);

    pool.insert_regime_transition(
        symbol,
        "Normal",
        "Trending",
        transition_time,
        Some(120),
        Some(0.42),
        Some(52.0),
        true,
    )
    .await
    .expect("Failed to insert transition");

    // Step 4: Insert new regime state (Trending)
    pool.insert_regime_state(
        symbol,
        "Trending",
        0.88,
        transition_time,
        Some(3.5),
        Some(-0.5),
        Some(52.0),
        Some(0.85),
    )
    .await
    .expect("Failed to insert Trending regime");

    // Step 5: Insert adaptive strategy metrics for Trending regime
    pool.upsert_adaptive_strategy_metrics(
        symbol,
        "Trending",
        transition_time,
        1.5,
        2.5,
        Some(2.2),
        Some(0.85),
        15,
        12,
        25000,
    )
    .await
    .expect("Failed to insert Trending metrics");

    // Step 6: Verify latest regime
    let latest = pool
        .get_latest_regime(symbol)
        .await
        .expect("Failed to get latest regime");
    assert_eq!(latest.regime, "Trending");

    // Step 7: Verify performance metrics
    let performance = pool
        .get_regime_performance(Some(symbol), 24)
        .await
        .expect("Failed to get performance");
    assert!(!performance.is_empty());

    cleanup_test_data(pool.pool(), symbol).await;
}

#[tokio::test]
async fn test_concurrent_regime_updates() {
    let pool = create_test_pool().await;
    let symbol = "TEST.CONCURRENT";
    cleanup_test_data(pool.pool(), symbol).await;

    let base_time = chrono::Utc::now();

    // Spawn multiple concurrent updates
    let mut handles = vec![];

    for i in 0..5 {
        let pool_clone = pool.pool().clone();
        let symbol_clone = symbol.to_string();
        let timestamp = base_time + chrono::Duration::seconds(i64::from(i));

        let handle = tokio::spawn(async move {
            let result = sqlx::query!(
                r#"
                INSERT INTO regime_states (
                    symbol, regime, confidence, event_timestamp,
                    cusum_s_plus, cusum_s_minus, adx, stability
                )
                VALUES ($1, $2, $3, $4, $5, $6, $7, $8)
                "#,
                symbol_clone,
                "Normal",
                0.90,
                timestamp,
                Some(0.5),
                Some(-0.3),
                Some(25.0),
                Some(0.95)
            )
            .execute(&pool_clone)
            .await;
            result.is_ok()
        });

        handles.push(handle);
    }

    // Wait for all updates
    for handle in handles {
        let success = handle.await.expect("Task panicked");
        assert!(success, "Concurrent update failed");
    }

    cleanup_test_data(pool.pool(), symbol).await;
}

// ============================================================================
// Database Function Tests
// ============================================================================

#[tokio::test]
async fn test_get_regime_transition_matrix_function() {
    let pool = create_test_pool().await;
    let symbol = "TEST.TRANSITION.MATRIX";
    cleanup_test_data(pool.pool(), symbol).await;

    let base_time = chrono::Utc::now();

    // Insert multiple transitions to build a matrix
    let transitions = vec![
        ("Normal", "Trending"),
        ("Trending", "Volatile"),
        ("Volatile", "Normal"),
        ("Normal", "Trending"), // Duplicate to test probability calculation
    ];

    for (idx, (from, to)) in transitions.iter().enumerate() {
        pool.insert_regime_transition(
            symbol,
            from,
            to,
            base_time + chrono::Duration::seconds(i64::try_from(idx).unwrap() * 60),
            Some(100),
            None,
            None,
            false,
        )
        .await
        .expect("Failed to insert transition");
    }

    // Query transition matrix using database function
    let matrix = sqlx::query!(
        r#"
        SELECT
            from_regime,
            to_regime,
            transition_count,
            transition_probability
        FROM get_regime_transition_matrix($1, 24)
        "#,
        symbol
    )
    .fetch_all(pool.pool())
    .await
    .expect("Failed to get transition matrix");

    assert!(!matrix.is_empty(), "Transition matrix should not be empty");

    // Verify Normal->Trending has probability ~0.67 (2 out of 3 transitions from Normal)
    let normal_trending = matrix.iter().find(|r| {
        r.from_regime.as_deref() == Some("Normal") && r.to_regime.as_deref() == Some("Trending")
    });
    assert!(normal_trending.is_some());

    cleanup_test_data(pool.pool(), symbol).await;
}