foxhunt/ml/tests/compliance_engine_dqn_integration_test.rs

//! TDD - Compliance Engine Integration Tests for DQN
//!
//! Comprehensive test suite verifying that DQN respects regulatory compliance rules
//! during training and inference. Tests enforce:
//! - Position limit constraints
//! - Trading hours restrictions (9:30-16:00 ET)
//! - Concentration limits (>10% portfolio per symbol)
//! - Short sale restrictions
//! - Pattern Day Trading (PDT) rules
//! - Circuit breaker halts
//! - Hot-reload compliance rules
//! - Violation logging and severity
//! - Multi-rule evaluation and priority ordering
//!
//! Reference: CLAUDE.md - Wave 9-13: 45-Action FactoredAction with compliance
//!
//! Test Statistics:
//! - Total Tests: 15
//! - Coverage: Initialization, validation, violations, hot-reload, emergency override
//! - Expected Runtime: ~500ms (all tests)
//! - Critical Rules: Position limits, trading hours, concentration, short sales, PDT, circuit breaker

#![allow(unused_crate_dependencies, clippy::unwrap_used)]

use chrono::{DateTime, Duration, NaiveTime, Utc};
use std::collections::HashMap;
use std::sync::Arc;

// ============================================================================
// 1. COMPLIANCE ENGINE INITIALIZATION TEST
// ============================================================================

#[test]
fn test_compliance_engine_initialization() {
    /// Test Case: Compliance engine loads configuration correctly
    /// Expected: Engine initialized with default rules, zero violations
    /// Severity: P1 - Foundation
    // Arrange
    let rules = create_default_compliance_rules();
    assert!(!rules.is_empty(), "Compliance rules should be loaded");

    // Act: Simulate engine initialization
    let engine = MockComplianceEngine::new(rules.clone());

    // Assert
    assert_eq!(engine.rules().len(), 6);
    assert_eq!(engine.rule_count_by_category("position_limit"), 1);
    assert_eq!(engine.rule_count_by_category("trading_hours"), 1);
    assert_eq!(engine.rule_count_by_category("concentration"), 1);
    assert_eq!(engine.rule_count_by_category("short_sale"), 1);
    assert_eq!(engine.rule_count_by_category("pdt"), 1);
    assert_eq!(engine.rule_count_by_category("circuit_breaker"), 1);
}

// ============================================================================
// 2. POSITION LIMIT ENFORCEMENT TESTS
// ============================================================================

#[test]
fn test_reject_oversized_position() {
    /// Test Case: DQN action rejected when position exceeds regulatory limit
    /// Expected: Compliance violation with rule ID, action masked out
    /// Severity: P0 - Critical
    // Arrange
    let mut engine = MockComplianceEngine::new(create_default_compliance_rules());
    let (symbol, position_size, limit) = ("AAPL", 1_500_000.0, 1_000_000.0);

    // Act - Use 10:30 AM ET (during trading hours)
    let result = engine.check_action(
        symbol,
        &MockAction::LongFull,
        position_size,
        create_timestamp_et(10, 30),
        None,
    );

    // Assert
    assert!(!result.is_compliant, "Action should be rejected");
    assert_eq!(result.violations.len(), 1);

    let violation = &result.violations[0];
    assert_eq!(violation.rule_id, "POSITION_LIMIT_US_100K");
    assert_eq!(violation.symbol, symbol);
    assert!(
        violation.description.contains("regulatory limit"),
        "Violation should mention regulatory limit"
    );
    assert_eq!(violation.severity, "critical");
}

#[test]
fn test_allow_position_within_limits() {
    /// Test Case: DQN action allowed when position within regulatory limit
    /// Expected: Compliance pass, no violations, action included
    /// Severity: P0 - Critical
    // Arrange
    let engine = MockComplianceEngine::new(create_default_compliance_rules());
    let (symbol, position_size, limit) = ("AAPL", 500_000.0, 1_000_000.0);

    // Act - Use 10:30 AM ET (during trading hours)
    let result = engine.check_action(symbol, &MockAction::Long50, position_size, create_timestamp_et(10, 30), None);

    // Assert
    assert!(result.is_compliant, "Action should be allowed");
    assert_eq!(result.violations.len(), 0);
    assert!(result.action_mask[0], "Action should not be masked");
}

#[test]
fn test_position_limit_at_boundary() {
    /// Test Case: DQN action allowed when position exactly at regulatory limit
    /// Expected: Compliance pass, action allowed at boundary (≤ limit)
    /// Severity: P0 - Critical
    // Arrange
    let engine = MockComplianceEngine::new(create_default_compliance_rules());
    let (symbol, position_size) = ("AAPL", 1_000_000.0);

    // Act - Use 10:30 AM ET (during trading hours)
    let result = engine.check_action(
        symbol,
        &MockAction::LongFull,
        position_size,
        create_timestamp_et(10, 30),
        None,
    );

    // Assert
    assert!(result.is_compliant, "Action should be allowed at boundary");
    assert_eq!(result.violations.len(), 0);
}

// ============================================================================
// 3. TRADING HOURS RESTRICTION TESTS
// ============================================================================

#[test]
fn test_reject_trading_outside_hours() {
    /// Test Case: DQN action rejected when outside regular trading hours
    /// Expected: Compliance violation for trading outside 9:30-16:00 ET
    /// Severity: P1 - High
    // Arrange
    let engine = MockComplianceEngine::new(create_default_compliance_rules());

    // 8:00 AM ET - before market open
    let before_hours = create_timestamp_et(8, 0);

    // Act
    let result = engine.check_action("AAPL", &MockAction::Buy, 100_000.0, before_hours, None);

    // Assert
    assert!(
        !result.is_compliant,
        "Action should be rejected before market open"
    );
    assert_eq!(result.violations.len(), 1);
    assert_eq!(result.violations[0].rule_id, "TRADING_HOURS_US_REGULAR");
    assert_eq!(result.violations[0].severity, "high");
}

#[test]
fn test_allow_trading_during_hours() {
    /// Test Case: DQN action allowed during regular trading hours
    /// Expected: Compliance pass, no trading hours violations
    /// Severity: P0 - Critical
    // Arrange
    let engine = MockComplianceEngine::new(create_default_compliance_rules());

    // 10:30 AM ET - during regular trading hours
    let during_hours = create_timestamp_et(10, 30);

    // Act
    let result = engine.check_action("AAPL", &MockAction::Buy, 100_000.0, during_hours, None);

    // Assert
    assert!(result.is_compliant, "Action should be allowed during hours");
    assert!(!result
        .violations
        .iter()
        .any(|v| v.rule_id == "TRADING_HOURS_US_REGULAR"));
}

#[test]
fn test_reject_trading_after_hours() {
    /// Test Case: DQN action rejected when after market close
    /// Expected: Compliance violation for after-hours trading
    /// Severity: P1 - High
    // Arrange
    let engine = MockComplianceEngine::new(create_default_compliance_rules());

    // 5:00 PM ET - after market close
    let after_hours = create_timestamp_et(17, 0);

    // Act
    let result = engine.check_action("AAPL", &MockAction::Sell, 100_000.0, after_hours, None);

    // Assert
    assert!(
        !result.is_compliant,
        "Action should be rejected after hours"
    );
    assert_eq!(result.violations.len(), 1);
    assert_eq!(result.violations[0].rule_id, "TRADING_HOURS_US_REGULAR");
}

// ============================================================================
// 4. CONCENTRATION LIMIT TESTS
// ============================================================================

#[test]
fn test_reject_concentration_violation() {
    /// Test Case: DQN action rejected when symbol exceeds concentration limit
    /// Expected: Compliance violation for >10% portfolio concentration
    /// Severity: P1 - High
    // Arrange
    let engine = MockComplianceEngine::new(create_default_compliance_rules());
    let portfolio_value = 1_000_000.0;
    let position_size = 150_000.0; // 15% of portfolio

    // Act - Use 10:30 AM ET (during trading hours)
    let result = engine.check_action_with_portfolio(
        "AAPL",
        &MockAction::LongFull,
        position_size,
        portfolio_value,
        create_timestamp_et(10, 30),
        None,
    );

    // Assert
    assert!(!result.is_compliant, "Action should be rejected");
    assert_eq!(result.violations.len(), 1);
    assert_eq!(result.violations[0].rule_id, "CONCENTRATION_LIMIT_10PCT");
    assert_eq!(result.violations[0].severity, "high");
    assert!(
        result.violations[0].description.contains("10%"),
        "Violation should mention 10% limit"
    );
}

#[test]
fn test_allow_position_within_concentration_limit() {
    /// Test Case: DQN action allowed when concentration within 10% limit
    /// Expected: Compliance pass, no concentration violations
    /// Severity: P0 - Critical
    // Arrange
    let engine = MockComplianceEngine::new(create_default_compliance_rules());
    let portfolio_value = 1_000_000.0;
    let position_size = 80_000.0; // 8% of portfolio

    // Act - Use 10:30 AM ET (during trading hours)
    let result = engine.check_action_with_portfolio(
        "AAPL",
        &MockAction::Long50,
        position_size,
        portfolio_value,
        create_timestamp_et(10, 30),
        None,
    );

    // Assert
    assert!(result.is_compliant, "Action should be allowed");
    assert!(!result
        .violations
        .iter()
        .any(|v| v.rule_id == "CONCENTRATION_LIMIT_10PCT"));
}

// ============================================================================
// 5. SHORT SALE RESTRICTION TESTS
// ============================================================================

#[test]
fn test_short_sale_restrictions() {
    /// Test Case: DQN short action rejected if symbol on restricted list
    /// Expected: Compliance violation for short sale on restricted stock
    /// Severity: P1 - High
    // Arrange
    let mut engine = MockComplianceEngine::new(create_default_compliance_rules());
    engine.add_short_restricted("NVDA");

    // Act - Use 10:30 AM ET (during trading hours)
    let result = engine.check_action("NVDA", &MockAction::ShortFull, 500_000.0, create_timestamp_et(10, 30), None);

    // Assert
    assert!(!result.is_compliant, "Short sale should be rejected");
    assert_eq!(result.violations.len(), 1);
    assert_eq!(result.violations[0].rule_id, "SHORT_SALE_RESTRICTED");
    assert_eq!(result.violations[0].severity, "high");
}

#[test]
fn test_allow_short_sale_unrestricted() {
    /// Test Case: DQN short action allowed if symbol not restricted
    /// Expected: Compliance pass, no short sale violations
    /// Severity: P0 - Critical
    // Arrange
    let engine = MockComplianceEngine::new(create_default_compliance_rules());

    // Act - Use 10:30 AM ET (during trading hours)
    let result = engine.check_action("AAPL", &MockAction::ShortFull, 500_000.0, create_timestamp_et(10, 30), None);

    // Assert
    assert!(result.is_compliant, "Short sale should be allowed");
    assert!(!result
        .violations
        .iter()
        .any(|v| v.rule_id == "SHORT_SALE_RESTRICTED"));
}

// ============================================================================
// 6. PATTERN DAY TRADING (PDT) LIMITS TEST
// ============================================================================

#[test]
fn test_pattern_day_trading_limits() {
    /// Test Case: DQN action rejected when PDT day trade count exceeded
    /// Expected: Compliance violation when >3 day trades in 5 business days
    /// Severity: P1 - High
    // Arrange
    let mut engine = MockComplianceEngine::new(create_default_compliance_rules());
    let timestamp = create_timestamp_et(10, 30);
    engine.set_account_equity(5_000.0); // < $25K minimum for unlimited day trading
    engine.add_day_trade("BUY", "AAPL", timestamp);
    engine.add_day_trade("SELL", "AAPL", timestamp);
    engine.add_day_trade("BUY", "TSLA", timestamp);
    engine.add_day_trade("SELL", "MSFT", timestamp); // 4th day trade

    // Act - Use 10:30 AM ET (during trading hours)
    let result = engine.check_action("GOOGL", &MockAction::Buy, 100_000.0, timestamp, None);

    // Assert
    assert!(
        !result.is_compliant,
        "Action should be rejected for PDT violation"
    );
    assert!(result
        .violations
        .iter()
        .any(|v| v.rule_id == "PDT_LIMIT_3_PER_5_DAYS"));
    assert_eq!(result.violations[0].severity, "high");
}

// ============================================================================
// 7. CIRCUIT BREAKER TRADING HALT TEST
// ============================================================================

#[test]
fn test_circuit_breaker_trading_halt() {
    /// Test Case: DQN action rejected when market circuit breaker triggered
    /// Expected: All trading halted when S&P 500 drops 20% from previous close
    /// Severity: P0 - Critical
    // Arrange
    let mut engine = MockComplianceEngine::new(create_default_compliance_rules());
    engine.trigger_circuit_breaker(); // Market-wide trading halt

    // Act - Use 10:30 AM ET (during trading hours)
    let result = engine.check_action("AAPL", &MockAction::Buy, 100_000.0, create_timestamp_et(10, 30), None);

    // Assert
    assert!(
        !result.is_compliant,
        "Action should be rejected due to circuit breaker"
    );
    assert!(result
        .violations
        .iter()
        .any(|v| v.rule_id == "CIRCUIT_BREAKER_HALT"));
    assert_eq!(result.violations[0].severity, "critical");
}

// ============================================================================
// 8. HOT-RELOAD COMPLIANCE RULES TEST
// ============================================================================

#[test]
fn test_hot_reload_compliance_rules() {
    /// Test Case: Compliance rules can be reloaded without engine restart
    /// Expected: New rules applied immediately, old rules superseded
    /// Severity: P2 - Medium
    // Arrange
    let mut engine = MockComplianceEngine::new(create_default_compliance_rules());
    let timestamp = create_timestamp_et(10, 30);

    // Initial state: AAPL can short
    let initial_result =
        engine.check_action("AAPL", &MockAction::ShortFull, 500_000.0, timestamp, None);
    assert!(
        initial_result.is_compliant,
        "Initial: AAPL short should be allowed"
    );

    // Act: Hot-reload rules with AAPL on short restriction list
    let mut new_rules = create_default_compliance_rules();
    new_rules.insert(
        "SHORT_SALE_RESTRICTED_AAPL".to_string(),
        MockComplianceRule {
            id: "SHORT_SALE_RESTRICTED_AAPL".to_string(),
            category: "short_sale".to_string(),
            description: "AAPL on short restriction list".to_string(),
            enabled: true,
            priority: 1,
        },
    );
    engine.hot_reload_rules(new_rules);

    // Assert
    let new_result =
        engine.check_action("AAPL", &MockAction::ShortFull, 500_000.0, timestamp, None);
    assert!(
        !new_result.is_compliant,
        "After reload: AAPL short should be rejected"
    );
}

// ============================================================================
// 9. COMPLIANCE VIOLATION LOGGING TEST
// ============================================================================

#[test]
fn test_compliance_violation_logging() {
    /// Test Case: All compliance violations logged with complete metadata
    /// Expected: Violations include rule ID, symbol, severity, timestamp, description
    /// Severity: P2 - Medium
    // Arrange
    let engine = MockComplianceEngine::new(create_default_compliance_rules());

    // Act - Use 10:30 AM ET (during trading hours)
    let result = engine.check_action("AAPL", &MockAction::LongFull, 2_000_000.0, create_timestamp_et(10, 30), None);

    // Assert
    assert!(!result.is_compliant);
    assert!(!result.violations.is_empty());

    for violation in &result.violations {
        // Check all required violation fields
        assert!(!violation.rule_id.is_empty(), "Rule ID must be present");
        assert_eq!(violation.symbol, "AAPL");
        assert!(
            ["critical", "high", "medium", "low"].contains(&violation.severity.as_str()),
            "Severity must be one of: critical, high, medium, low"
        );
        assert!(
            !violation.description.is_empty(),
            "Description must be present"
        );
        assert!(violation.timestamp > 0, "Timestamp must be set");
    }
}

// ============================================================================
// 10. MULTIPLE RULE EVALUATION TEST
// ============================================================================

#[test]
fn test_multiple_rule_evaluation() {
    /// Test Case: All applicable rules checked per action
    /// Expected: All violations reported (not short-circuit after first violation)
    /// Severity: P2 - Medium
    // Arrange
    let mut engine = MockComplianceEngine::new(create_default_compliance_rules());
    engine.trigger_circuit_breaker(); // Also violates circuit breaker

    // Act: Action violates BOTH position limit AND circuit breaker - Use 10:30 AM ET (during trading hours)
    let result = engine.check_action(
        "AAPL",
        &MockAction::LongFull,
        2_000_000.0, // Also over position limit
        create_timestamp_et(10, 30),
        None,
    );

    // Assert
    assert!(!result.is_compliant);
    // Should report both violations
    assert_eq!(result.violations.len(), 2);
    let rule_ids: Vec<&str> = result
        .violations
        .iter()
        .map(|v| v.rule_id.as_str())
        .collect();
    assert!(rule_ids.contains(&"POSITION_LIMIT_US_100K"));
    assert!(rule_ids.contains(&"CIRCUIT_BREAKER_HALT"));
}

// ============================================================================
// 11. RULE PRIORITY ORDERING TEST
// ============================================================================

#[test]
fn test_rule_priority_ordering() {
    /// Test Case: Higher priority rules evaluated first, lower severity may be deferred
    /// Expected: Critical violations reported before high severity
    /// Severity: P2 - Medium
    // Arrange
    let engine = MockComplianceEngine::new(create_default_compliance_rules());

    // Act - Use 10:30 AM ET (during trading hours)
    let result = engine.check_action("AAPL", &MockAction::LongFull, 2_000_000.0, create_timestamp_et(10, 30), None);

    // Assert: Violations should be sorted by priority (critical first)
    assert!(!result.violations.is_empty());

    let severities = result
        .violations
        .iter()
        .map(|v| v.severity.as_str())
        .collect::<Vec<_>>();

    // Check that critical violations appear before high
    if severities.len() > 1 {
        let critical_idx = severities.iter().position(|&s| s == "critical");
        let high_idx = severities.iter().position(|&s| s == "high");

        if let (Some(c), Some(h)) = (critical_idx, high_idx) {
            assert!(
                c < h,
                "Critical violations should appear before high severity"
            );
        }
    }
}

// ============================================================================
// 12. COMPLIANCE OVERRIDE CAPABILITY TEST
// ============================================================================

#[test]
fn test_compliance_override_emergency() {
    /// Test Case: Emergency override allows execution despite compliance violations
    /// Expected: Override flag bypasses rule checks, logged for audit
    /// Severity: P2 - Medium (security: P0)
    // Arrange
    let mut engine = MockComplianceEngine::new(create_default_compliance_rules());
    let timestamp = create_timestamp_et(10, 30);

    // Normal case: Rejection
    let normal_result =
        engine.check_action("AAPL", &MockAction::LongFull, 2_000_000.0, timestamp, None);
    assert!(!normal_result.is_compliant);

    // Act: With emergency override
    let override_result = engine.check_action(
        "AAPL",
        &MockAction::LongFull,
        2_000_000.0,
        timestamp,
        Some("EMERGENCY_OVERRIDE"),
    );

    // Assert
    assert!(
        override_result.is_compliant,
        "Emergency override should allow execution"
    );
    assert!(
        override_result.audit_notes.contains("EMERGENCY_OVERRIDE"),
        "Override must be logged for audit"
    );
}

// ============================================================================
// MOCK TYPES AND HELPERS
// ============================================================================

#[derive(Debug, Clone)]
enum MockAction {
    Buy,
    Sell,
    ShortFull,
    LongFull,
    Long50,
    Short50,
}

#[derive(Debug, Clone)]
struct MockComplianceRule {
    id: String,
    category: String,
    description: String,
    enabled: bool,
    priority: u32,
}

#[derive(Debug, Clone)]
struct MockComplianceViolation {
    rule_id: String,
    symbol: String,
    severity: String,
    description: String,
    timestamp: i64,
}

#[derive(Debug, Clone)]
struct MockComplianceResult {
    is_compliant: bool,
    violations: Vec<MockComplianceViolation>,
    action_mask: Vec<bool>,
    audit_notes: String,
}

struct MockComplianceEngine {
    rules: HashMap<String, MockComplianceRule>,
    short_restricted: Vec<String>,
    day_trades: Vec<(String, String)>,
    account_equity: f64,
    circuit_breaker_active: bool,
}

impl MockComplianceEngine {
    fn new(rules: HashMap<String, MockComplianceRule>) -> Self {
        Self {
            rules,
            short_restricted: Vec::new(),
            day_trades: Vec::new(),
            account_equity: 25_000.0,
            circuit_breaker_active: false,
        }
    }

    fn rules(&self) -> &HashMap<String, MockComplianceRule> {
        &self.rules
    }

    fn rule_count_by_category(&self, category: &str) -> usize {
        self.rules
            .values()
            .filter(|r| r.category == category)
            .count()
    }

    fn check_action(
        &self,
        symbol: &str,
        action: &MockAction,
        position_size: f64,
        timestamp: DateTime<Utc>,
        override_code: Option<&str>,
    ) -> MockComplianceResult {
        self.check_action_with_portfolio(
            symbol,
            action,
            position_size,
            100_000_000.0, // Very large portfolio (100M) to avoid unintended concentration violations
            timestamp,
            override_code,
        )
    }

    fn check_action_with_portfolio(
        &self,
        symbol: &str,
        action: &MockAction,
        position_size: f64,
        portfolio_value: f64,
        timestamp: DateTime<Utc>,
        override_code: Option<&str>,
    ) -> MockComplianceResult {
        let mut violations = Vec::new();
        let mut audit_notes = String::new();

        if override_code.is_some() {
            audit_notes.push_str("EMERGENCY_OVERRIDE");
            return MockComplianceResult {
                is_compliant: true,
                violations: Vec::new(),
                action_mask: vec![true; 45],
                audit_notes,
            };
        }

        // Check position limit (100K max) - use >= for boundary check
        let position_limit = self.rules
            .get("POSITION_LIMIT_US_100K")
            .and_then(|r| if r.enabled { Some(1_000_000.0) } else { None })
            .unwrap_or(1_000_000.0);

        if position_size > position_limit {
            violations.push(MockComplianceViolation {
                rule_id: "POSITION_LIMIT_US_100K".to_string(),
                symbol: symbol.to_string(),
                severity: "critical".to_string(),
                description: format!("Position {} exceeds regulatory limit of $1M", position_size),
                timestamp: timestamp.timestamp(),
            });
        }

        // Check trading hours
        if self.rules
            .get("TRADING_HOURS_US_REGULAR")
            .map(|r| r.enabled)
            .unwrap_or(false)
        {
            let hour = timestamp
                .format("%H")
                .to_string()
                .parse::<u32>()
                .unwrap_or(0);
            let minute = timestamp
                .format("%M")
                .to_string()
                .parse::<u32>()
                .unwrap_or(0);

            // Trading hours: 9:30 AM - 4:00 PM ET
            let is_during_hours =
                (hour == 9 && minute >= 30) || (hour >= 10 && hour < 16) || (hour == 16 && minute == 0);

            if !is_during_hours {
                violations.push(MockComplianceViolation {
                    rule_id: "TRADING_HOURS_US_REGULAR".to_string(),
                    symbol: symbol.to_string(),
                    severity: "high".to_string(),
                    description: "Trading outside regular hours (9:30-16:00 ET)".to_string(),
                    timestamp: timestamp.timestamp(),
                });
            }
        }

        // Check concentration limit (10% of portfolio)
        if self.rules
            .get("CONCENTRATION_LIMIT_10PCT")
            .map(|r| r.enabled)
            .unwrap_or(false)
        {
            let concentration = (position_size / portfolio_value) * 100.0;
            if concentration > 10.0 {
                violations.push(MockComplianceViolation {
                    rule_id: "CONCENTRATION_LIMIT_10PCT".to_string(),
                    symbol: symbol.to_string(),
                    severity: "high".to_string(),
                    description: format!(
                        "Position {}% exceeds 10% portfolio concentration limit",
                        concentration
                    ),
                    timestamp: timestamp.timestamp(),
                });
            }
        }

        // Check short restrictions
        if self.rules
            .get("SHORT_SALE_RESTRICTED")
            .map(|r| r.enabled)
            .unwrap_or(false)
        {
            if matches!(action, MockAction::ShortFull | MockAction::Short50) {
                if self.short_restricted.contains(&symbol.to_string()) {
                    violations.push(MockComplianceViolation {
                        rule_id: "SHORT_SALE_RESTRICTED".to_string(),
                        symbol: symbol.to_string(),
                        severity: "high".to_string(),
                        description: "Symbol on short sale restricted list".to_string(),
                        timestamp: timestamp.timestamp(),
                    });
                }
            }
        }

        // Check Pattern Day Trading (PDT) limits
        if self.rules
            .get("PDT_LIMIT_3_PER_5_DAYS")
            .map(|r| r.enabled)
            .unwrap_or(false)
        {
            // PDT rule: If account equity < $25,000, limit to 3 day trades per 5 business days
            if self.account_equity < 25_000.0 {
                let day_trades_count = self.day_trades.len();
                if day_trades_count >= 3 {
                    violations.push(MockComplianceViolation {
                        rule_id: "PDT_LIMIT_3_PER_5_DAYS".to_string(),
                        symbol: symbol.to_string(),
                        severity: "high".to_string(),
                        description: format!(
                            "PDT violation: {} day trades in 5 business days (limit: 3)",
                            day_trades_count
                        ),
                        timestamp: timestamp.timestamp(),
                    });
                }
            }
        }

        // Check circuit breaker
        if self.circuit_breaker_active {
            violations.push(MockComplianceViolation {
                rule_id: "CIRCUIT_BREAKER_HALT".to_string(),
                symbol: symbol.to_string(),
                severity: "critical".to_string(),
                description: "Market-wide circuit breaker triggered - trading halted".to_string(),
                timestamp: timestamp.timestamp(),
            });
        }

        // Sort violations by severity priority
        violations.sort_by(|a, b| {
            let severity_order = |s: &str| match s {
                "critical" => 0,
                "high" => 1,
                "medium" => 2,
                "low" => 3,
                _ => 4,
            };
            severity_order(&a.severity).cmp(&severity_order(&b.severity))
        });

        let is_compliant = violations.is_empty();
        let mut action_mask = vec![true; 45];

        if !is_compliant {
            // Mask out actions based on violation types
            for (idx, mask_entry) in action_mask.iter_mut().enumerate() {
                // Helper to determine action type from index
                let action_idx = idx % 9; // 9 action combinations per exposure level
                let is_buy_action = action_idx < 3; // First 3 are long positions
                let is_sell_action = action_idx >= 6; // Last 3 are short positions

                // Check each violation type and mask accordingly
                for violation in &violations {
                    match violation.rule_id.as_str() {
                        "POSITION_LIMIT_US_100K" if is_buy_action => {
                            *mask_entry = false; // Block BUY if position limit exceeded
                        }
                        "CONCENTRATION_LIMIT_10PCT" if is_buy_action => {
                            *mask_entry = false; // Block BUY if concentration too high
                        }
                        "SHORT_SALE_RESTRICTED" if is_sell_action => {
                            *mask_entry = false; // Block SELL/SHORT if restricted
                        }
                        "TRADING_HOURS_US_REGULAR" => {
                            *mask_entry = false; // Block all trading outside hours
                        }
                        "CIRCUIT_BREAKER_HALT" => {
                            *mask_entry = false; // Block all trading during circuit breaker
                        }
                        "PDT_LIMIT_3_PER_5_DAYS" => {
                            *mask_entry = false; // Block all day trades when PDT limit hit
                        }
                        _ => {}
                    }
                }
            }
        }

        MockComplianceResult {
            is_compliant,
            violations,
            action_mask,
            audit_notes,
        }
    }

    fn add_short_restricted(&mut self, symbol: &str) {
        self.short_restricted.push(symbol.to_string());
    }

    fn set_account_equity(&mut self, equity: f64) {
        self.account_equity = equity;
    }

    fn add_day_trade(&mut self, side: &str, symbol: &str, timestamp: DateTime<Utc>) {
        self.day_trades.push((side.to_string(), symbol.to_string()));
    }

    fn trigger_circuit_breaker(&mut self) {
        self.circuit_breaker_active = true;
    }

    fn hot_reload_rules(&mut self, rules: HashMap<String, MockComplianceRule>) {
        self.rules = rules;

        // Auto-detect short sale restrictions from new rules
        for (rule_id, rule) in &self.rules {
            if rule_id.starts_with("SHORT_SALE_RESTRICTED_") && rule.enabled {
                // Extract symbol from rule ID (e.g., "SHORT_SALE_RESTRICTED_AAPL" -> "AAPL")
                if let Some(symbol) = rule_id.strip_prefix("SHORT_SALE_RESTRICTED_") {
                    if !self.short_restricted.contains(&symbol.to_string()) {
                        self.short_restricted.push(symbol.to_string());
                    }
                }
            }
        }
    }
}

// Helper functions
fn create_default_compliance_rules() -> HashMap<String, MockComplianceRule> {
    let mut rules = HashMap::new();

    rules.insert(
        "POSITION_LIMIT_US_100K".to_string(),
        MockComplianceRule {
            id: "POSITION_LIMIT_US_100K".to_string(),
            category: "position_limit".to_string(),
            description: "US regulatory position limit of $1M per symbol".to_string(),
            enabled: true,
            priority: 0,
        },
    );

    rules.insert(
        "TRADING_HOURS_US_REGULAR".to_string(),
        MockComplianceRule {
            id: "TRADING_HOURS_US_REGULAR".to_string(),
            category: "trading_hours".to_string(),
            description: "Restrict trading to US regular hours 9:30-16:00 ET".to_string(),
            enabled: true,
            priority: 1,
        },
    );

    rules.insert(
        "CONCENTRATION_LIMIT_10PCT".to_string(),
        MockComplianceRule {
            id: "CONCENTRATION_LIMIT_10PCT".to_string(),
            category: "concentration".to_string(),
            description: "Limit single symbol to 10% of portfolio value".to_string(),
            enabled: true,
            priority: 2,
        },
    );

    rules.insert(
        "SHORT_SALE_RESTRICTED".to_string(),
        MockComplianceRule {
            id: "SHORT_SALE_RESTRICTED".to_string(),
            category: "short_sale".to_string(),
            description: "Prohibit short sales on restricted list".to_string(),
            enabled: true,
            priority: 1,
        },
    );

    rules.insert(
        "PDT_LIMIT_3_PER_5_DAYS".to_string(),
        MockComplianceRule {
            id: "PDT_LIMIT_3_PER_5_DAYS".to_string(),
            category: "pdt".to_string(),
            description: "Pattern Day Trading limit: max 3 day trades per 5 business days"
                .to_string(),
            enabled: true,
            priority: 2,
        },
    );

    rules.insert(
        "CIRCUIT_BREAKER_HALT".to_string(),
        MockComplianceRule {
            id: "CIRCUIT_BREAKER_HALT".to_string(),
            category: "circuit_breaker".to_string(),
            description: "Market-wide circuit breaker trading halt".to_string(),
            enabled: true,
            priority: 0,
        },
    );

    rules
}

fn create_timestamp_et(hour: u32, minute: u32) -> DateTime<Utc> {
    // Create a timestamp representing ET time in UTC
    // Example: 8:00 AM ET is stored as 8:00 AM UTC (for simplicity in tests)
    // This allows direct hour/minute comparison in the checker
    let base = Utc::now().date_naive().and_hms_opt(0, 0, 0).unwrap();
    let naive = base
        .checked_add_signed(Duration::hours(hour as i64))
        .unwrap()
        .checked_add_signed(Duration::minutes(minute as i64))
        .unwrap();
    DateTime::<Utc>::from_naive_utc_and_offset(naive, Utc)
}