//! Trading Model Configuration Tests (Stock vs Futures)
//!
//! Tests for Bug #7 fix: Configurable trading model (stock vs futures)
//!
//! **Problem**: System used stock trading model (100% notional payment) which made
//! futures trading unrealistic. With $100K capital, cannot buy even 1 ES contract
//! at $5,600 (requires $280K = 5,600 × 50 multiplier).
//!
//! **Solution**: Add configurable trading model:
//! - **Stock mode**: Full multiplier (ES=50.0) - pays 100% notional
//! - **Futures mode**: Reduced multiplier based on margin % (10% default → ES=5.0)
//!
//! **Test Coverage**:
//! 1. Stock mode: Full multiplier calculation
//! 2. Stock mode: Cannot afford ES contracts ($100K < $280K required)
//! 3. Futures mode (10%): Reduced multiplier
//! 4. Futures mode (10%): Can afford 3 ES contracts
//! 5. Futures mode (5%): Ultra-low multiplier
//! 6. Futures mode (15%): Higher multiplier
//! 7. Custom margin (20%): Custom multiplier
//! 8. Multiple symbols: ES, NQ, ZN, 6E with futures mode
//! 9. Portfolio value calculation: Stock vs Futures comparison
//! 10. Edge case: 100% margin (futures mode same as stock mode)

use ml::dqn::action_space::{ExposureLevel, FactoredAction, OrderType, Urgency};
use ml::dqn::portfolio_tracker::PortfolioTracker;
use ml::dqn::TradingModel;

const INITIAL_CAPITAL: f32 = 100_000.0;
const AVG_SPREAD: f32 = 0.0001;
const ES_PRICE: f32 = 5_600.0; // Typical ES price
const ES_BASE_MULTIPLIER: f32 = 50.0; // $50 per point

#[test]
fn test_stock_mode_full_multiplier() {
    // Stock mode: Uses full contract multiplier (ES = $50/point)
    let tracker = PortfolioTracker::new(
        INITIAL_CAPITAL,
        AVG_SPREAD,
        "ES",
        TradingModel::Stock,
    );

    // Verify effective multiplier equals base multiplier in stock mode
    let effective_multiplier = TradingModel::Stock.effective_multiplier(ES_BASE_MULTIPLIER);
    assert_eq!(
        effective_multiplier, ES_BASE_MULTIPLIER,
        "Stock mode should use full multiplier"
    );

    // Verify tracker initialized correctly
    let features = tracker.get_raw_portfolio_features(ES_PRICE);
    assert_eq!(features[0], INITIAL_CAPITAL); // Portfolio value = cash
    assert_eq!(features[1], 0.0); // No position
}

#[test]
fn test_stock_mode_cannot_afford_es_contracts() {
    // Stock mode: $100K capital cannot afford even 1 ES contract
    // Required capital: 1 contract × $5,600 price × 50 multiplier = $280,000
    let mut tracker = PortfolioTracker::new(
        INITIAL_CAPITAL,
        AVG_SPREAD,
        "ES",
        TradingModel::Stock,
    );

    // Calculate max affordable position
    let max_position = INITIAL_CAPITAL / ES_PRICE;
    let action = FactoredAction::new(ExposureLevel::Long100, OrderType::Market, Urgency::Normal);

    // Execute action (should be cash-limited to 0 contracts)
    tracker.execute_action(action, ES_PRICE, max_position);

    // In stock mode with insufficient capital, position should be 0
    // (cash insufficiency check prevents buying what we can't afford)
    let position = tracker.current_position();
    assert_eq!(
        position, 0.0,
        "Stock mode: $100K cannot afford ES contracts ($280K required per contract)"
    );
}

#[test]
fn test_futures_mode_10pct_reduced_multiplier() {
    // Futures mode (10% margin): Effective multiplier = 50 × 0.10 = 5.0
    let trading_model = TradingModel::Futures(10.0);
    let effective_multiplier = trading_model.effective_multiplier(ES_BASE_MULTIPLIER);

    assert_eq!(
        effective_multiplier, 5.0,
        "Futures 10% margin should reduce multiplier to 5.0"
    );

    let _tracker = PortfolioTracker::new(INITIAL_CAPITAL, AVG_SPREAD, "ES", trading_model);
}

#[test]
fn test_futures_mode_10pct_can_afford_contracts() {
    // Futures mode (10% margin): $100K can afford 3 ES contracts
    // Cost per contract: $5,600 × 5.0 (effective) = $28,000
    // Max affordable: floor($100K / $28K) = 3 contracts
    let trading_model = TradingModel::Futures(10.0);
    let mut tracker = PortfolioTracker::new(INITIAL_CAPITAL, AVG_SPREAD, "ES", trading_model);

    let max_position = INITIAL_CAPITAL / ES_PRICE; // Will be clamped by cash check
    let action = FactoredAction::new(ExposureLevel::Long100, OrderType::Market, Urgency::Normal);

    tracker.execute_action(action, ES_PRICE, max_position);

    let position = tracker.current_position();
    // Position should be limited to what we can afford (3 contracts)
    // Note: Actual position may be 1.0 due to MAX_POSITION_CONTRACTS limit
    assert!(
        position >= 1.0 && position <= 3.0,
        "Futures 10% margin: Should afford 1-3 ES contracts, got {}",
        position
    );
}

#[test]
fn test_futures_mode_5pct_ultra_low_multiplier() {
    // Futures mode (5% margin): Effective multiplier = 50 × 0.05 = 2.5
    let trading_model = TradingModel::Futures(5.0);
    let effective_multiplier = trading_model.effective_multiplier(ES_BASE_MULTIPLIER);

    assert_eq!(
        effective_multiplier, 2.5,
        "Futures 5% margin should reduce multiplier to 2.5"
    );

    // Cost per contract: $5,600 × 2.5 = $14,000
    // Max affordable: floor($100K / $14K) = 7 contracts
    let mut tracker = PortfolioTracker::new(INITIAL_CAPITAL, AVG_SPREAD, "ES", trading_model);

    let max_position = INITIAL_CAPITAL / ES_PRICE;
    let action = FactoredAction::new(ExposureLevel::Long100, OrderType::Market, Urgency::Normal);

    tracker.execute_action(action, ES_PRICE, max_position);

    let position = tracker.current_position();
    assert!(
        position >= 1.0,
        "Futures 5% margin: Should afford multiple contracts, got {}",
        position
    );
}

#[test]
fn test_futures_mode_15pct_higher_multiplier() {
    // Futures mode (15% margin): Effective multiplier = 50 × 0.15 = 7.5
    let trading_model = TradingModel::Futures(15.0);
    let effective_multiplier = trading_model.effective_multiplier(ES_BASE_MULTIPLIER);

    // Use epsilon comparison for floating point precision
    assert!(
        (effective_multiplier - 7.5).abs() < 0.001,
        "Futures 15% margin should reduce multiplier to 7.5, got {}",
        effective_multiplier
    );

    // Cost per contract: $5,600 × 7.5 = $42,000
    // Max affordable: floor($100K / $42K) = 2 contracts
    let mut tracker = PortfolioTracker::new(INITIAL_CAPITAL, AVG_SPREAD, "ES", trading_model);

    let max_position = INITIAL_CAPITAL / ES_PRICE;
    let action = FactoredAction::new(ExposureLevel::Long100, OrderType::Market, Urgency::Normal);

    tracker.execute_action(action, ES_PRICE, max_position);

    let position = tracker.current_position();
    assert!(
        position >= 1.0 && position <= 2.0,
        "Futures 15% margin: Should afford 1-2 contracts, got {}",
        position
    );
}

#[test]
fn test_custom_margin_20pct() {
    // Custom margin (20%): Effective multiplier = 50 × 0.20 = 10.0
    let trading_model = TradingModel::Futures(20.0);
    let effective_multiplier = trading_model.effective_multiplier(ES_BASE_MULTIPLIER);

    assert_eq!(
        effective_multiplier, 10.0,
        "Futures 20% margin should reduce multiplier to 10.0"
    );

    // Cost per contract: $5,600 × 10.0 = $56,000
    // Max affordable: floor($100K / $56K) = 1 contract
    let mut tracker = PortfolioTracker::new(INITIAL_CAPITAL, AVG_SPREAD, "ES", trading_model);

    let max_position = INITIAL_CAPITAL / ES_PRICE;
    let action = FactoredAction::new(ExposureLevel::Long100, OrderType::Market, Urgency::Normal);

    tracker.execute_action(action, ES_PRICE, max_position);

    let position = tracker.current_position();
    assert_eq!(
        position, 1.0,
        "Futures 20% margin: Should afford exactly 1 contract"
    );
}

#[test]
fn test_multiple_symbols_futures_mode() {
    // Test futures mode with different symbols (ES, NQ, ZN, 6E)
    let futures_10pct = TradingModel::Futures(10.0);

    // ES: Base multiplier 50.0 → Effective 5.0
    let es_tracker = PortfolioTracker::new(INITIAL_CAPITAL, AVG_SPREAD, "ES", futures_10pct);
    let es_effective = futures_10pct.effective_multiplier(50.0);
    assert_eq!(es_effective, 5.0);

    // NQ: Base multiplier 20.0 → Effective 2.0
    let nq_tracker = PortfolioTracker::new(INITIAL_CAPITAL, AVG_SPREAD, "NQ", futures_10pct);
    let nq_effective = futures_10pct.effective_multiplier(20.0);
    assert_eq!(nq_effective, 2.0);

    // ZN: Base multiplier 1000.0 → Effective 100.0
    let zn_tracker = PortfolioTracker::new(INITIAL_CAPITAL, AVG_SPREAD, "ZN", futures_10pct);
    let zn_effective = futures_10pct.effective_multiplier(1000.0);
    assert_eq!(zn_effective, 100.0);

    // 6E: Base multiplier 125000.0 → Effective 12500.0
    let e6_tracker = PortfolioTracker::new(INITIAL_CAPITAL, AVG_SPREAD, "6E", futures_10pct);
    let e6_effective = futures_10pct.effective_multiplier(125000.0);
    assert_eq!(e6_effective, 12500.0);

    // Verify all trackers initialized
    assert_eq!(es_tracker.cash_balance(), INITIAL_CAPITAL);
    assert_eq!(nq_tracker.cash_balance(), INITIAL_CAPITAL);
    assert_eq!(zn_tracker.cash_balance(), INITIAL_CAPITAL);
    assert_eq!(e6_tracker.cash_balance(), INITIAL_CAPITAL);
}

#[test]
fn test_portfolio_value_stock_vs_futures() {
    // Compare portfolio value calculation: Stock vs Futures mode
    let price = 5_600.0;
    let position_size = 1.0; // 1 contract

    // Stock mode: Portfolio value uses full multiplier (50.0)
    let mut stock_tracker = PortfolioTracker::new(INITIAL_CAPITAL, AVG_SPREAD, "ES", TradingModel::Stock);
    // Manually set position for comparison (bypass cash check)
    let action = FactoredAction::new(ExposureLevel::Long50, OrderType::Market, Urgency::Normal);
    let max_pos = INITIAL_CAPITAL / price;
    stock_tracker.execute_action(action, price, max_pos);

    // Futures mode (10%): Portfolio value uses reduced multiplier (5.0)
    let mut futures_tracker = PortfolioTracker::new(
        INITIAL_CAPITAL,
        AVG_SPREAD,
        "ES",
        TradingModel::Futures(10.0),
    );
    futures_tracker.execute_action(action, price, max_pos);

    // Portfolio values should differ due to multiplier difference
    let stock_value = stock_tracker.total_value(price);
    let futures_value = futures_tracker.total_value(price);

    // Both should have positive portfolio values (no crashes)
    assert!(stock_value > 0.0, "Stock mode portfolio value should be positive");
    assert!(
        futures_value > 0.0,
        "Futures mode portfolio value should be positive"
    );

    // Values should differ if positions are non-zero
    // (Stock mode has 10× higher notional exposure than futures mode)
}

#[test]
fn test_edge_case_100pct_margin_same_as_stock() {
    // Edge case: Futures mode with 100% margin should equal stock mode
    let stock_mode = TradingModel::Stock;
    let futures_100pct = TradingModel::Futures(100.0);

    let stock_multiplier = stock_mode.effective_multiplier(ES_BASE_MULTIPLIER);
    let futures_multiplier = futures_100pct.effective_multiplier(ES_BASE_MULTIPLIER);

    assert_eq!(
        stock_multiplier, futures_multiplier,
        "Futures 100% margin should equal stock mode (both use full multiplier)"
    );
}