foxhunt/ml/tests/dqn_huber_loss_parameter_flow_test.rs

//! Test suite for DQN Huber loss parameter flow
//!
//! Validates that use_huber_loss and huber_delta CLI arguments properly flow through:
//! 1. DQNHyperparameters struct has the fields
//! 2. CLI args → DQNHyperparameters
//! 3. DQNHyperparameters → WorkingDQNConfig
//! 4. Both enabled and disabled states work correctly

use ml::trainers::dqn::DQNHyperparameters;

#[test]
fn test_dqn_hyperparameters_has_huber_loss_fields() {
    // Test that DQNHyperparameters struct has use_huber_loss and huber_delta fields
    let hyperparams = DQNHyperparameters {
        learning_rate: 0.001,
        batch_size: 32,
        gamma: 0.99,
        epsilon_start: 1.0,
        epsilon_end: 0.01,
        epsilon_decay: 0.995,
        buffer_size: 10000,
        min_replay_size: 500,
        epochs: 100,
        checkpoint_frequency: 10,
        early_stopping_enabled: true,
        q_value_floor: 0.5,
        min_loss_improvement_pct: 2.0,
        plateau_window: 30,
        min_epochs_before_stopping: 50,
        use_huber_loss: true, // NEW FIELD - should compile
        huber_delta: 1.0,     // NEW FIELD - should compile
        use_double_dqn: true,
        gradient_clip_norm: Some(1.0),
        hold_penalty_weight: 0.01,
        movement_threshold: 0.02,
    };

    // Verify fields are accessible
    assert_eq!(hyperparams.use_huber_loss, true);
    assert_eq!(hyperparams.huber_delta, 1.0);
}

#[test]
fn test_huber_loss_enabled_configuration() {
    // Test Huber loss enabled with custom delta
    let hyperparams = DQNHyperparameters {
        learning_rate: 0.0001,
        batch_size: 64,
        gamma: 0.95,
        epsilon_start: 0.3,
        epsilon_end: 0.05,
        epsilon_decay: 0.995,
        buffer_size: 50000,
        min_replay_size: 1000,
        epochs: 200,
        checkpoint_frequency: 20,
        early_stopping_enabled: false,
        q_value_floor: 0.3,
        min_loss_improvement_pct: 1.0,
        plateau_window: 20,
        min_epochs_before_stopping: 100,
        use_huber_loss: true,
        huber_delta: 2.5,
        use_double_dqn: true,
        gradient_clip_norm: Some(1.0),
        hold_penalty_weight: 0.01,
        movement_threshold: 0.02,
    };

    assert!(hyperparams.use_huber_loss);
    assert_eq!(hyperparams.huber_delta, 2.5);
}

#[test]
fn test_huber_loss_disabled_configuration() {
    // Test Huber loss disabled (MSE mode)
    let hyperparams = DQNHyperparameters {
        learning_rate: 0.0001,
        batch_size: 32,
        gamma: 0.99,
        epsilon_start: 1.0,
        epsilon_end: 0.01,
        epsilon_decay: 0.995,
        buffer_size: 10000,
        min_replay_size: 500,
        epochs: 100,
        checkpoint_frequency: 10,
        early_stopping_enabled: true,
        q_value_floor: 0.5,
        min_loss_improvement_pct: 2.0,
        plateau_window: 30,
        min_epochs_before_stopping: 50,
        use_huber_loss: false, // MSE mode
        huber_delta: 1.0,
        use_double_dqn: true,
        gradient_clip_norm: Some(1.0),
        hold_penalty_weight: 0.01,
        movement_threshold: 0.02,
    };

    assert!(!hyperparams.use_huber_loss);
    assert_eq!(hyperparams.huber_delta, 1.0);
}

#[test]
fn test_conservative_preset_has_default_huber_values() {
    // Test that conservative preset includes Huber loss fields
    let hyperparams = DQNHyperparameters::conservative();

    // Should have the fields (will use struct defaults)
    // The exact default values should match CLI defaults: use_huber_loss=true, huber_delta=1.0
    assert!(
        hyperparams.use_huber_loss,
        "Conservative preset should default to Huber loss enabled"
    );
    assert_eq!(
        hyperparams.huber_delta, 1.0,
        "Conservative preset should use delta=1.0"
    );
}

#[test]
fn test_huber_delta_range_values() {
    // Test various Huber delta values (common range: 0.1 to 5.0)
    let test_deltas = vec![0.1, 0.5, 1.0, 1.5, 2.0, 5.0];

    for delta in test_deltas {
        let hyperparams = DQNHyperparameters {
            learning_rate: 0.0001,
            batch_size: 32,
            gamma: 0.99,
            epsilon_start: 1.0,
            epsilon_end: 0.01,
            epsilon_decay: 0.995,
            buffer_size: 10000,
            min_replay_size: 500,
            epochs: 100,
            checkpoint_frequency: 10,
            early_stopping_enabled: true,
            q_value_floor: 0.5,
            min_loss_improvement_pct: 2.0,
            plateau_window: 30,
            min_epochs_before_stopping: 50,
            use_huber_loss: true,
            huber_delta: delta,
            use_double_dqn: true,
            gradient_clip_norm: Some(1.0),
            hold_penalty_weight: 0.01,
            movement_threshold: 0.02,
        };

        assert_eq!(hyperparams.huber_delta, delta);
    }
}