foxhunt/ml/tests/dqn_rainbow_test.rs

//! Simplified Rainbow DQN Tests
//!
//! Tests matching the ACTUAL exported types:
//! - RainbowAgentConfig from rainbow_config.rs
//! - RainbowAgentMetrics from rainbow_agent.rs (only 4 fields!)
#![allow(unused_crate_dependencies)]

use ml::dqn::{RainbowAgentConfig, RainbowAgentMetrics};

/// Test: Basic Rainbow agent configuration creation
#[test]
fn test_rainbow_config_creation() {
    let config = RainbowAgentConfig::default();

    // Verify default values exist and are reasonable
    assert!(config.learning_rate > 0.0);
    assert!(config.gamma > 0.0 && config.gamma <= 1.0);
    assert!(config.batch_size > 0);
    assert!(config.replay_buffer_size > 0);
    assert!(config.min_replay_size > 0);
    assert!(config.target_update_freq > 0);
}

/// Test: Rainbow agent metrics - simple struct with only 4 fields
#[test]
fn test_rainbow_metrics_structure() {
    let metrics = RainbowAgentMetrics {
        total_steps: 100,
        replay_buffer_size: 5000,
        epsilon: 0.5,
        average_loss: 0.25,
    };

    assert_eq!(metrics.total_steps, 100);
    assert_eq!(metrics.replay_buffer_size, 5000);
    assert_eq!(metrics.epsilon, 0.5);
    assert_eq!(metrics.average_loss, 0.25);
}

/// Test: Config validation - learning rate bounds
#[test]
fn test_config_learning_rate_validation() {
    let mut config = RainbowAgentConfig::default();

    config.learning_rate = 0.001;
    assert!(config.learning_rate > 0.0);

    config.learning_rate = 0.1;
    assert!(config.learning_rate > 0.0);
}

/// Test: Config validation - gamma bounds
#[test]
fn test_config_gamma_validation() {
    let mut config = RainbowAgentConfig::default();

    config.gamma = 0.99;
    assert!(config.gamma > 0.0 && config.gamma <= 1.0);

    config.gamma = 0.95;
    assert!(config.gamma > 0.0 && config.gamma <= 1.0);
}

/// Test: Config validation - batch size
#[test]
fn test_config_batch_size_validation() {
    let mut config = RainbowAgentConfig::default();

    config.batch_size = 32;
    assert!(config.batch_size > 0);

    config.batch_size = 64;
    assert!(config.batch_size > 0);
}

/// Test: Config validation - replay buffer size
#[test]
fn test_config_replay_buffer_size() {
    let config = RainbowAgentConfig::default();

    // Replay buffer should be larger than min replay size
    assert!(config.replay_buffer_size >= config.min_replay_size);

    // Replay buffer should be larger than batch size
    assert!(config.replay_buffer_size >= config.batch_size);
}

/// Test: Config validation - priority parameters
#[test]
fn test_config_priority_parameters() {
    let config = RainbowAgentConfig::default();

    // Priority alpha should be in (0, 1]
    assert!(config.priority_alpha > 0.0 && config.priority_alpha <= 1.0);

    // Priority beta should be in (0, 1]
    assert!(config.priority_beta > 0.0 && config.priority_beta <= 1.0);

    // Priority beta increment should be small positive
    assert!(config.priority_beta_increment > 0.0);
    assert!(config.priority_beta_increment < 0.01);
}

/// Test: Config validation - update frequencies
#[test]
fn test_config_update_frequencies() {
    let config = RainbowAgentConfig::default();

    assert!(config.target_update_freq > 0);
    assert!(config.train_freq > 0);
    assert!(config.noise_reset_freq > 0);
}

/// Test: Metrics with realistic training values
#[test]
fn test_metrics_realistic_values() {
    let metrics = RainbowAgentMetrics {
        total_steps: 100000,
        replay_buffer_size: 50000,
        epsilon: 0.15,
        average_loss: 0.25,
    };

    assert_eq!(metrics.total_steps, 100000);
    assert_eq!(metrics.replay_buffer_size, 50000);
    assert_eq!(metrics.epsilon, 0.15);
    assert_eq!(metrics.average_loss, 0.25);
}

/// Test: Config clone functionality
#[test]
fn test_config_clone() {
    let config = RainbowAgentConfig::default();
    let cloned = config.clone();

    assert_eq!(cloned.learning_rate, config.learning_rate);
    assert_eq!(cloned.gamma, config.gamma);
    assert_eq!(cloned.batch_size, config.batch_size);
    assert_eq!(cloned.replay_buffer_size, config.replay_buffer_size);
}

/// Test: Config serialize/deserialize compatibility
#[test]
fn test_config_serialization() {
    let config = RainbowAgentConfig::default();

    let json = serde_json::to_string(&config);
    assert!(json.is_ok());

    if let Ok(json_str) = json {
        let deserialized: Result<RainbowAgentConfig, _> = serde_json::from_str(&json_str);
        assert!(deserialized.is_ok());

        if let Ok(c) = deserialized {
            assert_eq!(c.learning_rate, config.learning_rate);
            assert_eq!(c.gamma, config.gamma);
        }
    }
}

/// Test: Config with custom values
#[test]
fn test_config_custom_values() {
    let mut config = RainbowAgentConfig::default();

    config.device = "cuda".to_string();
    config.min_replay_size = 5000;
    config.replay_buffer_size = 50000;
    config.batch_size = 64;
    config.learning_rate = 0.0005;
    config.gamma = 0.95;
    config.target_update_freq = 2000;
    config.train_freq = 8;
    config.priority_alpha = 0.7;
    config.priority_beta = 0.5;
    config.noise_reset_freq = 200;

    assert_eq!(config.device, "cuda");
    assert_eq!(config.min_replay_size, 5000);
    assert_eq!(config.replay_buffer_size, 50000);
    assert_eq!(config.batch_size, 64);
    assert_eq!(config.learning_rate, 0.0005);
    assert_eq!(config.gamma, 0.95);
    assert_eq!(config.target_update_freq, 2000);
    assert_eq!(config.train_freq, 8);
    assert_eq!(config.priority_alpha, 0.7);
    assert_eq!(config.priority_beta, 0.5);
    assert_eq!(config.noise_reset_freq, 200);
}

/// Test: Epsilon decay tracking
#[test]
fn test_epsilon_tracking() {
    let metrics1 = RainbowAgentMetrics {
        total_steps: 0,
        replay_buffer_size: 0,
        epsilon: 1.0,
        average_loss: 0.0,
    };
    assert_eq!(metrics1.epsilon, 1.0);

    let metrics2 = RainbowAgentMetrics {
        total_steps: 50000,
        replay_buffer_size: 50000,
        epsilon: 0.5,
        average_loss: 1.5,
    };
    assert_eq!(metrics2.epsilon, 0.5);

    let metrics3 = RainbowAgentMetrics {
        total_steps: 100000,
        replay_buffer_size: 100000,
        epsilon: 0.1,
        average_loss: 0.5,
    };
    assert_eq!(metrics3.epsilon, 0.1);
}

/// Test: Loss tracking over time
#[test]
fn test_loss_tracking() {
    let early_metrics = RainbowAgentMetrics {
        total_steps: 1000,
        replay_buffer_size: 1000,
        epsilon: 0.9,
        average_loss: 5.0,
    };
    assert_eq!(early_metrics.average_loss, 5.0);

    let mid_metrics = RainbowAgentMetrics {
        total_steps: 50000,
        replay_buffer_size: 50000,
        epsilon: 0.5,
        average_loss: 1.0,
    };
    assert_eq!(mid_metrics.average_loss, 1.0);

    let late_metrics = RainbowAgentMetrics {
        total_steps: 100000,
        replay_buffer_size: 100000,
        epsilon: 0.1,
        average_loss: 0.1,
    };
    assert_eq!(late_metrics.average_loss, 0.1);
}

/// Test: Replay buffer size tracking
#[test]
fn test_replay_buffer_tracking() {
    let config = RainbowAgentConfig::default();

    let metrics = RainbowAgentMetrics {
        total_steps: 10000,
        replay_buffer_size: config.replay_buffer_size,
        epsilon: 0.5,
        average_loss: 0.25,
    };

    assert_eq!(metrics.replay_buffer_size, config.replay_buffer_size);
}

/// Test: Device configuration
#[test]
fn test_device_configuration() {
    let mut config = RainbowAgentConfig::default();

    assert_eq!(config.device, "cpu");

    config.device = "cuda".to_string();
    assert_eq!(config.device, "cuda");

    config.device = "cuda:0".to_string();
    assert_eq!(config.device, "cuda:0");
}

/// Test: Config multi-step learning settings
#[test]
fn test_config_multi_step_settings() {
    let config = RainbowAgentConfig::default();
    let _ = &config.multi_step;
}

/// Test: Config network settings
#[test]
fn test_config_network_settings() {
    let config = RainbowAgentConfig::default();
    let _ = &config.network_config;
}

/// Test: Metrics with zero values
#[test]
fn test_metrics_zero_values() {
    let metrics = RainbowAgentMetrics {
        total_steps: 0,
        replay_buffer_size: 0,
        epsilon: 0.0,
        average_loss: 0.0,
    };

    assert_eq!(metrics.total_steps, 0);
    assert_eq!(metrics.replay_buffer_size, 0);
    assert_eq!(metrics.epsilon, 0.0);
    assert_eq!(metrics.average_loss, 0.0);
}

/// Test: Metrics with max values
#[test]
fn test_metrics_max_values() {
    let metrics = RainbowAgentMetrics {
        total_steps: u64::MAX,
        replay_buffer_size: 1000000,
        epsilon: 1.0,
        average_loss: 100.0,
    };

    assert_eq!(metrics.total_steps, u64::MAX);
    assert_eq!(metrics.replay_buffer_size, 1000000);
    assert_eq!(metrics.epsilon, 1.0);
    assert_eq!(metrics.average_loss, 100.0);
}

/// Test: Training progress simulation
#[test]
fn test_training_progress_simulation() {
    // Early training
    let early = RainbowAgentMetrics {
        total_steps: 100,
        replay_buffer_size: 100,
        epsilon: 0.99,
        average_loss: 10.0,
    };

    // Mid training
    let mid = RainbowAgentMetrics {
        total_steps: 50000,
        replay_buffer_size: 50000,
        epsilon: 0.5,
        average_loss: 2.0,
    };

    // Late training
    let late = RainbowAgentMetrics {
        total_steps: 100000,
        replay_buffer_size: 100000,
        epsilon: 0.05,
        average_loss: 0.5,
    };

    // Verify progression
    assert!(early.epsilon > mid.epsilon);
    assert!(mid.epsilon > late.epsilon);
    assert!(early.average_loss > mid.average_loss);
    assert!(mid.average_loss > late.average_loss);
}

/// Test: Config default device is CPU
#[test]
fn test_config_default_device() {
    let config = RainbowAgentConfig::default();
    assert_eq!(config.device, "cpu");
}

/// Test: Config default learning rate is reasonable
#[test]
fn test_config_default_learning_rate() {
    let config = RainbowAgentConfig::default();
    assert!(config.learning_rate > 0.0);
    assert!(config.learning_rate < 0.01); // Reasonable upper bound for DQN
}

/// Test: Config default gamma is reasonable
#[test]
fn test_config_default_gamma() {
    let config = RainbowAgentConfig::default();
    assert!(config.gamma > 0.9); // Should be high for RL
    assert!(config.gamma <= 1.0);
}