use pacman::systems::components::EntityType;

// Helper functions that extract the core scoring logic from item_system
// This allows us to test the business rules without ECS complexity

fn calculate_score_for_item(entity_type: EntityType) -> Option<u32> {
    match entity_type {
        EntityType::Pellet => Some(10),
        EntityType::PowerPellet => Some(50),
        _ => None,
    }
}

fn is_collectible_item(entity_type: EntityType) -> bool {
    matches!(entity_type, EntityType::Pellet | EntityType::PowerPellet)
}

fn should_trigger_audio_on_collection(entity_type: EntityType) -> bool {
    is_collectible_item(entity_type)
}

#[test]
fn test_pellet_scoring() {
    assert_eq!(calculate_score_for_item(EntityType::Pellet), Some(10));
}

#[test]
fn test_power_pellet_scoring() {
    assert_eq!(calculate_score_for_item(EntityType::PowerPellet), Some(50));
}

#[test]
fn test_non_collectible_items_no_score() {
    assert_eq!(calculate_score_for_item(EntityType::Player), None);
    assert_eq!(calculate_score_for_item(EntityType::Ghost), None);
}

#[test]
fn test_collectible_item_detection() {
    assert!(is_collectible_item(EntityType::Pellet));
    assert!(is_collectible_item(EntityType::PowerPellet));
    assert!(!is_collectible_item(EntityType::Player));
    assert!(!is_collectible_item(EntityType::Ghost));
}

#[test]
fn test_audio_trigger_for_collectibles() {
    assert!(should_trigger_audio_on_collection(EntityType::Pellet));
    assert!(should_trigger_audio_on_collection(EntityType::PowerPellet));
    assert!(!should_trigger_audio_on_collection(EntityType::Player));
    assert!(!should_trigger_audio_on_collection(EntityType::Ghost));
}

#[test]
fn test_score_progression() {
    // Test that power pellets are worth more than regular pellets
    let pellet_score = calculate_score_for_item(EntityType::Pellet).unwrap();
    let power_pellet_score = calculate_score_for_item(EntityType::PowerPellet).unwrap();

    assert!(power_pellet_score > pellet_score);
    assert_eq!(power_pellet_score / pellet_score, 5); // Power pellets are worth 5x regular pellets
}

#[test]
fn test_entity_type_variants() {
    // Test all EntityType variants to ensure they're handled appropriately
    let all_types = vec![
        EntityType::Player,
        EntityType::Ghost,
        EntityType::Pellet,
        EntityType::PowerPellet,
    ];

    let mut collectible_count = 0;
    let mut non_collectible_count = 0;

    for entity_type in all_types {
        if is_collectible_item(entity_type) {
            collectible_count += 1;
            // All collectible items should have a score
            assert!(calculate_score_for_item(entity_type).is_some());
        } else {
            non_collectible_count += 1;
            // Non-collectible items should not have a score
            assert!(calculate_score_for_item(entity_type).is_none());
        }
    }

    // Verify we have the expected number of each type
    assert_eq!(collectible_count, 2); // Pellet and PowerPellet
    assert_eq!(non_collectible_count, 2); // Player and Ghost
}

#[test]
fn test_score_accumulation() {
    // Test score accumulation logic (simulating multiple collections)
    let mut total_score = 0u32;

    // Collect some items
    let collected_items = vec![
        EntityType::Pellet,
        EntityType::Pellet,
        EntityType::PowerPellet,
        EntityType::Pellet,
        EntityType::PowerPellet,
    ];

    for item in collected_items {
        if let Some(score) = calculate_score_for_item(item) {
            total_score += score;
        }
    }

    // Expected: 3 pellets (30) + 2 power pellets (100) = 130
    assert_eq!(total_score, 130);
}

#[test]
fn test_collision_filtering_logic() {
    // Test the logic for determining valid collision pairs
    // This mirrors the logic in item_system that checks entity types

    let test_cases = vec![
        (EntityType::Player, EntityType::Pellet, true),
        (EntityType::Player, EntityType::PowerPellet, true),
        (EntityType::Player, EntityType::Ghost, false), // Not handled by item system
        (EntityType::Player, EntityType::Player, false), // Not a valid collision
        (EntityType::Ghost, EntityType::Pellet, false), // Ghosts don't collect items
        (EntityType::Pellet, EntityType::PowerPellet, false), // Items don't interact
    ];

    for (entity1, entity2, should_be_valid) in test_cases {
        let is_valid_item_collision = (entity1 == EntityType::Player && is_collectible_item(entity2))
            || (entity2 == EntityType::Player && is_collectible_item(entity1));

        assert_eq!(
            is_valid_item_collision, should_be_valid,
            "Failed for collision between {:?} and {:?}",
            entity1, entity2
        );
    }
}

#[test]
fn test_item_collection_side_effects() {
    // Test that collecting items should trigger the expected side effects
    let collectible_items = vec![EntityType::Pellet, EntityType::PowerPellet];

    for item in collectible_items {
        // Should provide score
        assert!(calculate_score_for_item(item).is_some());

        // Should trigger audio
        assert!(should_trigger_audio_on_collection(item));

        // Should be marked as collectible
        assert!(is_collectible_item(item));
    }
}