cirnogodot/Scripts/Components/Actors/PlayerDamageReceiver.cs

using System;
using Godot;

namespace Cirno.Scripts.Components.Actors;

public partial class PlayerDamageReceiver : Area2D
{
    [Export]
    public bool Enabled { get; set; } = false;
    [Export]
    public bool Invulnerable { get; private set; } = false;
    [Export] public BulletOwner BulletGroup { get; set; } = BulletOwner.Player;

    [Export]
    private ActorResourceProvider _healthProvider;
    [Export]
    private ActorResourceProvider _shieldProvider;
    
    [Signal]
    public delegate void HealthChangedEventHandler(float newValue, float maxValue);
    
    [Signal]
    public delegate void ShieldChangedEventHandler(float newValue, float maxValue);
    
    [Signal]
    public delegate void DeathEventHandler();
    
    public float CurrentHealth
    {
        get => _healthProvider.CurrentResource;
        set => _healthProvider.CurrentResource = value;
    }

    public float CurrentShield
    {
        get => _shieldProvider.CurrentResource;
        set => _shieldProvider.CurrentResource = value;
    }
    
    public void Init()
    {
        _healthProvider.FillResource();
        _shieldProvider.FillResource();
        
        _healthProvider.ResourceChanged += ((value, maxValue) =>
        {
            if (!Enabled) return;
            EmitSignal(SignalName.HealthChanged, value, maxValue);
        });
        
        _shieldProvider.ResourceChanged += ((value, maxValue) =>
        {
            if (!Enabled) return;
            EmitSignal(SignalName.ShieldChanged, value, maxValue);
        });

        _healthProvider.ResourceDepleted += () =>
        {
            if (!Enabled) return;
            EmitSignal(SignalName.Death);
        };
    }
    
    private void _on_damage_hitbox_area_entered(Area2D area)
    {
        if (!Enabled) return;
        if (Invulnerable) return;
        if (area is not Bullet bullet || bullet.BulletOwner == BulletGroup) return;
        this.Hit(bullet.Damage, bullet.DamageType);
        bullet.RequestCollisionDestruction();
    }
    
    public void Hit(float damage, DamageType type = DamageType.Neutral)
    {
        if (!Enabled) return;

        if (CurrentShield > 0 && type is not DamageType.Explosive or DamageType.Acid)
        {
            // Reduce shield
            //PlayShieldAnimation(); // Let this be handled by event
            CurrentShield -= damage;
            if (CurrentShield < 0)
            {
                CurrentHealth -= Math.Abs(CurrentShield);
                CurrentShield = 0;
            }
        }
        else
        {
            if (type is DamageType.Fire)
            {
                CurrentHealth -= damage * 2;
            }
            else
            {
                CurrentHealth -= damage;
            }

            //Blink(); // Let this be handled by event
        }

        if (!(CurrentHealth <= 0)) return;
    }
}