using System;
using Astra;

[ComponentId("docs.heart-hud")]
public sealed class HeartHud : Behavior
{
    [PropertyId("player")]
    public ObjectReference Player;

    private GuiAccess hud = null!;
    private PlayerHealth health = null!;
    private readonly GuiElement[] hearts = new GuiElement[PlayerHealth.Capacity];
    private GuiElement status;
    private int lastHealth = -1;

    public override void Start()
    {
        var player = Resolve(Player)
            ?? throw new InvalidOperationException("Atribua Jogador ao campo Player do HeartHud.");
        health = player.GetBehavior<PlayerHealth>()
            ?? throw new InvalidOperationException("Jogador precisa de PlayerHealth.");
        hud = Gui.ForCanvas(Object);
        for (int i = 0; i < hearts.Length; ++i)
        {
            hearts[i] = hud.Find($"Heart{i + 1}");
            if (hearts[i].Kind != GuiKind.Image)
                throw new InvalidOperationException($"Heart{i + 1} precisa ser Image.");
        }
        status = hud.Find("Status");
        hud.Find("Damage");
        hud.Find("Heal");
        Refresh();
    }

    public override void Update(float deltaTime)
    {
        // Este script é o consumidor da fila deste Canvas.
        while (hud.Poll(out var message))
        {
            if (message.Kind != GuiEventKind.Click) continue;
            if (message.Element.Name == "Damage") health.TakeDamage(1);
            else if (message.Element.Name == "Heal") health.Heal(1);
        }
        if (lastHealth != health.Current) Refresh();
    }

    private void Refresh()
    {
        lastHealth = health.Current;
        for (int i = 0; i < hearts.Length; ++i)
            hearts[i].Visible = i < lastHealth;
        status.Text = $"Vida: {lastHealth}/{PlayerHealth.Capacity}"
            + (health.IsDead ? " | Sem vida" : "");
    }
}