/// <summary>
/// A projectile. It explodes when it hits something.
/// </summary>
public class Projectile : Component, Component.ICollisionListener, IInstigator
{
	[RequireComponent] public Rigidbody Rigidbody { get; set; }

	[Sync( SyncFlags.FromHost )] public PlayerData Instigator { get; set; }

	protected TimeSince TimeSinceCreated;

	protected override void OnStart()
	{
		Tags.Add( "projectile" );
	}

	protected override void OnEnabled()
	{
		TimeSinceCreated = 0;
	}

	void ICollisionListener.OnCollisionStart( Collision collision )
	{
		if ( IsProxy )
			return;

		var player = collision.Other.GameObject.GetComponentInParent<Player>();
		if ( Instigator.IsValid() && player.IsValid() && player.PlayerData == Instigator )
		{
			return;
		}

		OnHit( collision );
	}

	protected virtual void OnHit( Collision collision = default )
	{
		GameObject.Destroy();
	}

	/// <summary>
	/// Tell the instigator their projectile hit, so they can do things like show a hitmarker
	/// </summary>
	protected void NotifyHit( IDamageable target, Vector3 point )
	{
		if ( !Instigator.IsValid() ) return;
		
		var connection = Instigator.Connection;
		if ( connection is null ) return;

		using ( Rpc.FilterInclude( connection ) )
		{
			OnClientHit( target, point );
		}
	}

	[Rpc.Broadcast]
	protected virtual void OnClientHit( IDamageable target, Vector3 point )
	{
		HitMarker.CreateAt( point );
	}

	/// <summary>
	/// Updates the current direction of the projectile
	/// </summary>
	/// <param name="direction"></param>
	/// <param name="speed"></param>
	public void UpdateDirection( Vector3 direction, float speed )
	{
		WorldRotation = Rotation.LookAt( direction, Vector3.Up );
		Rigidbody.Velocity = WorldRotation.Forward * speed;
	}
}