using System.Collections.Generic;
using System.Linq;
using Godot;

namespace BITKit;
/// <summary>
/// 摄像头服务，该服务需要加载到Camera3D节点中
/// </summary>
public partial class CameraService:Camera3D
{
    public static CameraService Singleton { get; private set; }
    /// <summary>
    /// 场景中所有的摄像头
    /// </summary>
    private static readonly List<IVirtualCamera> _cameras=new();
    /// <summary>
    /// 当前已激活的摄像头
    /// </summary>
    public static IVirtualCamera ActiveCamera { get; private set; }
    /// <summary>
    /// 注册摄像头
    /// </summary>
    /// <param name="camera">摄像头</param>
    /// <returns></returns>
    public static bool Register(IVirtualCamera camera) => _cameras.TryAdd(camera);
    /// <summary>
    /// 注销摄像头
    /// </summary>
    /// <param name="camera">摄像头</param>
    /// <returns></returns>
    public static bool UnRegister(IVirtualCamera camera) => _cameras.TryRemove(camera);

    public override void _Ready()
    {
        Singleton = this;
    }

    /// <summary>
    /// 处理摄像头的位置
    /// </summary>
    /// <param name="delta"></param>
    public override void _Process(double delta)
    {
        //获取所有已启用的相机并加载一个虚拟相机的数据
        foreach (var x in _cameras.Where(x => x.IsEnabled))
        {
            //应用相机坐标
            Position = x.Position;
            //应用相机角度
            Rotation = x.Rotation;
            //已加载相机位置,退出循环
            break;
        }
    }
}