using Cryville.Common;
using Cryville.Common.Buffers;
using System.Collections.Generic;

namespace Cryville.Crtr.Event {
	internal class MotionCache {
		public bool Valid { get; set; }
		public Vector Value { get; set; }
		public void CopyTo(MotionCache dest) {
			dest.Valid = Valid;
			Value.CopyTo(dest.Value);
		}
	}
	internal class MotionCachePool {
		private class Bucket : ObjectPool<MotionCache> {
			readonly MotionRegistry _reg;
			public Bucket(string name, int capacity) : base(capacity) {
				_reg = ChartPlayer.motionRegistry[name];
			}
			protected override MotionCache Construct() {
				var result = new MotionCache();
				result.Value = (Vector)ReflectionHelper.InvokeEmptyConstructor(_reg.Type);
				return result;
			}
		}
		static Dictionary<Identifier, Bucket> _buckets;
		public static void Prepare() {
			_buckets = new Dictionary<Identifier, Bucket>(ChartPlayer.motionRegistry.Count);
			foreach (var reg in ChartPlayer.motionRegistry)
				_buckets.Add(reg.Key, new Bucket(reg.Key, 4096));
		}

		static readonly SimpleObjectPool<Dictionary<MotionCache, Identifier>> _dictPool
			= new SimpleObjectPool<Dictionary<MotionCache, Identifier>>(1024);
		Dictionary<MotionCache, Identifier> _rented;
		public MotionCache Rent(Identifier name) {
			var obj = _buckets[name].Rent();
			obj.Valid = false;
			if (_rented == null) _rented = _dictPool.Rent();
			_rented.Add(obj, name);
			return obj;
		}
		public void Return(MotionCache obj) {
			_buckets[_rented[obj]].Return(obj);
			_rented.Remove(obj);
		}
		public void ReturnAll() {
			if (_rented == null) return;
			foreach (var obj in _rented)
				_buckets[obj.Value].Return(obj.Key);
			_rented.Clear();
			_dictPool.Return(_rented);
			_rented = null;
		}
	}
}