using Cryville.Common;
using Cryville.Common.Buffers;
using Cryville.Crtr.Components;
using System;
using System.Collections.Generic;
using System.Globalization;
using System.Runtime.CompilerServices;
using UnityEngine;

namespace Cryville.Crtr.Event {
	public abstract class ContainerHandler {
		#region Struct
		public ContainerHandler() { }
		public abstract string TypeName { get; }

		/// <summary>
		/// Prehandling <see cref="ContainerState"/>, prehandling the events.
		/// </summary>
		public ContainerState ps;

		/// <summary>
		/// Backward <see cref="ContainerState"/>, disposing events at the backward clipping plane, firing anchor state and temporary state.
		/// </summary>
		public ContainerState bs;

		/// <summary>
		/// Current <see cref="ContainerState"/>, handling events occuring at the current time.
		/// </summary>
		public ContainerState cs;

		/// <summary>
		/// Anchor <see cref="ContainerState"/>, computing the start position of the temporary state.
		/// </summary>
		public ContainerState ns;

		/// <summary>
		/// Temporary <see cref="ContainerState"/>, rendering events between the clipping planes.
		/// </summary>
		public ContainerState ts;

		/// <summary>
		/// <see cref="GameObject"/> group, the <see cref="Transform"/> containing all the generated elements in the <see cref="ContainerHandler"/>.
		/// </summary>
		protected Transform gogroup;
		public SkinContext SkinContext;

		public Vector3 Position { get; protected set; }
		public Quaternion Rotation { get; protected set; }
		public bool Alive { get; private set; }
		bool PreGraphicalActive;
		public void SetPreGraphicalActive(bool value, ContainerState s) {
			if (PreGraphicalActive == value) return;
			PreGraphicalActive = value;
			if (PreGraphicalActive) StartPreGraphicalUpdate(s);
			else EndPreGraphicalUpdate(s);
		}
		bool GraphicalActive;
		public void SetGraphicalActive(bool value, ContainerState s) {
			if (GraphicalActive == value) return;
			GraphicalActive = value;
			if (GraphicalActive) StartGraphicalUpdate(s);
			else EndGraphicalUpdate(s);
		}

		public EventContainer Container {
			get { return cs.Container; }
		}

		SkinContainer skinContainer;
		protected Judge judge;
		public void AttachSystems(PdtSkin skin, Judge judge) {
			skinContainer = new SkinContainer(skin);
			this.judge = judge;
		}

		public readonly Dictionary<int, List<Anchor>> Anchors = new Dictionary<int, List<Anchor>>();
		public readonly Dictionary<int, Anchor> DynamicAnchors = new Dictionary<int, Anchor>();
		public readonly Dictionary<int, bool> DynamicAnchorSet = new Dictionary<int, bool>();
		public Anchor OpenedAnchor;
		protected Anchor a_cur;
		protected Anchor a_head;
		protected Anchor a_tail;
		protected readonly static int _a_cur = IdentifierManager.SharedInstance.Request("cur");
		protected readonly static int _a_head = IdentifierManager.SharedInstance.Request("head");
		protected readonly static int _a_tail = IdentifierManager.SharedInstance.Request("tail");
		public Anchor RegisterAnchor(int name, bool dyn = false, int propSrcCount = 0) {
			var strname = IdentifierManager.SharedInstance.Retrieve(name);
			var go = new GameObject("." + strname).transform;
			go.SetParent(gogroup, false);
			var result = new Anchor(name, go, propSrcCount);
			if (dyn) {
				if (DynamicAnchors.ContainsKey(name))
					throw new ArgumentException(string.Format("The anchor \"{0}\" already exists", strname));
				DynamicAnchors.Add(name, result);
				DynamicAnchorSet.Add(name, false);
			}
			List<Anchor> list;
			if (!Anchors.TryGetValue(name, out list))
				Anchors.Add(name, list = new List<Anchor>());
			list.Add(result);
			return result;
		}
		protected void OpenAnchor(Anchor anchor) {
			if (OpenedAnchor != null) throw new InvalidOperationException("An anchor has been opened");
			OpenedAnchor = anchor;
		}
		protected void CloseAnchor() {
			OpenedAnchor = null;
		}
		#endregion

		#region Logic
		#region Init methods: Called on prehandle
		public virtual void PreInit() {
			gogroup = new GameObject(TypeName + ":" + Container.GetHashCode().ToString(CultureInfo.InvariantCulture)).transform;
			SkinContext = new SkinContext(gogroup);
			if (cs.Parent != null)
				gogroup.SetParent(cs.Parent.Handler.gogroup, false);
			a_cur = RegisterAnchor(_a_cur);
			a_head = RegisterAnchor(_a_head, true);
			a_tail = RegisterAnchor(_a_tail, true);
		}
		public virtual void Init() {
			skinContainer.MatchStatic(ps);
			foreach (var i in gogroup.GetComponentsInChildren<SkinComponent>())
				i.Init();
		}
		public virtual void PostInit() {
			gogroup.gameObject.SetActive(false);
		}
		#endregion
		#region Start methods
		public virtual void StartPhysicalUpdate(ContainerState s) {
			if (s.CloneType < 16) Alive = true;
			else if (s.CloneType == 17) Init();
		}
		public virtual void StartLogicalUpdate(ContainerState s) { }
		public virtual void StartPreGraphicalUpdate(ContainerState s) { }
		public virtual void StartGraphicalUpdate(ContainerState s) {
			if (gogroup) gogroup.gameObject.SetActive(true);
		}
		#endregion
		public virtual void Update(ContainerState s, StampedEvent ev) {
			if (s.CloneType == 3) SetPreGraphicalActive(true, s);
			else if (ev is StampedEvent.Anchor) {
				var tev = (StampedEvent.Anchor)ev;
				if (tev.Target == a_head) {
					SetGraphicalActive(true, s);
				}
				else if (tev.Target == a_tail) {
					SetGraphicalActive(false, s);
				}
				if (gogroup) {
					OpenAnchor(tev.Target);
#if UNITY_5_6_OR_NEWER
					tev.Target.Transform.SetPositionAndRotation(Position, Rotation);
#else
					tev.Target.Transform.position = Position;
					tev.Target.Transform.rotation = Rotation;
#endif
					skinContainer.MatchDynamic(s);
					CloseAnchor();
				}
				anchorEvPool.Return(tev);
			}
			else if (gogroup && s.CloneType == 2) skinContainer.MatchDynamic(s);
		}
		#region End methods
		public virtual void EndGraphicalUpdate(ContainerState s) { }
		public virtual void EndPreGraphicalUpdate(ContainerState s) { }
		public virtual void EndLogicalUpdate(ContainerState s) { }
		public virtual void EndPhysicalUpdate(ContainerState s) { }
		public virtual void Dispose() {
			if (gogroup)
				GameObject.Destroy(gogroup.gameObject);
			Alive = false;
		}
		public virtual void DisposeAll() { }
		#endregion
		[MethodImpl(MethodImplOptions.AggressiveInlining)]
		protected static bool CanDoGraphicalUpdate(ContainerState s) { return s.CloneType >= 2 && s.CloneType < 16; }
		#region Anchor
		public virtual void Anchor() {
			foreach (var a in DynamicAnchors.Keys) DynamicAnchorSet[a] = false;
			skinContainer.MatchDynamic(cs);
			if (cs.Active) PushAnchorEvent(cs.Time, a_cur);
			if (Alive) {
				if (!DynamicAnchorSet[_a_head]) PushAnchorEvent(cs.StampedContainer.Time, a_head, -1, true);
				if (!DynamicAnchorSet[_a_tail]) PushAnchorEvent(cs.StampedContainer.Time + cs.StampedContainer.Duration, a_tail, 1, true);
			}
		}
		static readonly SimpleObjectPool<StampedEvent.Anchor> anchorEvPool
			= new SimpleObjectPool<StampedEvent.Anchor>(1024);
		public void PushAnchorEvent(double time, int name) {
			Anchor anchor;
			if (!DynamicAnchors.TryGetValue(name, out anchor))
				throw new ArgumentException(string.Format("Specified anchor \"{0}\" not found", IdentifierManager.SharedInstance.Retrieve(name)));
			if (DynamicAnchorSet[name])
				throw new InvalidOperationException(string.Format("Specified anchor \"{0}\" has been set", IdentifierManager.SharedInstance.Retrieve(name)));
			int priority = 0;
			bool forced = true;
			if (name == _a_head) priority = -1;
			else if (name == _a_tail) priority = 1;
			else forced = false;
			PushAnchorEvent(time, anchor, priority, forced);
			DynamicAnchorSet[name] = true;
		}
		void PushAnchorEvent(double time, Anchor anchor, int priority = 0, bool forced = false) {
			var tev = anchorEvPool.Rent();
			tev.Time = time;
			tev.Container = Container;
			tev.Target = anchor;
			tev.CanDiscard = !forced;
			tev.SetPriority(priority);
			ts.Bus.PushTempEvent(tev);
		}
		public virtual void Discard(ContainerState s, StampedEvent ev) {
			if (ev is StampedEvent.Anchor) {
				anchorEvPool.Return((StampedEvent.Anchor)ev);
			}
		}
		#endregion
		#endregion
	}
}