using Cryville.Common;
using Cryville.Common.Pdt;
using Cryville.Common.Unity.Input;
using System;
using System.Collections.Generic;
using UnityEngine;

namespace Cryville.Crtr {
	public class InputProxy {
		readonly PdtEvaluator _etor;
		readonly PdtRuleset _ruleset;
		readonly Judge _judge;
		public InputProxy(PdtRuleset ruleset, Judge judge) {
			unsafe {
				fixed (byte* ptr = _vecbuf) {
					*(int*)(ptr + 3 * sizeof(float)) = PdtInternalType.Number;
				}
			}
			_etor = ChartPlayer.etor;
			_ruleset = ruleset;
			_judge = judge;
			foreach (var i in ruleset.inputs) {
				_use.Add(i.Key, 0);
				_rev.Add(i.Key, new List<string>());
			}
			foreach (var i in ruleset.inputs) {
				if (i.Value.pass != null) {
					foreach (var p in i.Value.pass)
						_rev[p.Key].Add(i.Key);
				}
			}
		}
		#region Settings
		readonly Dictionary<string, InputProxyEntry> _tproxies = new Dictionary<string, InputProxyEntry>();
		readonly Dictionary<InputSource, InputProxyEntry> _sproxies = new Dictionary<InputSource, InputProxyEntry>();
		readonly Dictionary<string, int> _use = new Dictionary<string, int>();
		readonly Dictionary<string, List<string>> _rev = new Dictionary<string, List<string>>();
		public event EventHandler<ProxyChangedEventArgs> ProxyChanged;
		public void Set(InputProxyEntry proxy) {
			var name = proxy.Target;
			if (_tproxies.ContainsKey(name)) Remove(proxy);
			if (_use[proxy.Target] > 0)
				throw new InvalidOperationException("Input already assigned");
			if (proxy.Source != null) {
				proxy.Source.Value.Handler.OnInput -= OnInput; // Prevent duplicated hooks, no exception will be thrown
				proxy.Source.Value.Handler.OnInput += OnInput;
				_tproxies.Add(proxy.Target, proxy);
				_sproxies.Add(proxy.Source.Value, proxy);
				IncrementUseRecursive(name);
				IncrementReversedUseRecursive(name);
			}
		}
		void Remove(InputProxyEntry proxy) {
			var name = proxy.Target;
			proxy.Source.Value.Handler.OnInput -= OnInput;
			_sproxies.Remove(_tproxies[name].Source.Value);
			_tproxies.Remove(name);
			DecrementUseRecursive(name);
			DecrementReversedUseRecursive(name);
		}
		public bool IsUsed(InputSource src) {
			return _sproxies.ContainsKey(src);
		}
		void IncrementUseRecursive(string name) {
			BroadcastProxyChanged(name);
			var passes = _ruleset.inputs[name].pass;
			if (passes != null) {
				foreach (var p in _ruleset.inputs[name].pass) {
					_use[p.Key]++;
					IncrementUseRecursive(p.Key);
				}
			}
		}
		void IncrementReversedUseRecursive(string name) {
			foreach (var p in _rev[name]) {
				_use[p]++;
				BroadcastProxyChanged(p);
				IncrementReversedUseRecursive(p);
			}
		}
		void DecrementUseRecursive(string name) {
			BroadcastProxyChanged(name);
			var passes = _ruleset.inputs[name].pass;
			if (passes != null) {
				foreach (var p in _ruleset.inputs[name].pass) {
					_use[p.Key]--;
					DecrementUseRecursive(p.Key);
				}
			}
		}
		void DecrementReversedUseRecursive(string name) {
			foreach (var p in _rev[name]) {
				_use[p]--;
				BroadcastProxyChanged(p);
				DecrementReversedUseRecursive(p);
			}
		}
		void BroadcastProxyChanged(string name) {
			var del = ProxyChanged;
			if (del != null) del(this, new ProxyChangedEventArgs(name, _tproxies.ContainsKey(name) ? _tproxies[name].Source : null, _use[name] > 0));
		}
		#endregion

		#region Handling
		public void Activate() { foreach (var src in _sproxies.Keys) src.Handler.Activate(); }
		public void Deactivate() { foreach (var src in _sproxies.Keys) src.Handler.Deactivate(); }

		readonly object _lock = new object();
		static readonly int _var_value = IdentifierManager.SharedInstance.Request("value");
		static readonly PropOp.Arbitrary _arbop = new PropOp.Arbitrary();
		readonly byte[] _vecbuf = new byte[3 * sizeof(float) + sizeof(int)];
		readonly Dictionary<InputIdentifier, float> _vect = new Dictionary<InputIdentifier, float>();
		readonly Dictionary<ProxiedInputIdentifier, PropSrc.Arbitrary> _vecs = new Dictionary<ProxiedInputIdentifier, PropSrc.Arbitrary>();
		static readonly byte[] _nullvalue = new byte[0];
		unsafe void OnInput(InputIdentifier id, InputVector vec) {
			lock (_lock) {
				InputProxyEntry proxy;
				if (_sproxies.TryGetValue(id.Source, out proxy)) {
					_etor.ContextCascadeInsert();
					float ft, tt = (float)vec.Time;
					if (!_vect.TryGetValue(id, out ft)) ft = tt;
					if (vec.IsNull) {
						_etor.ContextCascadeUpdate(_var_value, new PropSrc.Arbitrary(PdtInternalType.Null, new byte[0]));
					}
					else {
						fixed (byte* ptr = _vecbuf) {
							*(Vector3*)ptr = vec.Vector;
						}
						_etor.ContextCascadeUpdate(_var_value, new PropSrc.Arbitrary(PdtInternalType.Vector, _vecbuf));
					}
					OnInput(id, proxy.Target, ft, tt);
					_vect[id] = tt;
					_etor.ContextCascadeDiscard();
				}
			}
		}
		static readonly int _var_fv = IdentifierManager.SharedInstance.Request("fv");
		static readonly int _var_tv = IdentifierManager.SharedInstance.Request("tv");
		unsafe void OnInput(InputIdentifier id, Identifier target, float ft, float tt) {
			var def = _ruleset.inputs[target];
			if (def.pass != null) {
				foreach (var p in def.pass) {
					_etor.ContextCascadeInsert();
					_arbop.Name = _var_value;
					_etor.Evaluate(_arbop, p.Value);
					OnInput(id, p.Key, ft, tt);
					_etor.ContextCascadeDiscard();
				}
			}
			else {
				var pid = new ProxiedInputIdentifier { Source = id, Target = target };
				PropSrc.Arbitrary fv, tv = _etor.ContextCascadeLookup(_var_value);
				if (!_vecs.TryGetValue(pid, out fv)) fv = new PropSrc.Arbitrary(PdtInternalType.Null, new byte[0]);
				if (fv.Type != PdtInternalType.Null || tv.Type != PdtInternalType.Null) {
					_etor.ContextCascadeInsert();
					_etor.ContextCascadeUpdate(_var_fv, fv);
					_etor.ContextCascadeUpdate(_var_tv, tv);
					_judge.Feed(target, ft, tt);
					_etor.ContextCascadeDiscard();
				}
				_judge.Cleanup(target, ft, tt);
				_vecs[pid] = tv;
			}
		}
		#endregion
	}

	public class ProxyChangedEventArgs : EventArgs {
		public string Name { get; private set; }
		public InputSource? Proxy { get; private set; }
		public bool Used { get; private set; }
		public ProxyChangedEventArgs(string name, InputSource? src, bool used) {
			Name = name;
			Proxy = src;
			Used = used;
		}
	}

	public class InputProxyEntry {
		public InputSource? Source { get; set; }
		public string Target { get; set; }
		public byte[] Mapping { get; private set; }
	}

	public struct ProxiedInputIdentifier : IEquatable<ProxiedInputIdentifier> {
		public InputIdentifier Source { get; set; }
		public Identifier Target { get; set; }
		public override bool Equals(object obj) {
			if (obj == null || !(obj is ProxiedInputIdentifier)) return false;
			return Equals((ProxiedInputIdentifier)obj);
		}
		public bool Equals(ProxiedInputIdentifier other) {
			return Source == other.Source && Target == other.Target;
		}
		public override int GetHashCode() {
			return Source.GetHashCode() ^ Target.GetHashCode();
		}
		public override string ToString() {
			return string.Format("{0}->{1}", Source, Target);
		}
		public static bool operator ==(ProxiedInputIdentifier lhs, ProxiedInputIdentifier rhs) {
			return lhs.Equals(rhs);
		}
		public static bool operator !=(ProxiedInputIdentifier lhs, ProxiedInputIdentifier rhs) {
			return !lhs.Equals(rhs);
		}
	}
}