using Cryville.Common;
using Cryville.Common.Buffers;
using Cryville.Common.Collections.Generic;
using Cryville.Common.Collections.Specialized;
using Cryville.Common.Pdt;
using System;
using System.Collections.Generic;
using System.Globalization;
using System.Runtime.Serialization;
using System.Text.Formatting;
using UnsafeIL;

namespace Cryville.Crtr {
	public struct JudgeEvent {
		public double StartTime { get; set; }
		public double EndTime { get; set; }
		public double StartClip { get; set; }
		public double EndClip { get; set; }
		public Chart.Judge BaseEvent { get; set; }
		public JudgeDefinition Definition { get; set; }
		public NoteHandler Handler { get; set; }
	}
	public interface IJudge {
		bool Pass(JudgeEvent ev, float time, Identifier[] ids, int depth);
		void UpdateScore(ScoreOperation op, PdtExpression exp);
	}
	public class Judge : IJudge {
		#region Data
		readonly ChartPlayer _sys;
		internal readonly PdtEvaluator _etor;
		readonly PdtRuleset _rs;
		internal Dictionary<Identifier, PdtExpression> _areaFuncs;
		readonly Dictionary<Identifier, List<JudgeEvent>> evs
			= new Dictionary<Identifier, List<JudgeEvent>>();
		readonly Dictionary<Identifier, List<JudgeEvent>> activeEvs
			= new Dictionary<Identifier, List<JudgeEvent>>();
		static readonly int _var_pause = IdentifierManager.Shared.Request("pause");
		readonly JudgeDefinition _judgePause;
		static readonly IComparer<JudgeEvent> _stcmp = new JudgeEventStartTimeComparer();
		class JudgeEventStartTimeComparer : IComparer<JudgeEvent> {
			public int Compare(JudgeEvent x, JudgeEvent y) {
				return x.StartClip.CompareTo(y.StartClip);
			}
		}
		public Judge(ChartPlayer sys, PdtRuleset rs) {
			_sys = sys;
			_etor = new PdtEvaluator();
			_etor.ContextJudge = this;
			_rs = rs;
			_areaFuncs = rs.judges.Areas;
			_numsrc1 = new PropSrc.Float(() => _numbuf1);
			_numsrc2 = new PropSrc.Float(() => _numbuf2);
			_numsrc3 = new PropSrc.Float(() => _numbuf3);
			_numsrc4 = new PropSrc.Float(() => _numbuf4);
			_rs.judges.Judges.TryGetValue(new Identifier(_var_pause), out _judgePause);
			foreach (var i in rs.inputs) {
				var id = i.Key;
				var l = new List<JudgeEvent>();
				evs.Add(id, l);
				activeEvs.Add(id, new List<JudgeEvent>());
				if (_judgePause != null && id.Key == _var_pause) {
					l.Add(new JudgeEvent {
						StartTime = double.NegativeInfinity, EndTime = double.PositiveInfinity,
						StartClip = double.NegativeInfinity, EndClip = double.PositiveInfinity,
						Definition = _judgePause,
					});
				}
			}
			InitJudges();
			InitScores();
		}
		public void Prepare(StampedEvent sev, NoteHandler handler) {
			var tev = (Chart.Judge)sev.Unstamped;
			if (tev.Id.Key == _var_pause) throw new InvalidOperationException("Cannot assign the special judge \"pause\" to notes");
			Identifier input = default(Identifier);
			Clip clip = default(Clip);
			var def = _rs.judges.Judges[tev.Id];
			_etor.Evaluate(new PropOp.Identifier(v => input = new Identifier(v)), def.input);
			_etor.Evaluate(new PropOp.Clip(v => clip = v), def.clip);
			double st = sev.Time, et = st + sev.Duration;
			var list = evs[input];
			var ev = new JudgeEvent {
				StartTime = st,
				EndTime = et,
				StartClip = st + clip.Behind,
				EndClip = et + clip.Ahead,
				BaseEvent = tev,
				Definition = def,
				Handler = handler,
			};
			var index = list.BinarySearch(ev, _stcmp);
			if (index < 0) index = ~index;
			list.Insert(index, ev);
		}
		#endregion
		#region Judge
		internal readonly IntKeyedDictionary<int> judgeMap = new IntKeyedDictionary<int>();
		void InitJudges() {
			foreach (var i in _rs.judges.Judges) {
				var id = i.Key;
				judgeMap.Add(id.Key, IdentifierManager.Shared.Request("judge_" + id.Name));
			}
		}
		static bool _flag;
		static readonly PropOp.Boolean _flagop = new PropOp.Boolean(v => _flag = v);
		static readonly HitOp _hitop = new HitOp();
		class HitOp : PdtOperator {
			const int MAX_SORTS = 16;
			readonly float[] _buf = new float[MAX_SORTS];
			readonly float[] _sorts = new float[MAX_SORTS];
			public bool LastHit { get; private set; }

			public HitOp() : base(MAX_SORTS) { }

			protected override unsafe void Execute() {
				LastHit = false;
				for (int i = 0; i < LoadedOperandCount; i++) {
					var sort = GetOperand(i).AsNumber();
					if (sort <= 0) return;
					if (!LastHit && sort < _sorts[i]) return;
					if (sort > _sorts[i]) LastHit = true;
					_buf[i] = sort;
				}
				if (!LastHit) return;
				Array.Clear(_buf, LoadedOperandCount, MAX_SORTS - LoadedOperandCount);
				fixed (float* ptrsrc = _buf, ptrdest = _sorts) {
					Unsafe.CopyBlock(ptrdest, ptrsrc, MAX_SORTS * sizeof(float));
				}
			}

			public void Clear() { Array.Clear(_sorts, 0, MAX_SORTS); }
		}
		static readonly int _var_fn = IdentifierManager.Shared.Request("judge_clip_from");
		static readonly int _var_tn = IdentifierManager.Shared.Request("judge_clip_to");
		static readonly int _var_ft = IdentifierManager.Shared.Request("input_time_from");
		static readonly int _var_tt = IdentifierManager.Shared.Request("input_time_to");
		float _numbuf1, _numbuf2, _numbuf3, _numbuf4;
		readonly PropSrc _numsrc1, _numsrc2, _numsrc3, _numsrc4;
		unsafe void LoadNum(byte[] buffer, float value) {
			fixed (byte* ptr = buffer) *(float*)ptr = value;
		}
		// Adopted from System.Collections.Generic.ArraySortHelper<T>.InternalBinarySearch(T[] array, int index, int length, T value, IComparer<T> comparer)
		int BinarySearch(List<JudgeEvent> list, float time, int stack) {
			int num = 0;
			int num2 = list.Count - 1;
			while (num <= num2) {
				int num3 = num + (num2 - num >> 1);
				int num4 = -list[num3].Definition.stack.CompareTo(stack);
				if (num4 == 0) num4 = list[num3].StartClip.CompareTo(time);
				if (num4 == 0) return num3;
				else if (num4 < 0) num = num3 + 1;
				else num2 = num3 - 1;
			}
			return ~num;
		}
		int BinarySearchFirst(List<JudgeEvent> list, int stack) {
			if (list[0].Definition.stack == stack) return 0;
			int num = 0;
			int num2 = list.Count - 1;
			while (num <= num2) {
				int num3 = num + (num2 - num >> 1);
				int num4 = -list[num3].Definition.stack.CompareTo(stack);
				if (num4 > 0) num2 = num3 - 1;
				else if (num4 < 0) num = num3 + 1;
				else if (num != num3) num2 = num3;
				else return num;
			}
			return ~num;
		}
		public void Feed(Identifier target, float ft, float tt) {
			Forward(target, tt);
			var actlist = activeEvs[target];
			if (actlist.Count > 0) {
				_numbuf3 = ft; _numsrc3.Invalidate(); _etor.ContextCascadeUpdate(_var_ft, _numsrc3);
				_numbuf4 = tt; _numsrc4.Invalidate(); _etor.ContextCascadeUpdate(_var_tt, _numsrc4);
				int index = 0, iter = 0;
				while (index < actlist.Count) {
					if (iter++ >= 16) throw new JudgePropagationException();
					_hitop.Clear();
					int cstack = actlist[index].Definition.stack;
					int hitIndex = -1;
					while (index >= 0 && index < actlist.Count) {
						var ev = actlist[index];
						if (ev.Definition.stack != cstack) break;
						_numbuf1 = (float)ev.StartTime; _numsrc1.Invalidate(); _etor.ContextCascadeUpdate(_var_fn, _numsrc1);
						_numbuf2 = (float)ev.EndTime; _numsrc2.Invalidate(); _etor.ContextCascadeUpdate(_var_tn, _numsrc2);
						var def = ev.Definition;
						if (def.hit != null) {
							_etor.Evaluate(_hitop, def.hit);
							if (_hitop.LastHit) hitIndex = index;
						}
						else if (hitIndex == -1) hitIndex = index;
						index++;
					}
					if (hitIndex != -1) {
						var hitEvent = actlist[hitIndex];
						_numbuf1 = (float)hitEvent.StartTime; _numsrc1.Invalidate(); _etor.ContextCascadeUpdate(_var_fn, _numsrc1);
						_numbuf2 = (float)hitEvent.EndTime; _numsrc2.Invalidate(); _etor.ContextCascadeUpdate(_var_tn, _numsrc2);
						var def = hitEvent.Definition;
						if (def == _judgePause) _sys.TogglePause();
						if (def.on_hit != null) Execute(hitEvent, (ft + tt) / 2, def.on_hit);
						if (def.persist != null) _etor.Evaluate(_flagop, def.persist);
						else _flag = false;
						if (!_flag) {
							actlist.RemoveAt(hitIndex);
							--index;
						}
						if (def.prop != 0 && actlist.Count > 0) {
							index = BinarySearchFirst(actlist, def.stack - def.prop);
							if (index < 0) index = ~index;
						}
					}
				}
			}
		}
		public void Cleanup(Identifier target, float tt) {
			lock (_etor) {
				Forward(target, tt);
				var actlist = activeEvs[target];
				for (int i = actlist.Count - 1; i >= 0; i--) {
					JudgeEvent ev = actlist[i];
					if (tt > ev.EndClip) {
						actlist.RemoveAt(i);
						if (ev.Definition.on_miss != null) Execute(ev, tt, ev.Definition.on_miss);
					}
				}
			}
		}
		void Forward(Identifier target, float tt) {
			var list = evs[target];
			var actlist = activeEvs[target];
			JudgeEvent ev;
			while (list.Count > 0 && (ev = list[0]).StartClip <= tt) {
				list.RemoveAt(0);
				var index = BinarySearch(actlist, (float)ev.StartClip, ev.Definition.stack);
				if (index < 0) index = ~index;
				actlist.Insert(index, ev);
			}
		}
		void Execute(JudgeEvent ev, float time, PairList<JudgeAction, PdtExpression> actions, int depth = 0) {
			foreach (var a in actions) {
				if (a.Key.Execute(this, ev, time, a.Value, depth)) break;
			}
		}
		bool IJudge.Pass(JudgeEvent ev, float time, Identifier[] ids, int depth) {
			if (depth >= 16) throw new JudgePropagationException();
			foreach (var i in ids) {
				var def = _rs.judges.Judges[i];
				if (def.hit != null) _etor.Evaluate(_flagop, def.hit);
				else _flag = true;
				if (_flag) {
					if (def.on_hit != null) Execute(ev, time, def.on_hit, depth + 1);
					ev.Handler.ReportJudge(ev, time, i);
					return true;
				}
			}
			return false;
		}
		void IJudge.UpdateScore(ScoreOperation op, PdtExpression exp) {
			_etor.ContextSelfValue = scoreSrcs[op.name.Key];
			_etor.Evaluate(scoreOps[op.name.Key], exp);
			InvalidateScore(op.name.Key);
			foreach (var s in _rs.scores) {
				if (s.Value.value != null) {
					_etor.ContextSelfValue = scoreSrcs[s.Key.Key];
					_etor.Evaluate(scoreOps[s.Key.Key], s.Value.value);
					InvalidateScore(s.Key.Key);
				}
			}
		}
		#endregion
		#region Score
		readonly IntKeyedDictionary<int> scoreStringKeys = new IntKeyedDictionary<int>();
		readonly IntKeyedDictionary<int> scoreStringKeysRev = new IntKeyedDictionary<int>();
		readonly IntKeyedDictionary<PropSrc> scoreSrcs = new IntKeyedDictionary<PropSrc>();
		readonly IntKeyedDictionary<PropOp> scoreOps = new IntKeyedDictionary<PropOp>();
		readonly IntKeyedDictionary<ScoreDefinition> scoreDefs = new IntKeyedDictionary<ScoreDefinition>();
		readonly IntKeyedDictionary<float> scores = new IntKeyedDictionary<float>();
		readonly IntKeyedDictionary<string> scoreStringCache = new IntKeyedDictionary<string>();
		readonly ArrayPool<byte> scoreStringPool = new ArrayPool<byte>();
		readonly IntKeyedDictionary<string> scoreFormatCache = new IntKeyedDictionary<string>();
		readonly TargetString scoreFullStr = new TargetString();
		readonly StringBuffer scoreFullBuf = new StringBuffer();
		void InitScores() {
			foreach (var s in _rs.scores) {
				var key = s.Key.Key;
				var strkey = IdentifierManager.Shared.Request("_score_" + (string)s.Key.Name);
				scoreStringKeys.Add(key, strkey);
				scoreStringKeysRev.Add(strkey, key);
				scoreSrcs.Add(key, new PropSrc.Float(() => scores[key]));
				scoreOps.Add(key, new PropOp.Float(v => scores[key] = v));
				scoreDefs.Add(key, s.Value);
				scores.Add(key, s.Value.init);
				scoreStringCache.Add(scoreStringKeys[key], null);
				scoreSrcs.Add(scoreStringKeys[key], new ScoreStringSrc(scoreStringPool, () => scores[key], scoreDefs[key].format));
				scoreFormatCache[key] = string.Format("{{0:{0}}}", s.Value.format);
			}
		}
		void InvalidateScore(int key) {
			scoreSrcs[key].Invalidate();
			scoreStringCache[scoreStringKeys[key]] = null;
			scoreSrcs[scoreStringKeys[key]].Invalidate();
		}
		public bool TryGetScoreSrc(int key, out PropSrc value) {
			return scoreSrcs.TryGetValue(key, out value);
		}
		public TargetString GetFullFormattedScoreString() {
			lock (_etor) {
				bool flag = false;
				scoreFullBuf.Clear();
				foreach (var s in scores) {
					var id = s.Key;
					scoreFullBuf.AppendFormat(flag ? "\n{0}: " : "{0}: ", (string)IdentifierManager.Shared.Retrieve(id));
					scoreFullBuf.AppendFormat(scoreFormatCache[id], scores[id]);
					flag = true;
				}
				scoreFullStr.Length = scoreFullBuf.Count;
				var arr = scoreFullStr.TrustedAsArray();
				scoreFullBuf.CopyTo(0, arr, 0, scoreFullBuf.Count);
				return scoreFullStr;
			}
		}
		class ScoreStringSrc : PropSrc {
			readonly Func<float> _cb;
			readonly string _format;
			readonly ArrayPool<byte> _pool;
			readonly StringBuffer _buf = new StringBuffer() { Culture = CultureInfo.InvariantCulture };
			public ScoreStringSrc(ArrayPool<byte> pool, Func<float> cb, string format)
				: base(PdtInternalType.String) {
				_pool = pool;
				_cb = cb;
				_format = string.Format("{{0:{0}}}", format);
			}
			public override void Invalidate() {
				if (buf != null) {
					_pool.Return(buf);
					base.Invalidate();
				}
			}
			protected override unsafe void InternalGet() {
				var src = _cb();
				_buf.Clear();
				_buf.AppendFormat(_format, src);
				int strlen = _buf.Count;
				buf = _pool.Rent(sizeof(int) + strlen * sizeof(char));
				fixed (byte* _ptr = buf) {
					*(int*)_ptr = strlen;
					char* ptr = (char*)(_ptr + sizeof(int));
					_buf.CopyTo(ptr, 0, strlen);
				}
			}
		}
		#endregion
	}

	[Serializable]
	public class JudgePropagationException : Exception {
		public JudgePropagationException() : base("Judge propagation limit reached\nThe ruleset has invalid judge definitions") { }
		public JudgePropagationException(string message) : base(message) { }
		public JudgePropagationException(string message, Exception inner) : base(message, inner) { }
		protected JudgePropagationException(SerializationInfo info, StreamingContext context) : base(info, context) { }
	}
}