using Cryville.Common;
using Cryville.Common.Buffers;
using Cryville.Common.Pdt;
using System;
using System.Collections.Generic;
using System.Globalization;
using System.Text.Formatting;

namespace Cryville.Crtr {
	public class Judge {
		#region Data
		readonly ChartPlayer _sys;
		readonly PdtEvaluator _etor;
		readonly PdtRuleset _rs;
		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.SharedInstance.Request("pause");
		readonly JudgeDefinition _judgePause;
		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; }
		}
		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 = ChartPlayer.etor;
			_rs = rs;
			_numsrc1 = new PropSrc.Float(() => _numbuf1);
			_numsrc2 = new PropSrc.Float(() => _numbuf2);
			_numsrc3 = new PropSrc.Float(() => _numbuf3);
			_numsrc4 = new PropSrc.Float(() => _numbuf4);
			_rs.judges.TryGetValue(new Identifier(_var_pause), out _judgePause);
			foreach (var i in rs.inputs.Keys) {
				var l = new List<JudgeEvent>();
				evs.Add(i, l);
				activeEvs.Add(i, new List<JudgeEvent>());
				if (_judgePause != null && i.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);
			ChartPlayer.etor.Evaluate(new PropOp.Identifier(v => input = new Identifier(v)), _rs.judges[tev.Id].input);
			double st = sev.Time, et = st + sev.Duration;
			var list = evs[input];
			var def = _rs.judges[tev.Id];
			var ev = new JudgeEvent {
				StartTime = st,
				EndTime = et,
				StartClip = st + def.clip.Behind,
				EndClip = et + def.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 Dictionary<int, int> judgeMap = new Dictionary<int, int>();
		void InitJudges() {
			foreach (var i in _rs.judges.Keys) {
				judgeMap.Add(i.Key, IdentifierManager.SharedInstance.Request("judge_" + i.Name));
			}
		}
		static bool _flag;
		static readonly PropOp.Boolean _flagop = new PropOp.Boolean(v => _flag = v);
		static readonly int _var_fn = IdentifierManager.SharedInstance.Request("fn");
		static readonly int _var_tn = IdentifierManager.SharedInstance.Request("tn");
		static readonly int _var_ft = IdentifierManager.SharedInstance.Request("ft");
		static readonly int _var_tt = IdentifierManager.SharedInstance.Request("tt");
		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, float time, int stack) {
			if (list[0].Definition.stack == stack && list[0].StartClip == time) 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) num4 = list[num3].StartClip.CompareTo(time);
				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);
				var index = 0;
				while (index >= 0 && index < actlist.Count) {
					var ev = actlist[index];
					_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(_flagop, def.hit);
					else _flag = true;
					if (_flag) {
						if (ev.Definition == _judgePause) _sys.TogglePause();
						if (def.scores != null) UpdateScore(def.scores);
						if (def.pass != null) Pass(ev, (ft + tt) / 2, def.pass);
						if (def.persist != null) _etor.Evaluate(_flagop, def.persist);
						else _flag = false;
						if (!_flag) actlist.RemoveAt(index);
						if (def.prop != 0 && actlist.Count > 0) {
							index = BinarySearchFirst(actlist, (float)ev.StartClip, def.stack - def.prop);
							if (index < 0) index = ~index;
						}
						else index++;
					}
					else index++;
				}
			}
		}
		bool Pass(JudgeEvent ev, float time, Identifier[] ids) {
			foreach (var i in ids) {
				var def = _rs.judges[i];
				if (def.hit != null) _etor.Evaluate(_flagop, def.hit);
				else _flag = true;
				if (_flag) {
					if (def.scores != null) UpdateScore(def.scores);
					if (def.pass != null) Pass(ev, time, def.pass);
					ev.Handler.ReportJudge(ev, time, i);
					return true;
				}
			}
			return false;
		}
		public void Cleanup(Identifier target, float tt) {
			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.miss != null) Pass(ev, tt, ev.Definition.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 UpdateScore(Dictionary<ScoreOperation, PdtExpression> scoreops) {
			foreach (var scoreop in scoreops) {
				var key = scoreop.Key;
				_etor.ContextSelfValue = scoreSrcs[key.name.Key];
				_etor.Evaluate(scoreOps[key.name.Key], scoreop.Value);
				InvalidateScore(key.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 Dictionary<int, int> scoreStringKeys = new Dictionary<int, int>();
		readonly Dictionary<int, int> scoreStringKeysRev = new Dictionary<int, int>();
		readonly Dictionary<int, PropSrc> scoreSrcs = new Dictionary<int, PropSrc>();
		readonly Dictionary<int, PropOp> scoreOps = new Dictionary<int, PropOp>();
		readonly Dictionary<int, ScoreDefinition> scoreDefs = new Dictionary<int, ScoreDefinition>();
		readonly Dictionary<int, float> scores = new Dictionary<int, float>();
		readonly Dictionary<int, string> scoreStringCache = new Dictionary<int, string>();
		readonly ArrayPool<byte> scoreStringPool = new ArrayPool<byte>();
		readonly Dictionary<int, string> scoreFormatCache = new Dictionary<int, 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.SharedInstance.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() {
			bool flag = false;
			scoreFullBuf.Clear();
			foreach (var s in scores.Keys) {
				scoreFullBuf.AppendFormat(flag ? "\n{0}: " : "{0}: ", (string)IdentifierManager.SharedInstance.Retrieve(s));
				scoreFullBuf.AppendFormat(scoreFormatCache[s], scores[s]);
				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
	}
	#region Definitions
	public class InputDefinition {
		public int dim;
		public bool notnull;
		public Dictionary<Identifier, PdtExpression> pass;
	}
	public class JudgeDefinition {
		public Clip clip;
		public PdtExpression input;
		public PdtExpression hit;
		public PdtExpression persist;
		public Identifier[] pass;
		public Identifier[] miss;
		public Dictionary<ScoreOperation, PdtExpression> scores;
		public int stack;
		public int prop = 1;
	}
	public class ScoreOperation {
		public Identifier name;
		public Identifier op;
		public override string ToString() {
			if (op == default(Identifier)) return name.ToString();
			else return string.Format("{0} {1}", name, op);
		}
	}
	public class ScoreDefinition {
		public PdtExpression value;
		public float init = 0;
		public string format = "";
	}
	#endregion
}