using Cryville.Common;
using Cryville.Common.Pdt;
using Cryville.Crtr.Components;
using System;
using System.Collections.Generic;
using System.Reflection;

namespace Cryville.Crtr {
	public class SkinInterpreter : PdtInterpreter {
		public SkinInterpreter(string src, Binder binder) : base(src, typeof(PdtSkin), binder) { }

		readonly List<SkinSelector> s = new List<SkinSelector>();
		readonly HashSet<string> a = new HashSet<string>();
		readonly List<string> k = new List<string>(2);
		protected override object InterpretKey(Type type) {
			s.Clear(); a.Clear(); k.Clear();
			bool invalidKeyFlag = false, compKeyFlag = false;
			while (true) {
				int pp = Position;
				switch (cc) {
					case '@':
						GetChar();
						a.Add(GetIdentifier());
						break;
					case '$':
						GetChar();
						s.Add(new SkinSelector.CreateObject());
						invalidKeyFlag = true;
						break;
					case '.':
						GetChar();
						if (cc == '.') {
							GetChar();
							s.Add(new SkinSelector.AtAnchor(GetIdentifier()));
							invalidKeyFlag = true;
						}
						else {
							var p3 = GetIdentifier();
							s.Add(new SkinSelector.Anchor(p3));
							if (!invalidKeyFlag) {
								if (k.Count != 1) invalidKeyFlag = true;
								else k.Add(p3);
							}
						}
						break;
					case '>':
						GetChar();
						s.Add(new SkinSelector.Property(GetExp()));
						break;
					case ';':
					case ':':
						if (invalidKeyFlag) throw new FormatException("Invalid key format");
						if (a.Contains("has")) {
							if (k.Count != 1) throw new FormatException("Invalid anchor name");
							return new SkinPropertyKey.CreateAnchor {
								Name = IdentifierManager.SharedInstance.Request(k[0])
							};
						}
						else if (a.Contains("at")) {
							if (k.Count != 1) throw new FormatException("Invalid anchor name");
							return new SkinPropertyKey.SetAnchor {
								Name = IdentifierManager.SharedInstance.Request(k[0])
							};
						}
						switch (k.Count) {
							case 1:
								if (compKeyFlag) return new SkinPropertyKey.CreateComponent {
									Component = GetComponentByName(k[0])
								};
								else return new SkinPropertyKey.SetProperty {
									Component = typeof(TransformInterface),
									Name = IdentifierManager.SharedInstance.Request(k[0])
								};
							case 2:
								return new SkinPropertyKey.SetProperty {
									Component = GetComponentByName(k[0]),
									Name = IdentifierManager.SharedInstance.Request(k[1])
								};
							default:
								throw new FormatException("Unknown error"); // Unreachable
						}
					case '{':
						return new SkinSelectors(s, a);
					case '}':
						return null;
					case '*':
						GetChar();
						compKeyFlag = true;
						break;
					default:
						var p4 = GetIdentifier();
						s.Add(new SkinSelector.ElementType(p4));
						if (!invalidKeyFlag) {
							if (k.Count != 0) invalidKeyFlag = true;
							else k.Add(p4);
						}
						break;
				}
				ws();
				if (Position == pp) throw new FormatException("Invalid selector or key format");
			}
		}
		static Type GetComponentByName(string name) {
			Type result;
			if (GenericResources.Components.TryGetValue(name, out result)) return result;
			throw new ArgumentException(string.Format("Component type \"{0}\" not found", name));
		}
	}
}