#if UNITY_EDITOR
using System.Collections.Generic;

namespace SLZ.Bonelab
{
	public class SILexer
	{
		string fileName;
		int index = 0;
		int lineNumber = 0;
		int lineStartIndex = 0;

		//public List<CommandInfo> commands;

		public class CommandInfo
		{
			public SILexicon.CmdType cmdType;
			public int line;
			public int beginIndex;
			public int endIndex;
			public List<string> parameters;
		}

		public List<CommandInfo> LexFile(ref string file)
		{
			List<CommandInfo> commands = new List<CommandInfo>();
			index = 0;
			lineNumber = 0;
			lineStartIndex = 0;
			while (!HasReachedEOF())
			{
				JumpToNextCommand(ref file);
				if (!HasReachedEOF())
				{
					LexCommand(ref file, ref commands);
				}
			}
			/*
			foreach (CommandInfo cmd in commands)
			{
				string logOut = "Shader Injector Lexer Debug\n";
				logOut += "Command Type: " +cmd.cmdType + "\n";
				logOut += "Line: " + cmd.line + "\n";
				logOut += "Begin: " + cmd.beginIndex + "\n";
				logOut += "End: " + cmd.endIndex + "\n";
				logOut += "Parameters: \n";
				foreach (string pm in cmd.parameters)
				{
					logOut += pm + "\n";
				}
				//Debug.Log(logOut);
			}
			*/
			return commands;
		}
		void LexCommand(ref string file, ref List<CommandInfo> commands)
		{
			int nextWS = peekToWhiteSpace(ref file);
			SILexicon.CmdType command = SILexicon.Instance.parseCommand(file.Substring(index, nextWS - index));
			JumpToPeek(ref file, nextWS);
			CommandInfo cmd = new CommandInfo();
			cmd.cmdType = command;
			cmd.line = lineNumber;
			cmd.beginIndex = lineStartIndex;
			cmd.parameters = new List<string>();
			skipWhiteSpaceNoNewLine(ref file);
			while (!HasReachedEOF() && file[index] != '\n')
			{
				nextWS = peekToWhiteSpace(ref file);
				cmd.parameters.Add(file.Substring(index, nextWS - index));
				JumpToPeek(ref file, nextWS);
				if (!HasReachedEOF())
				{
					skipWhiteSpaceNoNewLine(ref file);
				}
			}
			cmd.endIndex = HasReachedEOF() ? file.Length - 1 : index;
			commands.Add(cmd);
		}

		void JumpToNextCommand(ref string file)
		{
			if (HasReachedEOF())
			{
				return;
			}
			int end = file.Length - SILexicon.injectorPrefix.Length;
			while (index < end && index != -1)
			{
				skipWhiteSpace(ref file);
				if (index == -1)
				{
					ReachedEOF();
					return;
				}
				if (isHeader(ref file))
				{
					index += SILexicon.injectorPrefix.Length;
					return;
				}
				skipToNewLine(ref file);
			}
			ReachedEOF();
			return;
		}

		void skipToNewLine(ref string file)
		{
			if (HasReachedEOF())
			{
				return;
			}
			while (index < file.Length - 1)
			{
				if (file[index] == '\n')
				{
					lineNumber++;
					index++;
					lineStartIndex = index;
					return;
				}
				index++;
			}
			ReachedEOF();
			return;
		}


		void skipWhiteSpace(ref string file)
		{
			if (HasReachedEOF())
			{
				return;
			}
			while (index < file.Length)
			{
				if (!char.IsWhiteSpace(file[index]))
				{
					return;
				}
				else if (file[index] == '\n')
				{
					lineNumber++;
					lineStartIndex = index + 1;
				}
				index++;
			}
			ReachedEOF();
		}

		void skipWhiteSpaceNoNewLine(ref string file)
		{
			if (HasReachedEOF())
			{
				return;
			}
			while (index < file.Length)
			{
				if (!char.IsWhiteSpace(file[index]) || file[index] == '\n')
				{
					return;
				}
				index++;
			}
			ReachedEOF();
		}

		int peekToWhiteSpace(ref string file)
		{
			int peekIndex = index;
			while (peekIndex < file.Length)
			{
				if (char.IsWhiteSpace(file[peekIndex]))
				{
					break;
				}
				peekIndex++;
			}
			return peekIndex;
		}

		void JumpToPeek(ref string file, int peekIndex)
		{
			if (peekIndex < file.Length)
			{
				index = peekIndex;
			}
			else
			{
				ReachedEOF();
			}
		}

		bool isHeader(ref string file)
		{
			for (int i = 0; i < SILexicon.injectorPrefix.Length; i++)
			{
				if (file[i + index] != SILexicon.injectorPrefix[i])
				{
					return false;
				}
			}
			return true;
		}

		void ReachedEOF()
		{
			index = -1;
		}

		bool HasReachedEOF()
		{
			return index == -1;
		}
	}
}
#endif