using System.Collections.Generic;
namespace Ink
{
	public partial class InkParser
	{
		// Handles both newline and endOfFile
		protected object EndOfLine()
		{
            return OneOf(Newline, EndOfFile);
		}
        // Allow whitespace before the actual newline
        protected object Newline()
        {
            Whitespace();
            bool gotNewline = ParseNewline () != null;
            // Optional \r, definite \n to support Windows (\r\n) and Mac/Unix (\n)
            if( !gotNewline ) {
                return null;
            } else {
                return ParseSuccess;
            }
        }
		protected object EndOfFile()
		{
			Whitespace();
            if (!endOfInput)
                return null;
            return ParseSuccess;
		}
		// General purpose space, returns N-count newlines (fails if no newlines)
		protected object MultilineWhitespace()
		{
            List<object> newlines = OneOrMore(Newline);
            if (newlines == null)
                return null;
			// Use content field of Token to say how many newlines there were
			// (in most circumstances it's unimportant)
			int numNewlines = newlines.Count;
			if (numNewlines >= 1) {
                return ParseSuccess;
			} else {
                return null;
			}
		}
		protected object Whitespace()
		{
			if( ParseCharactersFromCharSet(_inlineWhitespaceChars) != null ) {
				return ParseSuccess;
			}
			return null;
		}
        protected ParseRule Spaced(ParseRule rule)
        {
            return () => {
                Whitespace ();
                var result = ParseObject(rule);
                if (result == null) {
                    return null;
                }
                Whitespace ();
                return result;
            };
        }
        protected object AnyWhitespace ()
        {
            bool anyWhitespace = false;
            while (OneOf (Whitespace, MultilineWhitespace) != null) {
                anyWhitespace = true;
            }
            return anyWhitespace ? ParseSuccess : null;
        }
        protected ParseRule MultiSpaced (ParseRule rule)
        {
            return () => {
                AnyWhitespace ();
                var result = ParseObject (rule);
                if (result == null) {
                    return null;
                }
                AnyWhitespace ();
                return result;
            };
        }
		private CharacterSet _inlineWhitespaceChars = new CharacterSet(" \t");
	}
}