using System.Collections.Generic;
using System.Text;

namespace TableParser
{
    public class FieldsParserTask
    {
        public static List<string> ParseLine(string inputLine)
        {
            var word = new StringBuilder();
            var line = inputLine + " ";
            var parsedLine = new List<string>();

            for (var i = 0; i < line.Length; i++)
            {
                var ch = line[i];
                if (ch == '\"' || ch == '\'')
                {
                    AddNotEmptyWord(word, parsedLine);
                    var token = ReadField(line, i, parsedLine);
                    AddNotEmptyWord(new StringBuilder(token.Value), parsedLine);
                    i += token.Length;
                }
                else if (ch == ' ')
                    AddNotEmptyWord(word, parsedLine);
                else
                    word.Append(ch);
            }
            if (parsedLine.Count == 0 && inputLine != "")
                parsedLine.Add("");
            return parsedLine;
        }

        private static Token ReadField(string line, int startIndex, List<string> parsedLine)
        {
            var field = new StringBuilder();
            var typeOfQuote = line[startIndex];
            for (var i = startIndex + 1; i < line.Length; i++)
            {
                var ch = line[i];
                if (ch == '\\')
                    field.Append(line[++i]);
                else if (ch != typeOfQuote)
                    field.Append(ch);
                if (ch == typeOfQuote || i == line.Length - 2)
                {
                    var length = i - (startIndex + 1);
                    return new Token(field.ToString(), startIndex, length + 1);
                }
            }
            return new Token("", startIndex, 0);
        }

        private static void AddNotEmptyWord(StringBuilder word, List<string> list)
        {
            if (word.Length != 0)
                list.Add(word.ToString());
            word.Clear();
        }
    }
}