OOP 4

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using NUnit.Framework;

namespace TableParser
{
    [TestFixture]
    public class QuotedFieldTaskTests
    {
        [TestCase("''", 0, "", 2)]
        [TestCase("'a'", 0, "a", 3)]
        [TestCase("asd\"bad\"ds", 3, "bad", 5)]
        [TestCase("\"\\\\\" b", 0, "\\", 4)]
        [TestCase("'a\\\' b'", 0, "a' b", 7)]
        [TestCase("'\\\\\\\\\\\\\\\\\\' 1", 0, "\\\\\\\\' 1", 13)]
        [TestCase("\"a \\\"c\\\"\"", 0, "a \"c\"", 9)]
        public void Test(string line, int startIndex, string expectedValue, int expectedLength)
        {
            var actualToken = QuotedFieldTask.ReadQuotedField(line, startIndex);
            Assert.AreEqual(new Token(expectedValue, startIndex, expectedLength), actualToken);
        }
    }

    class QuotedFieldTask
    {
        public static Token ReadQuotedField(string line, int startIndex)
        {
            string value = "";
            bool flag = false;
            if ((line[startIndex] == '"') || (line[startIndex] == '\''))
            {
                for (int i = startIndex + 1; i < line.Length; i++)
                {
                    if ((line[i] == '\\') && (flag == false))
                    {
                        flag = true;
                        continue;
                    }
                    if ((line[i] == line[startIndex]) && (flag == false))
                        return new Token(value, startIndex, i - startIndex + 1);
                    value += line[i];
                    flag = false;
                }
            }
            else
            {
                for (int i = startIndex; i < line.Length; i++)
                {
                    if ((line[i] == '"') || (line[i] == '\'')) return new Token(value, startIndex, i - startIndex + 1);
                    value += line[i];
                }
            }
            return new Token(value, startIndex, line.Length - startIndex);
        }
    }
}