BF2Statistics.Gamespy.MasterClient.FixFilterQuotes C# (CSharp) Method

        private static string FixFilterQuotes(string filter)
        {
            StringBuilder newFilter = new StringBuilder(filter);

            for (int i = 0; i < filter.Length; i++)
            {
                int length = 0;
                bool isOperator = IsOperator(filter, i, out length);

                if (isOperator)
                {
                    i += length;
                    bool isInsideString = false;
                    for (; i < filter.Length; i++)
                    {
                        if (filter[i] == '\'' || filter[i] == '"')
                        {
                            if (isInsideString)
                            {
                                // check what's after the quote to see if we terminate the string
                                if (i >= filter.Length - 1)
                                {
                                    // end of string
                                    isInsideString = false;
                                    break;
                                }
                                for (int j = i + 1; j < filter.Length; j++)
                                {
                                    // continue along whitespace
                                    if (filter[j] == ' ')
                                    {
                                        continue;
                                    }
                                    else
                                    {
                                        // if it's a logical operator, then we terminate
                                        bool op = IsLogical(filter, j, out length);
                                        if (op)
                                        {
                                            isInsideString = false;
                                            j += length;
                                            i = j;
                                        }
                                        break;
                                    }
                                }
                                if (isInsideString)
                                {
                                    // and if we're still inside the string, replace the quote with a wildcard character
                                    newFilter[i] = '_';
                                }
                                continue;
                            }
                            else
                            {
                                isInsideString = true;
                            }
                        }
                    }
                }
            }

            return newFilter.ToString();
        }