Sharp7Reactive/Sharp7.Rx/S7VariableNameParser.cs

using System.Globalization;
using System.Text.RegularExpressions;
using Sharp7.Rx.Enums;
using Sharp7.Rx.Interfaces;

namespace Sharp7.Rx;

internal class S7VariableNameParser : IS7VariableNameParser
{
    private static readonly Regex regex = new Regex(@"^(?<operand>db{1})(?<dbNr>\d{1,4})\.?(?<type>dbx|x|s|string|b|dbb|d|int|dbw|w|dint|dul|dulint|dulong|){1}(?<start>\d+)(\.(?<bitOrLength>\d+))?$", RegexOptions.IgnoreCase | RegexOptions.Compiled | RegexOptions.CultureInvariant);

    private static readonly IReadOnlyDictionary<string, DbType> types = new Dictionary<string, DbType>(StringComparer.OrdinalIgnoreCase)
    {
        {"x", DbType.Bit},
        {"dbx", DbType.Bit},
        {"s", DbType.String},
        {"string", DbType.String},
        {"b", DbType.Byte},
        {"dbb", DbType.Byte},
        {"d", DbType.Double},
        {"int", DbType.Integer},
        {"dint", DbType.DInteger},
        {"w", DbType.Integer},
        {"dbw", DbType.Integer},
        {"dul", DbType.ULong},
        {"dulint", DbType.ULong},
        {"dulong", DbType.ULong}
    };

    public S7VariableAddress Parse(string input)
    {
        var match = regex.Match(input);
        if (match.Success)
        {
            var operand = (Operand) Enum.Parse(typeof(Operand), match.Groups["operand"].Value, true);
            var dbNr = ushort.Parse(match.Groups["dbNr"].Value, NumberStyles.Integer, CultureInfo.InvariantCulture);
            var start = ushort.Parse(match.Groups["start"].Value, NumberStyles.Integer, CultureInfo.InvariantCulture);
            if (!types.TryGetValue(match.Groups["type"].Value, out var type))
                return null;


            var s7VariableAddress = new S7VariableAddress
            {
                Operand = operand,
                DbNr = dbNr,
                Start = start,
                Type = type,
            };

            switch (type)
            {
                case DbType.Bit:
                    s7VariableAddress.Length = 1;
                    s7VariableAddress.Bit = byte.Parse(match.Groups["bitOrLength"].Value);
                    break;
                case DbType.Byte:
                    s7VariableAddress.Length = match.Groups["bitOrLength"].Success ? ushort.Parse(match.Groups["bitOrLength"].Value) : (ushort) 1;
                    break;
                case DbType.String:
                    s7VariableAddress.Length = match.Groups["bitOrLength"].Success ? ushort.Parse(match.Groups["bitOrLength"].Value) : (ushort) 0;
                    break;
                case DbType.Integer:
                    s7VariableAddress.Length = 2;
                    break;
                case DbType.DInteger:
                    s7VariableAddress.Length = 4;
                    break;
                case DbType.ULong:
                    s7VariableAddress.Length = 8;
                    break;
                case DbType.Double:
                    s7VariableAddress.Length = 4;
                    break;
            }

            return s7VariableAddress;
        }

        return null;
    }
}