Implementation of the basic functionallity

AMWD.Protocols.Modbus.Common/Extensions/ModbusExtensions.cs

@@ -0,0 +1,175 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+
+namespace AMWD.Protocols.Modbus.Common
+{
+	/// <summary>
+	/// Custom extensions for <see cref="ModbusObject"/>s.
+	/// </summary>
+	public static class ModbusExtensions
+	{
+		/// <summary>
+		/// Converts a <see cref="ModbusObject"/> into a <see cref="bool"/> value.
+		/// </summary>
+		/// <param name="obj">The Modbus object.</param>
+		/// <returns>The objects bool value.</returns>
+		/// <exception cref="ArgumentNullException">when the object is null.</exception>
+		public static bool GetBoolean(this ModbusObject obj)
+		{
+#if NET8_0_OR_GREATER
+			ArgumentNullException.ThrowIfNull(obj);
+#else
+			if (obj == null)
+				throw new ArgumentNullException(nameof(obj));
+#endif
+
+			if (obj is Coil coil)
+				return coil.Value;
+
+			if (obj is DiscreteInput discreteInput)
+				return discreteInput.Value;
+
+			return obj.HighByte > 0 || obj.LowByte > 0;
+		}
+
+		/// <summary>
+		/// Converts multiple <see cref="ModbusObject"/>s into a <see cref="string"/> value.
+		/// </summary>
+		/// <param name="list">The list of Modbus objects.</param>
+		/// <param name="length">The number of registers to use.</param>
+		/// <param name="startIndex">The first index to use.</param>
+		/// <param name="encoding">The encoding used to convert the text. (Default: <see cref="Encoding.ASCII"/>)</param>
+		/// <param name="reverseRegisterOrder">Indicates whehter the taken registers should be reversed.</param>
+		/// <param name="reverseByteOrderPerRegister">Indicates whether to reverse high and low byte per register.</param>
+		/// <returns>The objects text value.</returns>
+		/// <exception cref="ArgumentNullException">when the list is null.</exception>
+		/// <exception cref="ArgumentException">when the list is too short or the list contains mixed/incompatible objects.</exception>
+		/// <exception cref="ArgumentOutOfRangeException">when the <paramref name="startIndex"/> is too high.</exception>
+		public static string GetString(this IEnumerable<ModbusObject> list, int length, int startIndex = 0, Encoding encoding = null, bool reverseRegisterOrder = false, bool reverseByteOrderPerRegister = false)
+		{
+#if NET8_0_OR_GREATER
+			ArgumentNullException.ThrowIfNull(list);
+#else
+			if (list == null)
+				throw new ArgumentNullException(nameof(list));
+#endif
+
+			int count = list.Count();
+			if (count < length)
+				throw new ArgumentException($"At least {length} registers required", nameof(list));
+
+			if (startIndex < 0 || startIndex + length > count)
+				throw new ArgumentOutOfRangeException(nameof(startIndex));
+
+			if (!list.All(o => o.Type == ModbusObjectType.HoldingRegister) && !list.All(o => o.Type == ModbusObjectType.InputRegister))
+				throw new ArgumentException("Mixed object types found", nameof(list));
+
+			var registers = list.OrderBy(o => o.Address).Skip(startIndex).Take(length).ToArray();
+			if (reverseRegisterOrder)
+				Array.Reverse(registers);
+
+			byte[] blob = new byte[registers.Length * 2];
+			for (int i = 0; i < registers.Length; i++)
+			{
+				blob[i * 2] = reverseByteOrderPerRegister
+					? registers[i].LowByte
+					: registers[i].HighByte;
+
+				blob[i * 2 + 1] = reverseByteOrderPerRegister
+					? registers[i].HighByte
+					: registers[i].LowByte;
+			}
+
+			string text = (encoding ?? Encoding.ASCII).GetString(blob).Trim([' ', '\t', '\0', '\r', '\n']);
+			int nullIndex = text.IndexOf('\0');
+
+			if (nullIndex > 0)
+			{
+#if NET6_0_OR_GREATER
+				return text[..nullIndex];
+#else
+				return text.Substring(0, nullIndex);
+#endif
+			}
+
+			return text;
+		}
+
+		/// <summary>
+		/// Converts a <see cref="bool"/> value to a <see cref="Coil"/>.
+		/// </summary>
+		/// <param name="value">The bool value.</param>
+		/// <param name="address">The coil address.</param>
+		/// <returns>The coil.</returns>
+		public static Coil ToCoil(this bool value, ushort address)
+		{
+			return new Coil
+			{
+				Address = address,
+				Value = value
+			};
+		}
+
+		/// <summary>
+		/// Converts a <see cref="bool"/> value to a <see cref="HoldingRegister"/>.
+		/// </summary>
+		/// <param name="value">The bool value.</param>
+		/// <param name="address">The register address.</param>
+		/// <returns>The register.</returns>
+		public static HoldingRegister ToRegister(this bool value, ushort address)
+		{
+			return new HoldingRegister
+			{
+				Address = address,
+				Value = (ushort)(value ? 1 : 0)
+			};
+		}
+
+		/// <summary>
+		/// Converts a <see cref="string"/> value to a <see cref="HoldingRegister"/>.
+		/// </summary>
+		/// <param name="value">The text.</param>
+		/// <param name="address">The address of the text.</param>
+		/// <param name="encoding">The encoding used to convert the text. (Default: <see cref="Encoding.ASCII"/>)</param>
+		/// <param name="reverseRegisterOrder">Indicates whehter the taken registers should be reversed.</param>
+		/// <param name="reverseByteOrderPerRegister">Indicates whether to reverse high and low byte per register.</param>
+		/// <returns>The registers.</returns>
+		/// <exception cref="ArgumentNullException">when the text is null.</exception>
+		public static IEnumerable<HoldingRegister> ToRegisters(this string value, ushort address, Encoding encoding = null, bool reverseRegisterOrder = false, bool reverseByteOrderPerRegister = false)
+		{
+#if NET8_0_OR_GREATER
+			ArgumentNullException.ThrowIfNull(value);
+#else
+			if (value == null)
+				throw new ArgumentNullException(nameof(value));
+#endif
+
+			byte[] blob = (encoding ?? Encoding.ASCII).GetBytes(value);
+			int numRegisters = (int)Math.Ceiling(blob.Length / 2.0);
+
+			for (int i = 0; i < numRegisters; i++)
+			{
+				int addr = reverseRegisterOrder
+					? address + numRegisters - 1 - i
+					: address + i;
+
+				var register = new HoldingRegister
+				{
+					Address = (ushort)addr,
+
+					HighByte = reverseByteOrderPerRegister
+						? (i * 2 + 1 < blob.Length ? blob[i * 2 + 1] : (byte)0)
+						: blob[i * 2],
+
+					LowByte = reverseByteOrderPerRegister
+						? blob[i * 2]
+						: (i * 2 + 1 < blob.Length ? blob[i * 2 + 1] : (byte)0)
+				};
+
+				yield return register;
+			}
+		}
+	}
+}