Different types of units. Writing values, relay unit

esp_server/Unit/UnitFactory.cs

@@ -0,0 +1,36 @@
+using System;
+using System.Collections.Generic;
+using System.Text;
+using System.Text.Json;
+
+namespace ESPServer
+{
+	static class UnitFactory
+	{
+		public static Unit CreateUnit(JsonElement config)
+		{
+			var type = "";
+			JsonElement val;
+			if (config.TryGetProperty("type", out val))
+			{
+				type = val.GetString();
+			}
+			Unit u;
+			if (type == "relay") u = new RelayUnit();
+			else u = new Unit();
+			u.id = config.GetProperty("id").GetString();
+			u.name = config.GetProperty("name").GetString();
+			u.baseAddress = config.GetProperty("address").GetInt32();
+			u.values = new Dictionary<string, UnitValue>();
+			foreach (var knownValue in config.GetProperty("values").EnumerateArray())
+			{
+				var uv = new UnitValue();
+				uv.name = knownValue.GetProperty("name").GetString();
+				uv.addressOffset = knownValue.GetProperty("offset").GetInt32();
+				u.values[uv.name] = uv;
+			}
+			
+			return u;
+		}
+	}
+}