Initial commit carried over from private repo. This is V2.

code/MessengerApi.Configuration/Parsers/EnvironmentPersistenceConfigurationParser.cs

@@ -0,0 +1,25 @@
+using MessengerApi.Configuration.Model.Persistence;
+using MessengerApi.Configuration.Model.Persistence.Base;
+using MessengerApi.Configuration.Sources.Environment;
+
+namespace MessengerApi.Configuration.Parsers
+{
+    public static class EnvironmentPersistenceConfigurationParser
+    {
+        public static PersistenceConfiguration Parse(IEnvironmentConfigurationSource config)
+        {
+            var type = PersistenceTypeParser.Parse(config.GetValue<string>(Constants.EnvironmentVariables.PERSISTENCE_TYPE));
+            
+            if(type == Enums.PersistenceTypes.Sql)
+            {
+                return new SqlPersistenceConfiguration(config);
+            }
+            else if(type == Enums.PersistenceTypes.PostgreSql)
+            {
+                return new NpgPersistenceConfiguration(config);
+            }
+
+            throw new InvalidOperationException("Unrecognized persistence type.");
+        }
+    }
+}