SerializableType CompileNonContractTypes()

in src/Serialization/AmqpContractSerializer.cs [422:506]
71 lines of code
13 McCabe index (conditional complexity)

        SerializableType CompileNonContractTypes(Type type)
        {
            if (type.GetTypeInfo().IsGenericType &&
                type.GetGenericTypeDefinition() == typeof(Nullable<>))
            {
                Type[] argTypes = type.GetGenericArguments();
                Fx.Assert(argTypes.Length == 1, "Nullable type must have one argument");
                return this.GetType(argTypes[0]);
            }

            if (type.GetTypeInfo().IsInterface)
            {
                if (typeof(IEnumerable).GetTypeInfo().IsAssignableFrom(type.GetTypeInfo()))
                {
                    // if a member is defined as enumerable interface, we have to change it
                    // to list, otherwise the decoder cannot initialize an object of an interface
                    Type itemType = typeof(object);
                    Type listType = typeof(List<object>);
                    if (type.GetTypeInfo().IsGenericType)
                    {
                        Type[] argTypes = type.GetGenericArguments();
                        Fx.Assert(argTypes.Length == 1, "IEnumerable type must have one argument");
                        itemType = argTypes[0];
                        listType = typeof(List<>).MakeGenericType(argTypes);
                    }

                    MethodAccessor addAccess = MethodAccessor.Create(listType.GetMethod("Add", new Type[] { itemType }));
                    return new SerializableType.List(this, listType, itemType, addAccess) { Final = true };
                }

                return null;
            }

            if (type.GetTypeInfo().IsEnum)
            {
                Type underlyingType = Enum.GetUnderlyingType(type);
                return new SerializableType.Converted(
                    AmqpType.Converted,
                    type,
                    underlyingType,
                    static (o, t) => Convert.ChangeType(o, t),
                    static (o, t) => Enum.ToObject(t, o));
            }

            if (type.GetInterfaces().Any(it => it == typeof(IAmqpSerializable)))
            {
                return new SerializableType.Serializable(this, type);
            }

            if (type.IsArray)
            {
                // validate item type to be AMQP types only
                AmqpEncoding.GetEncoding(type.GetElementType());
                return SerializableType.CreatePrimitiveType(type);
            }

            foreach (Type it in type.GetInterfaces())
            {
                if (it.GetTypeInfo().IsGenericType)
                {
                    Type genericTypeDef = it.GetGenericTypeDefinition();
                    if (genericTypeDef == typeof(IDictionary<,>))
                    {
                        Type[] argTypes = it.GetGenericArguments();
                        Type itemType = typeof(KeyValuePair<,>).MakeGenericType(argTypes);
                        MemberAccessor keyAccessor = MemberAccessor.Create(itemType.GetProperty("Key"), false);
                        MemberAccessor valueAccessor = MemberAccessor.Create(itemType.GetProperty("Value"), false);
                        MethodAccessor addAccess = MethodAccessor.Create(type.GetMethod("Add", argTypes));

                        return new SerializableType.Map(this, type, keyAccessor, valueAccessor, addAccess);
                    }

                    if (genericTypeDef == typeof(ICollection<>))
                    {
                        Type[] argTypes = it.GetGenericArguments();
                        Type itemType = argTypes[0];
                        MethodAccessor addAccess = MethodAccessor.Create(type.GetMethod("Add", argTypes));

                        return new SerializableType.List(this, type, itemType, addAccess);
                    }
                }
            }

            return null;
        }