// Copyright 2004-2021 Castle Project - http://www.castleproject.org/
// 
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
// 
//     http://www.apache.org/licenses/LICENSE-2.0
// 
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

namespace Castle.DynamicProxy.Generators
{
	using System.Reflection;

	using Castle.DynamicProxy.Contributors;
	using Castle.DynamicProxy.Generators.Emitters;
	using Castle.DynamicProxy.Generators.Emitters.SimpleAST;

	internal class MinimalisticMethodGenerator : MethodGenerator
	{
		public MinimalisticMethodGenerator(MetaMethod method, OverrideMethodDelegate overrideMethod)
			: base(method, overrideMethod)
		{
		}

		protected override MethodEmitter BuildProxiedMethodBody(MethodEmitter emitter, ClassEmitter @class,
		                                                        INamingScope namingScope)
		{
			InitOutParameters(emitter, MethodToOverride.GetParameters());

			if (emitter.ReturnType == typeof(void))
			{
				emitter.CodeBuilder.AddStatement(new ReturnStatement());
			}
			else
			{
				emitter.CodeBuilder.AddStatement(new ReturnStatement(new DefaultValueExpression(emitter.ReturnType)));
			}

			return emitter;
		}

		private void InitOutParameters(MethodEmitter emitter, ParameterInfo[] parameters)
		{
			for (var index = 0; index < parameters.Length; index++)
			{
				var parameter = parameters[index];
				if (parameter.IsOut)
				{
					emitter.CodeBuilder.AddStatement(
						new AssignArgumentStatement(new ArgumentReference(parameter.ParameterType, index + 1),
						                            new DefaultValueExpression(parameter.ParameterType)));
				}
			}
		}
	}
}