/**
 * Copyright (C) 2010-2011 eBusiness Information, Excilys Group
 *
 * 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.
 */
package com.googlecode.androidannotations.processing;

import java.lang.annotation.Annotation;

import javax.lang.model.element.Element;
import javax.lang.model.element.ExecutableElement;

import com.googlecode.androidannotations.annotations.Background;
import com.googlecode.androidannotations.api.BackgroundExecutor;
import com.googlecode.androidannotations.helper.APTCodeModelHelper;
import com.sun.codemodel.JBlock;
import com.sun.codemodel.JCatchBlock;
import com.sun.codemodel.JClass;
import com.sun.codemodel.JClassAlreadyExistsException;
import com.sun.codemodel.JCodeModel;
import com.sun.codemodel.JDefinedClass;
import com.sun.codemodel.JExpr;
import com.sun.codemodel.JInvocation;
import com.sun.codemodel.JMethod;
import com.sun.codemodel.JMod;
import com.sun.codemodel.JTryBlock;
import com.sun.codemodel.JVar;

public class BackgroundProcessor implements ElementProcessor {

	private final APTCodeModelHelper helper = new APTCodeModelHelper();

	@Override
	public Class<? extends Annotation> getTarget() {
		return Background.class;
	}

	@Override
	public void process(Element element, JCodeModel codeModel, EBeansHolder activitiesHolder) throws JClassAlreadyExistsException {

		EBeanHolder holder = activitiesHolder.getEnclosingActivityHolder(element);

		// Method
		ExecutableElement executableElement = (ExecutableElement) element;
		JMethod backgroundMethod = helper.overrideAnnotatedMethod(executableElement, holder);
		
		JBlock previousMethodBody = helper.removeBody(backgroundMethod);

		JDefinedClass anonymousRunnableClass = codeModel.anonymousClass(Runnable.class);

		JMethod runMethod = anonymousRunnableClass.method(JMod.PUBLIC, codeModel.VOID, "run");
		runMethod.annotate(Override.class);

		JBlock runMethodBody = runMethod.body();
		JTryBlock runTry = runMethodBody._try();
		
		runTry.body().add(previousMethodBody);

		JCatchBlock runCatch = runTry._catch(holder.refClass(RuntimeException.class));
		JVar exceptionParam = runCatch.param("e");

		JClass logClass = holder.refClass("android.util.Log");

		JInvocation errorInvoke = logClass.staticInvoke("e");

		errorInvoke.arg(holder.eBean.name());
		errorInvoke.arg("A runtime exception was thrown while executing code in a background thread");
		errorInvoke.arg(exceptionParam);

		runCatch.body().add(errorInvoke);

		JBlock backgroundBody = backgroundMethod.body();

		JClass backgroundExecutorClass = codeModel.ref(BackgroundExecutor.class);

		JInvocation executeCall = backgroundExecutorClass.staticInvoke("execute").arg(JExpr._new(anonymousRunnableClass));

		backgroundBody.add(executeCall);
	}

}
