/**
 * Copyright (C) 2010-2013 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 org.androidannotations.handler;

import static com.sun.codemodel.JExpr._new;
import static com.sun.codemodel.JExpr._null;
import static com.sun.codemodel.JExpr.cast;
import static com.sun.codemodel.JExpr.invoke;

import java.util.List;

import javax.annotation.processing.ProcessingEnvironment;
import javax.lang.model.element.Element;
import javax.lang.model.element.ExecutableElement;
import javax.lang.model.element.VariableElement;
import javax.lang.model.type.TypeMirror;

import org.androidannotations.helper.AndroidManifest;
import org.androidannotations.helper.IdAnnotationHelper;
import org.androidannotations.helper.IdValidatorHelper;
import org.androidannotations.holder.EComponentWithViewSupportHolder;
import org.androidannotations.model.AndroidSystemServices;
import org.androidannotations.model.AnnotationElements;
import org.androidannotations.process.IsValid;
import org.androidannotations.rclass.IRClass;

import com.sun.codemodel.JBlock;
import com.sun.codemodel.JClass;
import com.sun.codemodel.JDefinedClass;
import com.sun.codemodel.JExpression;
import com.sun.codemodel.JFieldRef;
import com.sun.codemodel.JInvocation;
import com.sun.codemodel.JMethod;
import com.sun.codemodel.JType;
import com.sun.codemodel.JVar;

public abstract class AbstractListenerHandler extends BaseAnnotationHandler<EComponentWithViewSupportHolder> {

	private IdAnnotationHelper helper;
	private EComponentWithViewSupportHolder holder;
	private String methodName;

	public AbstractListenerHandler(Class<?> targetClass, ProcessingEnvironment processingEnvironment) {
		super(targetClass, processingEnvironment);
	}

	public AbstractListenerHandler(String target, ProcessingEnvironment processingEnvironment) {
		super(target, processingEnvironment);
	}

	@Override
	public void setAndroidEnvironment(IRClass rClass, AndroidSystemServices androidSystemServices, AndroidManifest androidManifest) {
		super.setAndroidEnvironment(rClass, androidSystemServices, androidManifest);
		helper = new IdAnnotationHelper(processingEnv, getTarget(), rClass);
	}

	@Override
	public void validate(Element element, AnnotationElements validatedElements, IsValid valid) {
		validatorHelper.enclosingElementHasEnhancedViewSupportAnnotation(element, validatedElements, valid);

		validatorHelper.resIdsExist(element, IRClass.Res.ID, IdValidatorHelper.FallbackStrategy.USE_ELEMENT_NAME, valid);

		validatorHelper.isNotPrivate(element, valid);

		validatorHelper.doesntThrowException(element, valid);

		validatorHelper.uniqueId(element, validatedElements, valid);
	}

	@Override
	public void process(Element element, EComponentWithViewSupportHolder holder) {
		this.holder = holder;
		this.methodName = element.getSimpleName().toString();

		ExecutableElement executableElement = (ExecutableElement) element;
		List<? extends VariableElement> parameters = executableElement.getParameters();
		TypeMirror returnType = executableElement.getReturnType();

		List<JFieldRef> idsRefs = helper.extractAnnotationFieldRefs(processHolder, element, IRClass.Res.ID, true);

		JDefinedClass listenerAnonymousClass = codeModel().anonymousClass(getListenerClass());
		JMethod listenerMethod = createListenerMethod(listenerAnonymousClass);
		listenerMethod.annotate(Override.class);

		JBlock listenerMethodBody = listenerMethod.body();

		JExpression activityRef = holder.getGeneratedClass().staticRef("this");
		JInvocation call = invoke(activityRef, methodName);

		makeCall(listenerMethodBody, call, returnType);

		processParameters(listenerMethod, call, parameters);

		for (JFieldRef idRef : idsRefs) {
            if (idRef != null) {
                JBlock block = holder.getOnViewChangedBody().block();

                JExpression findViewExpression = holder.findViewById(idRef);
                if (!getViewClass().equals(classes().VIEW)) {
                    findViewExpression = cast(getViewClass(), findViewExpression);
                }

                JVar view = block.decl(getViewClass(), "view", findViewExpression);
                block._if(view.ne(_null()))._then().invoke(view, getSetterName()).arg(_new(listenerAnonymousClass));
            }
		}
	}

	protected abstract void makeCall(JBlock listenerMethodBody, JInvocation call, TypeMirror returnType);

	protected abstract void processParameters(JMethod listenerMethod, JInvocation call, List<? extends VariableElement> userParameters);

	protected abstract JMethod createListenerMethod(JDefinedClass listenerAnonymousClass);

	protected abstract String getSetterName();

	protected abstract JClass getListenerClass();

	protected JType getViewClass() {
		return classes().VIEW;
	}

	protected String getMethodName() {
		return methodName;
	}

	protected final EComponentWithViewSupportHolder getHolder() {
		return holder;
	}
}