SubResourceMethod.java

/*
 * Copyright 2015 ArcBees Inc.
 *
 * 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.gwtplatform.dispatch.rest.processors.subresource;

import java.util.Collection;

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

import com.google.common.base.Optional;
import com.google.common.collect.FluentIterable;
import com.gwtplatform.dispatch.rest.processors.details.EndPointDetails;
import com.gwtplatform.dispatch.rest.processors.details.EndPointDetails.Factory;
import com.gwtplatform.dispatch.rest.processors.resource.Resource;
import com.gwtplatform.dispatch.rest.processors.resource.ResourceMethod;
import com.gwtplatform.dispatch.rest.processors.resource.ResourceMethodUtils;
import com.gwtplatform.processors.tools.domain.Method;

import static com.google.auto.common.MoreTypes.asTypeElement;
import static com.google.common.base.Optional.absent;
import static com.google.common.base.Optional.of;

public class SubResourceMethod implements ResourceMethod {
    private final ResourceMethodUtils resourceMethodUtils;
    private final SubResource.Factory subResourceFactory;
    private final EndPointDetails.Factory endPointDetailsFactory;
    private final Resource parentResource;
    private final ExecutableElement element;

    private Optional<Method> method = absent();
    private Optional<EndPointDetails> endPointDetails = absent();
    private Optional<SubResource> subResource = absent();

    SubResourceMethod(
            ResourceMethodUtils resourceMethodUtils,
            Factory endPointDetailsFactory, SubResource.Factory subResourceFactory,
            Resource parentResource,
            ExecutableElement element) {
        this.resourceMethodUtils = resourceMethodUtils;
        this.subResourceFactory = subResourceFactory;
        this.endPointDetailsFactory = endPointDetailsFactory;
        this.parentResource = parentResource;
        this.element = element;
    }

    @Override
    public Resource getParentResource() {
        return parentResource;
    }

    @Override
    public Method getMethod() {
        if (!method.isPresent()) {
            method = of(resourceMethodUtils.processMethod(parentResource, element));
        }

        return method.get();
    }

    @Override
    public EndPointDetails getEndPointDetails() {
        if (!endPointDetails.isPresent()) {
            endPointDetails = of(endPointDetailsFactory.create(parentResource.getEndPointDetails(), getMethod()));
        }

        return endPointDetails.get();
    }

    public SubResource getSubResource() {
        if (!subResource.isPresent()) {
            createSubResource();
        }

        return subResource.get();
    }

    private void createSubResource() {
        TypeElement returnTypeElement = asTypeElement(element.getReturnType());

        subResource = of(subResourceFactory.create(this, returnTypeElement));
    }

    @Override
    public Collection<String> getImports() {
        return FluentIterable.from(getMethod().getImports())
                .append(getSubResource().getType().getImports())
                .toList();
    }
}