/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You 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.apache.camel.component.fhir.api;

import java.util.Map;

import ca.uhn.fhir.rest.client.api.IGenericClient;
import ca.uhn.fhir.rest.gclient.IGetPageTyped;
import org.hl7.fhir.instance.model.api.IBaseBundle;

/**
 * API that Loads the previous/next bundle of resources from a paged set, using the link specified in the "link
 * type=next" tag within the atom bundle.
 */
public class FhirLoadPage {

    private final IGenericClient client;

    public FhirLoadPage(IGenericClient client) {
        this.client = client;
    }

    /**
     * Load the next page of results using the link with relation "next" in the bundle. This method accepts a DSTU2
     * Bundle resource
     * 
     * @param  <T>             extends {@link IBaseBundle}
     * @param  bundle          the {@link IBaseBundle}
     * @param  extraParameters see {@link ExtraParameters} for a full list of parameters that can be passed, may be NULL
     * @return                 the next {@link IBaseBundle}
     */
    public <T extends IBaseBundle> T next(T bundle, Map<ExtraParameters, Object> extraParameters) {
        IGetPageTyped<T> getPageTyped = client.loadPage().next(bundle);
        ExtraParameters.process(extraParameters, getPageTyped);
        return getPageTyped.execute();
    }

    /**
     * Load the previous page of results using the link with relation "prev" in the bundle. This method accepts a DSTU2+
     * Bundle resource
     * 
     * @param  <T>             extends {@link IBaseBundle}
     * @param  bundle          the {@link IBaseBundle}
     * @param  extraParameters see {@link ExtraParameters} for a full list of parameters that can be passed, may be NULL
     * @return                 the previous {@link IBaseBundle}
     */
    public <T extends IBaseBundle> T previous(T bundle, Map<ExtraParameters, Object> extraParameters) {
        IGetPageTyped<T> getPageTyped = client.loadPage().previous(bundle);
        ExtraParameters.process(extraParameters, getPageTyped);
        return getPageTyped.execute();
    }

    /**
     * Load a page of results using the given URL and bundle type and return a DSTU1 Atom bundle
     * 
     * @param  extraParameters see {@link ExtraParameters} for a full list of parameters that can be passed, may be NULL
     * @param  <T>             extends {@link IBaseBundle}
     * @param  url             the search url
     * @param  returnType      the return type
     * @return                 the {@link IBaseBundle} page
     */
    public <T extends IBaseBundle> T byUrl(String url, Class<T> returnType, Map<ExtraParameters, Object> extraParameters) {
        IGetPageTyped<T> getPageTyped = client.loadPage().byUrl(url).andReturnBundle(returnType);
        ExtraParameters.process(extraParameters, getPageTyped);
        return getPageTyped.execute();
    }

}
