package ca.uhn.fhir.rest.method;
   
   /*
    * #%L
    * HAPI FHIR - Core Library
    * %%
    * Copyright (C) 2014 University Health Network
    * %%
    * 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.
   * #L%
   */
  
  import java.io.UnsupportedEncodingException;
  import java.net.URLEncoder;
  import java.util.HashMap;
  import java.util.List;
  import java.util.Map;
  import java.util.Map.Entry;
  
  import org.apache.commons.lang3.StringUtils;
  import org.apache.http.client.methods.HttpGet;
  import org.apache.http.client.methods.HttpRequestBase;
  
  import ca.uhn.fhir.context.ConfigurationException;
  import ca.uhn.fhir.rest.client.BaseHttpClientInvocation;
  import ca.uhn.fhir.rest.server.EncodingEnum;
  
  /**
   * @author James Agnew
   * @author Doug Martin (Regenstrief Center for Biomedical Informatics)
   */
  public class HttpGetClientInvocation extends BaseHttpClientInvocation {
  
  	private final Map<String, List<String>> myParameters;
  	private final String myUrlPath;
  
  	public HttpGetClientInvocation(Map<String, List<String>> theParameters, String... theUrlFragments) {
  		myParameters = theParameters;
  		myUrlPath = StringUtils.join(theUrlFragments, '/');
  	}
  
  	public HttpGetClientInvocation(Map<String, List<String>> theParameters, List<String> theUrlFragments) {
  		myParameters = theParameters;
  		myUrlPath = StringUtils.join(theUrlFragments, '/');
  	}
  
  	public HttpGetClientInvocation(String theUrlPath) {
  		myParameters = new HashMap<String, List<String>>();
  		myUrlPath = theUrlPath;
  	}
  
  	public HttpGetClientInvocation(String... theUrlFragments) {
  		myParameters = new HashMap<String, List<String>>();
  		myUrlPath = StringUtils.join(theUrlFragments, '/');
  	}
  
  
  	public HttpGetClientInvocation(List<String> theUrlFragments) {
  		myParameters = new HashMap<String, List<String>>();
  		myUrlPath = StringUtils.join(theUrlFragments, '/');
  	}
  
  	public Map<String, List<String>> getParameters() {
  		return myParameters;
  	}
  
  	public String getUrlPath() {
  		return myUrlPath;
  	}
  
  	@Override
  	public HttpRequestBase asHttpRequest(String theUrlBase, Map<String, List<String>> theExtraParams, EncodingEnum theEncoding) {
  		StringBuilder b = new StringBuilder();
  		
  		if (!myUrlPath.contains("://")) {
              b.append(theUrlBase);
              if (!theUrlBase.endsWith("/")) {
                  b.append('/');
              }
          }
          b.append(myUrlPath);
  		
  		boolean first = b.indexOf("?") == -1;
  		for (Entry<String, List<String>> next : myParameters.entrySet()) {
  			if (next.getValue() == null || next.getValue().isEmpty()) {
  				continue;
  			}
  			String nextKey = next.getKey();
  			for (String nextValue : next.getValue()) {
 				first = addQueryParameter(b, first, nextKey, nextValue);
 			}
 		}
 
 		appendExtraParamsWithQuestionMark(theExtraParams, b, first);
 
 		HttpGet retVal = new HttpGet(b.toString());
 		super.addHeadersToRequest(retVal);
 
 		return retVal;
 	}
 
 	private boolean addQueryParameter(StringBuilder b, boolean first, String nextKey, String nextValue) {
 		boolean retVal = first;
 		if (retVal) {
 			b.append('?');
 			retVal = false;
 		} else {
 			b.append('&');
 		}
 		try {
 			b.append(URLEncoder.encode(nextKey, "UTF-8"));
 			b.append('=');
 			b.append(URLEncoder.encode(nextValue, "UTF-8"));
 		} catch (UnsupportedEncodingException e) {
 			throw new ConfigurationException("Could not find UTF-8 encoding. This shouldn't happen.", e);
 		}
 		return retVal;
 	}
 
 }