package ca.uhn.fhir.rest.client;
   
   /*
    * #%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.ArrayList;
  import java.util.List;
  import java.util.Map;
  import java.util.Map.Entry;
  
  import org.apache.http.Header;
  import org.apache.http.client.methods.HttpRequestBase;
  import org.apache.http.message.BasicHeader;
  
  import ca.uhn.fhir.rest.server.EncodingEnum;
  import ca.uhn.fhir.util.VersionUtil;
  
  public abstract class BaseHttpClientInvocation {
  
  	private List<Header> myHeaders;
  
  	public void addHeader(String theName, String theValue) {
  		if (myHeaders == null) {
  			myHeaders = new ArrayList<Header>();
  		}
  		myHeaders.add(new BasicHeader(theName, theValue));
  	}
  
  	/**
  	 * Create an HTTP request out of this client request
  	 * 
  	 * @param theUrlBase
  	 *            The FHIR server base url (with a trailing "/")
  	 * @param theExtraParams
  	 *            Any extra request parameters the server wishes to add
  	 * @param theEncoding
  	 *            The encoding to use for any serialized content sent to the
  	 *            server
  	 */
  	public abstract HttpRequestBase asHttpRequest(String theUrlBase, Map<String, List<String>> theExtraParams, EncodingEnum theEncoding);
  
  	protected static void appendExtraParamsWithQuestionMark(Map<String, List<String>> theExtraParams, StringBuilder theUrlBuilder, boolean theWithQuestionMark) {
  		boolean first = theWithQuestionMark;
  
  		if (theExtraParams != null && theExtraParams.isEmpty() == false) {
  			for (Entry<String, List<String>> next : theExtraParams.entrySet()) {
  				for (String nextValue : next.getValue()) {
  					if (first) {
  						theUrlBuilder.append('?');
  						first = false;
  					} else {
  						theUrlBuilder.append('&');
  					}
  					try {
  						theUrlBuilder.append(URLEncoder.encode(next.getKey(), "UTF-8"));
  						theUrlBuilder.append('=');
  						theUrlBuilder.append(URLEncoder.encode(nextValue, "UTF-8"));
  					} catch (UnsupportedEncodingException e) {
  						throw new Error("UTF-8 not supported - This should not happen");
  					}
  				}
  			}
  		}
  	}
  
  	public void addHeadersToRequest(HttpRequestBase theHttpRequest) {
  		if (myHeaders != null) {
  			for (Header next : myHeaders) {
  				theHttpRequest.addHeader(next);
  			}
  		}
  		
  		theHttpRequest.addHeader("User-Agent", "HAPI-FHIR/" + VersionUtil.getVersion() + " (FHIR Client)");
  		theHttpRequest.addHeader("Accept-Charset", "utf-8");
  		theHttpRequest.addHeader("Accept-Encoding", "gzip");
  		
  	}
  
  }