package ca.uhn.hl7v2.hoh.encoder;
   
   import static ca.uhn.hl7v2.hoh.util.StringUtils.*;
   
   import java.io.IOException;
   import java.io.InputStream;
   
   import ca.uhn.hl7v2.hoh.api.DecodeException;
   import ca.uhn.hl7v2.hoh.api.IAuthorizationServerCallback;
  import ca.uhn.hl7v2.hoh.util.StringUtils;
  
  public class Hl7OverHttpRequestDecoder extends AbstractHl7OverHttpDecoder {
  
  	private IAuthorizationServerCallback myAuthorizationCallback;
  	private String myActionLine;
  	private static final org.slf4j.Logger ourLog = org.slf4j.LoggerFactory.getLogger(Hl7OverHttpRequestDecoder.class);
  
  	protected void authorize() throws AuthorizationFailureException {
  		if (myAuthorizationCallback != null) {
  			String username = getUsername();
  			if (!myAuthorizationCallback.authorize(getPath(), username, getPassword())) {
  				if (StringUtils.isBlank(username)) {
  					throw new AuthorizationFailureException("Authorization failed: No username provided");
  				} else {
  					throw new AuthorizationFailureException("Authorization failed for user: " + getUsername());
  				}
  			}
  		} else {
  			if (isNotBlank(getUsername()) || isNotBlank(getPassword())) {
  				ourLog.warn("Request contains username and/or password, but no authorization callback has been set so credentials can not be validated");
  			}
  		}
  	}
  
  	@Override
  	protected String readActionLineAndDecode(InputStream theInputStream) throws DecodeException, IOException, NoMessageReceivedException {
  		ourLog.trace("Entering readActionLineAndDecode(InputStream)");
  		
  		if (myActionLine == null) {
  			String firstLine = readFirstLine(theInputStream);
  			if (firstLine == null || isBlank(firstLine)) {
  				throw new NoMessageReceivedException();
  			}
  
  			if (!firstLine.startsWith("POST ")) {
  				throw new DecodeException("HTTP request line message is not valid. Only POST action is supported. Request line was: " + firstLine);
  			}
  
  			firstLine = firstLine.substring(5);
  			int nextSpace = firstLine.indexOf(' ');
  			if (nextSpace == -1) {
  				throw new DecodeException("HTTP request line message is not valid. Not HTTP version found. Request line was: " + firstLine);
  			}
  
  			setPath(firstLine.substring(0, nextSpace));
  			if (isBlank(getPath())) {
  				throw new DecodeException("HTTP request line message is not valid. No request URI found. Request line was: " + firstLine);
  			}
  
  			String protocolVersion = firstLine.substring(nextSpace + 1);
  			if (!"HTTP/1.1".equals(protocolVersion)) {
  				throw new DecodeException("HTTP request line message is not valid. HTTP version not supported. Request line was: " + firstLine);
  			}
  
  			myActionLine = firstLine;
  			ourLog.trace("Action line is {}", myActionLine);
  
  		} else {
  			ourLog.trace("Already have an action line");
  		}
  		
  		return myActionLine;
  	}
  
  	/**
  	 * @param theAuthorizationCallback
  	 *            the authorizationCallback to set
  	 */
  	public void setAuthorizationCallback(IAuthorizationServerCallback theAuthorizationCallback) {
  		myAuthorizationCallback = theAuthorizationCallback;
  	}
  
  }