package org.springframework.security.oauth2.common.exceptions;
   
   import java.util.Map;
   import java.util.Set;
   import java.util.TreeMap;
   
   /**
    * Base exception for OAuth 2 exceptions.
    * 
   * @author Ryan Heaton
   * @author Rob Winch
   * @author Dave Syer
   */
  @SuppressWarnings("serial")
  @com.fasterxml.jackson.databind.annotation.JsonSerialize(using = OAuth2ExceptionJackson2Serializer.class)
  @com.fasterxml.jackson.databind.annotation.JsonDeserialize(using = OAuth2ExceptionJackson2Deserializer.class)
  public class OAuth2Exception extends RuntimeException {
  
  	public static final String ERROR = "error";
  	public static final String DESCRIPTION = "error_description";
  	public static final String URI = "error_uri";
  	public static final String INVALID_REQUEST = "invalid_request";
  	public static final String INVALID_CLIENT = "invalid_client";
  	public static final String INVALID_GRANT = "invalid_grant";
  	public static final String UNAUTHORIZED_CLIENT = "unauthorized_client";
  	public static final String UNSUPPORTED_GRANT_TYPE = "unsupported_grant_type";
  	public static final String INVALID_SCOPE = "invalid_scope";
  	public static final String INSUFFICIENT_SCOPE = "insufficient_scope";
  	public static final String INVALID_TOKEN = "invalid_token";
  	public static final String REDIRECT_URI_MISMATCH ="redirect_uri_mismatch";
  	public static final String UNSUPPORTED_RESPONSE_TYPE ="unsupported_response_type";
  	public static final String ACCESS_DENIED = "access_denied";
  
  	private Map<String, String> additionalInformation = null;
  
  	public OAuth2Exception(String msg, Throwable t) {
  		super(msg, t);
  	}
  
  	public OAuth2Exception(String msg) {
  		super(msg);
  	}
  
  	/**
  	 * The OAuth2 error code.
  	 * 
  	 * @return The OAuth2 error code.
  	 */
  	public String getOAuth2ErrorCode() {
  		return "invalid_request";
  	}
  
  	/**
  	 * The HTTP error code associated with this error.
  	 * 
  	 * @return The HTTP error code associated with this error.
  	 */
  	public int getHttpErrorCode() {
  		return 400;
  	}
  
  	/**
  	 * Get any additional information associated with this error.
  	 * 
  	 * @return Additional information, or null if none.
  	 */
  	public Map<String, String> getAdditionalInformation() {
  		return this.additionalInformation;
  	}
  
  	/**
  	 * Add some additional information with this OAuth error.
  	 * 
  	 * @param key The key.
  	 * @param value The value.
  	 */
  	public void addAdditionalInformation(String key, String value) {
  		if (this.additionalInformation == null) {
  			this.additionalInformation = new TreeMap<String, String>();
  		}
  
  		this.additionalInformation.put(key, value);
  
  	}
  
  	/**
  	 * Creates the appropriate subclass of OAuth2Exception given the errorCode.
  	 * @param errorCode
  	 * @param errorMessage
  	 * @return
  	 */
  	public static OAuth2Exception create(String errorCode, String errorMessage) {
  		if (errorMessage == null) {
  			errorMessage = errorCode == null ? "OAuth Error" : errorCode;
  		}
  		if (INVALID_CLIENT.equals(errorCode)) {
  			return new InvalidClientException(errorMessage);
  		}
  		else if (UNAUTHORIZED_CLIENT.equals(errorCode)) {
 			return new UnauthorizedClientException(errorMessage);
 		}
 		else if (INVALID_GRANT.equals(errorCode)) {
 			return new InvalidGrantException(errorMessage);
 		}
 		else if (INVALID_SCOPE.equals(errorCode)) {
 			return new InvalidScopeException(errorMessage);
 		}
 		else if (INVALID_TOKEN.equals(errorCode)) {
 			return new InvalidTokenException(errorMessage);
 		}
 		else if (INVALID_REQUEST.equals(errorCode)) {
 			return new InvalidRequestException(errorMessage);
 		}
 		else if (REDIRECT_URI_MISMATCH.equals(errorCode)) {
 			return new RedirectMismatchException(errorMessage);
 		}
 		else if (UNSUPPORTED_GRANT_TYPE.equals(errorCode)) {
 			return new UnsupportedGrantTypeException(errorMessage);
 		}
 		else if (UNSUPPORTED_RESPONSE_TYPE.equals(errorCode)) {
 			return new UnsupportedResponseTypeException(errorMessage);
 		}
 		else if (ACCESS_DENIED.equals(errorCode)) {
 			return new UserDeniedAuthorizationException(errorMessage);
 		}
 		else {
 			return new OAuth2Exception(errorMessage);
 		}
 	}
 
 	/**
 	 * Creates an {@link OAuth2Exception} from a Map&lt;String,String&gt;.
 	 * 
 	 * @param errorParams
 	 * @return
 	 */
 	public static OAuth2Exception valueOf(Map<String, String> errorParams) {
 		String errorCode = errorParams.get(ERROR);
 		String errorMessage = errorParams.containsKey(DESCRIPTION) ? errorParams.get(DESCRIPTION)
 				: null;
 		OAuth2Exception ex = create(errorCode, errorMessage);
 		Set<Map.Entry<String, String>> entries = errorParams.entrySet();
 		for (Map.Entry<String, String> entry : entries) {
 			String key = entry.getKey();
 			if (!ERROR.equals(key) && !DESCRIPTION.equals(key)) {
 				ex.addAdditionalInformation(key, entry.getValue());
 			}
 		}
 
 		return ex;
 	}
 	
 	@Override
 	public String toString() {
 		return getSummary();
 	}
 
 	/**
 	 * @return a comma-delimited list of details (key=value pairs)
 	 */
 	public String getSummary() {
 		
 		StringBuilder builder = new StringBuilder();
 
 		String delim = "";
 
 		String error = this.getOAuth2ErrorCode();
 		if (error != null) {
 			builder.append(delim).append("error=\"").append(error).append("\"");
 			delim = ", ";
 		}
 
 		String errorMessage = this.getMessage();
 		if (errorMessage != null) {
 			builder.append(delim).append("error_description=\"").append(errorMessage).append("\"");
 			delim = ", ";
 		}
 
 		Map<String, String> additionalParams = this.getAdditionalInformation();
 		if (additionalParams != null) {
 			for (Map.Entry<String, String> param : additionalParams.entrySet()) {
 				builder.append(delim).append(param.getKey()).append("=\"").append(param.getValue()).append("\"");
 				delim = ", ";
 			}
 		}
 		
 		return builder.toString();
 
 	}
 }