/*
    * Copyright 2008-2009 Web Cohesion, Andrew McCall
    *
    * 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
    *
    *   https://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.springframework.security.oauth.provider.filter;
  
  import org.springframework.security.core.AuthenticationException;
  import org.springframework.security.core.context.SecurityContextHolder;
  import org.springframework.security.oauth.common.OAuthCodec;
  import org.springframework.security.oauth.common.OAuthConsumerParameter;
  import org.springframework.security.oauth.common.OAuthProviderParameter;
  import org.springframework.security.oauth.provider.ConsumerAuthentication;
  import org.springframework.security.oauth.provider.ConsumerDetails;
  import org.springframework.security.oauth.provider.InvalidOAuthParametersException;
  import org.springframework.security.oauth.provider.token.OAuthProviderToken;
  
  import javax.servlet.FilterChain;
  import javax.servlet.http.HttpServletRequest;
  import javax.servlet.http.HttpServletResponse;
  import java.io.IOException;
  import java.util.Map;
  
  /**
   * Processing filter for handling a request for an OAuth token. The default implementation assumes a request for a new
   * unauthenticated request token. The default {@link #setFilterProcessesUrl(String) processes URL} is "/oauth_request_token".
   *
   * @author Ryan Heaton
   * @author Andrew McCall
   */
  public class UnauthenticatedRequestTokenProcessingFilter extends OAuthProviderProcessingFilter {
  
    // The OAuth spec doesn't specify a content-type of the response.  However, it's NOT
    // "application/x-www-form-urlencoded" because the response isn't URL-encoded. Until
    // something is specified, we'll assume that it's just "text/plain".
    private String responseContentType = "text/plain;charset=utf-8";
  
    private boolean require10a = true;
  
    public UnauthenticatedRequestTokenProcessingFilter() {
      setFilterProcessesUrl("/oauth_request_token");
    }
  
    @Override
    protected void validateAdditionalParameters(ConsumerDetails consumerDetails, Map<String, String> oauthParams) {
      super.validateAdditionalParameters(consumerDetails, oauthParams);
  
      if (isRequire10a()) {
        String token = oauthParams.get(OAuthConsumerParameter.oauth_callback.toString());
        if (token == null) {
          throw new InvalidOAuthParametersException(messages.getMessage("AccessTokenProcessingFilter.missingCallback", "Missing callback."));
        }
      }
    }
  
    protected void onValidSignature(HttpServletRequest request, HttpServletResponse response, FilterChain chain) throws IOException {
      //signature is verified; create the token, send the response.
      ConsumerAuthenticationringframework/security/oauth/provider/ConsumerAuthentication.html#ConsumerAuthentication">ConsumerAuthentication authentication = (ConsumerAuthentication) SecurityContextHolder.getContext().getAuthentication();
      OAuthProviderToken authToken = createOAuthToken(authentication);
      if (!authToken.getConsumerKey().equals(authentication.getConsumerDetails().getConsumerKey())) {
        throw new IllegalStateException("The consumer key associated with the created auth token is not valid for the authenticated consumer.");
      }
  
      String tokenValue = authToken.getValue();
      String callback = authentication.getOAuthParameters().get(OAuthConsumerParameter.oauth_callback.toString());
  
      StringBuilder responseValue = new StringBuilder(OAuthProviderParameter.oauth_token.toString())
        .append('=')
        .append(OAuthCodec.oauthEncode(tokenValue))
        .append('&')
        .append(OAuthProviderParameter.oauth_token_secret.toString())
        .append('=')
        .append(OAuthCodec.oauthEncode(authToken.getSecret()));
      if (callback != null) {
        responseValue.append('&')
          .append(OAuthProviderParameter.oauth_callback_confirmed.toString())
          .append("=true");
      }
      response.setContentType(getResponseContentType());
      response.getWriter().print(responseValue.toString());
      response.flushBuffer();
    }
  
    @Override
    protected void onNewTimestamp() throws AuthenticationException {
      //no-op. A new timestamp should be supplied for a request for a new unauthenticated request token.
    }
  
   /**
    * Create the OAuth token for the specified consumer key.
    *
    * @param authentication The authentication request.
    * @return The OAuth token.
    */
   protected OAuthProviderToken createOAuthToken(ConsumerAuthentication authentication) {
     return getTokenServices().createUnauthorizedRequestToken(authentication.getConsumerDetails().getConsumerKey(),
                                                              authentication.getOAuthParameters().get(OAuthConsumerParameter.oauth_callback.toString()));
   }
 
   /**
    * The content type of the response.
    *
    * @return The content type of the response.
    */
   public String getResponseContentType() {
     return responseContentType;
   }
 
   /**
    * The content type of the response.
    *
    * @param responseContentType The content type of the response.
    */
   public void setResponseContentType(String responseContentType) {
     this.responseContentType = responseContentType;
   }
 
   /**
    * Whether to require 1.0a support.
    *
    * @return Whether to require 1.0a support.
    */
   public boolean isRequire10a() {
     return require10a;
   }
 
   /**
    * Whether to require 1.0a support.
    *
    * @param require10a Whether to require 1.0a support.
    */
   public void setRequire10a(boolean require10a) {
     this.require10a = require10a;
   }
 }