// Copyright (C) 2002 IAIK
// http://jce.iaik.tugraz.at
//
// Copyright (C) 2007 Stiftung Secure Information and 
//                    Communication Technologies SIC
// http://www.sic.st
//
// All rights reserved.
//
// This source is provided for inspection purposes and recompilation only,
// unless specified differently in a contract with IAIK. This source has to
// be kept in strict confidence and must not be disclosed to any third party
// under any circumstances. Redistribution in source and binary forms, with
// or without modification, are <not> permitted in any case!
//
// THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
// ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
// ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
// FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
// DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
// OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
// HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
// LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
// OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
// SUCH DAMAGE.

package at.gv.egovernment.moa.id.config.proxy;

import java.io.ByteArrayInputStream;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;

import org.w3c.dom.Element;
import org.w3c.dom.NodeList;
import org.w3c.dom.traversal.NodeIterator;

import at.gv.egovernment.moa.id.config.ConfigurationBuilder;
import at.gv.egovernment.moa.id.config.ConfigurationException;
import at.gv.egovernment.moa.id.config.ConnectionParameter;
import at.gv.egovernment.moa.logging.Logger;
import at.gv.egovernment.moa.util.DOMUtils;
import at.gv.egovernment.moa.util.FileUtils;
import at.gv.egovernment.moa.util.XPathUtils;

/**
 * Builds the configuration for MOA-ID Proxy.
 * 
 */
public class ProxyConfigurationBuilder extends ConfigurationBuilder {
  
  /**
   * Default online application configuration file name
   * (used when <code>/OnlineApplication/ProxyComponent@configFileURL</code> is <code>null</code>).
   */
  public static final String DEFAULT_OA_CONFIG_FILENAME = "MOAConfig.xml";

  /** an XPATH-Expression */ 
  private static final String PROXY_AUTH_XPATH =
    ROOT + CONF + "ProxyComponent/" + CONF + "AuthComponent";
  /** an XPATH-Expression */ 
  protected static final String ROOTOA = "/" + CONF + "Configuration/";
    /** an XPATH-Expression */ 
  private static final String OA_PROXY_COMPONENT_XPATH = CONF + "ProxyComponent";
  /** an XPATH-Expression */ 
  private static final String OA_PROXY_COMPONENT_ABSOLUTE_XPATH = ROOT + CONF + "OnlineApplication/" + CONF + "ProxyComponent";
  /** an XPATH-Expression */ 
  private static final String OA_PROXY_URL_XPATH = CONF + "ProxyComponent/@configFileURL";
  /** an XPATH-Expression */ 
  private static final String OA_PROXY_SESSION_TIMEOUT_XPATH = CONF + "ProxyComponent/@sessionTimeOut";
  /** an XPATH-Expression */ 
  private static final String OA_PROXY_LOGIN_PARA_XPATH = CONF + "ProxyComponent/@loginParameterResolverImpl";
  /** an XPATH-Expression */
  private static final String OA_PROXY_LOGIN_PARA_CONF_XPATH = CONF + "ProxyComponent/@loginParameterResolverConfiguration";
    /** an XPATH-Expression */ 
  private static final String OA_PROXY_CONNECTION_BUILDER_XPATH = CONF + "ProxyComponent/@connectionBuilderImpl";
  /** an XPATH-Expression */ 
  protected static final String OACONF_LOGIN_TYPE_XPATH =
    ROOTOA + CONF + "LoginType";
  /** an XPATH-Expression */ 
  protected static final String OACONF_BINDING_TYPE_XPATH =
    ROOTOA + CONF + "Binding";
  /** an XPATH-Expression */ 
  protected static final String OACONF_PARAM_AUTH_PARAMETER_XPATH =
    ROOTOA + CONF + "ParamAuth/" + CONF + "Parameter";
  /** an XPATH-Expression */ 
  protected static final String OACONF_USER_ID_XPATH =
    ROOTOA + CONF + "BasicAuth/" + CONF + "UserID";
  /** an XPATH-Expression */ 
  protected static final String OACONF_PASSWORD_XPATH =
    ROOTOA + CONF + "BasicAuth/" + CONF + "Password";
  /** an XPATH-Expression */ 
  protected static final String OACONF_HEADER_AUTH_HEADER_XPATH =
    ROOTOA + CONF + "HeaderAuth/" + CONF + "Header";

   /**
   * Creates a new <code>MOAConfigurationProvider</code>.
   * 
   * @param configElem The root element of the MOA-ID configuration.
   */
  public ProxyConfigurationBuilder(Element configElem, String rootConfigDir) {
    super(configElem, rootConfigDir);
  }
  
  /**
   * Method buildOAConfiguration.
   * 
   * Build an {@link OAConfiguration} Object from the given configuration DOM element
   * 
   * @param root
   * @return OAConfiguration
   * @throws ConfigurationException
   */
  public OAConfiguration buildOAConfiguration(Element root) throws ConfigurationException{

    OAConfiguration oaConfiguration = new OAConfiguration();

    //The LoginType hast to be "stateless" or "stateful" to be valid

    oaConfiguration.setLoginType(
      XPathUtils.getElementValue(root, OACONF_LOGIN_TYPE_XPATH, null));
    
    oaConfiguration.setBinding(
      XPathUtils.getElementValue(root, OACONF_BINDING_TYPE_XPATH, OAConfiguration.BINDUNG_FULL));    
      
    //Try to build the Parameter Auth Parameters
    NodeIterator paramAuthIter =
      XPathUtils.selectNodeIterator(
        root,
        OACONF_PARAM_AUTH_PARAMETER_XPATH);
    Element paramAuthElem;
    HashMap paramAuthMap = new HashMap();
    while ((paramAuthElem = (Element) paramAuthIter.nextNode()) != null) {
      String name = XPathUtils.getAttributeValue(paramAuthElem, "@Name", null);
      String value = XPathUtils.getAttributeValue(paramAuthElem, "@Value", null);
      if (paramAuthMap.containsKey(name))
        throw new ConfigurationException("config.06", new Object[]{"Doppelter Wert für Parameter per HeaderAuthentication"});
      paramAuthMap.put(name, value);
    }
    oaConfiguration.setParamAuthMapping(paramAuthMap);
    // Try to build the BasicAuthParameters
    oaConfiguration.setBasicAuthUserIDMapping(
      XPathUtils.getElementValue(root, OACONF_USER_ID_XPATH, null));
    oaConfiguration.setBasicAuthPasswordMapping(
      XPathUtils.getElementValue(root, OACONF_PASSWORD_XPATH, null));

    //Try to build the Parameter Auth Parameters
    NodeIterator headerAuthIter = XPathUtils.selectNodeIterator(root,OACONF_HEADER_AUTH_HEADER_XPATH);

    Element headerAuthElem;
    HashMap headerAuthMap = new HashMap();
    while ((headerAuthElem = (Element) headerAuthIter.nextNode()) != null) {
      String name =
        XPathUtils.getAttributeValue(headerAuthElem, "@Name", null);
      String value =
        XPathUtils.getAttributeValue(headerAuthElem, "@Value", null);
      // Contains Key (Neue Config-Exception: doppelte werte)
      if (headerAuthMap.containsKey(name))
        throw new ConfigurationException("config.06", new Object[]{"Doppelter Wert für Parameter per HeaderAuthentication"});
      headerAuthMap.put(name, value);
    }
    oaConfiguration.setHeaderAuthMapping(headerAuthMap);

    if (paramAuthMap.size() == 0) {
      if (oaConfiguration.getBasicAuthUserIDMapping() == null) {
        oaConfiguration.setAuthType(OAConfiguration.HEADER_AUTH);
      }
      else
        oaConfiguration.setAuthType(OAConfiguration.BASIC_AUTH);
    }
    else
      oaConfiguration.setAuthType(OAConfiguration.PARAM_AUTH);

    return oaConfiguration;
  }
  
  
  /**
   * Build an array of OnlineApplication Parameter Beans containing information 
   * about the proxy component
   * @return An OAProxyParameter array containing beans
   * with all relevant information for the proxy component of the online 
   * application
   */
  public OAProxyParameter[] buildOnlineApplicationProxyParameters() throws ConfigurationException{

    List oA_list = new ArrayList();
    NodeList OAIter = XPathUtils.selectNodeList(configElem_, OA_XPATH);

    for (int i = 0; i < OAIter.getLength(); i++) {
      Element oAElem = (Element) OAIter.item(i);
      
      Element proxyComponentElem = (Element) XPathUtils.selectSingleNode(oAElem,OA_PROXY_COMPONENT_XPATH);        
      if (proxyComponentElem != null) {
        OAProxyParameter oap = new OAProxyParameter();
      
        oap.setPublicURLPrefix(oAElem.getAttribute("publicURLPrefix"));
        oap.setOaType(oAElem.getAttribute("type"));
        oap.setConfigFileURL(XPathUtils.getAttributeValue(oAElem, OA_PROXY_URL_XPATH, null));
        oap.setConfigFileURL(FileUtils.makeAbsoluteURL(oap.getConfigFileURL(), rootConfigFileDir_));
        // default session time out: 3600 sec = 1 h
        oap.setSessionTimeOut(new Integer(XPathUtils.getAttributeValue(oAElem,OA_PROXY_SESSION_TIMEOUT_XPATH,"3600")).intValue());
        oap.setLoginParameterResolverImpl(XPathUtils.getAttributeValue(oAElem, OA_PROXY_LOGIN_PARA_XPATH, null));
        oap.setLoginParameterResolverConfiguration(XPathUtils.getAttributeValue(oAElem, OA_PROXY_LOGIN_PARA_CONF_XPATH, null));
        oap.setLoginParameterResolverConfiguration(FileUtils.makeAbsoluteURL(oap.getLoginParameterResolverConfiguration(), rootConfigFileDir_));
        oap.setConnectionBuilderImpl(XPathUtils.getAttributeValue(oAElem,OA_PROXY_CONNECTION_BUILDER_XPATH, null));
            
        ConnectionParameter conPara = buildConnectionParameter(proxyComponentElem);
        oap.setConnectionParameter(conPara);
  
        OAConfiguration oaConf = buildOAConfiguration(getOAConfigElement(oap));
        oap.setOaConfiguration(oaConf);
        
        oA_list.add(oap);
      }
    }
    OAProxyParameter[] result =
      new OAProxyParameter[oA_list.size()];
    oA_list.toArray(result);

    return result;

  }
  
  /**
   * Reads the configuration file of the online application, and creates a DOM tree from it.
   * If <code>/OnlineApplication/ProxyComponent@configFileURL</code> is not given, 
   * uses default configuration file location.
   * 
   * @param oap configuration data of online application, meant for use by MOA-ID-PROXY
   * @return Element DOM tree root element
   * @throws ConfigurationException on any exception thrown
   */
  private Element getOAConfigElement(OAProxyParameter oap) throws ConfigurationException
  {  
    try {
      String configFileURL = oap.getConfigFileURL();
      if (configFileURL == null) {
        // use default config file URL, when config file URL is not given
        configFileURL = oap.getConnectionParameter().getUrl();
        if (configFileURL.charAt(configFileURL.length() - 1) != '/')
          configFileURL += "/";
        configFileURL += DEFAULT_OA_CONFIG_FILENAME;
      }
      Logger.info("Loading MOA-OA configuration " + configFileURL);
      Element configElem = DOMUtils.parseXmlValidating(
        new ByteArrayInputStream(FileUtils.readURL(configFileURL)));
      return configElem;
    }
    catch (Throwable t) {
      throw new ConfigurationException("config.03", new Object[] {"OAConfiguration"} , t);
    }
  }
  
  /**
   * Build a bean containing all information about the ProxyComponent
   * @return The ConnectionParameter for the Proxy Component
   */
  public ConnectionParameter buildAuthComponentConnectionParameter() 
  {

    Element connectionParameter = (Element) XPathUtils.selectSingleNode(configElem_, PROXY_AUTH_XPATH);
    if (connectionParameter==null) return null;
    return buildConnectionParameter(connectionParameter);

  }
  
}