package at.gv.egovernment.moa.id.auth.builder;

import java.text.MessageFormat;

import at.gv.egovernment.moa.id.BuildException;
import at.gv.egovernment.moa.id.data.AuthenticationData;
import at.gv.egovernment.moa.util.Constants;

/**
 * Builder for the authentication data <code>&lt;saml:Assertion&gt;</code>
 * to be provided by the MOA ID Auth component.
 *
 * @author Paul Ivancsics
 * @version $Id$
 */
public class AuthenticationDataAssertionBuilder implements Constants {
  /** private static String NL contains the NewLine representation in Java*/
	private static final String NL = "\n";
	/**
	 * XML template for the <code>&lt;saml:Assertion&gt;</code> to be built
	 */
	private static final String AUTH_DATA =
		"<?xml version=\"1.0\" encoding=\"UTF-8\" ?>" + NL +
	  "<saml:Assertion xmlns:saml=''" + SAML_NS_URI + "'' xmlns:pr=''" + PD_NS_URI + "'' xmlns:xsi=''" + XSI_NS_URI + "''" +
	  " xmlns:si=''" +  XSI_NS_URI + "''" +
    " MajorVersion=''1'' MinorVersion=''0'' AssertionID=''{0}'' Issuer=''{1}'' IssueInstant=''{2}''>" + NL +
	  "	<saml:AttributeStatement>" + NL + 
	  "		<saml:Subject>" + NL +
	  "			<saml:NameIdentifier NameQualifier=''urn:publicid:gv.at:cdid+bPK''>{3}</saml:NameIdentifier>" + NL +
	  "     <saml:SubjectConfirmation>" + NL +
	  "       <saml:ConfirmationMethod>" + MOA_NS_URI + "cm</saml:ConfirmationMethod>" + NL +
	  "       <saml:SubjectConfirmationData>{4}{5}</saml:SubjectConfirmationData>" + NL +
	  "     </saml:SubjectConfirmation>" + NL +
	  "		</saml:Subject>" + NL +
	  "		<saml:Attribute AttributeName=''PersonData'' AttributeNamespace=''" + PD_NS_URI + "''>" + NL +
	  "			<saml:AttributeValue>{6}</saml:AttributeValue>" + NL +
	  "		</saml:Attribute>" + NL +
	  "		<saml:Attribute AttributeName=''isQualifiedCertificate'' AttributeNamespace=''" + MOA_NS_URI + "''>" + NL +
	  "			<saml:AttributeValue>{7}</saml:AttributeValue>" + NL +
	  "		</saml:Attribute>" + NL +
	  "{8}" + 
	  "	</saml:AttributeStatement>" + NL +
	  "</saml:Assertion>";
	/**
	 * XML template for the <code>&lt;saml:Attribute&gt;</code> named <code>"isPublicAuthority"</code>,
	 * to be inserted into the <code>&lt;saml:Assertion&gt;</code>
	 */
	private static final String PUBLIC_AUTHORITY_ATT = 
	  "		<saml:Attribute AttributeName=''isPublicAuthority'' AttributeNamespace=''urn:oid:1.2.40.0.10.1.1.1''>" + NL +
	  "			<saml:AttributeValue>{0}</saml:AttributeValue>" + NL +
	  "		</saml:Attribute>" + NL;
	  
  /**
   * Constructor for AuthenticationDataAssertionBuilder.
   */
  public AuthenticationDataAssertionBuilder() {
    super();
  }

  /**
   * Builds the authentication data <code>&lt;saml:Assertion&gt;</code>.
   * 
   * @param authData the <code>AuthenticationData</code> to build the 
   * 				 <code>&lt;saml:Assertion&gt;</code> from
   * @param xmlPersonData <code>lt;pr:Person&gt;</code> element as a String
   * @param xmlAuthBlock authentication block to be included in a 
   * 				 <code>lt;saml:SubjectConfirmationData&gt;</code> element; may include
   * 				 the <code>"Stammzahl"</code> or not; may be empty
   * @param xmlIdentityLink the IdentityLink
   * @return the <code>&lt;saml:Assertion&gt;</code>
   * @throws BuildException if an error occurs during the build process
   */
  public String build(
  	AuthenticationData authData, 
  	String xmlPersonData, 
  	String xmlAuthBlock, 
  	String xmlIdentityLink) throws BuildException {
  		
  	String isQualifiedCertificate = authData.isQualifiedCertificate() ? "true" : "false";
  	String publicAuthorityAttribute = "";
  	if (authData.isPublicAuthority()) {
  		String publicAuthorityIdentification = authData.getPublicAuthorityCode();
  		if (publicAuthorityIdentification == null)
  			publicAuthorityIdentification = "True";
  		publicAuthorityAttribute = MessageFormat.format(
  			PUBLIC_AUTHORITY_ATT, new Object[] { publicAuthorityIdentification });
  	}

  	String assertion = MessageFormat.format(AUTH_DATA, new Object[] {
  		authData.getAssertionID(),
  		authData.getIssuer(), 
  		authData.getIssueInstant(), 
  		authData.getPBK(), 
  		removeXMLDeclaration(xmlAuthBlock),
  		removeXMLDeclaration(xmlIdentityLink),
  		removeXMLDeclaration(xmlPersonData), 
  		isQualifiedCertificate, 
  		publicAuthorityAttribute});
    return assertion;
  }
  
  /**
   * Removes the XML declaration from an XML expression.
   * @param xmlString XML expression as String
   * @return XML expression, XML declaration removed
   */
  private String removeXMLDeclaration(String xmlString) {
    if (xmlString.startsWith("<?xml")) {
      int firstElement = xmlString.indexOf("<", 1);
      return xmlString.substring(firstElement);
    }
      else return xmlString;
  }

}