package at.gv.egovernment.moa.ss.erechtclient.moainvoker;

import java.io.InputStream;
import java.util.Properties;

import javax.servlet.ServletContext;

import org.apache.log4j.Logger;
import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.w3c.dom.NodeList;

import at.gv.egovernment.moa.ss.erechtclient.ERechtClientException;
import at.gv.egovernment.moa.ss.erechtclient.init.Constants;
import at.gv.egovernment.moa.ss.erechtclient.util.DOMUtils;
import at.gv.egovernment.moa.ss.erechtclient.util.Utils;
import at.gv.egovernment.moa.ss.erechtclient.util.XPathUtils;

public class RequestBuilder 
{
  private static final String XPATH_KEYID_ = 
    "/" + Constants.NSPRE_MOA_13_ + ":" + "CreateXMLSignatureRequest" + 
    "/" + Constants.NSPRE_MOA_13_ + ":" + "KeyIdentifier";

  private static final String XPATH_XMLDOC_ = 
    "/" + Constants.NSPRE_MOA_13_ + ":" + "CreateXMLSignatureRequest" + 
    "/" + Constants.NSPRE_MOA_13_ + ":" + "SingleSignatureInfo" +
    "/" + Constants.NSPRE_MOA_13_ + ":" + "DataObjectInfo" +
    "/" + Constants.NSPRE_MOA_13_ + ":" + "DataObject" +
    "/" + Constants.NSPRE_MOA_13_ + ":" + "LocRefContent";
    
  private static final String XPATH_STYLESHEET_ = 
    "/" + Constants.NSPRE_MOA_13_ + ":" + "CreateXMLSignatureRequest" + 
    "/" + Constants.NSPRE_MOA_13_ + ":" + "SingleSignatureInfo" +
    "/" + Constants.NSPRE_MOA_13_ + ":" + "DataObjectInfo" +
    "/" + Constants.NSPRE_MOA_13_ + ":" + "CreateTransformsInfoProfile" +
    "/" + Constants.NSPRE_MOA_13_ + ":" + "Supplement" +
    "/" + Constants.NSPRE_MOA_13_ + ":" + "Content" + "[@Reference=\"stylesheet.xsl\"]" +
    "/" + Constants.NSPRE_MOA_13_ + ":" + "LocRefContent";

  private static final String XPATH_IMAGE_ = 
    "/" + Constants.NSPRE_MOA_13_ + ":" + "CreateXMLSignatureRequest" + 
    "/" + Constants.NSPRE_MOA_13_ + ":" + "SingleSignatureInfo";
  
  private static final String ELEM_NAME_DOI_ = "DataObjectInfo";

  private static final String ATTR_VALUE_DO_STRUCTURE_ = "detached";

  private static final String ELEM_NAME_DO_ = "DataObject";

  private static final String ATTR_NAME_DOI_STRUCTURE_ = "Structure";

  private static final String ATTR_NAME_DO_REFERENCE_ = "Reference";

  private static final String ELEM_NAME_CTIP_ = "CreateTransformsInfoProfile";

  private static final String ELEM_NAME_CTI_ = "CreateTransformsInfo";

  private static final String ELEM_NAME_FDMI_ = "FinalDataMetaInfo";

  private static final String ELEM_NAME_FDMIMIMETYPE_ = "MimeType";

  private static final String ELEM_VALUE_FDMIMIMETYPE_ = "image";

  private static final String ELEM_NAME_FDMITYPE_ = "Type";

  private static final String ELEM_VALUE_FDMITYPE_ = "http://www.buergerkarte.at/specifications/" + 
    "Security-Layer/20031113?Name=SignedImage&InstanceDocRef=0";

  private static final String ELEM_NAME_LOCREF_ = "LocRefContent";
  
  private Document requestDoc_;
  
  private String contextPath_;
  
  private Properties initProps_;
  
  private ServletContext context_;

  private static Logger logger_ = Logger.getLogger(Constants.LH_MOAINVOKER_);

  public RequestBuilder(ServletContext context, String contextPath) throws ERechtClientException
  {
    contextPath_ = contextPath;
    context_ = context;
    initProps_ = (Properties) context.getAttribute(Constants.WSCP_INIT_PROPS_);
       
     // Load template
    String requestTemplateLocation = Utils.readInitProperty(initProps_, Constants.IP_SS_REQUEST_TEMPLATE_, logger_);
    try 
    {
      InputStream requestTemplateIS = context_.getResourceAsStream(requestTemplateLocation);
      requestDoc_ = DOMUtils.parseWellFormed(requestTemplateIS);
    } catch (Exception e) 
    {
      String message = "Could not parse MOA SS signature creation request template.";
      logger_.error(message, e);
      throw new ERechtClientException(message, e);
    }
     
    // Insert key identifier
    Element keyIdentifierElem = xPathGetElement(XPATH_KEYID_, requestDoc_);
    String keyIdentifierStr = Utils.readInitProperty(initProps_, Constants.IP_SS_KEYID_, logger_);
    keyIdentifierElem.appendChild(requestDoc_.createTextNode(keyIdentifierStr));
  }
   
  public void setXMLDocument(String locationRef) throws ERechtClientException
  {
    // Set XML document location reference
    Element xMLDocLocRefElem = xPathGetElement(XPATH_XMLDOC_, requestDoc_);
    String webAppHostPortFromMOASS = Utils.readInitProperty(initProps_, Constants.IP_WEBAPP_HOST_PORT_FROM_MOA_SS_, logger_);
    xMLDocLocRefElem.appendChild(requestDoc_.createTextNode(webAppHostPortFromMOASS + contextPath_ + locationRef));
  }

  public void setStylesheet(String locationRef) throws ERechtClientException
  {
    Element stylesheetLocRefElem = xPathGetElement(XPATH_STYLESHEET_, requestDoc_);
    String webAppHostPortFromMOASS = Utils.readInitProperty(initProps_, Constants.IP_WEBAPP_HOST_PORT_FROM_MOA_SS_, logger_);
    String stylesheetLocRefStr = webAppHostPortFromMOASS + contextPath_ + locationRef;
    stylesheetLocRefElem.appendChild(requestDoc_.createTextNode(webAppHostPortFromMOASS + contextPath_ + locationRef));
    logger_.debug("Setting stylesheet location to: " + stylesheetLocRefStr);
  }
  
  public void useDefaultStylesheet() throws ERechtClientException
  {
    // Insert stylesheet reference, if it has not been set explicitly
    Element stylesheetLocRefElem = xPathGetElement(XPATH_STYLESHEET_, requestDoc_);
    String stylesheetLocRefStr = Utils.readInitProperty(initProps_, Constants.IP_SS_STYLESHEET_, logger_);
    String webAppHostPortFromMOASS = Utils.readInitProperty(initProps_, Constants.IP_WEBAPP_HOST_PORT_FROM_MOA_SS_, logger_);
    stylesheetLocRefStr = webAppHostPortFromMOASS + contextPath_ + stylesheetLocRefStr;
    stylesheetLocRefElem.appendChild(requestDoc_.createTextNode(stylesheetLocRefStr));
    logger_.debug("No stylesheet set explicitly, using default one: " + stylesheetLocRefStr);
  }

  public void addImage(String name, String locationRef) throws ERechtClientException
  {
    // Add supplement for image to be signed
    Element parentElem = xPathGetElement(XPATH_IMAGE_, requestDoc_);
    String webAppHostPortFromMOASS = Utils.readInitProperty(initProps_, Constants.IP_WEBAPP_HOST_PORT_FROM_MOA_SS_, logger_);
    
    Element dataObjInfo = requestDoc_.createElementNS(Constants.NSURI_MOA_13_, ELEM_NAME_DOI_);
    dataObjInfo.setAttributeNS(null, ATTR_NAME_DOI_STRUCTURE_, ATTR_VALUE_DO_STRUCTURE_);
    Element dataObj = requestDoc_.createElementNS(Constants.NSURI_MOA_13_, ELEM_NAME_DO_);
    Element locRefCont = requestDoc_.createElementNS(Constants.NSURI_MOA_13_, ELEM_NAME_LOCREF_);
    locRefCont.appendChild(requestDoc_.createTextNode(webAppHostPortFromMOASS + contextPath_ + locationRef));
    dataObj.appendChild(locRefCont);
    dataObj.setAttributeNS(null, ATTR_NAME_DO_REFERENCE_, name);
    dataObjInfo.appendChild(dataObj);
    Element createTIProf = requestDoc_.createElementNS(Constants.NSURI_MOA_13_, ELEM_NAME_CTIP_);
    Element createTI = requestDoc_.createElementNS(Constants.NSURI_MOA_13_, ELEM_NAME_CTI_);
    Element finalDataMI = requestDoc_.createElementNS(Constants.NSURI_MOA_13_, ELEM_NAME_FDMI_);
    Element finalDataMIMimeType = requestDoc_.createElementNS(Constants.NSURI_MOA_13_, ELEM_NAME_FDMIMIMETYPE_);
    finalDataMIMimeType.appendChild(requestDoc_.createTextNode(ELEM_VALUE_FDMIMIMETYPE_));
    finalDataMI.appendChild(finalDataMIMimeType);
    Element finalDataMIType = requestDoc_.createElementNS(Constants.NSURI_MOA_13_, ELEM_NAME_FDMITYPE_);
    finalDataMIType.appendChild(requestDoc_.createTextNode(ELEM_VALUE_FDMITYPE_));
    finalDataMI.appendChild(finalDataMIType);

    createTI.appendChild(finalDataMI);
    createTIProf.appendChild(createTI);
    dataObjInfo.appendChild(createTIProf);
    
    parentElem.appendChild(dataObjInfo);
  }
   
  public Document getRequest()
  {
    return requestDoc_;
  }
   
  private Element xPathGetElement(String xPath, Document doc) throws ERechtClientException
  {
    try {
     XPathUtils xpUtils = new XPathUtils();
      String additionalNSPrefixes = Constants.NSPRE_MOA_13_ + " " + Constants.NSURI_MOA_13_;
      xpUtils.setupContext(xPath, doc.getDocumentElement(), additionalNSPrefixes);
      NodeList nodeList = xpUtils.selectNodeSet(doc);
      if (nodeList == null) return null;
      if (nodeList.getLength() < 1) return null;
      if (!(nodeList.item(0) instanceof Element)) return null;
      return (Element) nodeList.item(0);
    } 
    catch (Exception e) 
    {
      String message = "MOA SS signature request template seems to be corrupted.";
      logger_.error(message, e);
      throw new ERechtClientException(message, e);
    }
  }
}