package net.sf.kernow.soapextension.SOAPExtension;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.io.StringWriter;
import java.io.UnsupportedEncodingException;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.ProtocolException;
import java.net.URL;
import java.net.URLConnection;
import javax.xml.transform.Transformer;
import javax.xml.transform.TransformerConfigurationException;
import javax.xml.transform.TransformerException;
import javax.xml.transform.TransformerFactory;
import javax.xml.transform.stream.StreamResult;
import net.sf.saxon.om.NodeInfo;

/**
 * Enables the calling of SOAP based web services from XSLT.  
 * @author Andrew Welch
 */
public class SOAPExtension {
    
    public static final String ENCODING = "UTF-8";
    public static final String CONTENT_LENGTH = "Content-Length";
    public static final String CONTENT_TYPE = "Content-Type";
    public static final String CONTENT_TYPE_VALUE = "text/xml; charset=utf-8";    
    public static final String SOAPACTION = "SOAPAction";
    public static final String POST = "POST";
            
    public static String soapRequest(NodeInfo requestXML, String endpoint) {
        String result = makeCall(transformToString(requestXML), endpoint);        
        return result;
    }    
    
    public static String soapRequest(String requestXML, String endpoint) {
        String result = makeCall(requestXML, endpoint);        
        return result;
    }  
    
    private static String transformToString(NodeInfo sourceXML) {

        StringWriter sw = new StringWriter();

        try {
            TransformerFactory tFactory = new net.sf.saxon.TransformerFactoryImpl();
            Transformer transformer = tFactory.newTransformer();
            transformer.transform(sourceXML, new StreamResult(sw));
        } catch (TransformerConfigurationException ex) {
            ex.printStackTrace();
        } catch (TransformerException ex) {
            ex.printStackTrace();
        }
        
        return sw.toString();
    }
    
    private static String makeCall(String requestXML, String endpoint) {
                
        String SOAPUrl = endpoint;
        StringBuilder responseBuf = new StringBuilder();
                
        try {            
            // Create the connection to the endpoint
            URL url = new URL(SOAPUrl);
            URLConnection connection = url.openConnection();
            HttpURLConnection httpConn = (HttpURLConnection) connection;
                                 
            byte[] b = requestXML.getBytes(ENCODING);
            
            // Set the appropriate HTTP parameters.
            httpConn.setRequestProperty(CONTENT_LENGTH, String.valueOf(b.length));
            httpConn.setRequestProperty(CONTENT_TYPE, CONTENT_TYPE_VALUE);
            httpConn.setRequestProperty(SOAPACTION, "");
            
            httpConn.setRequestMethod(POST);
            
            httpConn.setDoOutput(true);
            httpConn.setDoInput(true);
            
            // Send the the request
            OutputStream out = httpConn.getOutputStream();
            out.write(b);
            out.flush();
                       
            // Read the response and write it to the response buffer.            
            InputStreamReader isr = new InputStreamReader(httpConn.getInputStream());
            BufferedReader in = new BufferedReader(isr);
            
            String line;
            while ((line = in.readLine()) != null) {
                responseBuf.append(line);
            } 
            
            in.close();
            
        } catch (ProtocolException ex) {
            ex.printStackTrace();
            return error(ex.getMessage());
        } catch (MalformedURLException ex) {
            ex.printStackTrace();
            return error(ex.getMessage());
        } catch (UnsupportedEncodingException ex) {
            ex.printStackTrace();
            return error(ex.getMessage());
        } catch (IOException ex) {
            ex.printStackTrace();
            return error(ex.getMessage());
        }
        
        return responseBuf.toString();
    }
    
    private static String error(String msg) {
        return "" + msg + "";
    }
}