/*
 * This file is part of rasdaman community.
 *
 * Rasdaman community is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * Rasdaman community is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with rasdaman community.  If not, see <http://www.gnu.org/licenses/>.
 *
 * Copyright 2003 - 2010 Peter Baumann / rasdaman GmbH.
 *
 * For more information please see <http://www.rasdaman.org>
 * or contact Peter Baumann via <baumann@rasdaman.com>.
 */
package petascope.wcst.server.servlet;

import petascope.wcst.server.*;
import petascope.ConfigManager;
import org.apache.commons.io.FileUtils;
import java.io.File;
import java.io.IOException;
import java.io.PrintWriter;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import petascope.core.DbMetadataSource;
import petascope.exceptions.WCSException;
import petascope.exceptions.ExceptionCode;

/** Servlet interface for the WCS-Transactional server.
 *
 * @author Andrei Aiordachioaie
 */
public class wcstServlet extends HttpServlet {

    private String defaultHtmlResponse;
    private String relativeServletHtmlPath = "/templates/wcst-servlet.html";
    private String servletHtmlPath;
    private String relativeSettingsPath = "/settings.properties";
    private WcstServer server;
    private DbMetadataSource metadataSource;

    @Override
    public void init() throws ServletException {
        // Initialize the configuration manager. Now all classes can read the settings.
        String settingsPath = getServletContext().getRealPath(relativeSettingsPath);
        ConfigManager config = ConfigManager.getInstance(settingsPath, getServletContext().getRealPath("/"));

        try {
            metadataSource = new DbMetadataSource(
                    ConfigManager.METADATA_DRIVER, ConfigManager.METADATA_URL,
                    ConfigManager.METADATA_USER, ConfigManager.METADATA_PASS, false);
        } catch (Exception e) {
            throw new ServletException("Metadata Database Error.", e);
        }

        // Initialize the WCS-T server with proper metadata
        try {
            server = new WcstServer(metadataSource);
        } catch (WCSException e) {
            throw new ServletException(e);
        }

        // Load the servlet HTML response
        servletHtmlPath = getServletContext().getRealPath(relativeServletHtmlPath);
        try {
            defaultHtmlResponse = FileUtils.readFileToString(new File(servletHtmlPath));
        } catch (IOException e) {
            throw new ServletException(e);
        }
    }

    /**
     * Handles the HTTP <code>GET</code> method.
     * @param request wcstServlet request
     * @param response wcstServlet response
     * @throws ServletException if a wcstServlet-specific error occurs
     * @throws IOException if an I/O error occurs
     */
    @Override
    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws IOException {
        System.out.println("WCS-T: invoked with GET");
        printUsage(response);
    }

    /**
     * Handles the HTTP <code>POST</code> method.
     * @param request wcstServlet request
     * @param response wcstServlet response
     * @throws ServletException if a wcstServlet-specific error occurs
     * @throws IOException if an I/O error occurs
     */
    @Override
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        // Select the operation
        int op = -1;

        if (request.getParameter("TransactionXML") != null) {
            op = 4;
        }

        // Convert the WCS request into a WCPS request
        try {
            // initialize WebService operation arguments here
            String inputXml, outputXml;
            PrintWriter out;

            switch (op) {
                case 4:
                    inputXml = request.getParameter("TransactionXML");
                    outputXml = server.Transaction(inputXml);
                    out = new PrintWriter(response.getOutputStream());
                    out.write(outputXml);
                    out.flush();

                    break;
                default:
                    throw new Exception("No valid operation specified !");
            }

        } catch (Exception e) {
            e.printStackTrace();

            throw new ServletException("WCS-T servlet error !", e);
        }
    }

    /**
     * Returns a short description of the wcstServlet.
     * @return a String containing wcstServlet description
     */
    @Override
    public String getServletInfo() {
        return "WCS-T Extension. Petascope version " + ConfigManager.PETASCOPE_VERSION;
    }

    private void printUsage(HttpServletResponse response) throws IOException {
        System.out.println("WCS-T: returning usage message");
        response.setContentType("text/html; charset=utf-8");
        PrintWriter out = new PrintWriter(response.getOutputStream());

        out.println(defaultHtmlResponse);

        out.close();
        System.out.println("WCS-T: done nothing");

    }
}