package at.gv.egiz.simpleSigning;

import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.util.jar.Attributes;
import java.util.jar.Manifest;

import javax.servlet.ServletContext;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

public class VersionServlet extends HttpServlet {

	/**
	 * 
	 */
	private static final long serialVersionUID = 6716170050447201588L;

	@Override
	protected void doGet(HttpServletRequest req, HttpServletResponse resp)
			throws ServletException, IOException {
		this.doProcess(req, resp);
	}

	@Override
	protected void doPost(HttpServletRequest req, HttpServletResponse resp)
			throws ServletException, IOException {
		this.doProcess(req, resp);
	}

	protected void doProcess(HttpServletRequest req, HttpServletResponse resp)
			throws ServletException, IOException {
		StringBuilder sb = new StringBuilder();
		sb.append("{\"version\": \"");
		sb.append(getVersion());
		sb.append("\", \"scm\": \"");
		sb.append(getSCMRevision());
		sb.append("\"}");

		resp.setContentType("application/json");
		OutputStream os = resp.getOutputStream();
		os.write(sb.toString().getBytes());
		os.close();
	}

	/**
	 * Gets the PDF-AS SCM Revision
	 * 
	 * @return
	 */
	public String getSCMRevision() {
		try {
			ServletContext application = getServletConfig().getServletContext();
			InputStream inputStream = application
					.getResourceAsStream("/META-INF/MANIFEST.MF");
			Manifest manifest = new Manifest(inputStream);
			Attributes attributes = manifest.getMainAttributes();
			String impVersion = attributes.getValue("Specification-Version");
			return impVersion;
		} catch (Throwable e) {
			return "UNKOWN";
		}
	}

	/**
	 * Gets the PDF-AS Version
	 * 
	 * @return PDF-AS Verison string
	 */
	public String getVersion() {
		try {
			ServletContext application = getServletConfig().getServletContext();
			InputStream inputStream = application
					.getResourceAsStream("/META-INF/MANIFEST.MF");
			Manifest manifest = new Manifest(inputStream);
			Attributes attributes = manifest.getMainAttributes();
			String impVersion = attributes.getValue("Implementation-Version");
			return impVersion;
		} catch (Throwable e) {
			return "UNKOWN";
		}
	}
}