/**
 *
 */
package org.gcube.portlets.user.geoportaldataviewer.server;

import java.io.IOException;
import java.io.InputStream;
import java.net.HttpURLConnection;
import java.net.URL;
import java.util.Enumeration;

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

import org.apache.commons.io.IOUtils;
import org.apache.http.client.methods.HttpGet;
import org.gcube.portlets.user.geoportaldataviewer.client.GeoportalDataViewerConstants;
import org.gcube.portlets.user.geoportaldataviewer.server.mongoservice.GeoportalServiceIdentityProxy;
import org.gcube.portlets.user.uriresolvermanager.geoportal.GeoportalExporterAPI;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * The Class GeoportalExporterActionServlet.
 *
 * @author Francesco Mangiacrapa at ISTI-CNR francesco.mangiacrapa@isti.cnr.it
 * 
 *         Apr 23, 2024
 */
public class GeoportalExporterActionServlet extends HttpServlet {

	/**
	 * 
	 */
	private static final long serialVersionUID = 6037090280489238565L;
	protected static Logger logger = LoggerFactory.getLogger(GeoportalExporterActionServlet.class);

	/**
	 * {@inheritDoc}
	 */
	@Override
	public void init() throws ServletException {
		super.init();
		logger.trace(GeoportalExporterActionServlet.class.getSimpleName() + " ready.");
	}

	/**
	 * Do get.
	 *
	 * @param req  the req
	 * @param resp the resp
	 * @throws IOException      Signals that an I/O exception has occurred.
	 * @throws ServletException the servlet exception
	 */
	public void doGet(HttpServletRequest req, HttpServletResponse resp) throws IOException, ServletException {
//		setSecretManager();
		String projectID = req.getParameter(GeoportalDataViewerConstants.PROIECT_ID_PARAMETER);
		String ucdID = req.getParameter(GeoportalDataViewerConstants.UCD_ID_PARAMETER);

		logger.info("doGet called with Input Params [projectID: " + projectID + ", ucdID: " + ucdID + "]");

		try {

			GeoportalServiceIdentityProxy identity = new GeoportalServiceIdentityProxy(req);
			String theToken = identity.getToken();
			String theIdentity = identity.getIdentity();

			GeoportalExporterAPI geoportalExporterAPI = new GeoportalExporterAPI();
			URL urlRequest = geoportalExporterAPI.exportProject("pdf", ucdID, projectID, false);
			String urlToRedirect = urlRequest.toString();
			logger.info("Performing request to {} with identity {}", urlToRedirect, identity.getDescription());
			logger.info("Token is {}", theToken.substring(0, 20) + "_MASKED_TOKEN");

			InputStream is = performHttpRequestToSGService(urlToRedirect, theIdentity, theToken);
			IOUtils.copy(is, resp.getOutputStream());
			resp.flushBuffer();

		} catch (Exception e) {
			logger.error("Error occurred when exporting the Project with id: " + projectID, e);
			sendError(resp, "Error occurred when exporting the Project. Error is: " + e.getMessage());
			return;
		}

	}

	public static InputStream performHttpRequestToSGService(String urlToService, String identity, String token)
			throws IOException {
		logger.debug("performHttpRequestToSGService called");
		try {

			URL url = new URL(urlToService);
			HttpURLConnection conn = (HttpURLConnection) url.openConnection();
			// timeout at 60sec
			conn.setConnectTimeout(6000);
			conn.setDoOutput(true);

			if (token.length() > 50) {
				// is JWT TOKEN
				conn.setRequestProperty("Authorization", "Bearer " + token);
			} else {
				// is legacy Token
				conn.setRequestProperty("gcube-token", token);
			}

			conn.setRequestProperty("Content-Type", "text/html");
			conn.setRequestMethod("GET");
			logger.debug("performHttpRequestToSGService done, returning");
			return conn.getInputStream();
		} catch (IOException e) {
			logger.error("Error on performing request to url " + urlToService, e);
			throw e;
		}
	}

	/**
	 * Sets the headers to target.
	 *
	 * @param httpSource the http source
	 * @param response   the response
	 * @return the http servlet response
	 */
	public static HttpServletResponse setHeadersToTarget(HttpServletRequest httpSource, HttpServletResponse response) {

		Enumeration<String> headersNames = httpSource.getHeaderNames();
		while (headersNames.hasMoreElements()) {
			String headerName = (String) headersNames.nextElement();
			Enumeration<String> values = httpSource.getHeaders(headerName);
			while (values.hasMoreElements()) {
				String value = values.nextElement();
				logger.info("Copying header {} with value {}", headerName, value);
				response.addHeader(headerName, value);
			}
		}
		return response;
	}

	/**
	 * Sets the headers to target.
	 *
	 * @param httpSource the http source
	 * @param httpTarget the http target
	 * @return the http get
	 */
	public static HttpGet setHeadersToTarget(HttpServletRequest httpSource, HttpGet httpTarget) {

		Enumeration<String> headersNames = httpSource.getHeaderNames();
		while (headersNames.hasMoreElements()) {
			String headerName = (String) headersNames.nextElement();
			Enumeration<String> values = httpSource.getHeaders(headerName);
			while (values.hasMoreElements()) {
				String value = values.nextElement();
				logger.info("Copying header {} with value {}", headerName, value);
				httpTarget.addHeader(headerName, value);
			}
		}
		return httpTarget;
	}

	/**
	 * Sets the headers to response.
	 *
	 * @param httpSource the http source
	 * @param httpTarget the http target
	 * @return the http get
	 */
	public static HttpGet setHeadersToResponse(HttpServletRequest httpSource, HttpGet httpTarget) {

		Enumeration<String> headersNames = httpSource.getHeaderNames();
		while (headersNames.hasMoreElements()) {
			String headerName = (String) headersNames.nextElement();
			Enumeration<String> values = httpSource.getHeaders(headerName);
			while (values.hasMoreElements()) {
				String value = values.nextElement();
				logger.info("Copying header {} with value {}", headerName, value);
				httpTarget.addHeader(headerName, value);
			}
		}
		return httpTarget;
	}

	/**
	 * Send response.
	 *
	 * @param response the response
	 * @param message  the message
	 * @throws IOException Signals that an I/O exception has occurred.
	 */
	protected void sendError(HttpServletResponse response, String message) throws IOException {
		response.setStatus(HttpServletResponse.SC_INTERNAL_SERVER_ERROR);
		response.setContentType("text/html");
		response.getWriter().write("<html><head><title>Error</title></head><body>" + message + "</body></html>");
		response.flushBuffer();
	}

}