/*
 * Copyright (C) 2025 Ignite Realtime Foundation. All rights reserved.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.jivesoftware.util;

import org.apache.http.HttpStatus;
import org.dom4j.Element;
import org.jivesoftware.openfire.vcard.VCardManager;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.util.Base64;

/**
 * Servlet that outputs the photo that is part of a user's VCard as an image.<p>
 *
 * @author Guus der Kinderen
 */
public class VCardPhotoServlet extends HttpServlet
{
    private static final Logger Log = LoggerFactory.getLogger(VCardPhotoServlet.class);

    @Override
    public void doGet(HttpServletRequest request, HttpServletResponse response) throws IOException
    {
        final String username = request.getParameter("username");

        // Input validation.
        if (username == null || username.isEmpty()) {
            response.sendError(HttpStatus.SC_BAD_REQUEST, "Missing 'username' parameter.");
            return;
        }

        Log.debug("Request for vCard Photo of '{}'", username);

        // Check if there's a VCard for that user.
        final Element vCardElement = VCardManager.getInstance().getVCard(username);
        if (vCardElement == null) {
            Log.trace("No vCard for '{}'", username);
            response.setStatus(HttpStatus.SC_NO_CONTENT);
            return;
        }

        if (vCardElement.element( "PHOTO") == null) {
            Log.trace("No photo in vCard for '{}'", username);
            response.setStatus(HttpStatus.SC_NO_CONTENT);
            return;        }

        if (vCardElement.element( "PHOTO").element( "BINVAL") == null || vCardElement.element( "PHOTO").element( "TYPE") == null) {
            Log.trace("No vCard binval or type for '{}'", username);
            response.setStatus(HttpStatus.SC_NO_CONTENT);
            return;
        }

        final Element element = vCardElement.element( "PHOTO").element( "BINVAL");
        if (element.getTextTrim() == null || element.getTextTrim().isEmpty()) {
            Log.trace("No vCard binval content for '{}'", username);
            response.setStatus(HttpStatus.SC_NO_CONTENT);
            return;
        }

        final String contentType = vCardElement.element( "PHOTO" ).element( "TYPE" ).getTextTrim();
        if (contentType == null || contentType.isEmpty()) {
            Log.trace("No vCard type content for '{}'", username);
            response.setStatus(HttpStatus.SC_NO_CONTENT);
            return;
        }

        // Read data from VCard.
        final String value = element.getTextTrim().replaceAll("\\s","");
        final byte[] decoded = Base64.getDecoder().decode(value);

        // Output data.
        if (decoded != null) {
            writeBytesToStream(contentType, decoded, response);
        }
    }

    /**
     * Writes out a <code>byte</code> to the ServletOuputStream.
     *
     * @param bytes the bytes to write to the <code>ServletOutputStream</code>.
     */
    private void writeBytesToStream(String contentType, byte[] bytes, HttpServletResponse response) {
        response.setContentType(contentType);

        // Send image
        try (ServletOutputStream sos = response.getOutputStream()) {
            sos.write(bytes);
            sos.flush();
        }
        catch (IOException e) {
            // Do nothing
        }
    }
}