/*******************************************************************************
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you 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.apache.ofbiz.solr.webapp;

import java.io.InputStream;
import java.io.IOException;
import java.io.OutputStreamWriter;
import java.io.Writer;
import java.nio.charset.StandardCharsets;

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

import org.apache.commons.io.IOUtils;
import org.apache.commons.lang.StringUtils;
import org.apache.commons.lang.StringEscapeUtils;
import org.apache.solr.common.params.CommonParams;
import org.apache.solr.core.CoreContainer;
import org.apache.solr.core.SolrCore;

/**
 * A simple servlet to load the Solr Admin UI
 */
public class OFBizSolrLoadAdminUiServlet extends OFBizSolrRedirectServlet {

    private static final long serialVersionUID = 1L;
    private static final String MODULE = OFBizSolrLoadAdminUiServlet.class.getName();

    @Override
    public void doGet(HttpServletRequest request, HttpServletResponse response) throws IOException {
        boolean isForwarded = forwardUrl(request, response);
        if (isForwarded) {
            return;
        }
        // This attribute is set by the SolrDispatchFilter
        CoreContainer cores = (CoreContainer) request.getAttribute("org.apache.solr.CoreContainer");

        InputStream in = getServletContext().getResourceAsStream("/admin.html");
        if (in != null && cores != null) {
            try {
                response.setCharacterEncoding("UTF-8");
                response.setContentType("text/html");
                Writer out = new OutputStreamWriter(response.getOutputStream(), StandardCharsets.UTF_8);

                String html = IOUtils.toString(in, "UTF-8");
                Package pack = SolrCore.class.getPackage();

                String[] search = new String[] {"${contextPath}", "${adminPath}", "${version}" };
                String[] replace = new String[] {
                        StringEscapeUtils.escapeJavaScript(request.getContextPath()),
                        StringEscapeUtils.escapeJavaScript(CommonParams.CORES_HANDLER_PATH),
                        StringEscapeUtils.escapeJavaScript(pack.getSpecificationVersion()) };

                out.write(StringUtils.replaceEach(html, search, replace));
                out.flush();
            } finally {
                try {
                    if (in != null) {
                        in.close();
                    }
                } catch (final IOException ioe) {
                    // ignore
                }
            }
        } else {
            response.sendError(404);
        }
    }

}
