/**
 * Licensed to Apereo under one or more contributor license agreements. See the NOTICE file
 * distributed with this work for additional information regarding copyright ownership. Apereo
 * 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 the
 * following location:
 *
 * <p>http://www.apache.org/licenses/LICENSE-2.0
 *
 * <p>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.apereo.portal.web;

import java.io.IOException;
import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.http.HttpServletRequest;
import org.apache.commons.lang.StringUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * Filter that logs exceptions before re-throwing. Used to make sure that all portal related
 * exceptions end up in the portal log
 *
 */
public class ExceptionLoggingFilter implements Filter {
    protected final Logger logger = LoggerFactory.getLogger(getClass());

    @Override
    public void init(FilterConfig filterConfig) throws ServletException {}

    @Override
    public void destroy() {}

    @Override
    public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain)
            throws IOException, ServletException {

        try {
            chain.doFilter(request, response);
        } catch (Throwable t) {
            StringBuilder msg = new StringBuilder();
            if (request instanceof HttpServletRequest) {
                HttpServletRequest req = (HttpServletRequest) request;
                msg.append("for URL=" + req.getRequestURI());
                if (StringUtils.isNotBlank(req.getQueryString())) {
                    msg.append("?" + req.getQueryString());
                }
                msg.append(", user=" + req.getRemoteUser());
                msg.append(" ");
            }
            msg.append(", from IP=" + request.getRemoteAddr());
            this.logger.error(
                    "uPortal: unhandled exception '" + t.getMessage() + "' " + msg.toString(), t);

            if (t instanceof Error) {
                throw (Error) t;
            }
            if (t instanceof RuntimeException) {
                throw (RuntimeException) t;
            }
            if (t instanceof ServletException) {
                throw (ServletException) t;
            }
            if (t instanceof IOException) {
                throw (IOException) t;
            }
            throw new ServletException(t);
        }
    }
}