<%#
 Copyright 2013-2017 the original author or authors from the JBooter project.

 This file is part of the JBooter project, see https://jbooter.github.io/
 for more information.

 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 <%=packageName%>.config;

import io.github.jbooter.config.JBooterProperties;

import ch.qos.logback.classic.AsyncAppender;
import ch.qos.logback.classic.Level;
import ch.qos.logback.classic.LoggerContext;
import ch.qos.logback.classic.spi.LoggerContextListener;
import ch.qos.logback.core.spi.ContextAwareBase;
import net.logstash.logback.appender.LogstashSocketAppender;
import net.logstash.logback.stacktrace.ShortenedThrowableConverter;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.context.annotation.Configuration;

@Configuration
public class LoggingConfiguration {

    private final Logger log = LoggerFactory.getLogger(LoggingConfiguration.class);

    private LoggerContext context = (LoggerContext) LoggerFactory.getILoggerFactory();

    private final String appName;

    private final String serverPort;
    <%_ if (serviceDiscoveryType === "eureka") { _%>

    private final String instanceId;
    <%_ } _%>
    <%_ if (serviceDiscoveryType === "consul") { _%>

    private final String instanceId;
    <%_ } _%>

    private final JBooterProperties jBooterProperties;

    public LoggingConfiguration(@Value("${spring.application.name}") String appName, @Value("${server.port}") String serverPort,
        <% if (serviceDiscoveryType === "eureka") { %>@Value("${eureka.instance.instanceId}") String instanceId,<% } %><% if (serviceDiscoveryType === "consul") { %>@Value("${spring.cloud.consul.discovery.instanceId}") String instanceId,<% } %> JBooterProperties jBooterProperties) {
        this.appName = appName;
        this.serverPort = serverPort;
        <%_ if (serviceDiscoveryType !== false) { _%>
        this.instanceId = instanceId;
        <%_ } _%>
        this.jBooterProperties = jBooterProperties;
        if (jBooterProperties.getLogging().getLogstash().isEnabled()) {
            addLogstashAppender(context);

            // Add context listener
            LogbackLoggerContextListener loggerContextListener = new LogbackLoggerContextListener();
            loggerContextListener.setContext(context);
            context.addListener(loggerContextListener);
        }
    }

    public void addLogstashAppender(LoggerContext context) {
        log.info("Initializing Logstash logging");

        LogstashSocketAppender logstashAppender = new LogstashSocketAppender();
        logstashAppender.setName("LOGSTASH");
        logstashAppender.setContext(context);
        <%_ if (serviceDiscoveryType && (applicationType == 'microservice' || applicationType == 'gateway' || applicationType == 'uaa')) { _%>
        String customFields = "{\"app_name\":\"" + appName + "\",\"app_port\":\"" + serverPort + "\"," +
            "\"instance_id\":\"" + instanceId + "\"}";
        <%_ } else { _%>
        String customFields = "{\"app_name\":\"" + appName + "\",\"app_port\":\"" + serverPort + "\"}";
        <%_ } _%>

        // Set the Logstash appender config from JBooter properties
        logstashAppender.setSyslogHost(jBooterProperties.getLogging().getLogstash().getHost());
        logstashAppender.setPort(jBooterProperties.getLogging().getLogstash().getPort());
        logstashAppender.setCustomFields(customFields);

        // Limit the maximum length of the forwarded stacktrace so that it won't exceed the 8KB UDP limit of logstash
        ShortenedThrowableConverter throwableConverter = new ShortenedThrowableConverter();
        throwableConverter.setMaxLength(7500);
        throwableConverter.setRootCauseFirst(true);
        logstashAppender.setThrowableConverter(throwableConverter);

        logstashAppender.start();

        // Wrap the appender in an Async appender for performance
        AsyncAppender asyncLogstashAppender = new AsyncAppender();
        asyncLogstashAppender.setContext(context);
        asyncLogstashAppender.setName("ASYNC_LOGSTASH");
        asyncLogstashAppender.setQueueSize(jBooterProperties.getLogging().getLogstash().getQueueSize());
        asyncLogstashAppender.addAppender(logstashAppender);
        asyncLogstashAppender.start();

        context.getLogger("ROOT").addAppender(asyncLogstashAppender);
    }

    /**
     * Logback configuration is achieved by configuration file and API.
     * When configuration file change is detected, the configuration is reset.
     * This listener ensures that the programmatic configuration is also re-applied after reset.
     */
    class LogbackLoggerContextListener extends ContextAwareBase implements LoggerContextListener {

        @Override
        public boolean isResetResistant() {
            return true;
        }

        @Override
        public void onStart(LoggerContext context) {
            addLogstashAppender(context);
        }

        @Override
        public void onReset(LoggerContext context) {
            addLogstashAppender(context);
        }

        @Override
        public void onStop(LoggerContext context) {
            // Nothing to do.
        }

        @Override
        public void onLevelChange(ch.qos.logback.classic.Logger logger, Level level) {
            // Nothing to do.
        }
    }

}