package io.cm.accesslog;

import io.undertow.Undertow;
import io.undertow.UndertowOptions;
import io.undertow.server.handlers.accesslog.AccessLogHandler;
import io.undertow.server.handlers.accesslog.AccessLogReceiver;
import lombok.extern.slf4j.Slf4j;
import org.apache.commons.lang.StringUtils;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.boot.autoconfigure.web.ServerProperties;
import org.springframework.boot.web.embedded.undertow.ConfigurableUndertowWebServerFactory;
import org.springframework.boot.web.server.WebServerFactoryCustomizer;
import org.springframework.stereotype.Component;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

@SpringBootApplication
public class UndertowAccessLogApplication {

  public static void main(String[] args) {
    SpringApplication.run(UndertowAccessLogApplication.class, args);
  }
}

@RestController
class HelloController {

  @RequestMapping("/")
  public String index() {
    return "Hello world!";
  }
}

@Component
class UndertowWebServerAccessLogTimingEnabler implements WebServerFactoryCustomizer<ConfigurableUndertowWebServerFactory> {

  private final ServerProperties serverProperties;

  public UndertowWebServerAccessLogTimingEnabler(ServerProperties serverProperties) {
    this.serverProperties = serverProperties;
  }

  @Override
  public void customize(ConfigurableUndertowWebServerFactory factory) {
    String pattern = serverProperties.getUndertow().getAccesslog().getPattern();

    // Record request timing only if the pattern
    if (logRequestProcessingTiming(pattern)) {
      factory.addBuilderCustomizers(builder -> builder.setServerOption(UndertowOptions.RECORD_REQUEST_START_TIME, true));
    }

    // Custom access log receiver.
    factory.addDeploymentInfoCustomizers(deploymentInfo -> {
      deploymentInfo.addInitialHandlerChainWrapper(handler -> {
        Slf4jAccessLogReceiver accessLogReceiver = new Slf4jAccessLogReceiver();
        return new AccessLogHandler(handler, accessLogReceiver, pattern, Undertow.class.getClassLoader());
      });
    });
  }

  private boolean logRequestProcessingTiming(String pattern) {
    if (StringUtils.isBlank(pattern)) {
      return false;
    }
    return pattern.contains("%D") || pattern.contains("%T");
  }
}

/**
 * Direct access logs to slf4j. Can be sent to custom location with logger configuration.
 * Default undertow access logs are in the launchDirectory/logs of the process
 */
@Slf4j(topic = "ACCESS_LOG")
class Slf4jAccessLogReceiver implements AccessLogReceiver {

  @Override
  public void logMessage(String message) {
    log.info(message);
  }
}