/**
    * Logback: the reliable, generic, fast and flexible logging framework.
    * Copyright (C) 1999-2022, QOS.ch. All rights reserved.
    *
    * This program and the accompanying materials are dual-licensed under
    * either the terms of the Eclipse Public License v1.0 as published by
    * the Eclipse Foundation
    *
    *   or (per the licensee's choosing)
   *
   * under the terms of the GNU Lesser General Public License version 2.1
   * as published by the Free Software Foundation.
   */
  package ch.qos.logback.classic.model.processor;
  
  import ch.qos.logback.classic.joran.ReconfigureOnChangeTask;
  import ch.qos.logback.classic.model.ConfigurationModel;
  import ch.qos.logback.core.Context;
  import ch.qos.logback.core.joran.util.ConfigurationWatchListUtil;
  import ch.qos.logback.core.model.Model;
  import ch.qos.logback.core.model.processor.ModelHandlerBase;
  import ch.qos.logback.core.model.processor.ModelHandlerException;
  import ch.qos.logback.core.model.processor.ModelInterpretationContext;
  import ch.qos.logback.core.spi.ConfigurationEvent;
  import ch.qos.logback.core.util.Duration;
  import ch.qos.logback.core.util.OptionHelper;
  
  import java.net.URL;
  import java.util.concurrent.ScheduledExecutorService;
  import java.util.concurrent.ScheduledFuture;
  import java.util.concurrent.TimeUnit;
  
  /**
   * This is a subclass of {@link ConfigurationModelHandler} offering configuration reloading support.
   *
   */
  public class ConfigurationModelHandlerFull extends ConfigurationModelHandler {
  
      public static String FAILED_WATCH_PREDICATE_MESSAGE_1 = "Missing watchable .xml or .properties files.";
      public static String FAILED_WATCH_PREDICATE_MESSAGE_2 = "Watching .xml files requires that the main configuration file is reachable as a URL";
  
      public ConfigurationModelHandlerFull(Context context) {
          super(context);
      }
  
      static public ModelHandlerBase makeInstance2(Context context, ModelInterpretationContext mic) {
          return new ConfigurationModelHandlerFull(context);
      }
  
      @Override
      protected void processScanAttrib(ModelInterpretationContext mic, ConfigurationModel configurationModel) {
          // override parent to do nothing
      }
  
      @Override
      public void postHandle(ModelInterpretationContext mic, Model model) throws ModelHandlerException {
          ConfigurationModel configurationModel = (ConfigurationModel) model;
          // post handling of scan attribute works even we need to watch for included files because the main url is
          // set in GenericXMLConfigurator very early in the configuration process
          postProcessScanAttrib(mic, configurationModel);
      }
  
      protected void postProcessScanAttrib(ModelInterpretationContext mic, ConfigurationModel configurationModel) {
          String scanStr = mic.subst(configurationModel.getScanStr());
          String scanPeriodStr = mic.subst(configurationModel.getScanPeriodStr());
          detachedPostProcess(scanStr, scanPeriodStr);
      }
  
      /**
       * This method is called from this class but also from logback-tyler.
       *
       * This method assumes that the variables scanStr and scanPeriodStr have undergone variable substitution
       * as applicable to their current environment
       *
       * @param scanStr
       * @param scanPeriodStr
       * @since 1.5.0
       */
      public void detachedPostProcess(String scanStr, String scanPeriodStr) {
          if (!OptionHelper.isNullOrEmptyOrAllSpaces(scanStr) && !"false".equalsIgnoreCase(scanStr)) {
              ScheduledExecutorService scheduledExecutorService = context.getScheduledExecutorService();
              boolean watchPredicateFulfilled = ConfigurationWatchListUtil.watchPredicateFulfilled(context);
              if (!watchPredicateFulfilled) {
                  addWarn(FAILED_WATCH_PREDICATE_MESSAGE_1);
                  addWarn(FAILED_WATCH_PREDICATE_MESSAGE_2);
                  return;
              }
              ReconfigureOnChangeTask rocTask = new ReconfigureOnChangeTask();
              rocTask.setContext(context);
  
              addInfo("Registering a new ReconfigureOnChangeTask " + rocTask);
  
              context.fireConfigurationEvent(ConfigurationEvent.newConfigurationChangeDetectorRegisteredEvent(rocTask));
  
              Duration duration = getDurationOfScanPeriodAttribute(scanPeriodStr, SCAN_PERIOD_DEFAULT);
  
              addInfo("Will scan for changes in [" + ConfigurationWatchListUtil.getConfigurationWatchList(context) + "] ");
              // Given that included files are encountered at a later phase, the complete list
              // of files to scan can only be determined when the configuration is loaded in full.
             // However, scan can be active if mainURL is set. Otherwise, when changes are
             // detected the top level config file cannot be accessed.
             addInfo("Setting ReconfigureOnChangeTask scanning period to " + duration);
 
             ScheduledFuture<?> scheduledFuture = scheduledExecutorService.scheduleAtFixedRate(rocTask, duration.getMilliseconds(), duration.getMilliseconds(),
                             TimeUnit.MILLISECONDS);
             rocTask.setScheduredFuture(scheduledFuture);
             context.addScheduledFuture(scheduledFuture);
         }
 
     }
 
     private Duration getDurationOfScanPeriodAttribute(String scanPeriodAttrib, Duration defaultDuration) {
         Duration duration = null;
 
         if (!OptionHelper.isNullOrEmptyOrAllSpaces(scanPeriodAttrib)) {
             try {
                 duration = Duration.valueOf(scanPeriodAttrib);
             } catch (IllegalStateException | IllegalArgumentException e) {
                 addWarn("Failed to parse 'scanPeriod' attribute [" + scanPeriodAttrib + "]", e);
                 // default duration will be set below
             }
         }
 
         if (duration == null) {
             addInfo("No 'scanPeriod' specified. Defaulting to " + defaultDuration.toString());
             duration = defaultDuration;
         }
         return duration;
     }
 }