/**
    * Logback: the reliable, generic, fast and flexible logging framework.
    * Copyright (C) 1999-2011, 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.core.joran;
  
  import java.io.File;
  import java.io.FileInputStream;
  import java.io.IOException;
  import java.io.InputStream;
  import java.net.URL;
  import java.net.URLConnection;
  import java.util.List;
  
  import static ch.qos.logback.core.CoreConstants.SAFE_JORAN_CONFIGURATION;
  
  import ch.qos.logback.core.Context;
  import ch.qos.logback.core.joran.util.ConfigurationWatchListUtil;
  import ch.qos.logback.core.status.StatusChecker;
  import org.xml.sax.InputSource;
  
  import ch.qos.logback.core.joran.event.SaxEvent;
  import ch.qos.logback.core.joran.event.SaxEventRecorder;
  import ch.qos.logback.core.joran.spi.DefaultNestedComponentRegistry;
  import ch.qos.logback.core.joran.spi.InterpretationContext;
  import ch.qos.logback.core.joran.spi.Interpreter;
  import ch.qos.logback.core.joran.spi.JoranException;
  import ch.qos.logback.core.joran.spi.Pattern;
  import ch.qos.logback.core.joran.spi.RuleStore;
  import ch.qos.logback.core.joran.spi.SimpleRuleStore;
  import ch.qos.logback.core.spi.ContextAwareBase;
  
  public abstract class GenericConfigurator extends ContextAwareBase {
  
    protected Interpreter interpreter;
  
    public final void doConfigure(URL url) throws JoranException {
      try {
        informContextOfURLUsedForConfiguration(getContext(), url);
        URLConnection urlConnection = url.openConnection();
        // per http://jira.qos.ch/browse/LBCORE-105
        // per http://jira.qos.ch/browse/LBCORE-127
        urlConnection.setUseCaches(false);
  
        InputStream in = urlConnection.getInputStream();
        doConfigure(in);
        in.close();
      } catch (IOException ioe) {
        String errMsg = "Could not open URL [" + url + "].";
        addError(errMsg, ioe);
        throw new JoranException(errMsg, ioe);
      }
    }
  
    public final void doConfigure(String filename) throws JoranException {
      doConfigure(new File(filename));
    }
  
    public final void doConfigure(File file) throws JoranException {
      FileInputStream fis = null;
      try {
        informContextOfURLUsedForConfiguration(getContext(), file.toURI().toURL());
        fis = new FileInputStream(file);
        doConfigure(fis);
      } catch (IOException ioe) {
        String errMsg = "Could not open [" + file.getPath() + "].";
        addError(errMsg, ioe);
        throw new JoranException(errMsg, ioe);
      } finally {
        if (fis != null) {
          try {
            fis.close();
          } catch (java.io.IOException ioe) {
            String errMsg = "Could not close [" + file.getName() + "].";
            addError(errMsg, ioe);
            throw new JoranException(errMsg, ioe);
          }
        }
      }
    }
  
    public static void informContextOfURLUsedForConfiguration(Context context, URL url) {
      ConfigurationWatchListUtil.setMainWatchURL(context, url);
    }
  
    public final void doConfigure(InputStream inputStream) throws JoranException {
      doConfigure(new InputSource(inputStream));
    }
  
    protected abstract void addInstanceRules(RuleStore rs);
 
   protected abstract void addImplicitRules(Interpreter interpreter);
 
   protected void addDefaultNestedComponentRegistryRules(DefaultNestedComponentRegistry registry) {
 
   }
 
   protected Pattern initialPattern() {
     return new Pattern();
   }
 
   protected void buildInterpreter() {
     RuleStore rs = new SimpleRuleStore(context);
     addInstanceRules(rs);
     this.interpreter = new Interpreter(context, rs, initialPattern());
     InterpretationContext ec = interpreter.getInterpretationContext();
     ec.setContext(context);
     addImplicitRules(interpreter);
     addDefaultNestedComponentRegistryRules(ec.getDefaultNestedComponentRegistry());
   }
 
   // this is the most inner form of doConfigure whereto other doConfigure
   // methods ultimately delegate
   public final void doConfigure(final InputSource inputSource)
           throws JoranException {
 
     long threshold = System.currentTimeMillis();
     if (!ConfigurationWatchListUtil.wasConfigurationWatchListReset(context)) {
       informContextOfURLUsedForConfiguration(getContext(), null);
     }
     SaxEventRecorder recorder = new SaxEventRecorder();
     recorder.setContext(context);
     recorder.recordEvents(inputSource);
     doConfigure(recorder.saxEventList);
     // no exceptions a this level
     StatusChecker statusChecker = new StatusChecker(context);
     if(statusChecker.noXMLParsingErrorsOccurred(threshold)) {
       addInfo("Registering current configuration as safe fallback point");
       registerSafeConfiguration();
     }
   }
 
   public void doConfigure(final List<SaxEvent> eventList)
           throws JoranException {
     buildInterpreter();
     // disallow simultaneous configurations of the same context
     synchronized (context.getConfigurationLock()) {
       interpreter.getEventPlayer().play(eventList);
     }
   }
 
   /**
    * Register the current event list in currently in the interpreter as a safe
    * configuration point.
    *
    * @since 0.9.30
    */
   public void registerSafeConfiguration() {
     context.putObject(SAFE_JORAN_CONFIGURATION, interpreter.getEventPlayer().getCopyOfPlayerEventList());
   }
 
   /**
    * Recall the event list previously registered as a safe point.
    */
   public List<SaxEvent> recallSafeConfiguration() {
     return (List<SaxEvent>) context.getObject(SAFE_JORAN_CONFIGURATION);
   }
 }