/*
    * Licensed to the Apache Software Foundation (ASF) under one or more
    * contributor license agreements. See the NOTICE file distributed with
    * this work for additional information regarding copyright ownership.
    * The ASF 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
    *
    *      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 org.apache.logging.log4j.core.config;
  
  import org.apache.logging.log4j.Logger;
  import org.apache.logging.log4j.core.Appender;
  import org.apache.logging.log4j.core.Filter;
  import org.apache.logging.log4j.core.LogEvent;
  import org.apache.logging.log4j.core.config.plugins.PluginAttr;
  import org.apache.logging.log4j.core.config.plugins.PluginConfiguration;
  import org.apache.logging.log4j.core.config.plugins.PluginFactory;
  import org.apache.logging.log4j.core.config.plugins.PluginManager;
  import org.apache.logging.log4j.core.config.plugins.PluginElement;
  import org.apache.logging.log4j.core.config.plugins.PluginNode;
  import org.apache.logging.log4j.core.config.plugins.PluginType;
  import org.apache.logging.log4j.core.config.plugins.PluginValue;
  import org.apache.logging.log4j.core.filter.Filterable;
  import org.apache.logging.log4j.core.helpers.NameUtil;
  import org.apache.logging.log4j.core.lookup.Interpolator;
  import org.apache.logging.log4j.core.lookup.StrLookup;
  import org.apache.logging.log4j.core.lookup.StrSubstitutor;
  import org.apache.logging.log4j.status.StatusLogger;
  
  import java.lang.annotation.Annotation;
  import java.lang.reflect.Array;
  import java.lang.reflect.Method;
  import java.lang.reflect.Modifier;
  import java.util.ArrayList;
  import java.util.Collections;
  import java.util.List;
  import java.util.Map;
  import java.util.concurrent.ConcurrentHashMap;
  import java.util.concurrent.ConcurrentMap;
  import java.util.concurrent.CopyOnWriteArrayList;
  
  /**
   * The Base Configuration. Many configuration implementations will extend this class.
   */
  public class BaseConfiguration extends Filterable implements Configuration {
      /**
       * Allow subclasses access to the status logger without creating another instance.
       */
      protected static final Logger LOGGER = StatusLogger.getLogger();
  
      /**
       * The root node of the configuration.
       */
      protected Node rootNode;
  
      /**
       * The Plugin Manager.
       */
      protected PluginManager pluginManager;
  
      /**
       * Listeners for configuration changes.
       */
      protected final List<ConfigurationListener> listeners =
          new CopyOnWriteArrayList<ConfigurationListener>();
  
      /**
       * The ConfigurationMonitor that checks for configuration changes.
       */
      protected ConfigurationMonitor monitor = new DefaultConfigurationMonitor();
  
      private String name;
  
      private ConcurrentMap<String, Appender> appenders = new ConcurrentHashMap<String, Appender>();
  
      private ConcurrentMap<String, LoggerConfig> loggers = new ConcurrentHashMap<String, LoggerConfig>();
  
      private StrSubstitutor subst = new StrSubstitutor();
  
      private LoggerConfig root = new LoggerConfig();
  
      private boolean started = false;
  
      private ConcurrentMap<String, Object> componentMap = new ConcurrentHashMap<String, Object>();
  
      /**
       * Constructor.
       */
      protected BaseConfiguration() {
          pluginManager = new PluginManager("Core");
          rootNode = new Node();
     }
 
     /**
      * Initialize the configuration.
      */
     public void start() {
         pluginManager.collectPlugins();
         setup();
         doConfigure();
         for (LoggerConfig logger : loggers.values()) {
             logger.startFilter();
         }
         for (Appender appender : appenders.values()) {
             appender.start();
         }
 
         startFilter();
     }
 
     /**
      * Tear down the configuration.
      */
     public void stop() {
         for (LoggerConfig logger : loggers.values()) {
             logger.clearAppenders();
             logger.stopFilter();
         }
         for (Appender appender : appenders.values()) {
             appender.stop();
         }
         stopFilter();
     }
 
     protected void setup() {
     }
 
     public Object getComponent(String name) {
         return componentMap.get(name);
     }
 
     public void addComponent(String name, Object obj) {
         componentMap.putIfAbsent(name, obj);
     }
 
     protected void doConfigure() {
         boolean setRoot = false;
         boolean setLoggers = false;
         for (Node child : rootNode.getChildren()) {
             createConfiguration(child, null);
             if (child.getObject() == null) {
                 continue;
             }
             if (child.getName().equalsIgnoreCase("properties")) {
                 if (subst.getVariableResolver() == null) {
                     subst.setVariableResolver((StrLookup) child.getObject());
                 } else {
                     LOGGER.error("Properties declaration must be the first element in the configuration");
                 }
                 continue;
             } else if (subst.getVariableResolver() == null) {
                 subst.setVariableResolver(new Interpolator(null));
             }
             if (child.getName().equalsIgnoreCase("appenders")) {
                 appenders = (ConcurrentMap<String, Appender>) child.getObject();
             } else if (child.getObject() instanceof Filter) {
                 addFilter((Filter) child.getObject());
             } else if (child.getName().equalsIgnoreCase("loggers")) {
                 Loggers l = (Loggers) child.getObject();
                 loggers = l.getMap();
                 setLoggers = true;
                 if (l.getRoot() != null) {
                     root = l.getRoot();
                     setRoot = true;
                 }
             } else {
                 LOGGER.error("Unknown object \"" + child.getName() + "\" of type " +
                     child.getObject().getClass().getName() + " is ignored");
             }
         }
 
         if (!setLoggers) {
             LOGGER.warn("No Loggers were configured, using default");
         } else if (!setRoot) {
             LOGGER.warn("No Root logger was configured, using default");
         }
 
         root.setConfigurationMonitor(monitor);
 
         for (Map.Entry<String, LoggerConfig> entry : loggers.entrySet()) {
             LoggerConfig l = entry.getValue();
             l.setConfigurationMonitor(monitor);
             for (AppenderRef ref : l.getAppenderRefs()) {
                 Appender app = appenders.get(ref.getRef());
                 if (app != null) {
                     l.addAppender(app, ref.getLevel(), ref.getFilter());
                 } else {
                     LOGGER.error("Unable to locate appender " + ref.getRef() + " for logger " + l.getName());
                 }
             }
 
         }
 
         setParents();
     }
 
     protected PluginManager getPluginManager() {
         return pluginManager;
     }
 
     /**
      * Set the name of the configuration.
      * @param name The name.
      */
     public void setName(String name) {
         this.name = name;
     }
 
     /**
      * Return the name of the configuration.
      * @return the name of the configuration.
      */
     public String getName() {
         return name;
     }
 
     /**
      * Add a listener for changes on the configuration.
      * @param listener The ConfigurationListener to add.
      */
     public void addListener(ConfigurationListener listener) {
         listeners.add(listener);
     }
 
     /**
      * Remove a ConfigurationListener.
      * @param listener The ConfigurationListener to remove.
      */
     public void removeListener(ConfigurationListener listener) {
         listeners.remove(listener);
     }
 
     /**
      * Return the Appender with the specified name.
      * @param name The name of the Appender.
      * @return the Appender with the specified name or null if the Appender cannot be located.
      */
     public Appender getAppender(String name) {
         return appenders.get(name);
     }
 
     /**
      * Return a Map containing all the Appenders and their name.
      * @return A Map containing each Appender's naem and the Appender object.
      */
     public Map<String, Appender> getAppenders() {
         return appenders;
     }
 
     /**
      * Adds an Appender to the configuration.
      * @param appender The Appender to add.
      */
     public void addAppender(Appender appender) {
         appenders.put(appender.getName(), appender);
     }
 
     public StrSubstitutor getSubst() {
         return subst;
     }
 
     /**
      * Associates an Appender with a LoggerConfig. This method is synchronized in case a Logger with the
      * same name is being updated at the same time.
      *
      * Note: This method is not used when configuring via configuration. It is primarily used by
      * unit tests.
      * @param logger The Logger the Appender will be associated with.
      * @param appender The Appender.
      */
     public synchronized void addLoggerAppender(org.apache.logging.log4j.core.Logger logger, Appender appender) {
         String name = logger.getName();
         appenders.putIfAbsent(name, appender);
         LoggerConfig lc = getLoggerConfig(name);
         if (lc.getName().equals(name)) {
             lc.addAppender(appender, null, null);
         } else {
             LoggerConfig nlc = new LoggerConfig(name, lc.getLevel(), lc.isAdditive());
             nlc.setConfigurationMonitor(monitor);
             nlc.addAppender(appender, null, null);
             nlc.setParent(lc);
             loggers.putIfAbsent(name, nlc);
             setParents();
             logger.getContext().updateLoggers();
         }
     }
     /**
      * Associates a Filter with a LoggerConfig. This method is synchronized in case a Logger with the
      * same name is being updated at the same time.
      *
      * Note: This method is not used when configuring via configuration. It is primarily used by
      * unit tests.
      * @param logger The Logger the Fo;ter will be associated with.
      * @param filter The Filter.
      */
     public synchronized void addLoggerFilter(org.apache.logging.log4j.core.Logger logger, Filter filter) {
         String name = logger.getName();
         LoggerConfig lc = getLoggerConfig(name);
         if (lc.getName().equals(name)) {
 
             lc.addFilter(filter);
         } else {
             LoggerConfig nlc = new LoggerConfig(name, lc.getLevel(), lc.isAdditive());
             nlc.setConfigurationMonitor(monitor);
             nlc.addFilter(filter);
             nlc.setParent(lc);
             loggers.putIfAbsent(name, nlc);
             setParents();
             logger.getContext().updateLoggers();
         }
     }
     /**
      * Marks a LoggerConfig as additive. This method is synchronized in case a Logger with the
      * same name is being updated at the same time.
      *
      * Note: This method is not used when configuring via configuration. It is primarily used by
      * unit tests.
      * @param logger The Logger the Appender will be associated with.
      * @param additive True if the LoggerConfig should be additive, false otherwise.
      */
     public synchronized void setLoggerAdditive(org.apache.logging.log4j.core.Logger logger, boolean additive) {
         String name = logger.getName();
         LoggerConfig lc = getLoggerConfig(name);
         if (lc.getName().equals(name)) {
             lc.setAdditive(additive);
         } else {
             LoggerConfig nlc = new LoggerConfig(name, lc.getLevel(), additive);
             nlc.setConfigurationMonitor(monitor);
             nlc.setParent(lc);
             loggers.putIfAbsent(name, nlc);
             setParents();
             logger.getContext().updateLoggers();
         }
     }
 
     /**
      * Remove an Appender. First removes any associations between LoggerContigs and the Appender, removes
      * the Appender from this appender list and then stops the appender. This method is synchronized in
      * case an Appender with the same name is being added during the removal.
      * @param name the name of the appender to remove.
      */
     public synchronized void removeAppender(String name) {
         for (LoggerConfig logger : loggers.values()) {
             logger.removeAppender(name);
         }
         Appender app = appenders.remove(name);
 
         if (app != null) {
             app.stop();
         }
     }
 
     /**
      * Locates the appropriate LoggerConfig for a Logger name. This will remove tokens from the
      * package name as necessary or return the root LoggerConfig if no other matches were found.
      * @param name The Logger name.
      * @return The located LoggerConfig.
      */
     public LoggerConfig getLoggerConfig(String name) {
         if (loggers.containsKey(name)) {
             return loggers.get(name);
         }
         String substr = name;
         while ((substr = NameUtil.getSubName(substr)) != null) {
             if (loggers.containsKey(substr)) {
                 return loggers.get(substr);
             }
         }
         return root;
     }
 
     /**
      * Returns the root Logger.
      * @return the root Logger.
      */
     public LoggerConfig getRootLogger() {
         return root;
     }
 
     /**
      * Return a Map of all the LoggerConfigs.
      * @return a Map with each entry containing the name of the Logger and the LoggerConfig.
      */
     public Map<String, LoggerConfig> getLoggers() {
         return Collections.unmodifiableMap(loggers);
     }
 
     /**
      * Returns the LoggerConfig with the specified name.
      * @param name The Logger name.
      * @return The LoggerConfig or null if no match was found.
      */
     public LoggerConfig getLogger(String name) {
         return loggers.get(name);
     }
 
     /**
      * Adding a logger cannot be done atomically so is not allowed in an active configuration. Adding
      * or removing a Logger requires creating a new configuration and then switching.
      *
      * @param name The name of the Logger.
      * @param loggerConfig The LoggerConfig.
      */
     public void addLogger(String name, LoggerConfig loggerConfig) {
         if (started) {
             String msg = "Cannot add logger " + name + " to an active configuration";
             LOGGER.warn(msg);
             throw new IllegalStateException(msg);
         }
         loggers.put(name, loggerConfig);
         setParents();
     }
 
     /**
      * Removing a logger cannot be done atomically so is not allowed in an active configuration. Adding
      * or removing a Logger requires creating a new configuration and then switching.
      *
      * @param name The name of the Logger.
      */
     public void removeLogger(String name) {
         if (started) {
             String msg = "Cannot remove logger " + name + " in an active configuration";
             LOGGER.warn(msg);
             throw new IllegalStateException(msg);
         }
         loggers.remove(name);
         setParents();
     }
 
     public void createConfiguration(Node node, LogEvent event) {
         PluginType type = node.getType();
         if (type != null && type.isDeferChildren()) {
             node.setObject(createPluginObject(type, node, event));
         } else {
             for (Node child : node.getChildren()) {
                 createConfiguration(child, event);
             }
 
             if (type == null) {
                 if (node.getParent() != null) {
                     LOGGER.error("Unable to locate plugin for " + node.getName());
                 }
             } else {
                 node.setObject(createPluginObject(type, node, event));
             }
         }
     }
 
    /*
     * Retrieve a static public 'method to create the desired object. Every parameter
     * will be annotated to identify the appropriate attribute or element to use to
     * set the value of the paraemter.
     * Parameters annotated with PluginAttr will always be set as Strings.
     * Parameters annotated with PluginElement may be Objects or arrays. Collections
     * and Maps are currently not supported, although the factory method that is called
     * can create these from an array.
     *
     * Although the happy path works, more work still needs to be done to log incorrect
     * parameters. These will generally result in unhelpful InvocationTargetExceptions.
     * @param classClass the class.
     * @return the instantiate method or null if there is none by that
     * description.
     */
     private Object createPluginObject(PluginType type, Node node, LogEvent event)
     {
         Class clazz = type.getPluginClass();
 
         if (Map.class.isAssignableFrom(clazz)) {
             try {
                 Map<String, Object> map = (Map<String, Object>) clazz.newInstance();
                 for (Node child : node.getChildren()) {
                     map.put(child.getName(), child.getObject());
                 }
                 return map;
             } catch (Exception ex) {
                 LOGGER.warn("Unable to create Map for " + type.getElementName() + " of class " +
                     clazz);
             }
         }
 
         if (List.class.isAssignableFrom(clazz)) {
             try {
                 List<Object> list = (List<Object>) clazz.newInstance();
                 for (Node child : node.getChildren()) {
                     list.add(child.getObject());
                 }
                 return list;
             } catch (Exception ex) {
                 LOGGER.warn("Unable to create List for " + type.getElementName() + " of class " +
                     clazz);
             }
         }
 
         Method factoryMethod = null;
 
         for (Method method : clazz.getMethods()) {
             if (method.isAnnotationPresent(PluginFactory.class)) {
                 factoryMethod = method;
                 break;
             }
         }
         if (factoryMethod == null) {
             return null;
         }
 
         Annotation[][] parmArray = factoryMethod.getParameterAnnotations();
         Class[] parmClasses = factoryMethod.getParameterTypes();
         if (parmArray.length != parmClasses.length) {
             LOGGER.error("Number of parameter annotations does not equal the number of paramters");
         }
         Object[] parms = new Object[parmClasses.length];
 
         int index = 0;
         Map<String, String> attrs = node.getAttributes();
         List<Node> children = node.getChildren();
         StringBuilder sb = new StringBuilder();
         List<Node> used = new ArrayList<Node>();
 
         /*
          * For each parameter:
          * If the parameter is an attribute store the value of the attribute in the parameter array.
          * If the parameter is an element:
          *   Determine if the required parameter is an array.
          *     If so, if a child contains the array, use it,
          *      otherwise create the array from all child nodes of the correct type.
          *     Store the array into the parameter array.
          *   If not an array, store the object in the child node into the parameter array.
          */
         for (Annotation[] parmTypes : parmArray) {
             for (Annotation a : parmTypes) {
                 if (sb.length() == 0) {
                     sb.append(" with params(");
                 } else {
                     sb.append(", ");
                 }
                 if (a instanceof PluginNode) {
                     parms[index] = node;
                     sb.append("Node=").append(node.getName());
                 } else if (a instanceof PluginConfiguration) {
                     parms[index] = this;
                     if (this.name != null) {
                         sb.append("Configuration(").append(name).append(")");
                     } else {
                         sb.append("Configuration");
                     }
                 } else if (a instanceof PluginValue) {
                     String name = ((PluginValue) a).value();
                     String v = node.getValue();
                     if (v == null) {
                         v = getAttrValue("value", attrs);
                     }
                     String value = subst.replace(event, v);
                     sb.append(name).append("=\"").append(value).append("\"");
                     parms[index] = value;
                 } else if (a instanceof PluginAttr) {
                     String name = ((PluginAttr) a).value();
                     String value = subst.replace(event, getAttrValue(name, attrs));
                     sb.append(name).append("=\"").append(value).append("\"");
                     parms[index] = value;
                 } else if (a instanceof PluginElement) {
                     PluginElement elem = (PluginElement) a;
                     String name = elem.value();
                     if (parmClasses[index].isArray()) {
                         Class parmClass = parmClasses[index].getComponentType();
                         List<Object> list = new ArrayList<Object>();
                         sb.append(name).append("={");
                         boolean first = true;
                         for (Node child : children) {
                             PluginType childType = child.getType();
                             if (elem.value().equalsIgnoreCase(childType.getElementName()) ||
                                 parmClass.isAssignableFrom(childType.getPluginClass())) {
                                 used.add(child);
                                 if (!first) {
                                     sb.append(", ");
                                 }
                                 first = false;
                                 Object obj = child.getObject();
                                 if (obj == null) {
                                     System.out.println("Null object returned for " + child.getName());
                                 }
                                 if (obj.getClass().isArray()) {
                                     printArray(sb, (Object[]) obj);
                                     parms[index] = obj;
                                     break;
                                 }
                                 sb.append(child.toString());
                                 list.add(obj);
                             }
                         }
                         sb.append("}");
                         if (parms[index] != null) {
                             break;
                         }
                         if (list.size() > 0 && !parmClass.isAssignableFrom(list.get(0).getClass())) {
                             LOGGER.error("Attempted to assign List containing class " +
                                 list.get(0).getClass().getName() + " to array of type " + parmClass +
                                 " for attribute " + name);
                             break;
                         }
                         Object[] array = (Object[]) Array.newInstance(parmClass, list.size());
                         int i = 0;
                         for (Object obj : list) {
                             array[i] = obj;
                             ++i;
                         }
                         parms[index] = array;
                     } else {
                         Class parmClass = parmClasses[index];
                         boolean present = false;
                         for (Node child : children) {
                             PluginType childType = child.getType();
                             if (elem.value().equals(childType.getElementName()) ||
                                 parmClass.isAssignableFrom(childType.getPluginClass())) {
                                 sb.append(child.getName()).append("(").append(child.toString()).append(")");
                                 present = true;
                                 used.add(child);
                                 parms[index] = child.getObject();
                                 break;
                             }
                         }
                         if (!present) {
                             sb.append("null");
                         }
                     }
                 }
             }
             ++index;
         }
         if (sb.length() > 0) {
             sb.append(")");
         }
 
         if (attrs.size() > 0) {
             StringBuilder eb = new StringBuilder();
             for (String key : attrs.keySet()) {
                 if (eb.length() == 0) {
                     eb.append(node.getName());
                     eb.append(" contains ");
                     if (attrs.size() == 1) {
                         eb.append("an invalid element or attribute ");
                     } else {
                         eb.append("invalid attributes ");
                     }
                 } else {
                     eb.append(", ");
                 }
                 eb.append("\"");
                 eb.append(key);
                 eb.append("\"");
 
             }
             LOGGER.error(eb.toString());
         }
 
         if (!type.isDeferChildren() && used.size() != children.size()) {
             for (Node child : children) {
                 if (used.contains(child)) {
                     continue;
                 }
                 String nodeType = node.getType().getElementName();
                 String start = nodeType.equals(node.getName()) ? node.getName() : nodeType + " " + node.getName();
                 LOGGER.error(start + " has no parameter that matches element " + child.getName());
             }
         }
 
         try {
             int mod = factoryMethod.getModifiers();
             if (!Modifier.isStatic(mod)) {
                 LOGGER.error(factoryMethod.getName() + " method is not static on class " +
                     clazz.getName() + " for element " + node.getName());
                 return null;
             }
             LOGGER.debug("Calling {} on class {} for element {}", factoryMethod.getName(), clazz.getName(),
                 node.getName(), sb.toString());
             //if (parms.length > 0) {
                 return factoryMethod.invoke(null, parms);
             //}
             //return factoryMethod.invoke(null, node);
         } catch (Exception e) {
             LOGGER.error("Unable to invoke method " + factoryMethod.getName() + " in class " +
                 clazz.getName() + " for element " + node.getName(), e);
         }
         return null;
     }
 
     private void printArray(StringBuilder sb, Object[] array) {
         boolean first = true;
         for (Object obj : array) {
             if (!first) {
                 sb.append(", ");
             }
             sb.append(obj.toString());
             first = false;
         }
     }
 
     private String getAttrValue(String name, Map<String, String> attrs) {
         for (String key : attrs.keySet()) {
             if (key.equalsIgnoreCase(name)) {
                 String attr = attrs.get(key);
                 attrs.remove(key);
                 return attr;
             }
         }
         return null;
     }
 
     private void setParents() {
          for (Map.Entry<String, LoggerConfig> entry : loggers.entrySet()) {
             LoggerConfig logger = entry.getValue();
             String name = entry.getKey();
             if (!name.equals("")) {
                 int i = name.lastIndexOf(".");
                 if (i > 0) {
                     name = name.substring(0, i);
                     LoggerConfig parent = getLoggerConfig(name);
                     if (parent == null) {
                         parent = root;
                     }
                     logger.setParent(parent);
                 }
             }
         }
     }
 }