/*
 * Copyright 2012 LinkedIn Corp.
 * 
 * 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 azkaban.trigger;

import java.util.HashMap;
import java.util.Map;
import java.util.Set;

import org.apache.log4j.Logger;

import azkaban.utils.Props;
import azkaban.utils.Utils;

public class ActionTypeLoader {

  private static Logger logger = Logger.getLogger(ActionTypeLoader.class);

  public static final String DEFAULT_TRIGGER_ACTION_PLUGIN_DIR =
      "plugins/triggeractions";

  protected static Map<String, Class<? extends TriggerAction>> actionToClass =
      new HashMap<String, Class<? extends TriggerAction>>();

  public void init(Props props) throws TriggerException {
    // load built-in actions

    //
    // loadBuiltinActions();
    //
    // loadPluginActions(props);

  }

  public synchronized void registerActionType(String type,
      Class<? extends TriggerAction> actionClass) {
    logger.info("Registering action " + type);
    if (!actionToClass.containsKey(type)) {
      actionToClass.put(type, actionClass);
    }
  }

  // private void loadPluginActions(Props props) throws TriggerException {
  // String checkerDir = props.getString("azkaban.trigger.action.plugin.dir",
  // DEFAULT_TRIGGER_ACTION_PLUGIN_DIR);
  // File pluginDir = new File(checkerDir);
  // if(!pluginDir.exists() || !pluginDir.isDirectory() || !pluginDir.canRead())
  // {
  // logger.info("No trigger action plugins to load.");
  // return;
  // }
  //
  // logger.info("Loading plugin trigger actions from " + pluginDir);
  // ClassLoader parentCl = this.getClass().getClassLoader();
  //
  // Props globalActionConf = null;
  // File confFile = Utils.findFilefromDir(pluginDir, COMMONCONFFILE);
  // try {
  // if(confFile != null) {
  // globalActionConf = new Props(null, confFile);
  // } else {
  // globalActionConf = new Props();
  // }
  // } catch (IOException e) {
  // throw new TriggerException("Failed to get global properties." + e);
  // }
  //
  // for(File dir : pluginDir.listFiles()) {
  // if(dir.isDirectory() && dir.canRead()) {
  // try {
  // loadPluginTypes(globalActionConf, pluginDir, parentCl);
  // } catch (Exception e) {
  // logger.info("Plugin actions failed to load. " + e.getCause());
  // throw new TriggerException("Failed to load all trigger actions!", e);
  // }
  // }
  // }
  // }
  //
  // @SuppressWarnings("unchecked")
  // private void loadPluginTypes(Props globalConf, File dir, ClassLoader
  // parentCl) throws TriggerException {
  // Props actionConf = null;
  // File confFile = Utils.findFilefromDir(dir, ACTIONTYPECONFFILE);
  // if(confFile == null) {
  // logger.info("No action type found in " + dir.getAbsolutePath());
  // return;
  // }
  // try {
  // actionConf = new Props(globalConf, confFile);
  // } catch (IOException e) {
  // throw new TriggerException("Failed to load config for the action type", e);
  // }
  //
  // String actionName = dir.getName();
  // String actionClass = actionConf.getString("action.class");
  //
  // List<URL> resources = new ArrayList<URL>();
  // for(File f : dir.listFiles()) {
  // try {
  // if(f.getName().endsWith(".jar")) {
  // resources.add(f.toURI().toURL());
  // logger.info("adding to classpath " + f.toURI().toURL());
  // }
  // } catch (MalformedURLException e) {
  // // TODO Auto-generated catch block
  // throw new TriggerException(e);
  // }
  // }
  //
  // // each job type can have a different class loader
  // ClassLoader actionCl = new URLClassLoader(resources.toArray(new
  // URL[resources.size()]), parentCl);
  //
  // Class<? extends TriggerAction> clazz = null;
  // try {
  // clazz = (Class<? extends TriggerAction>)actionCl.loadClass(actionClass);
  // actionToClass.put(actionName, clazz);
  // }
  // catch (ClassNotFoundException e) {
  // throw new TriggerException(e);
  // }
  //
  // if(actionConf.getBoolean("need.init")) {
  // try {
  // Utils.invokeStaticMethod(actionCl, actionClass, "init", actionConf);
  // } catch (Exception e) {
  // e.printStackTrace();
  // logger.error("Failed to init the action type " + actionName);
  // throw new TriggerException(e);
  // }
  // }
  //
  // logger.info("Loaded action type " + actionName + " " + actionClass);
  // }
  //
  // private void loadBuiltinActions() {
  // actionToClass.put(ExecuteFlowAction.type, ExecuteFlowAction.class);
  // logger.info("Loaded ExecuteFlowAction type.");
  // }

  public static void registerBuiltinActions(
      Map<String, Class<? extends TriggerAction>> builtinActions) {
    actionToClass.putAll(builtinActions);
    for (String type : builtinActions.keySet()) {
      logger.info("Loaded " + type + " action.");
    }
  }

  public TriggerAction createActionFromJson(String type, Object obj)
      throws Exception {
    TriggerAction action = null;
    Class<? extends TriggerAction> actionClass = actionToClass.get(type);
    if (actionClass == null) {
      throw new Exception("Action Type " + type + " not supported!");
    }
    action =
        (TriggerAction) Utils.invokeStaticMethod(actionClass.getClassLoader(),
            actionClass.getName(), "createFromJson", obj);

    return action;
  }

  public TriggerAction createAction(String type, Object... args) {
    TriggerAction action = null;
    Class<? extends TriggerAction> actionClass = actionToClass.get(type);
    action = (TriggerAction) Utils.callConstructor(actionClass, args);

    return action;
  }

  public Set<String> getSupportedActions() {
    return actionToClass.keySet();
  }
}
