/**
* 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.hadoop.yarn.server.resourcemanager.webapp;

import static org.apache.hadoop.yarn.util.StringHelper.join;
import static org.apache.hadoop.yarn.webapp.YarnWebParams.QUEUE_NAME;

import org.apache.hadoop.yarn.server.resourcemanager.ResourceManager;
import org.apache.hadoop.yarn.server.resourcemanager.rmapp.RMAppState;
import org.apache.hadoop.yarn.server.resourcemanager.scheduler.ResourceScheduler;
import org.apache.hadoop.yarn.server.resourcemanager.scheduler.capacity.CapacityScheduler;
import org.apache.hadoop.yarn.server.resourcemanager.scheduler.fair.FairScheduler;
import org.apache.hadoop.yarn.util.StringHelper;
import org.apache.hadoop.yarn.webapp.Controller;
import org.apache.hadoop.yarn.webapp.WebAppException;
import org.apache.hadoop.yarn.webapp.YarnWebParams;

import com.google.inject.Inject;

// Do NOT rename/refactor this to RMView as it will wreak havoc
// on Mac OS HFS as its case-insensitive!
public class RmController extends Controller {

  @Inject
  RmController(RequestContext ctx) {
    super(ctx);
  }

  @Override public void index() {
    setTitle("Applications");
  }

  public void about() {
    setTitle("About the Cluster");
    render(AboutPage.class);
  }

  public void app() {
    render(AppPage.class);
  }

  public void nodes() {
    render(NodesPage.class);
  }

  public void scheduler() {
    // limit applications to those in states relevant to scheduling
    set(YarnWebParams.APP_STATE, StringHelper.cjoin(
        RMAppState.NEW.toString(),
        RMAppState.SUBMITTED.toString(),
        RMAppState.ACCEPTED.toString(),
        RMAppState.RUNNING.toString(),
        RMAppState.FINISHING.toString()));

    ResourceManager rm = getInstance(ResourceManager.class);
    ResourceScheduler rs = rm.getResourceScheduler();
    if (rs == null || rs instanceof CapacityScheduler) {
      setTitle("Capacity Scheduler");
      render(CapacitySchedulerPage.class);
      return;
    }
    
    if (rs instanceof FairScheduler) {
      setTitle("Fair Scheduler");
      render(FairSchedulerPage.class);
      return;
    }
    
    setTitle("Default Scheduler");
    render(DefaultSchedulerPage.class);
  }

  public void queue() {
    setTitle(join("Queue ", get(QUEUE_NAME, "unknown")));
  }

  public void submit() {
    setTitle("Application Submission Not Allowed");
  }
}
