/*
 *  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 com.github.sakserv.minicluster.yarn.simpleyarnapp;

import java.io.File;
import java.io.IOException;
import java.util.Collections;
import java.util.HashMap;
import java.util.Map;

import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.FileStatus;
import org.apache.hadoop.fs.FileSystem;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.yarn.api.ApplicationConstants;
import org.apache.hadoop.yarn.api.ApplicationConstants.Environment;
import org.apache.hadoop.yarn.api.records.ApplicationId;
import org.apache.hadoop.yarn.api.records.ApplicationReport;
import org.apache.hadoop.yarn.api.records.ApplicationSubmissionContext;
import org.apache.hadoop.yarn.api.records.ContainerLaunchContext;
import org.apache.hadoop.yarn.api.records.LocalResource;
import org.apache.hadoop.yarn.api.records.LocalResourceType;
import org.apache.hadoop.yarn.api.records.LocalResourceVisibility;
import org.apache.hadoop.yarn.api.records.Resource;
import org.apache.hadoop.yarn.api.records.YarnApplicationState;
import org.apache.hadoop.yarn.client.api.YarnClient;
import org.apache.hadoop.yarn.client.api.YarnClientApplication;
import org.apache.hadoop.yarn.conf.YarnConfiguration;
import org.apache.hadoop.yarn.util.Apps;
import org.apache.hadoop.yarn.util.ConverterUtils;
import org.apache.hadoop.yarn.util.Records;


public class Client {

    Configuration conf = new YarnConfiguration();

    public void run(String[] args) throws Exception {
        final String command = args[0];
        final int n = Integer.valueOf(args[1]);
        final Path jarPath = new Path(args[2]);
        final String resourceManagerAddress = args[3];
        final String resourceManagerHostname = args[4];
        final String resourceManagerSchedulerAddress = args[5];
        final String resourceManagerResourceTrackerAddress = args[6];

        // Create yarnClient
        YarnConfiguration conf = new YarnConfiguration();
        conf.set("yarn.resourcemanager.address", resourceManagerAddress);
        conf.set("yarn.resourcemanager.hostname", resourceManagerHostname);
        conf.set("yarn.resourcemanager.scheduler.address", resourceManagerSchedulerAddress);
        conf.set("yarn.resourcemanager.resource-tracker.address", resourceManagerResourceTrackerAddress);
        YarnClient yarnClient = YarnClient.createYarnClient();
        yarnClient.init(conf);
        yarnClient.start();

        // Create application via yarnClient
        YarnClientApplication app = yarnClient.createApplication();

        // Set up the container launch context for the application master
        ContainerLaunchContext amContainer =
                Records.newRecord(ContainerLaunchContext.class);
        amContainer.setCommands(
                Collections.singletonList(
                        "$JAVA_HOME/bin/java" +
                                " -Xmx256M" +
                                " com.hortonworks.simpleyarnapp.ApplicationMaster" +
                                " " + command +
                                " " + String.valueOf(n) +
                                " " + resourceManagerAddress +
                                " " + resourceManagerHostname +
                                " " + resourceManagerSchedulerAddress +
                                " " + resourceManagerResourceTrackerAddress +
                                " 1>" + ApplicationConstants.LOG_DIR_EXPANSION_VAR + "/stdout" +
                                " 2>" + ApplicationConstants.LOG_DIR_EXPANSION_VAR + "/stderr"
                )
        );

        // Setup jar for ApplicationMaster
        LocalResource appMasterJar = Records.newRecord(LocalResource.class);
        setupAppMasterJar(jarPath, appMasterJar);
        amContainer.setLocalResources(
                Collections.singletonMap("simple-yarn-app-1.1.0.jar", appMasterJar));

        // Setup CLASSPATH for ApplicationMaster
        Map<String, String> appMasterEnv = new HashMap<String, String>();
        setupAppMasterEnv(appMasterEnv);
        amContainer.setEnvironment(appMasterEnv);

        // Set up resource type requirements for ApplicationMaster
        Resource capability = Records.newRecord(Resource.class);
        capability.setMemory(256);
        capability.setVirtualCores(1);

        // Finally, set-up ApplicationSubmissionContext for the application
        ApplicationSubmissionContext appContext =
                app.getApplicationSubmissionContext();
        appContext.setApplicationName("simple-yarn-app"); // application name
        appContext.setAMContainerSpec(amContainer);
        appContext.setResource(capability);
        appContext.setQueue("default"); // queue

        // Submit application
        ApplicationId appId = appContext.getApplicationId();
        System.out.println("Submitting application " + appId);
        yarnClient.submitApplication(appContext);

        ApplicationReport appReport = yarnClient.getApplicationReport(appId);
        YarnApplicationState appState = appReport.getYarnApplicationState();
        while (appState != YarnApplicationState.FINISHED &&
                appState != YarnApplicationState.KILLED &&
                appState != YarnApplicationState.FAILED) {
            Thread.sleep(100);
            appReport = yarnClient.getApplicationReport(appId);
            appState = appReport.getYarnApplicationState();
        }

        System.out.println(
                "Application " + appId + " finished with" +
                        " state " + appState +
                        " at " + appReport.getFinishTime());

    }

    private void setupAppMasterJar(Path jarPath, LocalResource appMasterJar) throws IOException {
        FileStatus jarStat = FileSystem.get(conf).getFileStatus(jarPath);
        appMasterJar.setResource(ConverterUtils.getYarnUrlFromPath(jarPath));
        appMasterJar.setSize(jarStat.getLen());
        appMasterJar.setTimestamp(jarStat.getModificationTime());
        appMasterJar.setType(LocalResourceType.FILE);
        appMasterJar.setVisibility(LocalResourceVisibility.PUBLIC);
    }

    @SuppressWarnings("deprecation")
    private void setupAppMasterEnv(Map<String, String> appMasterEnv) {
        for (String c : conf.getStrings(
                YarnConfiguration.YARN_APPLICATION_CLASSPATH,
                YarnConfiguration.DEFAULT_YARN_APPLICATION_CLASSPATH)) {
            Apps.addToEnvironment(appMasterEnv, Environment.CLASSPATH.name(),
                    c.trim());
        }
        Apps.addToEnvironment(appMasterEnv,
                Environment.CLASSPATH.name(),
                Environment.PWD.$() + File.separator + "*");
    }

    public static void main(String[] args) throws Exception {
        Client c = new Client();
        c.run(args);
    }
    
}