/*
 * Copyright 2010-2013 Amazon.com, Inc. or its affiliates. All Rights Reserved.
 *
 * Licensed under the Apache License, Version 2.0 (the "License").
 * You may not use this file except in compliance with the License.
 * A copy of the License is located at
 *
 *  http://aws.amazon.com/apache2.0
 *
 * or in the "license" file accompanying this file. This file 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.
 */

import java.util.ArrayList;
import java.util.List;

import com.amazonaws.AmazonServiceException;
import com.amazonaws.auth.ClasspathPropertiesFileCredentialsProvider;
import com.amazonaws.regions.Region;
import com.amazonaws.regions.Regions;
import com.amazonaws.services.ec2.AmazonEC2;
import com.amazonaws.services.ec2.AmazonEC2Client;
import com.amazonaws.services.ec2.model.CancelSpotInstanceRequestsRequest;
import com.amazonaws.services.ec2.model.DescribeSpotInstanceRequestsRequest;
import com.amazonaws.services.ec2.model.DescribeSpotInstanceRequestsResult;
import com.amazonaws.services.ec2.model.LaunchSpecification;
import com.amazonaws.services.ec2.model.RequestSpotInstancesRequest;
import com.amazonaws.services.ec2.model.RequestSpotInstancesResult;
import com.amazonaws.services.ec2.model.SpotInstanceRequest;
import com.amazonaws.services.ec2.model.TerminateInstancesRequest;

/**
 * Welcome to your new AWS Java SDK based project!
 *
 * This class is meant as a starting point for your console-based application that
 * makes one or more calls to the AWS services supported by the Java SDK, such as EC2,
 * SimpleDB, and S3.
 *
 * In order to use the services in this sample, you need:
 *
 *  - A valid Amazon Web Services account. You can register for AWS at:
 *       https://aws-portal.amazon.com/gp/aws/developer/registration/index.html
 *
 *  - Your account's Access Key ID and Secret Access Key:
 *       http://aws.amazon.com/security-credentials
 *
 *  - A subscription to Amazon EC2. You can sign up for EC2 at:
 *       http://aws.amazon.com/ec2/
 *
 */

public class InlineGettingStartedCodeSampleApp {

	/**
	 * @param args
	 */
	public static void main(String[] args) {
    	//============================================================================================//
    	//=============================== Submitting a Request =======================================//
    	//============================================================================================//

		// Create the AmazonEC2Client object so we can call various APIs.
		AmazonEC2 ec2 = new AmazonEC2Client(new ClasspathPropertiesFileCredentialsProvider());
		Region usWest2 = Region.getRegion(Regions.US_WEST_2);
		ec2.setRegion(usWest2);

		// Initializes a Spot Instance Request
    	RequestSpotInstancesRequest requestRequest = new RequestSpotInstancesRequest();

    	// Request 1 x t1.micro instance with a bid price of $0.03.
    	requestRequest.setSpotPrice("0.03");
    	requestRequest.setInstanceCount(Integer.valueOf(1));

    	// Setup the specifications of the launch. This includes the instance type (e.g. t1.micro)
    	// and the latest Amazon Linux AMI id available. Note, you should always use the latest
    	// Amazon Linux AMI id or another of your choosing.
    	LaunchSpecification launchSpecification = new LaunchSpecification();
    	launchSpecification.setImageId("ami-8c1fece5");
    	launchSpecification.setInstanceType("t1.micro");

    	// Add the security group to the request.
    	ArrayList<String> securityGroups = new ArrayList<String>();
    	securityGroups.add("GettingStartedGroup");
    	launchSpecification.setSecurityGroups(securityGroups);

    	// Add the launch specifications to the request.
    	requestRequest.setLaunchSpecification(launchSpecification);

    	//============================================================================================//
    	//=========================== Getting the Request ID from the Request ========================//
    	//============================================================================================//

    	// Call the RequestSpotInstance API.
    	RequestSpotInstancesResult requestResult = ec2.requestSpotInstances(requestRequest);
    	List<SpotInstanceRequest> requestResponses = requestResult.getSpotInstanceRequests();

    	// Setup an arraylist to collect all of the request ids we want to watch hit the running
    	// state.
    	ArrayList<String> spotInstanceRequestIds = new ArrayList<String>();

    	// Add all of the request ids to the hashset, so we can determine when they hit the
    	// active state.
    	for (SpotInstanceRequest requestResponse : requestResponses) {
    		System.out.println("Created Spot Request: "+requestResponse.getSpotInstanceRequestId());
    		spotInstanceRequestIds.add(requestResponse.getSpotInstanceRequestId());
    	}

    	//============================================================================================//
    	//=========================== Determining the State of the Spot Request ======================//
    	//============================================================================================//

        // Create a variable that will track whether there are any requests still in the open state.
	    boolean anyOpen;

	    // Initialize variables.
	    ArrayList<String> instanceIds = new ArrayList<String>();

	    do {
	        // Create the describeRequest with tall of the request id to monitor (e.g. that we started).
	        DescribeSpotInstanceRequestsRequest describeRequest = new DescribeSpotInstanceRequestsRequest();
	        describeRequest.setSpotInstanceRequestIds(spotInstanceRequestIds);

	        // Initialize the anyOpen variable to false ??? which assumes there are no requests open unless
	        // we find one that is still open.
	        anyOpen=false;

	    	try {
	    		// Retrieve all of the requests we want to monitor.
	    		DescribeSpotInstanceRequestsResult describeResult = ec2.describeSpotInstanceRequests(describeRequest);
	    		List<SpotInstanceRequest> describeResponses = describeResult.getSpotInstanceRequests();

	            // Look through each request and determine if they are all in the active state.
	            for (SpotInstanceRequest describeResponse : describeResponses) {
	            		// If the state is open, it hasn't changed since we attempted to request it.
	            		// There is the potential for it to transition almost immediately to closed or
	            		// cancelled so we compare against open instead of active.
	            		if (describeResponse.getState().equals("open")) {
	            			anyOpen = true;
	            			break;
	            		}

	            		// Add the instance id to the list we will eventually terminate.
	        			instanceIds.add(describeResponse.getInstanceId());
	            }
	    	} catch (AmazonServiceException e) {
	            // If we have an exception, ensure we don't break out of the loop.
	    		// This prevents the scenario where there was blip on the wire.
	    		anyOpen = true;
	        }

	    	try {
		    	// Sleep for 60 seconds.
		    	Thread.sleep(60*1000);
	    	} catch (Exception e) {
	    		// Do nothing because it woke up early.
	    	}
	    } while (anyOpen);

    	//============================================================================================//
    	//====================================== Canceling the Request ==============================//
    	//============================================================================================//

        try {
        	// Cancel requests.
        	CancelSpotInstanceRequestsRequest cancelRequest = new CancelSpotInstanceRequestsRequest(spotInstanceRequestIds);
        	ec2.cancelSpotInstanceRequests(cancelRequest);
        } catch (AmazonServiceException e) {
    	 // Write out any exceptions that may have occurred.
            System.out.println("Error cancelling instances");
            System.out.println("Caught Exception: " + e.getMessage());
            System.out.println("Reponse Status Code: " + e.getStatusCode());
            System.out.println("Error Code: " + e.getErrorCode());
            System.out.println("Request ID: " + e.getRequestId());
        }

    	//============================================================================================//
    	//=================================== Terminating any Instances ==============================//
    	//============================================================================================//
        try {
        	// Terminate instances.
        	TerminateInstancesRequest terminateRequest = new TerminateInstancesRequest(instanceIds);
        	ec2.terminateInstances(terminateRequest);
    	} catch (AmazonServiceException e) {
    		// Write out any exceptions that may have occurred.
           System.out.println("Error terminating instances");
    		System.out.println("Caught Exception: " + e.getMessage());
           System.out.println("Reponse Status Code: " + e.getStatusCode());
           System.out.println("Error Code: " + e.getErrorCode());
           System.out.println("Request ID: " + e.getRequestId());
        }

	}

}
