DealDates.java

/**
 *
 */
package com.westfieldlabs.restsdk.example;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.URL;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.TimeZone;
import java.util.concurrent.TimeUnit;
import java.util.logging.Logger;

import com.google.gson.Gson;
import com.google.gson.GsonBuilder;
import com.google.gson.JsonParser;
import com.westfieldlabs.restsdk.model.deal.DealInstance;
import com.westfieldlabs.restsdk.model.deal.DealResponse;
import com.westfieldlabs.restsdk.services.RestSdkApiService;
import com.westfieldlabs.restsdk.services.RestSdkApiServiceBuilder;

/**
 * @author jreece
 *
 */
public class DealDates {

	/**
	 * Logger
	 */
	protected static Logger LOGGER = Logger
			.getLogger(DealDates.class.getName());

	/**
	 * A Gson instance
	 */
	protected final Gson gson = new GsonBuilder().serializeNulls()
			.setPrettyPrinting().create();

	/**
	 * The WestfieldLabs REST API service-facade.
	 */
	private final RestSdkApiService service;
	private static String API_KEY = "123456789012345678901234";

	public DealDates() {
		this.service = (new RestSdkApiServiceBuilder.Builder()).setApiKey(
				API_KEY).build();

	}

	/**
	 * Fetch the contents at an url as a string.
	 *
	 * @param uri
	 *            the url to be read
	 * @return the contents at the url, or {@code null}
	 */
	protected String getUrlAsString(final String uri) {
		LOGGER.info("Raw URL: " + uri);
		try {
			final URL url = new URL(uri);
			final HttpURLConnection connection = (HttpURLConnection) url
					.openConnection();
			connection.addRequestProperty("Accept", "application/json");
			InputStream is;
			if ((connection.getResponseCode() > 199)
					&& (connection.getResponseCode() < 300)) {
				// read response-body for HTTP-2xx responses
				is = connection.getInputStream();
			} else {
				// read response-body for HTTP-3xx/4xx/5xx responses
				is = connection.getErrorStream();
			}
			final BufferedReader br = new BufferedReader(new InputStreamReader(
					is));
			final StringBuilder sb = new StringBuilder();
			String line;
			while ((line = br.readLine()) != null) {
				sb.append(line);
			}
			br.close();
			is.close();
			return sb.toString().trim();
		} catch (final IOException e) {
			LOGGER.severe("Response '" + e.getLocalizedMessage()
					+ "' when accessing " + uri);
			return null;
		}
	}

	private void getRawResponse(final Integer dealId) {
		final String url = "https://api.westfield.io/deals/" + dealId
				+ "?version=1";
		final String json = getUrlAsString(url);
		System.out.println(gson.toJson(new JsonParser().parse(json)));
	}

	private Date adjustDateTimezone(final Date rawDate, final TimeZone tz) {

		// the 'rawDate' was passed by the API as a 'local' date,
		// and this date has been parsed as if it were in UTC, so it needs to be
		// adjusted
		// to the 'local' time indicated by the TimeZone param.

		// get the 'raw' GMT-offset for the timezone (not accounting for DST)
		final Long tzOffset = (tz.getRawOffset() * -1L);
		int dstOffset;

		// account for DST if it is in effect for this date
		if (tz.inDaylightTime(rawDate)) {

			dstOffset = tz.getDSTSavings();
			if (tzOffset < 0) {
				dstOffset = dstOffset * -1;
			}
		} else {
			dstOffset = 0;
		}

		// adjust the UTC date back to 'local' time, including DST offset
		final Date adjustedDate = new Date(rawDate.getTime()
				+ (tzOffset + dstOffset));

		return adjustedDate;
	}

	private void adjustDealTimezone(final DealInstance deal, final TimeZone tz) {

		// Adjust and update the deal-dates

		deal.setPublished_at(adjustDateTimezone(deal.getPublished_at(), tz));
		deal.setStarts_at(adjustDateTimezone(deal.getStarts_at(), tz));
		deal.setEnds_at(adjustDateTimezone(deal.getEnds_at(), tz));
		deal.setUpdated_at(adjustDateTimezone(deal.getUpdated_at(), tz));
	}

	private void printAdjustedDates(final DealInstance deal,
			final String tzString, final Date now) {

		final SimpleDateFormat sdf = new SimpleDateFormat(
				"yyyy-MM-dd'T'HH:mm:ss.SSS'Z'");

		final TimeZone tz = TimeZone.getTimeZone(tzString);
		sdf.setTimeZone(tz);

		adjustDealTimezone(deal, tz);

		System.out.println("\n" + tzString);
		System.out.println("offset: \t" + tz.getRawOffset());
		System.out.println("now: \t\t" + sdf.format(now) + " - "
				+ now.getTime());

		System.out.println("published_at: \t"
				+ sdf.format(deal.getPublished_at()) + " - "
				+ deal.getPublished_at().getTime());

		System.out.println("starts_at: \t" + sdf.format(deal.getStarts_at())
				+ " - " + deal.getStarts_at().getTime());

		System.out.println("ends_at: \t" + sdf.format(deal.getEnds_at())
				+ " - " + deal.getEnds_at().getTime());

		System.out.println("updated_at: \t" + sdf.format(deal.getUpdated_at())
				+ " - " + deal.getUpdated_at().getTime());

		long endsIn = deal.getEnds_at().getTime() - now.getTime();
		final long oneSecond = TimeUnit.MILLISECONDS.convert(1,
				TimeUnit.SECONDS);
		final long oneMinute = TimeUnit.MILLISECONDS.convert(1,
				TimeUnit.MINUTES);
		final long oneHour = TimeUnit.MILLISECONDS.convert(1, TimeUnit.HOURS);
		final long oneDay = TimeUnit.MILLISECONDS.convert(1, TimeUnit.DAYS);

		final long days = endsIn / oneDay;
		endsIn = endsIn - (days * oneDay);
		final long hours = endsIn / oneHour;
		endsIn = endsIn - (hours * oneHour);
		final long minutes = endsIn / oneMinute;
		endsIn = endsIn - (minutes * oneMinute);
		final long seconds = endsIn / oneSecond;
		endsIn = endsIn - (seconds * oneSecond);

		System.out.println("ends_after: \t" + days + " days, " + hours + ":"
				+ minutes + ":" + seconds);

		if ((now.after(deal.getPublished_at()) || now.equals(deal
				.getPublished_at())) && (now.before(deal.getEnds_at()))) {
			System.out.println("Should be showing now ... ");
		} else {
			System.out.println("Should not be showing now ... ");
		}

	}

	public void dealDates() {

		final DealResponse response = service.deal.getDeal(46369, null);
		// getRawResponse(46369);
		// System.out.println("\n\n" + gson.toJson(response.getData()));

		final DealInstance deal = response.getData();

		final Date now = new Date();

		final DealInstance d = new DealInstance();

		d.setStarts_at(deal.getStarts_at());
		d.setPublished_at(deal.getPublished_at());
		d.setEnds_at(deal.getEnds_at());
		d.setUpdated_at(deal.getUpdated_at());
		printAdjustedDates(d, "America/Los_Angeles", now);

		d.setStarts_at(deal.getStarts_at());
		d.setPublished_at(deal.getPublished_at());
		d.setEnds_at(deal.getEnds_at());
		d.setUpdated_at(deal.getUpdated_at());
		printAdjustedDates(d, "America/New_York", now);

		d.setStarts_at(deal.getStarts_at());
		d.setPublished_at(deal.getPublished_at());
		d.setEnds_at(deal.getEnds_at());
		d.setUpdated_at(deal.getUpdated_at());
		printAdjustedDates(d, "Australia/NSW", now);

		d.setStarts_at(deal.getStarts_at());
		d.setPublished_at(deal.getPublished_at());
		d.setEnds_at(deal.getEnds_at());
		d.setUpdated_at(deal.getUpdated_at());
		printAdjustedDates(d, "NZ", now);

		d.setStarts_at(deal.getStarts_at());
		d.setPublished_at(deal.getPublished_at());
		d.setEnds_at(deal.getEnds_at());
		d.setUpdated_at(deal.getUpdated_at());
		printAdjustedDates(d, "Europe/London", now);

	}

	public static void main(final String[] args) throws Exception {
		final DealDates dd = new DealDates();
		dd.dealDates();

	}

}