StatusesFetcher.java

package com.papagiannis.tuberun.fetchers;

import java.util.ArrayList;
import java.util.Date;
import java.util.HashMap;
import java.util.concurrent.atomic.AtomicBoolean;

import com.papagiannis.tuberun.LineType;
import com.papagiannis.tuberun.Status;

public class StatusesFetcher extends Fetcher {
	private static final long serialVersionUID = 1L;
	// region private state
	protected ArrayList<Status> _all_statuses = new ArrayList<Status>();
	protected Date last_update;

	public Boolean forWeekend() {
		return statusurl == WEEKENDURL;
	}

	 private final String NOWURL = "http://www.tfl.gov.uk/tfl/livetravelnews/realtime/tube/default.html";
//	private final String NOWURL = "http://tuberun.dyndns.org:55559/getStatuses.php";
	// private final String NOWURL = "http://localhost:55559/getStatuses.php";
	private final String WEEKENDURL = "http://www.tfl.gov.uk/tfl/livetravelnews/realtime/track.aspx?offset=weekend";
	protected String statusurl;

	// region constructors
	public StatusesFetcher() {
	}

	public static StatusesFetcher fetcherNowSigleton;
	public static StatusesFetcher fetcherWeekendSigleton;

	public static StatusesFetcher getInstance() {
		return getInstance(false);
	}

	public static StatusesFetcher getInstance(Boolean forWeekend) {
		if (!forWeekend) {
			if (fetcherNowSigleton == null) {
				fetcherNowSigleton = new StatusesFetcher();
				fetcherNowSigleton.setNowUrl();
			}
			return fetcherNowSigleton;
		} else {
			if (fetcherWeekendSigleton == null) {
				fetcherWeekendSigleton = new StatusesFetcher();
				fetcherWeekendSigleton.setWeekendUrl();
			}
			return fetcherWeekendSigleton;
		}
	}

	// region set service url
	private void setNowUrl() {
		statusurl = NOWURL;
	}

	private void setWeekendUrl() {
		statusurl = WEEKENDURL;
	}

	@Override
	public Date getUpdateTime() {
		if (last_update == null)
			last_update = new Date();
		return (Date) last_update.clone();
	}

	// region issue request
	public Status getStatus(LineType req) {
		for (Status s : _all_statuses) {
			if (s.line_name == req)
				return s;
		}
		return null;
	}

	protected AtomicBoolean isFirst = new AtomicBoolean(true);
	protected transient RequestTask task=null;
	public void update() {
		boolean first = isFirst.compareAndSet(true, false);
		if (!first)
			return; // only one at a time
		task = new RequestTask(new HttpCallback() {
			public void onReturn(String s) {
				getStatusesCallBack(s);
			}
		});
		task.setDesktopUserAgent();
		task.execute(statusurl);
	}

	protected String beautify(String problem) {
		problem = problem.replaceAll("<(.*?)>", " ");
		problem = problem.replaceAll("(\\s)+", " ");
		problem = problem.replaceAll(" ", " ");
		return problem.trim();
	}

	protected void getStatusesCallBack(String reply) {
		try {
			reply = unCapitalizeTags(reply);
			HashMap<String, String> result = new HashMap<String, String>();
			HashMap<String, String> problems = new HashMap<String, String>();
			String[] lines = new String[] { "bakerloo", "central", "circle",
					"district", "hammersmithandcity", "jubilee",
					"metropolitan", "northern", "piccadilly", "victoria",
					"waterlooandcity", "dlr", "overground" };
			for (int i = 0; i < lines.length; i++) {
				String filter1 = "<h3 class=\"" + lines[i] + " ltn-name\">";
				int j = reply.indexOf(filter1) + filter1.length();
				if (j > filter1.length() /* sth found */) {
					String rest = reply.substring(j);
					String start = "<div class=\"status\">";
					String start2 = "<div class=\"problem status\">";
					String end = "</li>";
					j = rest.indexOf(start);
					int k = rest.indexOf(start2);
					int e = rest.indexOf(end);
					String status;
					if (j < e || k < e) {
						if (j < e)
							rest = rest.substring(j + start.length());
						else
							rest = rest.substring(k + start2.length());
						j = rest.indexOf("</div>");
						String statust = rest.substring(0, j);
						if (statust.contains("<h4")) {
							String l = "<h4 class=\"ltn-title\">";
							j = statust.indexOf(l) + l.length();
							status = statust.substring(j);
							j = status.indexOf("</h4>");
							/*
							 * k = status.IndexOf(","); if (k > 0 && k < j)
							 * status = status.Substring(0, k); else
							 */status = status.substring(0, j);
						} else
							status = statust;
					} else
						status = "Failed";
					if (!status.equals("Good service")) {
						j = rest.indexOf("<div class=\"message\">") + 21;
						rest = rest.substring(j);
						j = rest.indexOf("<a");
						k = rest.indexOf("<A");
						if (j == -1 && k > 0)
							j = k;
						String problem = rest.substring(0, j);
						// must remove hmtl tags here.
						problem = problem.replaceAll("\n", "");
						problem = problem.replaceAll("&", "and");
						problems.put(lines[i], problem);
					}
					result.put(lines[i], status);
				}
			}
			if (result.keySet().size() == 13) {
				Date now = new Date();
				// And lets write down the results
				last_update = now;
				_all_statuses = new ArrayList<Status>();
				for (String name : result.keySet()) {
					LineType ln = LineType.fromString(name);
					String rstatus;
					String rproblems;
					if (result.containsKey(name))
						rstatus = result.get(name);
					else
						throw new Exception("Failed to get a single status");
					if (problems.containsKey(name))
						rproblems = problems.get(name);
					else
						rproblems = "";
					_all_statuses.add(new Status(ln, rstatus,
							beautify(rproblems)));
				}
				notifyClients();
			} else
				throw new Exception("Wrong number of lines returned.");
		} catch (Exception e) {
			_all_statuses = new ArrayList<Status>();
			notifyClients();
		} finally {
			isFirst.set(true);
		}
	}

	private String unCapitalizeTags(String reply) {
		StringBuilder res=new StringBuilder(reply.length());
		boolean inTag=false;
		for (int i=0;i<reply.length();i++) {
			char c=reply.charAt(i);
			switch (c) {
			case '<':
				inTag=true;
				break;
			case '>':
			case ' ':
				inTag=false;
				break;
			default:
				if (inTag) c=Character.toLowerCase(c);
				break;
			}
			res.append(c);
		}
		return res.toString();
	}
	
	@Override
    public void abort() {
		isFirst.set(true);
    	if (task!=null) task.cancel(true);
    }
}