OysterFetcher.java

package com.papagiannis.tuberun.fetchers;

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

import org.apache.http.impl.client.BasicCookieStore;

public class OysterFetcher extends Fetcher {
	private static final long serialVersionUID = 1L;
	private String username="";
	private String password="";
	private String oyster_no="";
	private String oyster_balance="";
	private HashMap<String,String> cards=new HashMap<String,String>();
	@SuppressWarnings("deprecation")
	private Date update_time=new Date(2000,1,1);
	private transient RequestTask task=null;

	private static  HashMap<String,OysterFetcher> instances =new HashMap<String, OysterFetcher>();
	public static synchronized OysterFetcher getInstance(String username, String password) {
		if (!instances.containsKey(username+password)) {
			instances.put(username+password,new OysterFetcher(username, password));
		}
		return instances.get(username+password);
	}
	
	private OysterFetcher(String username, String password) {
		super();
		this.username=(username==null)?"":username.trim();
		this.password=(password==null)?"":password.trim();
	}

	@Override
	public Date getUpdateTime() {
		return update_time;
	}

	BasicCookieStore cookies;
	StringBuilder postData;
	private String errors="";
	public String getErrors() {
		return errors;
	}

	protected AtomicBoolean isFirst = new AtomicBoolean(true);
	
	@Override
	public void update() {
		boolean first = isFirst.compareAndSet(true, false);
		if (!first)	return; // only one at a time
		errors="";
		cards.clear();
		cardsReturned.set(0);
		postData = new StringBuilder();
		cookies = new BasicCookieStore();
		String q1 = "https://oyster.tfl.gov.uk/oyster/security_check";
		postData.append("j_username="+username+"&j_password="+password+"&Sign+in=Sign+in");

		PostRequestTask r = new PostRequestTask(new HttpCallback() {
			public void onReturn(String s) {
				getCallBack1(s);
			}
		});
		r.setPostData(postData);
		r.setCookies(cookies);
		task=r;
		r.execute(q1);
	}

	String param = "";
	private int totalCards=0;
	private AtomicInteger cardsReturned=new AtomicInteger(0);
	private static final String mark1="Choose card number";
	private static final String mark2="Balance: £";
	private static final String mark3="<span class=\"label\">Balance:</span>\r\n\t<span class=\"content\">£";
	
	private void getCallBack1(String response) {
		try {
			if (response==null || response.equals("")) 
				throw new Exception("The server oyster.tfl.gov.uk did not respond to your request (1)");
			if (response.contains("Login failed")) {
				throw new Exception("Login failed, please check your credentials.");
			}
			int i=response.indexOf(mark1);
			int j=response.indexOf(mark2);
			int k=response.indexOf(mark3);
			if (i>0) {
				totalCards=0;
				response=response.substring(i);
				while (true) {
					String mark="<option value=\"";
					int ni=response.indexOf(mark);
					if (ni==-1) {
						if (totalCards==0) throw new Exception("No cards detected"); 
						break;
					}
					response=response.substring(ni+mark.length());
					int end=response.indexOf("\"");
					oyster_no=response.substring(0, end);
					response=response.substring(end);
					
					postData = new StringBuilder();
					String q = "https://oyster.tfl.gov.uk/oyster/selectCard.do";
					postData.append("method=input&cardId="+oyster_no);

					PostRequestTask r = new PostRequestTask(new HttpCallback() {
						public void onReturn(String s) {
							getCallBack2(s);
						}
					});
					r.setPostData(postData);
					r.setCookies(cookies);
					task=r;
					r.execute(q);
					totalCards++;
				}
				
				//multiple cards parsing
			}
			else if (j>0 || k>0) {
				totalCards=1;
				//single card parsing
				getCallBack2(response);
			}
			else {
				errors+="Failed to locate card number";
				isFirst.set(true);
				notifyClients();
			}
			return;

		} catch (Exception e) {
			errors+=e.getMessage();
			isFirst.set(true);
			notifyClients();
		}
	}
	
	private void getCallBack2(String response) {
		try {
			if (response==null || response.equals("")) 
				throw new Exception("The server tfl.gov.uk did not respond to your request (3)");
			String mark="<h2>Card No: ";
			int i=response.indexOf(mark);
			if (i<0) throw new Exception("Cannot parse server response");
			response=response.substring(i+mark.length());
			String number=response.substring(0,response.indexOf("</h2>"));
			
			response=response.substring(response.indexOf("</h2>"));
			
			mark="Balance: £";
			i=response.indexOf(mark);
			if (i<0) {
				mark="£";
				i=response.indexOf(mark);
			}
			if (i<0) throw new Exception("Cannot parse server response");
			response=response.substring(i+mark.length());
			oyster_balance="£"+response.substring(0,response.indexOf("</span>"));
			
			cards.put(number, oyster_balance);
			update_time=new Date();
			
			cardsReturned.incrementAndGet();
			
		} catch (Exception e) {
			errors+=e.getMessage();
		} finally {
			isFirst.set(true);
			if (totalCards==cardsReturned.get()) notifyClients();
		}
	}
	
	public Boolean hasResult() {
		Date now=new Date();
		Boolean isFresh = (now.getTime() - update_time.getTime()) / 1000 < 5 * 60;
		return isFresh && !isErrorResult() && !oyster_balance.equals("");
	}

	public CharSequence getResult() {
		if (!errors.equals("")) return "ERROR";
		else return oyster_balance;
	}
	
	public boolean isErrorResult() {
		return !errors.equals("");
	}

	@Override
    public void abort() {
		isFirst.set(true);
    	if (task!=null) task.cancel(true);
    }

	public HashMap<String,String> getCards() {
		return cards;
	}
	
}