Schedule.java

package edu.purdue.app.schedule;

import java.io.OutputStream;
import java.io.PrintWriter;
import java.net.URL;
import java.util.ArrayList;
import java.util.Calendar;
import java.util.Collections;
import java.util.List;
import java.util.Random;
import java.util.Scanner;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

import javax.net.ssl.HttpsURLConnection;

import org.jsoup.Jsoup;
import org.jsoup.nodes.Document;
import org.jsoup.nodes.Element;
import org.jsoup.select.Elements;

public class Schedule {
	private UserInfo userInfo;
	private List<Class> classes;
	//all the cookies we need to get the schedule (may include not needed ones)
	private final static String[] okCookies = new String[] {
		"UserAgentId",
		"BIGipServer~BAN~pool_wl.mypurdue_443",
		"fos.web.server",
		"fos.secure.web.server",
		"runId",
		"JSESSIONID_LP4",
		"usid",
		"usidsec",
		"SESSID",
		"TESTID",
		"BANSSO",
		"CPSESSID"
	};

	//day map
	private final static int[] days = new int[] {
		Calendar.MONDAY,
		Calendar.TUESDAY,
		Calendar.WEDNESDAY,
		Calendar.THURSDAY,
		Calendar.FRIDAY,
		Calendar.SATURDAY,
		Calendar.SUNDAY
	};

	/**
	 *
	 * Set up a connection to a url (helper function)
	 * @param url Url of request
	 * @param host Host header for request
	 * @return connection you requested
	 */
	private static HttpsURLConnection setup(String url, String host) throws Exception {
			HttpsURLConnection conn = 
					(HttpsURLConnection) new URL(url).openConnection();
			conn.setInstanceFollowRedirects(false);
			conn.setRequestProperty("Accept", "text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8");
			conn.setRequestProperty("Accept-Encoding", "gzip, deflate");
			conn.setRequestProperty("Accept-Language", "en-US,en;q=0.5");
			conn.setRequestProperty("Connection", "keep-alive");
			conn.setRequestProperty("Host", host);
			conn.setRequestProperty("User-Agent", "Mozilla/5.0 (Windows NT 6.3; WOW64; rv:27.0) Gecko/20100101 Firefox/27.0");
			return conn;
	}

	/**
	 *Set up a connection to a url (helper function)
	 * @param url Url of request
	 * @param host host header for request
	 * @param referer referer header
	 * @param cookies Cookie structure to be converted to Cookie header
	 * @return connection you requested
	 */
	private static HttpsURLConnection setup(String url, String host, String referer, Cookies cookies) throws Exception {
		HttpsURLConnection conn = setup(url, host);
		conn.setRequestProperty("Referer", referer);
		conn.setRequestProperty("Cookie", cookies.toString());
		return conn;
	}

	/**
	 *Get contents of a connection (helper function)
	 * @param conn connection
	 * @return contents of response as 1 string
	 */
	private static String getContents(HttpsURLConnection conn) throws Exception {
		Scanner in = new Scanner(conn.getInputStream());
		in.useDelimiter("\\Z");
		String content = in.next();
		in.close();
		return content;
	}

	public Schedule(String user, String password) throws Exception {
		classes = new ArrayList<Class>();
		parseRawSchedule(getRawSchedule(user, password));	
	}

	private String getRawSchedule(String user, String password) throws Exception {
		//extract login cookies from page
		HttpsURLConnection conn = setup("https://wl.mypurdue.purdue.edu/cp/home/displaylogin", "wl.mypurdue.purdue.edu");
		Cookies cookies = new Cookies(okCookies, conn.getHeaderFields());
		String contents = getContents(conn);
		//extract clientServerDelta (current time - constant) from page
		Pattern pattern = Pattern.compile("[0-9]+;");
		Matcher matcher = pattern.matcher(contents);
		long clientServerDelta;
		if(matcher.find()) {
			String rawMatch = matcher.group();
			String constant = rawMatch.substring(0, rawMatch.length() - 1);
			clientServerDelta = System.currentTimeMillis() - Long.parseLong(constant);
		}
		else {
			throw new Exception("couldn't find clientServerDelta");
		}
		//post login info to next step
		conn = setup("https://wl.mypurdue.purdue.edu/cp/home/login", "wl.mypurdue.purdue.edu", "https://wl.mypurdue.purdue.edu/cp/home/displaylogin", cookies);
		conn.setRequestMethod("POST");
		conn.setDoOutput(true);
		conn.setRequestProperty("Content-Type", "application/x-www-form-urlencoded");
		//simulate uuid calculation (submit time - clientServerDelta) with sleep
		Random r = new Random();
		long time = r.nextInt(10000);
		Thread.sleep(time);
		long uuid = System.currentTimeMillis() - clientServerDelta;
		String content = "pass=" + password + "&user=" + user + "&uuid=" + uuid;
		conn.setRequestProperty("Content-Length", Integer.toString(content.length()));
		OutputStream out = conn.getOutputStream();
		PrintWriter writer = new PrintWriter(out);
		writer.print(content);
		writer.close();
		out.close();
		//check for failure
		if(conn.getResponseCode() != 302 || !conn.getHeaderFields().get("Location").get(0).equals("https://wl.mypurdue.purdue.edu/cps/welcome/loginok.html")) {
			throw new Exception("failed to login");
		}
		//go through login steps
		cookies.setCookies(conn.getHeaderFields());
		conn = setup("https://wl.mypurdue.purdue.edu/cps/welcome/loginok.html", "wl.mypurdue.purdue.edu", "https://wl.mypurdue.purdue.edu/cp/home/login", cookies);
		String response = getContents(conn);
		if(!response.contains("https://wl.mypurdue.purdue.edu/cp/home/next")) {
			throw new Exception("Failed to get next");
		}
		conn = setup("https://wl.mypurdue.purdue.edu/cp/home/next", "wl.mypurdue.purdue.edu", "https://wl.mypurdue.purdue.edu/cps/welcome/loginok.html", cookies);
		if(conn.getResponseCode() != 302 || !conn.getHeaderFields().get("Location").get(0).equals("https://wl.mypurdue.purdue.edu/render.userLayoutRootNode.uP?uP_root=root")) {
			throw new Exception("Failed to get root page!");
		}
		conn = setup("https://wl.mypurdue.purdue.edu/render.userLayoutRootNode.uP?uP_root=root", "wl.mypurdue.purdue.edu", "https://wl.mypurdue.purdue.edu/cps/welcome/loginok.html", cookies);
		response = getContents(conn);
		//set up sctSession cookie (increases with time)
		cookies.setCookie("sctSession", Integer.toString(r.nextInt(5) + 1));
		//go through steps to get week at a glance
		conn = setup("https://wl.mypurdue.purdue.edu/jsp/misc/ss_redir.jsp?pg=24", "wl.mypurdue.purdue.edu", "https://wl.mypurdue.purdue.edu/tag.7cee4c7293654c6f.render.userLayoutRootNode.uP?uP_root=root&uP_sparam=activeTab&activeTab=u12l1s2&uP_tparam=frm&frm=", cookies);

		cookies.setCookie("sctSession", Integer.toString(8 + r.nextInt(5)));
		conn = setup("https://wl.mypurdue.purdue.edu/cp/ip/login?sys=sctssb&url=https://selfservice.mypurdue.purdue.edu/prod/tzwkwbis.P_CheckAgreeAndRedir?ret_code=STU_WEEKGLANCE", "wl.mypurdue.purdue.edu", "https://wl.mypurdue.purdue.edu/render.UserLayoutRootNode.uP?uP_tparam=utf&utf=%2fcp%2fip%2flogin%3fsys%3dsctssb%26url%3dhttps://selfservice.mypurdue.purdue.edu/prod/tzwkwbis.P_CheckAgreeAndRedir?ret_code=STU_WEEKGLANCE", cookies);
		if(conn.getHeaderFields().get("Location") == null) {
			throw new Exception("unable to get schedule setup!");
		}
		String url = conn.getHeaderFields().get("Location").get(0);
		conn = setup(url, "selfservice.mypurdue.purdue.edu", "	https://wl.mypurdue.purdue.edu/render.UserLayoutRootNode.uP?uP_tparam=utf&utf=%2fcp%2fip%2flogin%3fsys%3dsctssb%26url%3dhttps://selfservice.mypurdue.purdue.edu/prod/tzwkwbis.P_CheckAgreeAndRedir?ret_code=STU_WEEKGLANCE", cookies);
		cookies.setCookies(conn.getHeaderFields());
		conn = setup("https://selfservice.mypurdue.purdue.edu/prod/tzwkwbis.P_CheckAgreeAndRedir?ret_code=STU_WEEKGLANCE", "selfservice.mypurdue.purdue.edu", "https://wl.mypurdue.purdue.edu/render.UserLayoutRootNode.uP?uP_tparam=utf&utf=%2fcp%2fip%2flogin%3fsys%3dsctssb%26url%3dhttps://selfservice.mypurdue.purdue.edu/prod/tzwkwbis.P_CheckAgreeAndRedir?ret_code=STU_WEEKGLANCE", cookies);
		cookies.setCookies(conn.getHeaderFields());
		//finally actually get week at a glance
		conn = setup("https://selfservice.mypurdue.purdue.edu/prod/bwskfshd.P_CrseSchd", "selfservice.mypurdue.purdue.edu", "https://selfservice.mypurdue.purdue.edu/prod/tzwkwbis.P_CheckAgreeAndRedir?ret_code=STU_WEEKGLANCE", cookies);
		return getContents(conn);
	}

	private void parseRawSchedule(String rawSchedule) throws Exception {
		Document doc = Jsoup.parse(rawSchedule);
		Elements elems = doc.select("[class=staticheaders]");
		if(elems.size() != 0) {
			userInfo = new UserInfo(elems.first().text());
		}
		elems = doc.select("[class=datadisplaytable]");
		if(elems.size() != 0) {
			Elements data = elems.first().select("tr");
			//keep track of occupied rows
			boolean tableLayout[][] = new boolean[7][90];
			int curRow = 0;
			int curCol = 0;
			for(int k = 1; k < data.size(); ++k) {
				Element e = data.get(k);
				Elements rawClasses = e.children().select("td");
				for(int i = 0; i < rawClasses.size(); ++i) {
					Element curClass = rawClasses.get(i);
					while(tableLayout[curCol][curRow]) {
						curCol++;
						if(curCol == 7) {
							curCol = 0;
							curRow++;
						}
					}
					//if this is a class label
					if(curClass.className().equals("ddlabel")) {
						//occupy rowspan rows in the current column if specified
						if(curClass.attr("rowspan") != null || curClass.attr("rowspan").length() != 0) {
							Integer rowspan = Integer.parseInt(curClass.attr("rowspan"));
							int addRow = curRow;
							for(int j = 0; j < rowspan; ++j) {
								tableLayout[curCol][addRow] = true;
								addRow++;
							}
						}
						classes.add(new Class(days[curCol], curClass.text()));
					}
					//the current row and col are always occupied
					tableLayout[curCol][curRow] = true;
				}
			}
		}
	}

	public List<Class> getClasses() {
		return Collections.unmodifiableList(classes);
	}

	public UserInfo getUserInfo() {
		return userInfo;
	}
}