import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.StringReader;
import java.net.MalformedURLException;
import java.net.URL;
import java.net.URLConnection;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
import java.util.ArrayList;
import java.util.logging.Level;
import java.util.logging.Logger;
import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.ParserConfigurationException;
import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.w3c.dom.NodeList;
import org.xml.sax.InputSource;
import org.xml.sax.SAXException;
 
class Task {
    String id;
    String title;
    String modified;
    String completed;
 
    String folder;
    String context;
    String tag;
    String status;
    String priority;
    String length;
    String note;
}
 
public class Toodledoo2html {
    // TODO you must get the 4 values below from Toodledo
    private static String appID = "x";
    private static String userID = "x";
    private static String userPW = "x";
    private static String applicationToken = "x";
 
    private static String fields = "folder,context,tag,status,priority,length,note"; // get these fields when downloading tasks
 
    private static String sessionToken;
    private static String key;
 
    private static String toodledoTokenURL = "https://api.toodledo.com/2/account/token.php";
    private static String toodledoGetTaskURL = "https://api.toodledo.com/2/tasks/get.php";
 
    public static void main(String[] args) {
        sessionToken = getSessionToken(md5(userID+applicationToken));
        key = md5(md5(userPW)+applicationToken+sessionToken);
        ArrayList<Task> tasks = getTasks();
        // do whatever to tasks
    }
 
    private static ArrayList<Task> getTasks() {
        try {
            String data = "?key=" + key + ";fields=" + fields + ";f=xml";
 
            System.out.println("Getting tasks: " + toodledoGetTaskURL + data);
 
            URL url = new URL(toodledoGetTaskURL + data);
            URLConnection connection = url.openConnection();
            connection.setDoOutput(true);
 
            BufferedReader in = new BufferedReader(new InputStreamReader(connection.getInputStream()));
            StringBuilder xml = new StringBuilder();
            String line = in.readLine();
            while( line != null) {
                System.out.println(line);
                xml.append(line);
                line = in.readLine();
            }
            in.close();
 
            ArrayList<Task> tasks = xmlToTasks(xml.toString());
 
            for(Task t : tasks) {
                System.out.println(t.id + " " + t.title);
            }
            return tasks;
 
        } catch (MalformedURLException ex) {
            System.out.println(ex);
        } catch (IOException ioe) {
            System.out.println(ioe);
        }
        return null;
    }
 
    private static ArrayList<Task> xmlToTasks(String xml) {
        ArrayList<Task> taskList = new ArrayList<Task>();
 
        try {
            DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();
            DocumentBuilder db = dbf.newDocumentBuilder();
            Document doc = db.parse(new InputSource(new StringReader(xml)));
 
            Element root = doc.getDocumentElement();
 
            NodeList tasks = root.getElementsByTagName("task");
            for (int i = 0; i < tasks.getLength(); i++) {
                Element task = (Element) tasks.item(i);
 
                Task t = new Task();
                t.id = getDomTextValue(task, "id");
                t.title = getDomTextValue(task, "title");
                t.modified = getDomTextValue(task, "modified");
                t.completed = getDomTextValue(task, "completed");
 
                t.folder = getDomTextValue(task, "folder");
                t.context = getDomTextValue(task, "context");
                t.tag = getDomTextValue(task, "tag");
                t.status = getDomTextValue(task, "status");
                t.priority = getDomTextValue(task, "priority");
                t.length = getDomTextValue(task, "length");
                t.note = getDomTextValue(task, "note");
                taskList.add(t);
            }
 
        } catch (ParserConfigurationException ex) {
            Logger.getLogger(Toodledoo2html.class.getName()).log(Level.SEVERE, null, ex);
        }
        catch(SAXException se) {
 
        }
        catch(IOException ioe) {
 
        }
 
        System.out.println("xmlToTasks got " + taskList.size() + " tasks");
        return taskList;
    }
 
    private static String getSessionToken(String signature) {
        try {
            String data = "?userid=" + userID + ";appid=" + appID + ";sig=" + signature + ";f=xml";
 
            System.out.println("Getting session token: " + toodledoTokenURL+data);
 
            URL url = new URL(toodledoTokenURL + data);
            URLConnection connection = url.openConnection();
            connection.setDoOutput(true);
 
            BufferedReader in = new BufferedReader(new InputStreamReader(connection.getInputStream()));
            String xml = in.readLine();
            in.close();
            String token = xml.substring(xml.indexOf("<token>")+7, xml.indexOf("</token>"));
            return token;
        } catch (MalformedURLException ex) {
            System.out.println(ex);
        }
        catch(IOException ioe) {
            System.out.println(ioe);
        }
        return "";
    }
 
    private static String md5(String input) {
        try {
            MessageDigest md = MessageDigest.getInstance("MD5");
            md.update(input.getBytes());
 
            byte byteData[] = md.digest();
            StringBuilder sb = new StringBuilder();
            for (int i = 0; i < byteData.length; i++) {
                sb.append(Integer.toString((byteData[i] & 0xff) + 0x100, 16).substring(1));
            }
            return sb.toString();
        } catch (NoSuchAlgorithmException nse) {
            System.err.println("ERROR. MD5 ALGORITHM NOT FOUND");
            return "";
        }
    }
 
    public static String getDomTextValue(Element element, String tag) {
        if (element != null) {
            NodeList nl = element.getElementsByTagName(tag);
            if (nl != null && nl.getLength() > 0) {
                Element el = (Element) nl.item(0);
                if(el != null && el.getFirstChild() != null) {
                    return el.getFirstChild().getNodeValue();
                }
            }
        }
        return "";
    }
}