package service;

import java.io.OutputStream;
import java.text.SimpleDateFormat;

import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.transform.TransformerFactory;
import javax.xml.transform.dom.DOMSource;
import javax.xml.transform.stream.StreamResult;

import model.Account;
import model.AccountBook;
import model.Category;
import model.Entry;

import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.w3c.dom.Text;



/**
 * Schreibt das Haushaltsbuch gemass des XML-Schemas auf den Output Stream
 * @author Fabi
 *
 */
public class ExportService {

	public static void export(AccountBook accountBook,OutputStream out) throws ExportException{

		if(accountBook == null){
			throw new NullPointerException();
		}

		try{
			/**
			 * Initialisierung
			 */
			DocumentBuilderFactory dbfac = DocumentBuilderFactory.newInstance();
			DocumentBuilder docbuilder =dbfac.newDocumentBuilder();
			Document doc = docbuilder.newDocument();
			/**Wurzel */
			Element accountBookRoot = doc.createElement("accountbook");

			/**Accounts*/

			Element accounts = doc.createElement("accounts");
			/**Der Wurzel wurde ein neues Kind hinzugefuegt*/
			accountBookRoot.appendChild(accounts);

			for(Account ac : accountBook.getAccounts()){

				Element account = doc.createElement("account");
				accounts.appendChild(account);

				/**Name und Anfangskontostand werden erzeugt*/
				Element name =doc.createElement("name");
				account.appendChild(name);

				Text text = doc.createTextNode(ac.getName());
				account.appendChild(text);

				Element openingBalance = doc.createElement("openingBalance");
				account.appendChild(openingBalance);
				Text textopening = doc.createTextNode("" + ac.getOpeningBalance());
				account.appendChild(textopening);

			}

			/** Incomes erstellen */
			Element incomes = doc.createElement("incomes");
			accountBookRoot.appendChild(incomes);

			for(Category i : accountBook.findAllIncomeCategories()){
				Element category  = doc.createElement("category");
				/** Wenn es eine Oberkategorie hat */
				if(i.getParent() != null){
					 category.setAttribute("parent", i.getParent().getUuid()
								.toString());
				 }
				incomes.appendChild(category);

				Element uuid = doc.createElement("uuid");
				category.appendChild(uuid);
				Text textuuid = doc.createTextNode(""+i.getUuid());
				category.appendChild(textuuid);

				Element name = doc.createElement("name");
				category.appendChild(name);
				Text textname = doc.createTextNode(i.getName());
				category.appendChild(textname);

				Element description = doc.createElement("description");
				category.appendChild(description);
				Text textdiscr = doc.createTextNode(i.getDiscription());
				category.appendChild(textdiscr);
			}


			/**Expenses erstellen */

			Element expenses = doc.createElement("expenses");
			accountBookRoot.appendChild(expenses);

			for(Category e : accountBook.findAllExpenseCategories()){

				Element category = doc.createElement("category");
				if(e.getParent() != null){
					category.setAttribute("parent", e.getParent().getUuid()
							.toString());
				}

				expenses.appendChild(category);

				Element uuid = doc.createElement("uuid");
				category.appendChild(uuid);
				Text textcat = doc.createTextNode(""+e.getUuid());
				category.appendChild(textcat);

				Element name = doc.createElement("name");
				category.appendChild(name);
				Text textname = doc.createTextNode(e.getName());
				category.appendChild(textname);

				Element description = doc.createElement("description");
				category.appendChild(description);
				Text textdescr = doc.createTextNode(e.getDiscription());
				category.appendChild(textdescr);
			}


			/**Entries erstellen*/
			Element entries = doc.createElement("entries");
			accountBookRoot.appendChild(entries);

			for(Entry entry : accountBook.getEntries()){

				Element en = doc.createElement("entry");
				en.setAttribute("account", entry.getAccount().getName());
				en.setAttribute("category", ""+entry.getCategory().getUuid());
				entries.appendChild(en);

				Element description = doc.createElement("description");
				en.appendChild(description);
				Text textdescription = doc.createTextNode(entry.getDescription());
				en.appendChild(textdescription);

				Element value = doc.createElement("value");
				en.appendChild(value);
				Text textvalue = doc.createTextNode(""+entry.getValue());
				en.appendChild(textvalue);

				Element timestamp = doc.createElement("timestamp");
				en.appendChild(timestamp);

				SimpleDateFormat sdf = new SimpleDateFormat();
				sdf.applyPattern("dd.MM.yyyy");
				String date = sdf.format(entry.getTimestamp().getTime());

				Text texttime = doc.createTextNode(date);
				en.appendChild(texttime);

			}

			TransformerFactory.newInstance().newTransformer()
			.transform(new DOMSource(doc), new StreamResult(out));

		} catch(Exception e){

		}



	}

}