package eg.edu.alexu.csd.oop.db;

import java.io.File;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.Iterator;
import java.util.LinkedList;
import java.util.List;
import java.util.Map;
import java.util.Set;

import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.ParserConfigurationException;
import javax.xml.transform.OutputKeys;
import javax.xml.transform.Transformer;
import javax.xml.transform.TransformerException;
import javax.xml.transform.TransformerFactory;
import javax.xml.transform.dom.DOMSource;
import javax.xml.transform.stream.StreamResult;

import org.w3c.dom.Document;
import org.w3c.dom.NodeList;
import org.w3c.dom.Node;
import org.w3c.dom.Element;


public class XMLtable {

	public void saveXML(String tableName,String path,Map<String,LinkedList> m,List<String> names ) {

		Set<String> keys = m.keySet();
		try {

				DocumentBuilderFactory docFactory = DocumentBuilderFactory.newInstance();
				DocumentBuilder docBuilder = docFactory.newDocumentBuilder();

				Document doc = docBuilder.newDocument();
				Element rootElement = doc.createElement("table");
				doc.appendChild(rootElement);
				rootElement.setAttribute("name", tableName);;

				Element data = doc.createElement("data");
				rootElement.appendChild(data);
				for(String key:names)
				{
					Element col = doc.createElement("columnData");
					col.appendChild(doc.createTextNode(key));
					data.appendChild(col);

				}

				for(String key:keys)
				{
					Element col = doc.createElement("column");
					col.setAttribute("name", key);
					rootElement.appendChild(col);
					//
					Iterator<Object> iterate = m.get(key).iterator();
					while(iterate.hasNext())
					{
						Element item = doc.createElement("item");
						item.appendChild(doc.createTextNode((String) iterate.next()));
						col.appendChild(item);
					}

				}

				// write the content into xml file
				TransformerFactory transformerFactory = TransformerFactory.newInstance();
				Transformer transformer = transformerFactory.newTransformer();
				transformer.setOutputProperty(OutputKeys.INDENT, "yes");
	            transformer.setOutputProperty(OutputKeys.METHOD, "xml");
	            transformer.setOutputProperty("{http://xml.apache.org/xslt}indent-amount", "4");
	            DOMSource source = new DOMSource(doc);
				StreamResult result = new StreamResult(new File(path));

				// Output to console for testing
				// StreamResult result = new StreamResult(System.out);

				transformer.transform(source, result);

				System.out.println("File saved!");

			  } catch (ParserConfigurationException pce) {
				pce.printStackTrace();
			  } catch (TransformerException tfe) {
				tfe.printStackTrace();
			  }

	}

	public Table loadXML(String path) {

		String tableName;
		Table t;
		Map<String, LinkedList> mapTable = new HashMap<String, LinkedList>();
		Map<String, String> mapDeclare = new HashMap<String, String>();
		ArrayList<String> names = new ArrayList<String>();

		try {

			File fXmlFile = new File(path);
			DocumentBuilderFactory dbFactory = DocumentBuilderFactory.newInstance();
			DocumentBuilder dBuilder = dbFactory.newDocumentBuilder();
			Document doc = dBuilder.parse(fXmlFile);
			doc.getDocumentElement().normalize();

			Element root = doc.getDocumentElement();
			tableName = root.getAttribute("name");

			Element data = (Element)root.getElementsByTagName("data").item(0);

			NodeList dataList = data.getElementsByTagName("columnData");

			for (int temp = 0; temp < dataList.getLength(); temp++) {

				Node nNode = dataList.item(temp);

				if (nNode.getNodeType() == Node.ELEMENT_NODE) {
					Element eElement = (Element) nNode;
					names.add(eElement.getTextContent());
				}
			}

			NodeList colList = root.getElementsByTagName("column");

			for (int temp = 0; temp < colList.getLength(); temp++) {

				Node nNode = colList.item(temp);

				if (nNode.getNodeType() == Node.ELEMENT_NODE) {

					Element eElement = (Element) nNode;
					NodeList itemList = eElement.getElementsByTagName("item");
					String key = eElement.getAttribute("name");
					LinkedList<Object> l = new LinkedList<Object>();
					//get column type
					try{
						int colType = Integer.parseInt(itemList.item(0).getTextContent());
						mapDeclare.put(key, "int");
					}catch(Exception exc)
					{
						mapDeclare.put(key, "varchar");
					}
					//
					for(int i=0;i<itemList.getLength();i++)
					{
						Node n = itemList.item(i);

						if(n.getNodeType() == Node.ELEMENT_NODE)
						{
							Element e = (Element)n;
							l.add(e.getTextContent());
						}
					}

					mapTable.put(key, l);

				}

			}
			//return table
			t = new Table(tableName, mapDeclare,names);
			t.setTable(mapTable);
			return t;
	    } catch (Exception e) {
	    	e.printStackTrace();
	    }
		return null;
	}

}