package org.hedgewars.hedgeroid.Downloader;

import java.io.BufferedReader;

import java.io.IOException;

import java.io.InputStreamReader;

import java.net.HttpURLConnection;

import java.net.URL;

import java.util.ArrayList;

import org.xmlpull.v1.XmlPullParser;

import org.xmlpull.v1.XmlPullParserException;

import org.xmlpull.v1.XmlPullParserFactory;

import android.graphics.Color;

import android.os.Bundle;

import android.support.v4.app.ListFragment;

import android.util.Log;

import android.view.View;

import android.widget.AbsListView;

import android.widget.AbsListView.OnScrollListener;

import android.widget.AdapterView;

import android.widget.AdapterView.OnItemClickListener;

import android.widget.ArrayAdapter;

public class DownloadListFragment extends ListFragment implements OnItemClickListener, OnScrollListener, Runnable{

	private View targetView = null;

	private ArrayList<OnItemMovementListener> listeners = new ArrayList<OnItemMovementListener>(); 

	public void onActivityCreated(Bundle savedInstanceState){

		super.onActivityCreated(savedInstanceState);

		ArrayList<DownloadPackage> tasks = new ArrayList<DownloadPackage>();

		ArrayAdapter<DownloadPackage> adapter = new ArrayAdapter<DownloadPackage>(getActivity().getApplicationContext(), android.R.layout.simple_list_item_1, tasks);

		setListAdapter(adapter);

		getListView().setOnItemClickListener(this);

		getListView().setOnScrollListener(this);

		if(getActivity() instanceof OnItemMovementListener){

			listeners.add((OnItemMovementListener)getActivity());

		}

		getListView().setCacheColorHint(Color.TRANSPARENT);//To prevent a blackish background while scrolling

		Thread t = new Thread(this, "DownloadListParser");

		t.start();

	}

	public void run(){

		XmlPullParserFactory xmlPullFactory;

		try {

			xmlPullFactory = XmlPullParserFactory.newInstance();

			XmlPullParser xmlPuller = xmlPullFactory.newPullParser();

			URL url = new URL("http://www.xelification.com/tmp/downloads.xml");

			HttpURLConnection conn = (HttpURLConnection)url.openConnection();

			BufferedReader br = new BufferedReader(new InputStreamReader(conn.getInputStream()), 1024);

			xmlPuller.setInput(br);

			final ArrayAdapter<DownloadPackage> adapter = (ArrayAdapter<DownloadPackage>) getListAdapter();

			int eventType = xmlPuller.getEventType();

			while(eventType != XmlPullParser.END_DOCUMENT){

				if(eventType == XmlPullParser.START_TAG){

					if(xmlPuller.getName().toLowerCase().equals("task")){

						final DownloadPackage task = DownloadPackage.getTaskFromXML(getActivity(), xmlPuller);

						getActivity().runOnUiThread(new Runnable(){

							public void run() {

								adapter.add(task);								

							}

						});

					}

				}

				eventType = getEventType(xmlPuller);

			}

		} catch (XmlPullParserException e) {

			e.printStackTrace();

		} catch (IOException e) {

			e.printStackTrace();

		}

	}

	/**

	 * Skips whitespaces..

	 */

	private static int getEventType(XmlPullParser xmlPuller)throws XmlPullParserException, IOException{

		int eventType = xmlPuller.next();

		while(eventType == XmlPullParser.TEXT && xmlPuller.isWhitespace()){

			eventType = xmlPuller.next();

		}

		return eventType;

	}

	public void onItemClick(AdapterView<?> arg0, View arg1, int position, long arg3) {

		FragmentTransaction ft = getFragmentManager().beginTransaction();

		Fragment prev = getFragmentManager().findFragmentByTag("dialog");

		//remove any old dialogs

		if(prev != null) ft.remove(prev);

		ft.addToBackStack(null);

		//create a new dialog based on this task

		DialogFragment newFragment = DownloadDialogFragment.newInstance(task);

		//show it

		targetView = arg1;

		//determine state

		int min = arg0.getTop();

		int max = arg0.getBottom();

		int top = targetView.getTop();

		previousXCoord = top;

		for(OnItemMovementListener listener : listeners){

			listener.onNewItemSelected(task, top, min, max, targetView.getHeight()*2);

		}

	}

	private int previousXCoord = 0;

	/*

	 * (non-Javadoc)

	 * @see android.widget.AbsListView.OnScrollListener#onScroll(android.widget.AbsListView, int, int, int)

	 * 

	 * Android renews the Items used in the view, so when a user scroll down the list, 

	 * as soon as the item has dissapeard from the list it gets reused at the bottom.

	 * 

	 * For this reason we cannot just keep sending the targetView.getTop() but we must

	 *  remember if the view is supposed to be at the top or bottom of the list. We 

	 *  remember this with int state, 

	 *     - 0 means we've got accurate reading from getTop()

	 *     - -1 means it's somewhere at the top of the list

	 *     - 1 means it's at the bottom somewhere

	 */

	public void onScroll(AbsListView view, int firstVisibleItem, int visibleItemCount, int totalItemCount) {

		if(targetView != null){

			int top = targetView.getTop() + (targetView.getHeight()/2);

			int min = view.getTop();

			int max = view.getBottom();

			if(Math.abs(previousXCoord - top) > targetView.getHeight()*2 ){

				top = previousXCoord;

			}

			for(OnItemMovementListener listener : listeners){

				listener.onViewMoved(top, min, max);

			}

			previousXCoord = top;

		}

	}

	public void onScrollStateChanged(AbsListView view, int scrollState) {

		switch(scrollState){

		case OnScrollListener.SCROLL_STATE_FLING: Log.d("tag", "fling"); break;

		case OnScrollListener.SCROLL_STATE_IDLE:Log.d("tag", "idle"); break;

		case OnScrollListener.SCROLL_STATE_TOUCH_SCROLL:Log.d("tag", "scroll"); break;

		}

	}

}

interface OnItemMovementListener{

	/**

	 * When I new item has been selected this method will be called

	 * @param task The task which goes with this item

	 * @param x The middle of this item

	 * @param minX The top of the parent of this item

	 * @param maxX The bottom of the parent of this item

	 */

	void onNewItemSelected(DownloadPackage task, int x, int minX, int maxX, int size);

	/**

	 * When the item has been moved this method is called

	 * @param x The middle of this item

	 * @param minX The top of the parent of this item

	 * @param maxX The bottom of the parent of this item

	 */

	void onViewMoved(int x, int minX, int maxX);

}