/* 
 * Copyright 2010-2013 Eric Kok et al.
 * 
 * Transdroid is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 * 
 * Transdroid is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 * 
 * You should have received a copy of the GNU General Public License
 * along with Transdroid.  If not, see <http://www.gnu.org/licenses/>.
 */
package org.transdroid.core.gui;

import java.util.ArrayList;
import java.util.Collections;
import java.util.Iterator;
import java.util.Locale;

import org.androidannotations.annotations.AfterViews;
import org.androidannotations.annotations.Bean;
import org.androidannotations.annotations.Click;
import org.androidannotations.annotations.EFragment;
import org.androidannotations.annotations.InstanceState;
import org.androidannotations.annotations.ItemClick;
import org.androidannotations.annotations.ViewById;
import org.transdroid.R;
import org.transdroid.core.app.settings.ApplicationSettings;
import org.transdroid.core.app.settings.SystemSettings;
import org.transdroid.core.gui.lists.TorrentsAdapter;
import org.transdroid.core.gui.lists.TorrentsAdapter_;
import org.transdroid.core.gui.navigation.Label;
import org.transdroid.core.gui.navigation.NavigationFilter;
import org.transdroid.core.gui.navigation.RefreshableActivity;
import org.transdroid.core.gui.navigation.SelectionManagerMode;
import org.transdroid.core.gui.navigation.SetLabelDialog;
import org.transdroid.core.gui.navigation.SetLabelDialog.OnLabelPickedListener;
import org.transdroid.daemon.Daemon;
import org.transdroid.daemon.Torrent;
import org.transdroid.daemon.TorrentsComparator;
import org.transdroid.daemon.TorrentsSortBy;

import android.app.Fragment;
import android.view.ActionMode;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.AbsListView.MultiChoiceModeListener;
import android.widget.ListView;
import android.widget.ProgressBar;
import android.widget.TextView;

/**
 * Fragment that shows a list of torrents that are active on the server. It supports sorting and filtering and can show
 * connection progress and issues. However, actual task starting and execution and overall navigation elements are part
 * of the containing activity, not this fragment.
 * @author Eric Kok
 */
@EFragment(resName = "fragment_torrents")
public class TorrentsFragment extends Fragment implements OnLabelPickedListener {

	// Local data
	@Bean
	protected ApplicationSettings applicationSettings;
	@Bean
	protected SystemSettings systemSettings;
	@InstanceState
	protected ArrayList<Torrent> torrents = null;
	@InstanceState
	protected ArrayList<Torrent> lastMultiSelectedTorrents;
	@InstanceState
	protected ArrayList<Label> currentLabels;
	@InstanceState
	protected NavigationFilter currentNavigationFilter = null;
	@InstanceState
	protected TorrentsSortBy currentSortOrder = TorrentsSortBy.Alphanumeric;
	@InstanceState
	protected boolean currentSortDescending = false;
	@InstanceState
	protected String currentTextFilter = null;
	@InstanceState
	protected boolean hasAConnection = false;
	@InstanceState
	protected boolean isLoading = true;
	@InstanceState
	protected String connectionErrorMessage = null;
	@InstanceState
	protected Daemon daemonType;

	// Views
	@ViewById(resName = "torrents_list")
	protected ListView torrentsList;
	@ViewById
	protected TextView emptyText;
	@ViewById
	protected TextView nosettingsText;
	@ViewById
	protected TextView errorText;
	@ViewById
	protected ProgressBar loadingProgress;

	@AfterViews
	protected void init() {

		// Load the requested sort order from the user settings
		this.currentSortOrder = applicationSettings.getLastUsedSortOrder();
		this.currentSortDescending = applicationSettings.getLastUsedSortDescending();

		// Set up the list adapter, which allows multi-select and fast scrolling
		torrentsList.setAdapter(TorrentsAdapter_.getInstance_(getActivity()));
		torrentsList.setMultiChoiceModeListener(onTorrentsSelected);
		torrentsList.setFastScrollEnabled(true);
		if (torrents != null)
			updateTorrents(torrents, currentLabels);
		// Allow pulls on the list view to refresh the torrents
		if (getActivity() != null && getActivity() instanceof RefreshableActivity) {
			((RefreshableActivity) getActivity()).addRefreshableView(torrentsList);
		}
		nosettingsText.setText(getString(R.string.navigation_nosettings, getString(R.string.app_name)));

	}

	/**
	 * Updates the list adapter to show a new list of torrent objects, replacing the old torrents completely
	 * @param newTorrents The new, updated list of torrents
	 */
	public void updateTorrents(ArrayList<Torrent> newTorrents, ArrayList<Label> currentLabels) {
		this.torrents = newTorrents;
		this.currentLabels = currentLabels;
		applyAllFilters();
	}

	/**
	 * Just look for a specific torrent in the currently shown list (by its unique id) and update only this
	 * @param affected The affected torrent to update
	 * @param wasRemoved Whether the affected torrent was indeed removed; otherwise it was updated somehow
	 */
	public void quickUpdateTorrent(Torrent affected, boolean wasRemoved) {
		// Remove the old torrent object first
		Iterator<Torrent> iter = this.torrents.iterator();
		while (iter.hasNext()) {
			Torrent torrent = iter.next();
			if (torrent.getUniqueID().equals(affected.getUniqueID())) {
				iter.remove();
				break;
			}
		}
		// In case it was an update, add the updated torrent object
		if (!wasRemoved)
			this.torrents.add(affected);
		// Now refresh the screen
		applyAllFilters();
	}

	/**
	 * Clears the currently visible list of torrents.
	 * @param b
	 */
	public void clear(boolean clearError, boolean clearFilter) {
		this.torrents = null;
		if (clearError)
			this.connectionErrorMessage = null;
		if (clearFilter) {
			this.currentTextFilter = null;
			this.currentNavigationFilter = null;
		}
		applyAllFilters();
	}

	/**
	 * Stores the new sort order (for future refreshes) and sorts the current visible list. If the given new sort
	 * property equals the existing property, the list sort order is reversed instead.
	 * @param newSortOrder The sort order that the user selected.
	 */
	public void sortBy(TorrentsSortBy newSortOrder) {
		// Update the sort order property and direction and store this last used setting
		if (this.currentSortOrder == newSortOrder) {
			this.currentSortDescending = !this.currentSortDescending;
		} else {
			this.currentSortOrder = newSortOrder;
			this.currentSortDescending = false;
		}
		applicationSettings.setLastUsedSortOrder(this.currentSortOrder, this.currentSortDescending);
		applyAllFilters();
	}

	public void applyTextFilter(String newTextFilter) {
		this.currentTextFilter = newTextFilter;
		// Show the new filtered list
		applyAllFilters();
	}

	/**
	 * Apply a filter on the current list of all torrents, showing the appropriate sublist of torrents only
	 * @param newFilter The new filter to apply to the local list of torrents
	 */
	public void applyNavigationFilter(NavigationFilter newFilter) {
		this.currentNavigationFilter = newFilter;
		applyAllFilters();
	}

	private void applyAllFilters() {

		// No torrents? Directly update views accordingly
		if (torrents == null) {
			updateViewVisibility();
			return;
		}

		// Filter the list of torrents to show according to navigation and text filters
		ArrayList<Torrent> filteredTorrents = new ArrayList<Torrent>(torrents);
		if (filteredTorrents != null && currentNavigationFilter != null) {
			// Remove torrents that do not match the selected navigation filter
			for (Iterator<Torrent> torrentIter = filteredTorrents.iterator(); torrentIter.hasNext();) {
				if (!currentNavigationFilter.matches(torrentIter.next(), systemSettings.treatDormantAsInactive()))
					torrentIter.remove();
			}
		}
		if (filteredTorrents != null && currentTextFilter != null) {
			// Remove torrent that do not contain the text filter string
			for (Iterator<Torrent> torrentIter = filteredTorrents.iterator(); torrentIter.hasNext();) {
				if (!torrentIter.next().getName().toLowerCase(Locale.getDefault())
						.contains(currentTextFilter.toLowerCase(Locale.getDefault())))
					torrentIter.remove();
			}
		}

		// Sort the list of filtered torrents
		Collections.sort(filteredTorrents, new TorrentsComparator(daemonType, this.currentSortOrder,
				this.currentSortDescending));

		((TorrentsAdapter) torrentsList.getAdapter()).update(filteredTorrents);
		updateViewVisibility();
	}

	private MultiChoiceModeListener onTorrentsSelected = new MultiChoiceModeListener() {

		SelectionManagerMode selectionManagerMode;

		@Override
		public boolean onCreateActionMode(ActionMode mode, Menu menu) {
			// Show contextual action bar to start/stop/remove/etc. torrents in batch mode
			mode.getMenuInflater().inflate(R.menu.fragment_torrents_cab, menu);
			selectionManagerMode = new SelectionManagerMode(torrentsList, R.plurals.navigation_torrentsselected);
			selectionManagerMode.onCreateActionMode(mode, menu);
			return true;
		}

		@Override
		public boolean onPrepareActionMode(ActionMode mode, Menu menu) {
			selectionManagerMode.onPrepareActionMode(mode, menu);
			// Hide/show options depending on the type of server we are connected to
			if (daemonType != null) {
				menu.findItem(R.id.action_start).setVisible(Daemon.supportsStoppingStarting(daemonType));
				menu.findItem(R.id.action_stop).setVisible(Daemon.supportsStoppingStarting(daemonType));
				menu.findItem(R.id.action_setlabel).setVisible(Daemon.supportsSetLabel(daemonType));
			}
			// Pause autorefresh
			if (getActivity() != null && getActivity() instanceof TorrentsActivity) {
				((TorrentsActivity) getActivity()).stopRefresh = true;
				((TorrentsActivity) getActivity()).stopAutoRefresh();
			}
			return true;
		}

		public boolean onActionItemClicked(ActionMode mode, MenuItem item) {

			// Get checked torrents
			ArrayList<Torrent> checked = new ArrayList<Torrent>();
			for (int i = 0; i < torrentsList.getCheckedItemPositions().size(); i++) {
				if (torrentsList.getCheckedItemPositions().valueAt(i) && i < torrentsList.getAdapter().getCount())
					checked.add((Torrent) torrentsList.getAdapter().getItem(
							torrentsList.getCheckedItemPositions().keyAt(i)));
			}

			int itemId = item.getItemId();
			if (itemId == R.id.action_resume) {
				for (Torrent torrent : checked) {
					getTasksExecutor().resumeTorrent(torrent);
				}
				mode.finish();
				return true;
			} else if (itemId == R.id.action_pause) {
				for (Torrent torrent : checked) {
					getTasksExecutor().pauseTorrent(torrent);
				}
				mode.finish();
				return true;
			} else if (itemId == R.id.action_start) {
				for (Torrent torrent : checked) {
					getTasksExecutor().startTorrent(torrent, false);
				}
				mode.finish();
				return true;
			} else if (itemId == R.id.action_stop) {
				for (Torrent torrent : checked) {
					getTasksExecutor().stopTorrent(torrent);
				}
				mode.finish();
				return true;
			} else if (itemId == R.id.action_remove_default) {
				for (Torrent torrent : checked) {
					getTasksExecutor().removeTorrent(torrent, false);
				}
				mode.finish();
				return true;
			} else if (itemId == R.id.action_remove_withdata) {
				for (Torrent torrent : checked) {
					getTasksExecutor().removeTorrent(torrent, true);
				}
				mode.finish();
				return true;
			} else if (itemId == R.id.action_setlabel) {
				lastMultiSelectedTorrents = checked;
				if (currentLabels != null)
					new SetLabelDialog().setOnLabelPickedListener(TorrentsFragment.this).setCurrentLabels(currentLabels)
						.show(getFragmentManager(), "SetLabelDialog");
				mode.finish();
				return true;
			} else {
				return false;
			}
		}

		@Override
		public void onItemCheckedStateChanged(ActionMode mode, int position, long id, boolean checked) {
			selectionManagerMode.onItemCheckedStateChanged(mode, position, id, checked);
		}

		@Override
		public void onDestroyActionMode(ActionMode mode) {
			// Resume autorefresh
			if (getActivity() != null && getActivity() instanceof TorrentsActivity) {
				((TorrentsActivity) getActivity()).stopRefresh = false;
				((TorrentsActivity) getActivity()).startAutoRefresh();
			}
			selectionManagerMode.onDestroyActionMode(mode);
		}

	};

	@Click
	protected void emptyTextClicked() {
		// Refresh the activity (that contains this fragment) when the empty view gear is clicked
		if (getActivity() != null && getActivity() instanceof RefreshableActivity) {
			((RefreshableActivity) getActivity()).refreshScreen();
		}
	}

	@Click
	protected void errorTextClicked() {
		// Refresh the activity (that contains this fragment) when the error view gear is clicked
		if (getActivity() != null && getActivity() instanceof RefreshableActivity) {
			((RefreshableActivity) getActivity()).refreshScreen();
		}
	}

	@ItemClick(resName = "torrents_list")
	protected void torrentsListClicked(Torrent torrent) {
		// Show the torrent details fragment
		((TorrentsActivity) getActivity()).openDetails(torrent);
	}

	@Override
	public void onLabelPicked(String newLabel) {
		for (Torrent torrent : lastMultiSelectedTorrents) {
			getTasksExecutor().updateLabel(torrent, newLabel);
		}
	}

	/**
	 * Updates the shown screen depending on whether we have a connection (so torrents can be shown) or not (in case we
	 * need to show a message suggesting help). This should only ever be called on the UI thread.
	 * @param hasAConnection True if the user has servers configured and therefore has a connection that can be used
	 */
	public void updateConnectionStatus(boolean hasAConnection, Daemon daemonType) {
		this.hasAConnection = hasAConnection;
		this.daemonType = daemonType;
		if (!hasAConnection) {
			torrentsList.setVisibility(View.GONE);
			emptyText.setVisibility(View.GONE);
			loadingProgress.setVisibility(View.GONE);
			errorText.setVisibility(View.GONE);
			nosettingsText.setVisibility(View.VISIBLE);
			clear(true, true); // Indirectly also calls updateViewVisibility()
		} else {
			updateViewVisibility();
		}
	}

	/**
	 * Updates the shown screen depending on whether the torrents are loading. This should only ever be called on the UI
	 * thread.
	 * @param isLoading True if the list of torrents is (re)loading, false otherwise
	 */
	public void updateIsLoading(boolean isLoading) {
		this.isLoading = isLoading;
		if (isLoading) {
			clear(true, false); // Indirectly also calls updateViewVisibility()
		} else {
			updateViewVisibility();
		}
	}

	/**
	 * Updates the shown screen depending on whether a connection error occurred. This should only ever be called on the
	 * UI thread.
	 * @param connectionErrorMessage The error message from the last failed connection attempt, or null to clear the
	 *            visible error text
	 */
	public void updateError(String connectionErrorMessage) {
		this.connectionErrorMessage = connectionErrorMessage;
		errorText.setText(connectionErrorMessage);
		if (connectionErrorMessage != null) {
			clear(false, false); // Indirectly also calls updateViewVisibility()
		} else {
			updateViewVisibility();
		}
	}

	private void updateViewVisibility() {
		if (!hasAConnection) {
			return;
		}
		boolean isEmpty = torrents == null || torrentsList.getAdapter().isEmpty();
		boolean hasError = connectionErrorMessage != null;
		nosettingsText.setVisibility(View.GONE);
		errorText.setVisibility(hasError ? View.VISIBLE : View.GONE);
		torrentsList.setVisibility(!hasError && !isLoading && !isEmpty ? View.VISIBLE : View.GONE);
		loadingProgress.setVisibility(!hasError && isLoading ? View.VISIBLE : View.GONE);
		emptyText.setVisibility(!hasError && !isLoading && isEmpty ? View.VISIBLE : View.GONE);
	}

	/**
	 * Returns the object responsible for executing torrent tasks against a connected server
	 * @return The executor for tasks on some torrent
	 */
	private TorrentTasksExecutor getTasksExecutor() {
		// NOTE: Assumes the activity implements all the required torrent tasks
		return (TorrentTasksExecutor) getActivity();
	}

}