/**
 *    MessageBay.java
 *    Copyright (C) 2010 New Zealand Digital Library, http://expeditee.org
 *
 *    This program 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.
 *
 *    This program 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 this program.  If not, see <http://www.gnu.org/licenses/>.
 */

package org.expeditee.gui;

import java.util.LinkedList;
import java.util.List;

import org.expeditee.Util;
import org.expeditee.actions.Misc;
import org.expeditee.auth.AuthenticatorBrowser;
import org.expeditee.core.Clip;
import org.expeditee.core.Colour;
import org.expeditee.core.Dimension;
import org.expeditee.core.Font;
import org.expeditee.core.Image;
import org.expeditee.encryption.items.surrogates.Label;
import org.expeditee.gio.EcosystemManager;
import org.expeditee.gio.GraphicsManager;
import org.expeditee.items.Item;
import org.expeditee.items.Text;
import org.expeditee.settings.UserSettings;

/**
 * The bay at the bottom of the expeditee browser which displays messages. TODO:
 * Make it thread safe!
 */
public final class MessageBay {

	/** The distance from the top of the message bay to the Message frame link. */
	private static final int MESSAGE_LINK_Y_OFFSET = 100;

	/** TODO: Comment. cts16 */
	private static final int MESSAGE_LINK_X = 50;

	/** TODO: Comment. cts16 */
	public static final Colour ERROR_COLOR = Colour.RED;

	/** TODO: Comment. cts16 */
	public static final String MESSAGES_FRAMESET_NAME = "Messages";

	/** The list of messages shown in the message bay. */
	private static List<Item> _messages = new LinkedList<Item>();

	/**
	 * Messages which were delayed because they couldn't be shown at time of
	 * creation.
	 */
	private static List<DelayedMessage> _delayedMessages = new LinkedList<DelayedMessage>();

	/** TODO: Comment. cts16 */
	private static Text _status = null;
	
	private static Text _authorisedUser = null;
	
	private static Text _surrogateMode = null;

	/** Buffer image of the message window. */
	private static Image _messageBuffer = null;

	/** Creator for creating the message frames. */
	private static FrameCreator _creator = null;
	
	/** The user we are providing messages for **/
	private static String _forUser = null;

	/** Font used for the messages. */
	private static Font _messageFont = new Font("Serif-Plain-16");

	/** The number of messages currently shown (used for scrolling up). */
	private static int _messageCount = 0;

	/** If true, error messages are not shown to the user. */
	private static boolean _suppressMessages = false;

	/** The link to the message frameset. */
	private static Item _messageLink = new Text(-2, "@" + MESSAGES_FRAMESET_NAME, Colour.BLACK, Colour.WHITE);

	/** TODO: Comment. cts16 */
	private static String _lastMessage = null;

	/** TODO: Comment. cts16 */
	private static boolean isLinkInitialized = false;

	/** Static-only class. */
	private MessageBay() {
	}

	/** Whether the message bay is ready to display messages. */
	public static boolean isReady() {
		return Browser.isInitComplete();
	}

	/** Syncs message bay size according to FrameGraphics max size. */
	private static void updateSize() {
		for (Item i : _messages) {
			if (i != null) {
				i.setOffset(0, -DisplayController.getMessageBayPaintArea().getMinY());
			}
		}

		_messageLink.setOffset(0, -DisplayController.getMessageBayPaintArea().getMinY());

		updateLink();
	}

	/** Whether the given item is an item in the message bay. */
	public static boolean isMessageItem(Item i) {
		return _messages.contains(i) || i == _messageLink || i == getStatus();
	}

	/** TODO: Comment. cts16 */
	public synchronized static Item getMessageLink() {
		return _messageLink;
	}

	/** TODO: Comment. cts16 */
	public synchronized static List<Item> getMessages() {
		return _messages;
	}

	/** Causes the entire message bay area to be invalidated. */
	public synchronized static void invalidateFullBay() {
		DisplayController.invalidateArea(DisplayController.getMessageBayPaintArea());
	}

	/** TODO: Comment. cts16 */
	private static void updateLink() {
		if (!isLinkInitialized && DisplayController.getFramePaintArea() != null
				&& DisplayController.getFramePaintAreaWidth() > 0) {
			// set up 'Messages' link on the right hand side
			_messageLink.setPosition(DisplayController.getMessageBayPaintArea().getWidth() - MESSAGE_LINK_Y_OFFSET,
					MESSAGE_LINK_X);
			_messageLink.setOffset(0, -DisplayController.getMessageBayPaintArea().getMinY());
			isLinkInitialized = true;
		} else {
			_messageLink.setPosition(DisplayController.getMessageBayPaintArea().getWidth() - MESSAGE_LINK_Y_OFFSET,
					MESSAGE_LINK_X);
		}
	}

	/** TODO: Comment. cts16 */
	public static Image getImage(Clip clip, Dimension size) {
		// Can't get an image with an invalid size
		if (size == null || size.width <= 0 || size.height <= 0) {
			return null;
		}

		// Update the buffer
		updateBuffer(Item.DEFAULT_BACKGROUND, clip, size);

		// Return the image buffer
		return _messageBuffer;
	}
	
	public static void clear() {
		MessageBay._messageCount = 0;
		MessageBay._messages.clear();
	}

	/** Updates the image buffer to reflect the current state of the message bay. */
	private synchronized static void updateBuffer(Colour background, Clip clip, Dimension size) {
		// If the buffer doesn't exist or is the wrong size, recreate it
		if (_messageBuffer == null || !_messageBuffer.getSize().equals(size)) {
			_messageBuffer = Image.createImage(size, true);
			clip = null; // Need to recreate the entire image;
			updateSize();
		}

		GraphicsManager g = EcosystemManager.getGraphicsManager();
		g.pushDrawingSurface(_messageBuffer);

		if (clip != null) {
			g.pushClip(clip);
		}
		g.setAntialiasing(true);

		g.clear(background);

		g.setFont(_messageFont);

		for (Item message : _messages) {
			if (message != null) {
				if (clip == null || clip.isNotClipped() || message.isInDrawingArea(clip.getBounds())) {
					FrameGraphics.PaintItem(message);
				}
			}
		}

		if (getStatus() != null) {
			FrameGraphics.PaintItem(getStatus());
		}
		
		if (AuthenticatorBrowser.isAuthenticated() && _authorisedUser != null) {
			FrameGraphics.PaintItem(_authorisedUser);
		}
		
		if (Label.isInSurrogateMode() && _surrogateMode != null) {
			FrameGraphics.PaintItem(_surrogateMode);
		}

		if (clip == null || clip.isNotClipped() || _messageLink.isInDrawingArea(clip.getBounds())) {
			FrameGraphics.PaintItem(_messageLink);
		}

		g.popDrawingSurface();
	}

	/** TODO: Comment. cts16 */
	private static Text displayMessage(String message, String link, List<String> actions, Colour color) {
		return displayMessage(message, link, actions, color, true);
	}

	/** TODO: Comment. cts16 */
	public synchronized static Text displayMessage(String message, String link, Colour color, boolean displayAlways,
			String action) {	
		List<String> actions = new LinkedList<String>();
		if (action != null) {
			actions.add(action);
		}
		return displayMessage(message, link, actions, color, displayAlways);
	}
	
	public static void updateFramesetLocation() {
		if (_forUser != UserSettings.UserName.get()) {
			if (AuthenticatorBrowser.isAuthenticated()) {
				_creator = new FrameCreator(MESSAGES_FRAMESET_NAME, FrameIO.MESSAGES_PATH, MESSAGES_FRAMESET_NAME, FrameCreator.ExistingFramesetOptions.OverrideExistingFrames,
						false, AuthenticatorBrowser.PROFILEENCRYPTIONLABEL);
			} else {
				_creator = new FrameCreator(MESSAGES_FRAMESET_NAME, FrameIO.MESSAGES_PATH, MESSAGES_FRAMESET_NAME, FrameCreator.ExistingFramesetOptions.OverrideExistingFrames,
						false, null);
			}
			_forUser = UserSettings.UserName.get();
		}
	}

	/** TODO: Comment. cts16 */
	private static Text newMessage(String message, String link, List<String> actions, Colour color) {
		Text t = new Text(getMessagePrefix(true) + message);
		t.setPosition(20, 15 + _messages.size() * 25);
		t.setOffset(0, -DisplayController.getFramePaintAreaHeight());
		t.setColor(color);
		t.setLink(link);
		t.setActions(actions);
		t.setFont(_messageFont.clone());
		_creator.addItem(t.copy(), true);
		if (link == null) {
			t.setLink(_creator.getCurrent());
		}
		return t;
	}
	
	/** TODO: Comment. cts16 */
	private synchronized static Text displayMessage(String message, String link, List<String> actions, Colour color,
			boolean displayAlways, boolean redraw) {
		assert (message != null);

		if (!isReady()) {
			delayMessage(message, link, actions, color, displayAlways, redraw);
			return null;
		}

		System.out.println(message);

		// Invalidate whole area
		invalidateFullBay();

		if (_suppressMessages) {
			return null;
		}

		if (!displayAlways && message.equals(_lastMessage)) {
			Item lastMessage = _messages.get(_messages.size() - 1);
			String text = lastMessage.getText();
			if (text.endsWith("}")) {
				int startOfRepeat = text.lastIndexOf("{");
				String repeatString = text.substring(startOfRepeat);
				repeatString = repeatString.substring(1, repeatString.length() - 1);
				try {
					int repeatCount = Integer.parseInt(repeatString) + 1;
					text = text.substring(0, startOfRepeat).trim() + " {" + repeatCount + "}";
				} catch (NumberFormatException e) {
					e.printStackTrace();
				}
			} else {
				text = text.trim() + " {2}";
			}
			lastMessage.setText(text);
			DisplayController.DisableMailMode();
			return null;
		}

		_lastMessage = message;

		if (_creator == null) {
			if (AuthenticatorBrowser.isAuthenticated()) {
				_creator = new FrameCreator(MESSAGES_FRAMESET_NAME, FrameIO.MESSAGES_PATH, MESSAGES_FRAMESET_NAME, FrameCreator.ExistingFramesetOptions.OverrideExistingFrames,
						false, AuthenticatorBrowser.PROFILEENCRYPTIONLABEL);
			} else {
				_creator = new FrameCreator(MESSAGES_FRAMESET_NAME, FrameIO.MESSAGES_PATH, MESSAGES_FRAMESET_NAME, FrameCreator.ExistingFramesetOptions.OverrideExistingFrames,
						false, null);
			}
			_forUser = UserSettings.UserName.get();
		}

		// set up 'Messages' link on the right hand side
		updateLink();

		if (_messages.size() >= 3) {
			_messages.remove(0);
			for (Item i : _messages) {
				i.setY(i.getY() - 25);
			}
		}

		Text t = newMessage(message, link, actions, color);

		_messages.add(t);

		// update the link to the latest message frame
		_messageLink.setLink(_creator.getCurrent());

		if (redraw) {
			DisplayController.DisableMailMode();
			DisplayController.requestRefresh(true);
		}

		return t;
	}

	/** TODO: Comment. cts16 */
	public synchronized static Text displayMessage(String message, String link, List<String> actions, Colour color,
			boolean displayAlways) {
		return displayMessage(message, link, actions, color, displayAlways, true);
	}

	/** TODO: Comment. cts16 */
	public synchronized static void overwriteMessage(String message) {
		overwriteMessage(message, null);
	}

	/** TODO: Comment. cts16 */
	public synchronized static void overwriteMessage(String message, Colour color) {
		_messages.remove(_messages.size() - 1);
		Text t = newMessage(message, null, null, color);
		_messages.add(t);
		DisplayController.requestRefresh(true);
	}

	/** TODO: Comment. cts16 */
	private static String getMessagePrefix(int counter) {
		return "@" + counter + ": ";
	}

	/** TODO: Comment. cts16 */
	private static String getMessagePrefix(boolean incrementCounter) {
		if (incrementCounter) {
			_messageCount++;
		}

		return getMessagePrefix(_messageCount);
	}

	/**
	 * Checks if the error message ends with a frame name after the
	 * frameNameSeparator symbol
	 * 
	 * @param message
	 *            the message to be displayed
	 */
	public synchronized static Text linkedErrorMessage(String message) {
		if (_suppressMessages) {
			return null;
		}
		Misc.beep();
		String[] tokens = message.split(Text.FRAME_NAME_SEPARATOR);
		String link = null;
		if (tokens.length > 1) {
			link = tokens[tokens.length - 1];
		}
		return displayMessage(message, link, null, ERROR_COLOR);
	}

	/** TODO: Comment. cts16 */
	public synchronized static Text errorMessage(String message) {
		if (_suppressMessages) {
			return null;
		}
		Misc.beep();
		return displayMessage(message, null, null, ERROR_COLOR, false);
	}

	/**
	 * Displays the given message in the message area of the Frame, any previous
	 * message is cleared from the screen.
	 * 
	 * @param message
	 *            The message to display to the user in the message area
	 */
	public synchronized static Text displayMessage(String message) {
		return displayMessageAlways(message);
	}

	/** TODO: Comment. cts16 */
	public synchronized static Text displayMessageOnce(String message) {
		return displayMessage(message, null, null, Colour.BLACK, false);
	}

	/** TODO: Comment. cts16 */
	public synchronized static Text displayMessage(String message, Colour textColor) {
		return displayMessage(message, null, null, textColor);
	}

	/** TODO: Comment. cts16 */
	public synchronized static Text displayMessage(Text message) {
		Text t = null;
		String link = message.getLink();
		List<String> action = message.getAction();
		Colour color = message.getColor();
		for (String s : message.getTextList()) {
			t = displayMessage(s, link, action, color);
		}
		return t;
	}

	/** TODO: Comment. cts16 */
	public synchronized static Text displayMessageAlways(String message) {
		return displayMessage(message, null, null, Colour.BLACK);
		// Misc.Beep();
	}

	/** TODO: Comment. cts16 */
	public synchronized static Text warningMessage(String message) {
		return displayMessage(message, null, null, Colour.MAGENTA);
	}

	/** TODO: Comment. cts16 */
	public synchronized static List<Text> warningMessages(List<String> messages) {
		if (messages == null) {
			return null;
		}
		List<Text> ret = new LinkedList<Text>();
		for (String message : messages) {
			ret.add(warningMessage(message));
		}
		return ret;
	}

	/** TODO: Comment. cts16 */
	public synchronized static void suppressMessages(boolean val) {
		_suppressMessages = val;
	}

	/** TODO: Comment. cts16 */
	public synchronized static void setStatus(String status) {
		if (_status == null) {
			_status = new Text(status);
			_status.setPosition(0, 85);
			_status.setOffset(0, -DisplayController.getMessageBayPaintArea().getMinY());
			_status.setLink(null); // maybe link to a help frame?
			_status.setFont(new Font(Text.MONOSPACED_FONT));
		} else {
			_status.setText(status);
		}
		
		_authorisedUser = new Text("Username: " + System.getProperty("user.name"));
		_authorisedUser.setFont(new Font(Text.MONOSPACED_FONT));
		_authorisedUser.setY(95);
		_authorisedUser.setAnchorRight(1);
		
		if (Label.isInSurrogateMode()) {
			String surrogateModeString = Label.surrogateModeString();
			
			_surrogateMode = new Text(surrogateModeString);
			_surrogateMode.setFont(new Font(Text.MONOSPACED_FONT));
			_surrogateMode.setY(75);
			_surrogateMode.setAnchorRight(1);
		} else {
			if (_surrogateMode != null) {
				_surrogateMode.setVisible(false);
			}
		}

		// invalidateFullBay();
		DisplayController.requestRefresh(true);
	}

	/** TODO: Comment. cts16 */
	public static final class Progress {
		/** The colour progress bars should be displayed in. */
		private static final Colour BAR_COLOUR = Colour.GREEN.darker();

		/**
		 * The character used to assemble the uncompleted portions of the progress bar.
		 */
		private static final char UNCOMPLETED_CHARACTER = '\u2591'; // ░
		/**
		 * The character used to assemble the completed portions of the progress bar.
		 */
		private static final char COMPLETED_CHARACTER = '\u2592'; // ▒

		/** What the progress bar should look like when at 100% completion. */
		private static final String COMPLETED_BAR = Util.nCopiesOf(20, COMPLETED_CHARACTER);
		/** What the progress bar should look like when at 0% completion. */
		private static final String UNCOMPLETED_BAR = Util.nCopiesOf(20, UNCOMPLETED_CHARACTER);

		private String _message;
		private Text _text;

		protected Progress(String text) {
			this._text = displayMessage(text, null, null, BAR_COLOUR, true, false);
			this._message = this._text.getText();
			this._text.setText(this._message + " [" + UNCOMPLETED_BAR + "] 0%");
			DisplayController.requestRefresh(true);
		}

		public void UpdateMessage(final String text, final int newProgress) throws Exception {
			this._message = text;
			set(newProgress);
		}

		public String GetMessage() {
			return _message;
		}

		/**
		 * 
		 * @param progress
		 *            progress value from 0 to 100
		 * @return true if the progress was updated, false if the progress was off the
		 *         screen
		 * @throws Exception
		 *             if progress out of bounds
		 */
		public boolean set(int progress) throws Exception {
			if (progress < 0 || progress > 100) {
				throw new Exception("Progress value out of bounds");
			}
			int p = progress / 5;
			if (isMessageItem(this._text)) {
				this._text.setText(this._message + " [" + COMPLETED_BAR.substring(0, p) + UNCOMPLETED_BAR.substring(p)
						+ "] " + progress + "%");
				DisplayController.requestRefresh(true);
				return true;
			}
			return false;
		}
	}

	/** TODO: Comment. cts16 */
	public synchronized static Progress displayProgress(String message) {
		return new Progress(message);
	}

	/** Remembers the arguments to a displayMessage call for later use. */
	private static class DelayedMessage {

		private String _message;
		private String _link;
		private List<String> _actions;
		private Colour _colour;
		private boolean _displayAlways;
		private boolean _redraw;

		public DelayedMessage(String message, String link, List<String> actions, Colour color, boolean displayAlways,
				boolean redraw) {
			_message = message;
			_link = link;
			if (actions == null) {
				_actions = null;
			} else {
				_actions = new LinkedList<String>();
				_actions.addAll(actions);
			}
			_colour = color == null ? null : color.clone();
			_displayAlways = displayAlways;
			_redraw = redraw;
		}

		public void display() {
			displayMessage(_message, _link, _actions, _colour, _displayAlways, _redraw);
		}

	}

	private static void delayMessage(String message, String link, List<String> actions, Colour color,
			boolean displayAlways, boolean redraw) {
		_delayedMessages.add(new DelayedMessage(message, link, actions, color, displayAlways, redraw));
	}

	public static void showDelayedMessages(final boolean requestRefresh) {
		if (isReady()) {
			for (DelayedMessage message : _delayedMessages) {
				message.display();
			}
			_delayedMessages.clear();
			invalidateFullBay();
			if(requestRefresh) {
				DisplayController.requestRefresh(true);
			}
		}
	}

	public static Text getStatus() {
		return _status;
	}
}