package org.expeditee.auth.mail.gui;

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

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.gio.EcosystemManager;
import org.expeditee.gio.GraphicsManager;
import org.expeditee.gui.DisplayController;
import org.expeditee.gui.FrameCreator;
import org.expeditee.gui.FrameGraphics;
import org.expeditee.gui.FrameIO;
import org.expeditee.gui.MessageBay;
import org.expeditee.items.Item;
import org.expeditee.items.Text;
import org.expeditee.settings.UserSettings;

public class MailBay {
	public static final String EXPEDITEE_MAIL_FRAMESET_NAME = "expediteemail";

	/** The y position of the header to the mail bay. */
	private static final int HEADER_OFFSET_Y = 15;
	
	/** Space between mail messages */
	private static final int SPACING = 25;
	
	/** The (x,y) of the top message. */
	private static final int MESSAGE_OFFSET_Y = 15 + SPACING;
	private static final int OFFSET_X = 20;

	/** Buffer image of the mail window. */
	private static Image _mailBuffer;
	
	/** The list of messages shown in the mail bay. */
	private static List<Item> _previewMessages = new LinkedList<Item>();
	private static List<Item> _messages = new LinkedList<Item>();
	
	/** Font used for mail messages. */
	private static Font _messageFont = new Font("Serif-Plain-16");

	/** Used to number messages. */
	private static int _messageCount;
	
	/** Creator for creating the mail frames. */
	private static FrameCreator _creator = null;
	
	/** The currently logged in user, consulted when deciding if a new FrameCreator is needed. */
	private static String _forUser = UserSettings.UserName.get();
	
	/** The link that the preview pane displays pointing towards unprocessed messages. */
	private static Text _mailLink = new Text(-2, "@Mail", Colour.BLACK, Colour.WHITE);

	/** Wether the link has been drawn before. */
	private static boolean isLinkInitialized = false;

	/** The position of the mail link. */
	private static int MAIL_LINK_Y_OFFSET = 100;
	private static int MAIL_LINK_X = 50;
	
	/**
	 * Obtain the two messages shown at the bottom of the screen as a preview to the entire collection of mail.
	 * @return
	 */
	public static List<Item> getPreviewMessages() {
		return _previewMessages;
	}
	
	/**
	 * An item is a 'preview mail item' if it is currently being previewed at the bottom of the screen.
	 * @param i
	 * @return
	 */
	public static boolean isPreviewMailItem(Item i) {
		return _previewMessages.contains(i) || i == _mailLink;
	}
	
	public static void disconnect() {
		if (_forUser != UserSettings.UserName.get()) {
			_creator = null;
			_forUser = UserSettings.UserName.get();
		}
	}
		
	/**
	 * Adds a message to the MailBay.
	 * @param message The basic text of the message, what is displayed in the bay window down the bottom.
	 * @options A map describing the buttons to be provided as reply options (Button Text, Action to run)
	 * @return
	 */
	public synchronized static Text addMessage(String timestamp, String message, String message2, Map<String, String> options) {
		// Invalidate whole area
		DisplayController.invalidateArea(DisplayController.getMessageBayPaintArea());
		
		// Ensure frame creator
		if (_creator == null || _forUser != UserSettings.UserName.get()) {
			_forUser = UserSettings.UserName.get();
			_creator = new FrameCreator(EXPEDITEE_MAIL_FRAMESET_NAME, FrameIO.MAIL_PATH, EXPEDITEE_MAIL_FRAMESET_NAME, FrameCreator.ExistingFramesetOptions.AppendAfterLastItem, false, AuthenticatorBrowser.PROFILEENCRYPTIONLABEL);
		}
				
		// We have enough space for the header + 2 preview messages
		if (_previewMessages.size() >= 2) {
			_previewMessages.remove(0);
			for (Item i : _previewMessages) {
				i.setY(i.getY() - SPACING);
			}
		}
		
		// Add new message
		Mail mail = new Mail(message, message2, options);
		Text t = mail.getPreviewMessage(true);
		_messages.add(t);
		_creator.addText(timestamp, Colour.BLACK, null, null, false);
		for (Text line: mail.getMessage()) {
			_creator.addItem(line.copy(), false);
		}
		t.setLink(_creator.getCurrentFrame().getName());
		_previewMessages.add(t);
		_creator.addSpace(SPACING);
		_creator.save();
		
		// Make sure the link points to the latest frame
		_mailLink.setLink(_creator.getCurrent());
		
		DisplayController.requestRefresh(true);
		
		return t;
	}

	/**
	 * Obtains the image item that is drawn to display the mail bay.
	 * @param clip
	 * @param size
	 * @return
	 */
	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 _mailBuffer;
	}
	
	public static void clear() {
		getPreviewMessages().clear();
		_messageCount = 0;
	}
	
	public static Item getMailLink() {
		return _mailLink;
	}
	
	public static void ensureLink() {
		if (_mailLink.getLink() == null && FrameIO.canAccessFrame(MailBay.EXPEDITEE_MAIL_FRAMESET_NAME + 1)) {
			_mailLink.setLink(MailBay.EXPEDITEE_MAIL_FRAMESET_NAME + 1);
		}
	}	
	
	/** Updates the image buffer to reflect the current state of the mail 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 (_mailBuffer == null || !_mailBuffer.getSize().equals(size)) {
			_mailBuffer = Image.createImage(size, true);
			clip = null; // Need to recreate the entire image;
			updateSize();
		}
		
		// Prepare graphics
		GraphicsManager g = EcosystemManager.getGraphicsManager();
		g.pushDrawingSurface(_mailBuffer);
		if (clip != null) {
			g.pushClip(clip);
		}
		g.setAntialiasing(true);
		g.clear(background);
		g.setFont(_messageFont);
		
		// Paint header
		FrameGraphics.PaintItem(getHeader(Colour.BLACK));
		
		// Paint the mail messages to the screen (preview)
		for (Item message : _previewMessages) {
			if (message != null) {
				if (clip == null || clip.isNotClipped() || message.isInDrawingArea(clip.getBounds())) {
					FrameGraphics.PaintItem(message);
				}
			}
		}
		
		// Paint the status from the MessageBay
		Item status = MessageBay.getStatus();
		if (status != null) {
			FrameGraphics.PaintItem(status);
		}
		
		// Paint the link to the mail frame
		if (clip == null || clip.isNotClipped() || _mailLink.isInDrawingArea(clip.getBounds())) {
			FrameGraphics.PaintItem(_mailLink);
		}
		
		g.popDrawingSurface();
	}
	
	/** Syncs message bay size according to FrameGraphics max size. */
	private static void updateSize() {
		for (Item i : _previewMessages) {
			if (i != null) {
				i.setOffset(0, -DisplayController.getMessageBayPaintArea().getMinY());
			}
		}
		
		_mailLink.setOffset(0, -DisplayController.getMessageBayPaintArea().getMinY());
		updateLink();
	}
	
	private static void updateLink() {
		if (!isLinkInitialized && DisplayController.getFramePaintArea() != null
				&& DisplayController.getFramePaintAreaWidth() > 0) {
			// set up 'Messages' link on the right hand side
			_mailLink.setPosition(DisplayController.getMessageBayPaintArea().getWidth() - MAIL_LINK_Y_OFFSET,
					MAIL_LINK_X);
			_mailLink.setOffset(0, -DisplayController.getMessageBayPaintArea().getMinY());
			isLinkInitialized = true;
		} else {
			_mailLink.setPosition(DisplayController.getMessageBayPaintArea().getWidth() - MAIL_LINK_Y_OFFSET,
					MAIL_LINK_X);
		}
	}

	private static Text getHeader(Colour fontColor) {
		Text t = new Text("You have [" + _messages.size() + "] unprocessed messages waiting.");
		if (_messages.size() >= 2) {
			t.setText(t.getText() + "  Two latest below:");
		}
		t.setPosition(OFFSET_X, HEADER_OFFSET_Y);
		t.setOffset(0, -DisplayController.getFramePaintAreaHeight());
		t.setColor(fontColor);
		t.setFont(_messageFont.clone());
		return t;
	}
	
	private static String getMessagePrefix() {
		_messageCount++;
		return "@" + _messageCount + ": ";
	}
	
	private static class Mail {
		private String message;
		private Map<String, String> options;
		private String message2;

		private Mail(String message, String message2, Map<String, String> options) {
			this.message = message;
			this.message2 = message2;
			this.options = options;
		}
		
		private Text getPreviewMessage(boolean usePrefix) {
			Text t = usePrefix ? new Text(getMessagePrefix() + message)	: new Text(message);
			int y = MESSAGE_OFFSET_Y + _previewMessages.size() * SPACING;
			t.setPosition(OFFSET_X, y);
			t.setColor(Colour.BLACK);
			t.setFont(_messageFont.clone());
			return t;
		}
		
		private Text getDetailLine() {
			if (message2 == null || message2.isEmpty()) { 
				return null;
			}
			Text t = new Text(message2);
			int y = MESSAGE_OFFSET_Y + _previewMessages.size() * SPACING;
			t.setPosition(OFFSET_X, y);
			t.setColor(Colour.BLACK);
			t.setFont(_messageFont.clone());
			return t;
		}
		
		private Text[] getMessage() {
			List<Text> items = new LinkedList<Text>();
			items.add(getPreviewMessage(false));
			Text detail = getDetailLine();
			if (detail != null) {
				items.add(detail);
			}
			
			int i = items.size();
			for (String content: options.keySet()) {
				String[] split = content.split(":::");
				String action = options.get(content);
				Text t = new Text(split[0]);
				for (int o = 1; o < split.length; o++) {
					t.addToData(split[o]);
				}
				int y = MESSAGE_OFFSET_Y + (_previewMessages.size() + i) * SPACING;
				t.setPosition(OFFSET_X, y);
				t.setColor(Colour.BLUE);
				t.setFont(_messageFont.clone());
				t.setAction(action);
				items.add(t);
				i++;
			}
			
			return items.toArray(new Text[] {});
		}
	}
}