// Copyright 2015 The Vanadium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

package io.v.syncslidepresenter;

import com.beust.jcommander.JCommander;
import com.beust.jcommander.Parameter;
import com.beust.jcommander.ParameterException;
import com.google.common.base.Preconditions;
import com.google.common.collect.ImmutableList;
import com.google.common.collect.ImmutableMap;

import org.joda.time.Duration;

import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import java.awt.Image;
import java.awt.Window;
import java.awt.event.ComponentAdapter;
import java.awt.event.ComponentEvent;
import java.awt.image.BufferedImage;
import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.lang.reflect.Method;
import java.util.UUID;
import java.util.logging.Level;
import java.util.logging.Logger;

import javax.imageio.ImageIO;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.WindowConstants;

import io.v.android.apps.syncslides.db.VCurrentSlide;
import io.v.android.apps.syncslides.db.VSlide;
import io.v.impl.google.naming.NamingUtil;
import io.v.impl.google.services.syncbase.SyncbaseServer;
import io.v.v23.V;
import io.v.v23.context.VContext;
import io.v.v23.naming.Endpoint;
import io.v.v23.rpc.Server;
import io.v.v23.security.BlessingPattern;
import io.v.v23.security.access.AccessList;
import io.v.v23.security.access.Permissions;
import io.v.v23.services.syncbase.nosql.KeyValue;
import io.v.v23.services.syncbase.nosql.SyncgroupMemberInfo;
import io.v.v23.services.watch.ResumeMarker;
import io.v.v23.syncbase.Syncbase;
import io.v.v23.syncbase.SyncbaseApp;
import io.v.v23.syncbase.SyncbaseService;
import io.v.v23.syncbase.nosql.BatchDatabase;
import io.v.v23.syncbase.nosql.Database;
import io.v.v23.syncbase.nosql.RowRange;
import io.v.v23.syncbase.nosql.Stream;
import io.v.v23.syncbase.nosql.Syncgroup;
import io.v.v23.syncbase.nosql.Table;
import io.v.v23.syncbase.nosql.WatchChange;
import io.v.v23.verror.VException;
import io.v.v23.vom.VomUtil;

/**
 * The entry point for syncslidepresenter.
 */
public class Main {
    private static final Logger logger = Logger.getLogger(Main.class.getName());
    private static final String SYNCBASE_APP = "syncslides";
    private static final String SYNCBASE_DB = "syncslides";
    private static final String PRESENTATIONS_TABLE = "Presentations";
    private static final String DECKS_TABLE = "Decks";
    private final Table presentations;
    private final Table decks;
    private final ImageViewer viewer;

    private Database db;

    private VContext context;

    public static void main(String[] args) throws SyncbaseServer.StartException, VException, IOException {
        Options options = new Options();
        JCommander commander = new JCommander(options);
        try {
            commander.parse(args);
        } catch (ParameterException e) {
            logger.warning("Could not parse parameters: " + e.getMessage());
            commander.usage();
            return;
        }

        if (options.help) {
            commander.usage();
            return;
        }

        // Make command-Q do the same as closing the main frame (i.e. exit).
        System.setProperty("apple.eawt.quitStrategy", "CLOSE_ALL_WINDOWS");

        JFrame frame = new JFrame();
        enableOSXFullscreen(frame);
        frame.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
        frame.setVisible(true);

        VContext baseContext = V.init();

        AccessList acl = new AccessList(ImmutableList.of(new BlessingPattern("...")),
                ImmutableList.<String>of());
        Permissions permissions = new Permissions(ImmutableMap.of("1", acl));
        String name = NamingUtil.join(options.mountPrefix, UUID.randomUUID().toString());
        logger.info("Mounting new syncbase server at " + name);
        baseContext = SyncbaseServer.withNewServer(
                baseContext.withTimeout(Duration.standardSeconds(options.mountTimeoutSeconds)),
                new SyncbaseServer.Params().withPermissions(permissions).withName(name));
        final Server server = V.getServer(baseContext);
        if (server.getStatus().getEndpoints().length > 0) {
            logger.info("Mounted syncbase server at the following endpoints: ");
            for (Endpoint e : server.getStatus().getEndpoints()) {
                logger.info("\t" + e);
            }
            logger.info("End of endpoint list");

            SyncbaseService service
                    = Syncbase.newService("/" + server.getStatus().getEndpoints()[0]);
            SyncbaseApp app = service.getApp(SYNCBASE_APP);
            if (!app.exists(baseContext)) {
                app.create(baseContext, permissions);
            }
            Database db = app.getNoSqlDatabase(SYNCBASE_DB, null);
            if (!db.exists(baseContext)) {
                db.create(baseContext, permissions);
            }
            Table decks = db.getTable(DECKS_TABLE);
            if (!decks.exists(baseContext)) {
                decks.create(baseContext, permissions);
            }
            Table presentations = db.getTable(PRESENTATIONS_TABLE);
            if (!presentations.exists(baseContext)) {
                presentations.create(baseContext, permissions);
            }

            JPanel panel = new JPanel(new GridBagLayout());
            ScaleToFitJPanel presentationPanel = new ScaleToFitJPanel();
            GridBagConstraints constraints = new GridBagConstraints();
            constraints.weightx = 1;
            constraints.weighty = 1;
            constraints.fill = GridBagConstraints.BOTH;
            panel.add(presentationPanel, constraints);
            frame.getContentPane().add(panel);
            frame.pack();

            Main m = new Main(baseContext, presentationPanel, db, decks, presentations);
            m.joinPresentation(options.presentationName, options.joinTimeoutSeconds,
                    options.currentSlideKey, options.slideRowFormat);
        }
    }

    public Main(VContext context, ImageViewer viewer, Database db, Table decks,
                Table presentations) throws VException {
        this.context = context;
        this.db = db;
        this.presentations = presentations;
        this.decks = decks;
        this.viewer = viewer;
    }

    public void joinPresentation(final String syncgroupName,
                                 int joinTimeoutSeconds,
                                 String currentSlideKey,
                                 String slideRowFormat) throws VException {
        Syncgroup syncgroup = db.getSyncgroup(syncgroupName);
        syncgroup.join(context.withTimeout(Duration.standardSeconds(joinTimeoutSeconds)),
                new SyncgroupMemberInfo((byte) 1));
        for (String member : syncgroup.getMembers(context).keySet()) {
            logger.info("Member: " + member);
        }

        for (KeyValue keyValue : presentations.scan(context, RowRange.prefix(""))) {
            System.out.println("Presentation: " + keyValue);
        }
        BatchDatabase batch = db.beginBatch(context, null);
        ResumeMarker marker = batch.getResumeMarker(context);
        Stream<WatchChange> watchStream = db.watch(context, presentations.name(), currentSlideKey,
                marker);

        for (WatchChange w : watchStream) {
            logger.info("Change detected in " + w.getRowName());
            logger.info("Type: " + w.getChangeType());
            try {
                VCurrentSlide currentSlide = (VCurrentSlide) VomUtil.decode(w.getVomValue(),
                        VCurrentSlide.class);
                logger.info("Current slide: " + currentSlide);
                // Read the corresponding slide.
                VSlide slide = (VSlide) decks.getRow(String.format(slideRowFormat,
                        currentSlide.getNum())).get(context, VSlide.class);
                final BufferedImage image = ImageIO.read(
                        new ByteArrayInputStream(slide.getThumbnail()));
                viewer.setImage(image);
            } catch (IOException | VException e) {
                logger.log(Level.WARNING, "exception encountered while handling change event", e);
            }
        }
    }

    private static void enableOSXFullscreen(Window window) {
        Preconditions.checkNotNull(window);
        try {
            // This class may not be present on the system (e.g. if we're not on MacOSX),
            // use reflection so that we can make this an optional dependency.
            Class util = Class.forName("com.apple.eawt.FullScreenUtilities");
            Class params[] = new Class[]{Window.class, Boolean.TYPE};

            @SuppressWarnings({"unchecked", "rawtypes"})
            Method method = util.getMethod("setWindowCanFullScreen", params);
            method.invoke(util, window, true);
        } catch (ClassNotFoundException e) {
            // Probably not on Mac OS X
        } catch (Exception e) {
            logger.log(Level.WARNING, "Couldn't enable fullscreen on Mac OS X", e);
        }
    }

    public static class Options {
        @Parameter(names = {"-m", "--mountPrefix"}, description = "the base path in the namespace"
                + " where the syncbase service will be mounted")
        private String mountPrefix = "/192.168.86.254:8101";

        @Parameter(names = {"-p", "--presentationName"},
                description = "the presentation to watch")
        private String presentationName = "/192.168.86.254:8101/990005300000537/%%sync/"
                + "syncslides/deckId1/randomPresentationId1";

        @Parameter(names = {"--mountTimeout"},
                description = "the number of seconds to wait for the syncbase server to be created")
        private int mountTimeoutSeconds = 10;

        @Parameter(names = {"--joinTimeout"},
                description = "the number of seconds to wait to join the presentation")
        private int joinTimeoutSeconds = 10;

        @Parameter(names = {"-k", "--currentSlideKey"},
                description = "the row key containing the current slide")
        private String currentSlideKey = "deckId1/randomPresentationId1/CurrentSlide";

        @Parameter(names = {"-f", "--slideRowFormat"},
                description = "a pattern specifying where slide rows are found")
        private String slideRowFormat = "deckId1/slides/%04d";

        @Parameter(names = {"-h", "--help"}, description = "display this help message", help = true)
        private boolean help = false;
    }

    private static class ScaleToFitJPanel extends JPanel implements ImageViewer {
        private Image image;

        public ScaleToFitJPanel() {
            super();
            setPreferredSize(new Dimension(250, 250));
            addComponentListener(new ComponentAdapter() {
                @Override
                public void componentResized(ComponentEvent e) {
                    repaint();
                }
            });
        }

        @Override
        protected void paintComponent(Graphics g) {
            super.paintComponent(g);

            if (image != null) {
                int width;
                int height;
                double containerRatio = 1.0d * getWidth() / getHeight();
                double imageRatio = 1.0d * image.getWidth(null) / image.getHeight(null);

                if (containerRatio < imageRatio) {
                    width = getWidth();
                    height = (int) (getWidth() / imageRatio);
                } else {
                    width = (int) (getHeight() * imageRatio);
                    height = getHeight();
                }

                // Center the image in the container.
                int x = (int) (((double) getWidth() / 2) - ((double) width / 2));
                int y = (int) (((double) getHeight()/ 2) - ((double) height / 2));

                g.drawImage(image, x, y, width, height, this);
            }
        }

        @Override
        public void setImage(Image image) {
            this.image = image;
            setPreferredSize(new Dimension(image.getWidth(null), image.getHeight(null)));
            repaint();
        }
    }

    private interface ImageViewer {
        void setImage(Image image);
    }
}