// License: GPL. For details, see LICENSE file.
package org.openstreetmap.josm.tools;

import static org.openstreetmap.josm.tools.I18n.tr;

import java.awt.Cursor;
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.GraphicsConfiguration;
import java.awt.GraphicsEnvironment;
import java.awt.Image;
import java.awt.Point;
import java.awt.RenderingHints;
import java.awt.Toolkit;
import java.awt.Transparency;
import java.awt.image.BufferedImage;
import java.io.ByteArrayInputStream;
import java.io.File;
import java.io.IOException;
import java.io.InputStream;
import java.io.StringReader;
import java.io.UnsupportedEncodingException;
import java.net.URI;
import java.net.URL;
import java.net.URLDecoder;
import java.net.URLEncoder;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collection;
import java.util.HashMap;
import java.util.Map;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
import java.util.zip.ZipEntry;
import java.util.zip.ZipFile;

import javax.imageio.ImageIO;
import javax.swing.Icon;
import javax.swing.ImageIcon;

import org.apache.commons.codec.binary.Base64;
import org.openstreetmap.josm.Main;
import org.openstreetmap.josm.data.osm.OsmPrimitiveType;
import org.openstreetmap.josm.io.MirroredInputStream;
import org.openstreetmap.josm.plugins.PluginHandler;
import org.xml.sax.Attributes;
import org.xml.sax.EntityResolver;
import org.xml.sax.InputSource;
import org.xml.sax.SAXException;
import org.xml.sax.XMLReader;
import org.xml.sax.helpers.DefaultHandler;
import org.xml.sax.helpers.XMLReaderFactory;

import com.kitfox.svg.SVGDiagram;
import com.kitfox.svg.SVGException;
import com.kitfox.svg.SVGUniverse;

/**
 * Helper class to support the application with images.
 *
 * How to use:
 *
 * <code>ImageIcon icon = new ImageProvider(name).setMaxWidth(24).setMaxHeight(24).get();</code>
 * (there are more options, see below)
 *
 * short form:
 * <code>ImageIcon icon = ImageProvider.get(name);</code>
 *
 * @author imi
 */
public class ImageProvider {

    /**
     * Position of an overlay icon
     * @author imi
     */
    public static enum OverlayPosition {
        NORTHWEST, NORTHEAST, SOUTHWEST, SOUTHEAST
    }

    /**
     * Supported image types
     */
    public static enum ImageType {
        /** Scalable vector graphics */
        SVG,
        /** Everything else, e.g. png, gif (must be supported by Java) */
        OTHER
    }

    protected Collection<String> dirs;
    protected String id;
    protected String subdir;
    protected String name;
    protected File archive;
    protected String inArchiveDir;
    protected int width = -1;
    protected int height = -1;
    protected int maxWidth = -1;
    protected int maxHeight = -1;
    protected boolean optional;
    protected boolean suppressWarnings;
    protected Collection<ClassLoader> additionalClassLoaders;

    private static SVGUniverse svgUniverse;

    /**
     * The icon cache
     */
    private static final Map<String, ImageResource> cache = new HashMap<>();

    /**
     * Caches the image data for rotated versions of the same image.
     */
    private static final Map<Image, Map<Long, ImageResource>> ROTATE_CACHE = new HashMap<>();

    private static final ExecutorService IMAGE_FETCHER = Executors.newSingleThreadExecutor();

    public interface ImageCallback {
        void finished(ImageIcon result);
    }

    /**
     * Constructs a new {@code ImageProvider} from a filename in a given directory.
     * @param subdir    subdirectory the image lies in
     * @param name      the name of the image. If it does not end with '.png' or '.svg',
     *                  both extensions are tried.
     */
    public ImageProvider(String subdir, String name) {
        this.subdir = subdir;
        this.name = name;
    }

    /**
     * Constructs a new {@code ImageProvider} from a filename.
     * @param name      the name of the image. If it does not end with '.png' or '.svg',
     *                  both extensions are tried.
     */
    public ImageProvider(String name) {
        this.name = name;
    }

    /**
     * Directories to look for the image.
     * @param dirs The directories to look for.
     * @return the current object, for convenience
     */
    public ImageProvider setDirs(Collection<String> dirs) {
        this.dirs = dirs;
        return this;
    }

    /**
     * Set an id used for caching.
     * If name starts with <tt>http://</tt> Id is not used for the cache.
     * (A URL is unique anyway.)
     * @return the current object, for convenience
     */
    public ImageProvider setId(String id) {
        this.id = id;
        return this;
    }

    /**
     * Specify a zip file where the image is located.
     *
     * (optional)
     * @return the current object, for convenience
     */
    public ImageProvider setArchive(File archive) {
        this.archive = archive;
        return this;
    }

    /**
     * Specify a base path inside the zip file.
     *
     * The subdir and name will be relative to this path.
     *
     * (optional)
     * @return the current object, for convenience
     */
    public ImageProvider setInArchiveDir(String inArchiveDir) {
        this.inArchiveDir = inArchiveDir;
        return this;
    }

    /**
     * Set the dimensions of the image.
     *
     * If not specified, the original size of the image is used.
     * The width part of the dimension can be -1. Then it will only set the height but
     * keep the aspect ratio. (And the other way around.)
     * @return the current object, for convenience
     */
    public ImageProvider setSize(Dimension size) {
        this.width = size.width;
        this.height = size.height;
        return this;
    }

    /**
     * @see #setSize
     * @return the current object, for convenience
     */
    public ImageProvider setWidth(int width) {
        this.width = width;
        return this;
    }

    /**
     * @see #setSize
     * @return the current object, for convenience
     */
    public ImageProvider setHeight(int height) {
        this.height = height;
        return this;
    }

    /**
     * Limit the maximum size of the image.
     *
     * It will shrink the image if necessary, but keep the aspect ratio.
     * The given width or height can be -1 which means this direction is not bounded.
     *
     * 'size' and 'maxSize' are not compatible, you should set only one of them.
     * @return the current object, for convenience
     */
    public ImageProvider setMaxSize(Dimension maxSize) {
        this.maxWidth = maxSize.width;
        this.maxHeight = maxSize.height;
        return this;
    }

    /**
     * Convenience method, see {@link #setMaxSize(Dimension)}.
     * @return the current object, for convenience
     */
    public ImageProvider setMaxSize(int maxSize) {
        return this.setMaxSize(new Dimension(maxSize, maxSize));
    }

    /**
     * @see #setMaxSize
     * @return the current object, for convenience
     */
    public ImageProvider setMaxWidth(int maxWidth) {
        this.maxWidth = maxWidth;
        return this;
    }

    /**
     * @see #setMaxSize
     * @return the current object, for convenience
     */
    public ImageProvider setMaxHeight(int maxHeight) {
        this.maxHeight = maxHeight;
        return this;
    }

    /**
     * Decide, if an exception should be thrown, when the image cannot be located.
     *
     * Set to true, when the image URL comes from user data and the image may be missing.
     *
     * @param optional true, if JOSM should <b>not</b> throw a RuntimeException
     * in case the image cannot be located.
     * @return the current object, for convenience
     */
    public ImageProvider setOptional(boolean optional) {
        this.optional = optional;
        return this;
    }

    /**
     * Suppresses warning on the command line in case the image cannot be found.
     *
     * In combination with setOptional(true);
     * @return the current object, for convenience
     */
    public ImageProvider setSuppressWarnings(boolean suppressWarnings) {
        this.suppressWarnings = suppressWarnings;
        return this;
    }

    /**
     * Add a collection of additional class loaders to search image for.
     * @return the current object, for convenience
     */
    public ImageProvider setAdditionalClassLoaders(Collection<ClassLoader> additionalClassLoaders) {
        this.additionalClassLoaders = additionalClassLoaders;
        return this;
    }

    /**
     * Execute the image request.
     * @return the requested image or null if the request failed
     */
    public ImageIcon get() {
        ImageResource ir = getIfAvailableImpl(additionalClassLoaders);
        if (ir == null) {
            if (!optional) {
                String ext = name.indexOf('.') != -1 ? "" : ".???";
                throw new RuntimeException(tr("Fatal: failed to locate image ''{0}''. This is a serious configuration problem. JOSM will stop working.", name + ext));
            } else {
                if (!suppressWarnings) {
                    Main.error(tr("Failed to locate image ''{0}''", name));
                }
                return null;
            }
        }
        if (maxWidth != -1 || maxHeight != -1)
            return ir.getImageIconBounded(new Dimension(maxWidth, maxHeight));
        else
            return ir.getImageIcon(new Dimension(width, height));
    }

    /**
     * Load the image in a background thread.
     *
     * This method returns immediately and runs the image request
     * asynchronously.
     *
     * @param callback a callback. It is called, when the image is ready.
     * This can happen before the call to this method returns or it may be
     * invoked some time (seconds) later. If no image is available, a null
     * value is returned to callback (just like {@link #get}).
     */
    public void getInBackground(final ImageCallback callback) {
        if (name.startsWith("http://") || name.startsWith("wiki://")) {
            Runnable fetch = new Runnable() {
                @Override
                public void run() {
                    ImageIcon result = get();
                    callback.finished(result);
                }
            };
            IMAGE_FETCHER.submit(fetch);
        } else {
            ImageIcon result = get();
            callback.finished(result);
        }
    }

    /**
     * Load an image with a given file name.
     *
     * @param subdir subdirectory the image lies in
     * @param name The icon name (base name with or without '.png' or '.svg' extension)
     * @return The requested Image.
     * @throws RuntimeException if the image cannot be located
     */
    public static ImageIcon get(String subdir, String name) {
        return new ImageProvider(subdir, name).get();
    }

    /**
     * @param name The icon name (base name with or without '.png' or '.svg' extension)
     * @return the requested image or null if the request failed
     * @see #get(String, String)
     */
    public static ImageIcon get(String name) {
        return new ImageProvider(name).get();
    }

    /**
     * Load an image with a given file name, but do not throw an exception
     * when the image cannot be found.
     *
     * @param subdir subdirectory the image lies in
     * @param name The icon name (base name with or without '.png' or '.svg' extension)
     * @return the requested image or null if the request failed
     * @see #get(String, String)
     */
    public static ImageIcon getIfAvailable(String subdir, String name) {
        return new ImageProvider(subdir, name).setOptional(true).get();
    }

    /**
     * @param name The icon name (base name with or without '.png' or '.svg' extension)
     * @return the requested image or null if the request failed
     * @see #getIfAvailable(String, String)
     */
    public static ImageIcon getIfAvailable(String name) {
        return new ImageProvider(name).setOptional(true).get();
    }

    /**
     * {@code data:[<mediatype>][;base64],<data>}
     * @see <a href="http://tools.ietf.org/html/rfc2397">RFC2397</a>
     */
    private static final Pattern dataUrlPattern = Pattern.compile(
            "^data:([a-zA-Z]+/[a-zA-Z+]+)?(;base64)?,(.+)$");

    private ImageResource getIfAvailableImpl(Collection<ClassLoader> additionalClassLoaders) {
        synchronized (cache) {
            // This method is called from different thread and modifying HashMap concurrently can result
            // for example in loops in map entries (ie freeze when such entry is retrieved)
            // Yes, it did happen to me :-)
            if (name == null)
                return null;

            if (name.startsWith("data:")) {
                String url = name;
                ImageResource ir = cache.get(url);
                if (ir != null) return ir;
                ir = getIfAvailableDataUrl(url);
                if (ir != null) {
                    cache.put(url, ir);
                }
                return ir;
            }

            ImageType type = name.toLowerCase().endsWith(".svg") ? ImageType.SVG : ImageType.OTHER;

            if (name.startsWith("http://") || name.startsWith("https://")) {
                String url = name;
                ImageResource ir = cache.get(url);
                if (ir != null) return ir;
                ir = getIfAvailableHttp(url, type);
                if (ir != null) {
                    cache.put(url, ir);
                }
                return ir;
            } else if (name.startsWith("wiki://")) {
                ImageResource ir = cache.get(name);
                if (ir != null) return ir;
                ir = getIfAvailableWiki(name, type);
                if (ir != null) {
                    cache.put(name, ir);
                }
                return ir;
            }

            if (subdir == null) {
                subdir = "";
            } else if (!subdir.isEmpty()) {
                subdir += "/";
            }
            String[] extensions;
            if (name.indexOf('.') != -1) {
                extensions = new String[] { "" };
            } else {
                extensions = new String[] { ".png", ".svg"};
            }
            final int ARCHIVE = 0, LOCAL = 1;
            for (int place : new Integer[] { ARCHIVE, LOCAL }) {
                for (String ext : extensions) {

                    if (".svg".equals(ext)) {
                        type = ImageType.SVG;
                    } else if (".png".equals(ext)) {
                        type = ImageType.OTHER;
                    }

                    String fullName = subdir + name + ext;
                    String cacheName = fullName;
                    /* cache separately */
                    if (dirs != null && !dirs.isEmpty()) {
                        cacheName = "id:" + id + ":" + fullName;
                        if(archive != null) {
                            cacheName += ":" + archive.getName();
                        }
                    }

                    ImageResource ir = cache.get(cacheName);
                    if (ir != null) return ir;

                    switch (place) {
                    case ARCHIVE:
                        if (archive != null) {
                            ir = getIfAvailableZip(fullName, archive, inArchiveDir, type);
                            if (ir != null) {
                                cache.put(cacheName, ir);
                                return ir;
                            }
                        }
                        break;
                    case LOCAL:
                        // getImageUrl() does a ton of "stat()" calls and gets expensive
                        // and redundant when you have a whole ton of objects. So,
                        // index the cache by the name of the icon we're looking for
                        // and don't bother to create a URL unless we're actually
                        // creating the image.
                        URL path = getImageUrl(fullName, dirs, additionalClassLoaders);
                        if (path == null) {
                            continue;
                        }
                        ir = getIfAvailableLocalURL(path, type);
                        if (ir != null) {
                            cache.put(cacheName, ir);
                            return ir;
                        }
                        break;
                    }
                }
            }
            return null;
        }
    }

    private static ImageResource getIfAvailableHttp(String url, ImageType type) {
        MirroredInputStream is = null;
        try {
            is = new MirroredInputStream(url,
                    new File(Main.pref.getCacheDirectory(), "images").getPath());
            switch (type) {
            case SVG:
                URI uri = getSvgUniverse().loadSVG(is, Utils.fileToURL(is.getFile()).toString());
                SVGDiagram svg = getSvgUniverse().getDiagram(uri);
                return svg == null ? null : new ImageResource(svg);
            case OTHER:
                BufferedImage img = null;
                try {
                    img = ImageIO.read(Utils.fileToURL(is.getFile()));
                } catch (IOException e) {
                    Main.warn("IOException while reading HTTP image: "+e.getMessage());
                }
                return img == null ? null : new ImageResource(img);
            default:
                throw new AssertionError();
            }
        } catch (IOException e) {
            return null;
        } finally {
            Utils.close(is);
        }
    }

    private static ImageResource getIfAvailableDataUrl(String url) {
        try {
            Matcher m = dataUrlPattern.matcher(url);
            if (m.matches()) {
                String mediatype = m.group(1);
                String base64 = m.group(2);
                String data = m.group(3);
                byte[] bytes;
                if (";base64".equals(base64)) {
                    bytes = Base64.decodeBase64(data);
                } else {
                    try {
                        bytes = URLDecoder.decode(data, "UTF-8").getBytes(Utils.UTF_8);
                    } catch (IllegalArgumentException ex) {
                        Main.warn("Unable to decode URL data part: "+ex.getMessage() + " (" + data + ")");
                        return null;
                    }
                }
                if (mediatype != null && mediatype.contains("image/svg+xml")) {
                    String s = new String(bytes, Utils.UTF_8);
                    URI uri = getSvgUniverse().loadSVG(new StringReader(s), URLEncoder.encode(s, "UTF-8"));
                    SVGDiagram svg = getSvgUniverse().getDiagram(uri);
                    if (svg == null) {
                        Main.warn("Unable to process svg: "+s);
                        return null;
                    }
                    return new ImageResource(svg);
                } else {
                    try {
                        return new ImageResource(ImageIO.read(new ByteArrayInputStream(bytes)));
                    } catch (IOException e) {
                        Main.warn("IOException while reading image: "+e.getMessage());
                    }
                }
            }
            return null;
        } catch (UnsupportedEncodingException ex) {
            throw new RuntimeException(ex.getMessage(), ex);
        }
    }

    private static ImageResource getIfAvailableWiki(String name, ImageType type) {
        final Collection<String> defaultBaseUrls = Arrays.asList(
                "http://wiki.openstreetmap.org/w/images/",
                "http://upload.wikimedia.org/wikipedia/commons/",
                "http://wiki.openstreetmap.org/wiki/File:"
                );
        final Collection<String> baseUrls = Main.pref.getCollection("image-provider.wiki.urls", defaultBaseUrls);

        final String fn = name.substring(name.lastIndexOf('/') + 1);

        ImageResource result = null;
        for (String b : baseUrls) {
            String url;
            if (b.endsWith(":")) {
                url = getImgUrlFromWikiInfoPage(b, fn);
                if (url == null) {
                    continue;
                }
            } else {
                final String fn_md5 = Utils.md5Hex(fn);
                url = b + fn_md5.substring(0,1) + "/" + fn_md5.substring(0,2) + "/" + fn;
            }
            result = getIfAvailableHttp(url, type);
            if (result != null) {
                break;
            }
        }
        return result;
    }

    private static ImageResource getIfAvailableZip(String fullName, File archive, String inArchiveDir, ImageType type) {
        ZipFile zipFile = null;
        try {
            zipFile = new ZipFile(archive);
            if (inArchiveDir == null || inArchiveDir.equals(".")) {
                inArchiveDir = "";
            } else if (!inArchiveDir.isEmpty()) {
                inArchiveDir += "/";
            }
            String entryName = inArchiveDir + fullName;
            ZipEntry entry = zipFile.getEntry(entryName);
            if(entry != null)
            {
                int size = (int)entry.getSize();
                int offs = 0;
                byte[] buf = new byte[size];
                InputStream is = null;
                try {
                    is = zipFile.getInputStream(entry);
                    switch (type) {
                    case SVG:
                        URI uri = getSvgUniverse().loadSVG(is, entryName);
                        SVGDiagram svg = getSvgUniverse().getDiagram(uri);
                        return svg == null ? null : new ImageResource(svg);
                    case OTHER:
                        while(size > 0)
                        {
                            int l = is.read(buf, offs, size);
                            offs += l;
                            size -= l;
                        }
                        BufferedImage img = null;
                        try {
                            img = ImageIO.read(new ByteArrayInputStream(buf));
                        } catch (IOException e) {
                            Main.warn(e);
                        }
                        return img == null ? null : new ImageResource(img);
                    default:
                        throw new AssertionError();
                    }
                } finally {
                    Utils.close(is);
                }
            }
        } catch (Exception e) {
            Main.warn(tr("Failed to handle zip file ''{0}''. Exception was: {1}", archive.getName(), e.toString()));
        } finally {
            Utils.close(zipFile);
        }
        return null;
    }

    private static ImageResource getIfAvailableLocalURL(URL path, ImageType type) {
        switch (type) {
        case SVG:
            URI uri = getSvgUniverse().loadSVG(path);
            SVGDiagram svg = getSvgUniverse().getDiagram(uri);
            return svg == null ? null : new ImageResource(svg);
        case OTHER:
            BufferedImage img = null;
            try {
                img = ImageIO.read(path);
            } catch (IOException e) {
                Main.warn(e);
            }
            return img == null ? null : new ImageResource(img);
        default:
            throw new AssertionError();
        }
    }

    private static URL getImageUrl(String path, String name, Collection<ClassLoader> additionalClassLoaders) {
        if (path != null && path.startsWith("resource://")) {
            String p = path.substring("resource://".length());
            Collection<ClassLoader> classLoaders = new ArrayList<>(PluginHandler.getResourceClassLoaders());
            if (additionalClassLoaders != null) {
                classLoaders.addAll(additionalClassLoaders);
            }
            for (ClassLoader source : classLoaders) {
                URL res;
                if ((res = source.getResource(p + name)) != null)
                    return res;
            }
        } else {
            File f = new File(path, name);
            if ((path != null || f.isAbsolute()) && f.exists())
                return Utils.fileToURL(f);
        }
        return null;
    }

    private static URL getImageUrl(String imageName, Collection<String> dirs, Collection<ClassLoader> additionalClassLoaders) {
        URL u = null;

        // Try passed directories first
        if (dirs != null) {
            for (String name : dirs) {
                try {
                    u = getImageUrl(name, imageName, additionalClassLoaders);
                    if (u != null)
                        return u;
                } catch (SecurityException e) {
                    Main.warn(tr(
                            "Failed to access directory ''{0}'' for security reasons. Exception was: {1}",
                            name, e.toString()));
                }

            }
        }
        // Try user-preference directory
        String dir = Main.pref.getPreferencesDir() + "images";
        try {
            u = getImageUrl(dir, imageName, additionalClassLoaders);
            if (u != null)
                return u;
        } catch (SecurityException e) {
            Main.warn(tr(
                    "Failed to access directory ''{0}'' for security reasons. Exception was: {1}", dir, e
                    .toString()));
        }

        // Absolute path?
        u = getImageUrl(null, imageName, additionalClassLoaders);
        if (u != null)
            return u;

        // Try plugins and josm classloader
        u = getImageUrl("resource://images/", imageName, additionalClassLoaders);
        if (u != null)
            return u;

        // Try all other resource directories
        for (String location : Main.pref.getAllPossiblePreferenceDirs()) {
            u = getImageUrl(location + "images", imageName, additionalClassLoaders);
            if (u != null)
                return u;
            u = getImageUrl(location, imageName, additionalClassLoaders);
            if (u != null)
                return u;
        }

        return null;
    }

    /**
     * Reads the wiki page on a certain file in html format in order to find the real image URL.
     */
    private static String getImgUrlFromWikiInfoPage(final String base, final String fn) {

        /** Quit parsing, when a certain condition is met */
        class SAXReturnException extends SAXException {
            private final String result;

            public SAXReturnException(String result) {
                this.result = result;
            }

            public String getResult() {
                return result;
            }
        }

        try {
            final XMLReader parser = XMLReaderFactory.createXMLReader();
            parser.setContentHandler(new DefaultHandler() {
                @Override
                public void startElement(String uri, String localName, String qName, Attributes atts) throws SAXException {
                    if (localName.equalsIgnoreCase("img")) {
                        String val = atts.getValue("src");
                        if (val.endsWith(fn))
                            throw new SAXReturnException(val);  // parsing done, quit early
                    }
                }
            });

            parser.setEntityResolver(new EntityResolver() {
                @Override
                public InputSource resolveEntity (String publicId, String systemId) {
                    return new InputSource(new ByteArrayInputStream(new byte[0]));
                }
            });

            parser.parse(new InputSource(new MirroredInputStream(
                    base + fn,
                    new File(Main.pref.getPreferencesDir(), "images").toString()
                    )));
        } catch (SAXReturnException r) {
            return r.getResult();
        } catch (Exception e) {
            Main.warn("Parsing " + base + fn + " failed:\n" + e);
            return null;
        }
        Main.warn("Parsing " + base + fn + " failed: Unexpected content.");
        return null;
    }

    public static Cursor getCursor(String name, String overlay) {
        ImageIcon img = get("cursor", name);
        if (overlay != null) {
            img = overlay(img, ImageProvider.get("cursor/modifier/" + overlay), OverlayPosition.SOUTHEAST);
        }
        Cursor c = Toolkit.getDefaultToolkit().createCustomCursor(img.getImage(),
                name.equals("crosshair") ? new Point(10, 10) : new Point(3, 2), "Cursor");
        return c;
    }

    /**
     * Decorate one icon with an overlay icon.
     *
     * @param ground the base image
     * @param overlay the overlay image (can be smaller than the base image)
     * @param pos position of the overlay image inside the base image (positioned
     * in one of the corners)
     * @return an icon that represent the overlay of the two given icons. The second icon is layed
     * on the first relative to the given position.
     */
    public static ImageIcon overlay(Icon ground, Icon overlay, OverlayPosition pos) {
        GraphicsConfiguration conf = GraphicsEnvironment.getLocalGraphicsEnvironment().getDefaultScreenDevice()
                .getDefaultConfiguration();
        int w = ground.getIconWidth();
        int h = ground.getIconHeight();
        int wo = overlay.getIconWidth();
        int ho = overlay.getIconHeight();
        BufferedImage img = conf.createCompatibleImage(w, h, Transparency.TRANSLUCENT);
        Graphics g = img.createGraphics();
        ground.paintIcon(null, g, 0, 0);
        int x = 0, y = 0;
        switch (pos) {
        case NORTHWEST:
            x = 0;
            y = 0;
            break;
        case NORTHEAST:
            x = w - wo;
            y = 0;
            break;
        case SOUTHWEST:
            x = 0;
            y = h - ho;
            break;
        case SOUTHEAST:
            x = w - wo;
            y = h - ho;
            break;
        }
        overlay.paintIcon(null, g, x, y);
        return new ImageIcon(img);
    }

    /** 90 degrees in radians units */
    static final double DEGREE_90 = 90.0 * Math.PI / 180.0;

    /**
     * Creates a rotated version of the input image.
     *
     * @param img the image to be rotated.
     * @param rotatedAngle the rotated angle, in degree, clockwise. It could be any double but we
     * will mod it with 360 before using it. More over for caching performance, it will be rounded to
     * an entire value between 0 and 360.
     *
     * @return the image after rotating.
     * @since 6172
     */
    public static Image createRotatedImage(Image img, double rotatedAngle) {
        return createRotatedImage(img, rotatedAngle, ImageResource.DEFAULT_DIMENSION);
    }

    /**
     * Creates a rotated version of the input image, scaled to the given dimension.
     *
     * @param img the image to be rotated.
     * @param rotatedAngle the rotated angle, in degree, clockwise. It could be any double but we
     * will mod it with 360 before using it. More over for caching performance, it will be rounded to
     * an entire value between 0 and 360.
     * @param dimension The requested dimensions. Use (-1,-1) for the original size
     * and (width, -1) to set the width, but otherwise scale the image proportionally.
     * @return the image after rotating and scaling.
     * @since 6172
     */
    public static Image createRotatedImage(Image img, double rotatedAngle, Dimension dimension) {
        CheckParameterUtil.ensureParameterNotNull(img, "img");

        // convert rotatedAngle to an integer value from 0 to 360
        Long originalAngle = Math.round(rotatedAngle % 360);
        if (rotatedAngle != 0 && originalAngle == 0) {
            originalAngle = 360L;
        }

        ImageResource imageResource = null;

        synchronized (ROTATE_CACHE) {
            Map<Long, ImageResource> cacheByAngle = ROTATE_CACHE.get(img);
            if (cacheByAngle == null) {
                ROTATE_CACHE.put(img, cacheByAngle = new HashMap<>());
            }

            imageResource = cacheByAngle.get(originalAngle);

            if (imageResource == null) {
                // convert originalAngle to a value from 0 to 90
                double angle = originalAngle % 90;
                if (originalAngle != 0.0 && angle == 0.0) {
                    angle = 90.0;
                }

                double radian = Math.toRadians(angle);

                new ImageIcon(img); // load completely
                int iw = img.getWidth(null);
                int ih = img.getHeight(null);
                int w;
                int h;

                if ((originalAngle >= 0 && originalAngle <= 90) || (originalAngle > 180 && originalAngle <= 270)) {
                    w = (int) (iw * Math.sin(DEGREE_90 - radian) + ih * Math.sin(radian));
                    h = (int) (iw * Math.sin(radian) + ih * Math.sin(DEGREE_90 - radian));
                } else {
                    w = (int) (ih * Math.sin(DEGREE_90 - radian) + iw * Math.sin(radian));
                    h = (int) (ih * Math.sin(radian) + iw * Math.sin(DEGREE_90 - radian));
                }
                Image image = new BufferedImage(w, h, BufferedImage.TYPE_INT_ARGB);
                cacheByAngle.put(originalAngle, imageResource = new ImageResource(image));
                Graphics g = image.getGraphics();
                Graphics2D g2d = (Graphics2D) g.create();

                // calculate the center of the icon.
                int cx = iw / 2;
                int cy = ih / 2;

                // move the graphics center point to the center of the icon.
                g2d.translate(w / 2, h / 2);

                // rotate the graphics about the center point of the icon
                g2d.rotate(Math.toRadians(originalAngle));

                g2d.setRenderingHint(RenderingHints.KEY_INTERPOLATION, RenderingHints.VALUE_INTERPOLATION_BICUBIC);
                g2d.drawImage(img, -cx, -cy, null);

                g2d.dispose();
                new ImageIcon(image); // load completely
            }
            return imageResource.getImageIcon(dimension).getImage();
        }
    }

    /**
     * Creates a scaled down version of the input image to fit maximum dimensions. (Keeps aspect ratio)
     *
     * @param img the image to be scaled down.
     * @param maxSize the maximum size in pixels (both for width and height)
     *
     * @return the image after scaling.
     * @since 6172
     */
    public static Image createBoundedImage(Image img, int maxSize) {
        return new ImageResource(img).getImageIconBounded(new Dimension(maxSize, maxSize)).getImage();
    }

    /**
     * Replies the icon for an OSM primitive type
     * @param type the type
     * @return the icon
     */
    public static ImageIcon get(OsmPrimitiveType type) {
        CheckParameterUtil.ensureParameterNotNull(type, "type");
        return get("data", type.getAPIName());
    }

    public static BufferedImage createImageFromSvg(SVGDiagram svg, Dimension dim) {
        float realWidth = svg.getWidth();
        float realHeight = svg.getHeight();
        int width = Math.round(realWidth);
        int height = Math.round(realHeight);
        Double scaleX = null, scaleY = null;
        if (dim.width != -1) {
            width = dim.width;
            scaleX = (double) width / realWidth;
            if (dim.height == -1) {
                scaleY = scaleX;
                height = (int) Math.round(realHeight * scaleY);
            } else {
                height = dim.height;
                scaleY = (double) height / realHeight;
            }
        } else if (dim.height != -1) {
            height = dim.height;
            scaleX = scaleY = (double) height / realHeight;
            width = (int) Math.round(realWidth * scaleX);
        }
        if (width == 0 || height == 0) {
            return null;
        }
        BufferedImage img = new BufferedImage(width, height, BufferedImage.TYPE_INT_ARGB);
        Graphics2D g = img.createGraphics();
        g.setClip(0, 0, width, height);
        if (scaleX != null && scaleY != null) {
            g.scale(scaleX, scaleY);
        }
        g.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
        try {
            svg.render(g);
        } catch (SVGException ex) {
            return null;
        }
        return img;
    }

    private static SVGUniverse getSvgUniverse() {
        if (svgUniverse == null) {
            svgUniverse = new SVGUniverse();
        }
        return svgUniverse;
    }
}
