001// License: GPL. For details, see Readme.txt file.
002package org.openstreetmap.gui.jmapviewer.tilesources;
003
004import java.awt.Image;
005import java.io.IOException;
006import java.net.MalformedURLException;
007import java.net.URL;
008import java.util.ArrayList;
009import java.util.List;
010import java.util.Locale;
011import java.util.concurrent.Callable;
012import java.util.concurrent.ExecutionException;
013import java.util.concurrent.Future;
014import java.util.concurrent.FutureTask;
015import java.util.concurrent.TimeUnit;
016import java.util.concurrent.TimeoutException;
017import java.util.regex.Pattern;
018
019import javax.xml.parsers.DocumentBuilder;
020import javax.xml.parsers.DocumentBuilderFactory;
021import javax.xml.parsers.ParserConfigurationException;
022import javax.xml.xpath.XPath;
023import javax.xml.xpath.XPathConstants;
024import javax.xml.xpath.XPathExpression;
025import javax.xml.xpath.XPathExpressionException;
026import javax.xml.xpath.XPathFactory;
027
028import org.openstreetmap.gui.jmapviewer.Coordinate;
029import org.openstreetmap.gui.jmapviewer.FeatureAdapter;
030import org.openstreetmap.gui.jmapviewer.JMapViewer;
031import org.openstreetmap.gui.jmapviewer.interfaces.ICoordinate;
032import org.w3c.dom.Document;
033import org.w3c.dom.Node;
034import org.w3c.dom.NodeList;
035import org.xml.sax.InputSource;
036import org.xml.sax.SAXException;
037
038/**
039 * Tile source for the Bing Maps REST Imagery API.
040 * @see <a href="https://msdn.microsoft.com/en-us/library/bb259689.aspx">MSDN (1)</a>
041 *  and <a href="https://msdn.microsoft.com/en-us/library/ff701724.aspx">MSDN (2)</a>
042 */
043public class BingAerialTileSource extends TMSTileSource {
044
045    private static final String API_KEY = "Arzdiw4nlOJzRwOz__qailc8NiR31Tt51dN2D7cm57NrnceZnCpgOkmJhNpGoppU";
046    private static volatile Future<List<Attribution>> attributions; // volatile is required for getAttribution(), see below.
047    private static String imageUrlTemplate;
048    private static Integer imageryZoomMax;
049    private static String[] subdomains;
050
051    private static final Pattern subdomainPattern = Pattern.compile("\\{subdomain\\}");
052    private static final Pattern quadkeyPattern = Pattern.compile("\\{quadkey\\}");
053    private static final Pattern culturePattern = Pattern.compile("\\{culture\\}");
054    private String brandLogoUri;
055
056    /**
057     * Constructs a new {@code BingAerialTileSource}.
058     */
059    public BingAerialTileSource() {
060        super(new TileSourceInfo("Bing", null, null));
061        minZoom = 1;
062    }
063
064    /**
065     * Constructs a new {@code BingAerialTileSource}.
066     * @param info imagery info
067     */
068    public BingAerialTileSource(TileSourceInfo info) {
069        super(info);
070    }
071
072    protected static class Attribution {
073        private String attributionText;
074        private int minZoom;
075        private int maxZoom;
076        private Coordinate min;
077        private Coordinate max;
078    }
079
080    @Override
081    public String getTileUrl(int zoom, int tilex, int tiley) throws IOException {
082        // make sure that attribution is loaded. otherwise subdomains is null.
083        if (getAttribution() == null)
084            throw new IOException("Attribution is not loaded yet");
085
086        int t = (zoom + tilex + tiley) % subdomains.length;
087        String subdomain = subdomains[t];
088
089        String url = imageUrlTemplate;
090        url = subdomainPattern.matcher(url).replaceAll(subdomain);
091        url = quadkeyPattern.matcher(url).replaceAll(computeQuadTree(zoom, tilex, tiley));
092
093        return url;
094    }
095
096    protected URL getAttributionUrl() throws MalformedURLException {
097        return new URL("https://dev.virtualearth.net/REST/v1/Imagery/Metadata/Aerial?include=ImageryProviders&output=xml&key="
098                + API_KEY);
099    }
100
101    protected List<Attribution> parseAttributionText(InputSource xml) throws IOException {
102        try {
103            DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
104            DocumentBuilder builder = factory.newDocumentBuilder();
105            Document document = builder.parse(xml);
106
107            XPathFactory xPathFactory = XPathFactory.newInstance();
108            XPath xpath = xPathFactory.newXPath();
109            imageUrlTemplate = xpath.compile("//ImageryMetadata/ImageUrl/text()").evaluate(document).replace(
110                    "http://ecn.{subdomain}.tiles.virtualearth.net/",
111                    "https://ecn.{subdomain}.tiles.virtualearth.net/");
112            imageUrlTemplate = culturePattern.matcher(imageUrlTemplate).replaceAll(Locale.getDefault().toString());
113            imageryZoomMax = Integer.valueOf(xpath.compile("//ImageryMetadata/ZoomMax/text()").evaluate(document));
114
115            NodeList subdomainTxt = (NodeList) xpath.compile("//ImageryMetadata/ImageUrlSubdomains/string/text()")
116                    .evaluate(document, XPathConstants.NODESET);
117            subdomains = new String[subdomainTxt.getLength()];
118            for (int i = 0; i < subdomainTxt.getLength(); i++) {
119                subdomains[i] = subdomainTxt.item(i).getNodeValue();
120            }
121
122            brandLogoUri = xpath.compile("/Response/BrandLogoUri/text()").evaluate(document);
123
124            XPathExpression attributionXpath = xpath.compile("Attribution/text()");
125            XPathExpression coverageAreaXpath = xpath.compile("CoverageArea");
126            XPathExpression zoomMinXpath = xpath.compile("ZoomMin/text()");
127            XPathExpression zoomMaxXpath = xpath.compile("ZoomMax/text()");
128            XPathExpression southLatXpath = xpath.compile("BoundingBox/SouthLatitude/text()");
129            XPathExpression westLonXpath = xpath.compile("BoundingBox/WestLongitude/text()");
130            XPathExpression northLatXpath = xpath.compile("BoundingBox/NorthLatitude/text()");
131            XPathExpression eastLonXpath = xpath.compile("BoundingBox/EastLongitude/text()");
132
133            NodeList imageryProviderNodes = (NodeList) xpath.compile("//ImageryMetadata/ImageryProvider")
134                    .evaluate(document, XPathConstants.NODESET);
135            List<Attribution> attributionsList = new ArrayList<>(imageryProviderNodes.getLength());
136            for (int i = 0; i < imageryProviderNodes.getLength(); i++) {
137                Node providerNode = imageryProviderNodes.item(i);
138
139                String attribution = attributionXpath.evaluate(providerNode);
140
141                NodeList coverageAreaNodes = (NodeList) coverageAreaXpath.evaluate(providerNode, XPathConstants.NODESET);
142                for (int j = 0; j < coverageAreaNodes.getLength(); j++) {
143                    Node areaNode = coverageAreaNodes.item(j);
144                    Attribution attr = new Attribution();
145                    attr.attributionText = attribution;
146
147                    attr.maxZoom = Integer.parseInt(zoomMaxXpath.evaluate(areaNode));
148                    attr.minZoom = Integer.parseInt(zoomMinXpath.evaluate(areaNode));
149
150                    Double southLat = Double.valueOf(southLatXpath.evaluate(areaNode));
151                    Double northLat = Double.valueOf(northLatXpath.evaluate(areaNode));
152                    Double westLon = Double.valueOf(westLonXpath.evaluate(areaNode));
153                    Double eastLon = Double.valueOf(eastLonXpath.evaluate(areaNode));
154                    attr.min = new Coordinate(southLat, westLon);
155                    attr.max = new Coordinate(northLat, eastLon);
156
157                    attributionsList.add(attr);
158                }
159            }
160
161            return attributionsList;
162        } catch (SAXException e) {
163            System.err.println("Could not parse Bing aerials attribution metadata.");
164            e.printStackTrace();
165        } catch (ParserConfigurationException | XPathExpressionException | NumberFormatException e) {
166            e.printStackTrace();
167        }
168        return null;
169    }
170
171    @Override
172    public int getMaxZoom() {
173        if (imageryZoomMax != null)
174            return imageryZoomMax;
175        else
176            return 22;
177    }
178
179    @Override
180    public boolean requiresAttribution() {
181        return true;
182    }
183
184    @Override
185    public String getAttributionLinkURL() {
186        // Terms of Use URL to comply with Bing Terms of Use
187        // (the requirement is that we have such a link at the bottom of the window)
188        return "https://www.microsoft.com/maps/assets/docs/terms.aspx";
189    }
190
191    @Override
192    public Image getAttributionImage() {
193        try {
194            final URL imageResource = JMapViewer.class.getResource("images/bing_maps.png");
195            if (imageResource != null) {
196                return FeatureAdapter.readImage(imageResource);
197            } else {
198                // Some Linux distributions (like Debian) will remove Bing logo from sources, so get it at runtime
199                for (int i = 0; i < 5 && getAttribution() == null; i++) {
200                    // Makes sure attribution is loaded
201                    if (JMapViewer.debug) {
202                        System.out.println("Bing attribution attempt " + (i+1));
203                    }
204                }
205                if (brandLogoUri != null && !brandLogoUri.isEmpty()) {
206                    System.out.println("Reading Bing logo from "+brandLogoUri);
207                    return FeatureAdapter.readImage(new URL(brandLogoUri));
208                }
209            }
210        } catch (IOException e) {
211            System.err.println("Error while retrieving Bing logo: "+e.getMessage());
212        }
213        return null;
214    }
215
216    @Override
217    public String getAttributionImageURL() {
218        return "https://opengeodata.org/microsoft-imagery-details";
219    }
220
221    @Override
222    public String getTermsOfUseText() {
223        return null;
224    }
225
226    @Override
227    public String getTermsOfUseURL() {
228        return "https://opengeodata.org/microsoft-imagery-details";
229    }
230
231    protected Callable<List<Attribution>> getAttributionLoaderCallable() {
232        return new Callable<List<Attribution>>() {
233
234            @Override
235            public List<Attribution> call() throws Exception {
236                int waitTimeSec = 1;
237                while (true) {
238                    try {
239                        InputSource xml = new InputSource(getAttributionUrl().openStream());
240                        List<Attribution> r = parseAttributionText(xml);
241                        System.out.println("Successfully loaded Bing attribution data.");
242                        return r;
243                    } catch (IOException ex) {
244                        System.err.println("Could not connect to Bing API. Will retry in " + waitTimeSec + " seconds.");
245                        Thread.sleep(TimeUnit.SECONDS.toMillis(waitTimeSec));
246                        waitTimeSec *= 2;
247                    }
248                }
249            }
250        };
251    }
252
253    protected List<Attribution> getAttribution() {
254        if (attributions == null) {
255            // see http://www.cs.umd.edu/~pugh/java/memoryModel/DoubleCheckedLocking.html
256            synchronized (BingAerialTileSource.class) {
257                if (attributions == null) {
258                  final FutureTask<List<Attribution>> loader = new FutureTask<>(getAttributionLoaderCallable());
259                  new Thread(loader, "bing-attribution-loader").start();
260                  attributions = loader;
261                }
262            }
263        }
264        try {
265            return attributions.get(0, TimeUnit.MILLISECONDS);
266        } catch (TimeoutException ex) {
267            System.err.println("Bing: attribution data is not yet loaded.");
268        } catch (ExecutionException ex) {
269            throw new RuntimeException(ex.getCause());
270        } catch (InterruptedException ign) {
271            System.err.println("InterruptedException: " + ign.getMessage());
272        }
273        return null;
274    }
275
276    @Override
277    public String getAttributionText(int zoom, ICoordinate topLeft, ICoordinate botRight) {
278        try {
279            final List<Attribution> data = getAttribution();
280            if (data == null)
281                return "Error loading Bing attribution data";
282            StringBuilder a = new StringBuilder();
283            for (Attribution attr : data) {
284                if (zoom <= attr.maxZoom && zoom >= attr.minZoom) {
285                    if (topLeft.getLon() < attr.max.getLon() && botRight.getLon() > attr.min.getLon()
286                            && topLeft.getLat() > attr.min.getLat() && botRight.getLat() < attr.max.getLat()) {
287                        a.append(attr.attributionText);
288                        a.append(' ');
289                    }
290                }
291            }
292            return a.toString();
293        } catch (RuntimeException e) {
294            e.printStackTrace();
295        }
296        return "Error loading Bing attribution data";
297    }
298
299    private static String computeQuadTree(int zoom, int tilex, int tiley) {
300        StringBuilder k = new StringBuilder();
301        for (int i = zoom; i > 0; i--) {
302            char digit = 48;
303            int mask = 1 << (i - 1);
304            if ((tilex & mask) != 0) {
305                digit += (char) 1;
306            }
307            if ((tiley & mask) != 0) {
308                digit += (char) 2;
309            }
310            k.append(digit);
311        }
312        return k.toString();
313    }
314}