protected String baseURL;

    private ImageryInfo info;

    private Map<String, String> props = new HashMap<>();

    public WMSGrabber(MapView mv, WMSLayer layer, boolean localOnly) {

        super(mv, layer, localOnly);

        this.info = layer.getInfo();

        this.baseURL = info.getUrl();

        if(layer.getInfo().getCookies() != null && !layer.getInfo().getCookies().isEmpty()) {

            props.put("Cookie", layer.getInfo().getCookies());

        }

        Pattern pattern = Pattern.compile("\\{header\\(([^,]+),([^}]+)\\)\\}");

        StringBuffer output = new StringBuffer();

        Matcher matcher = pattern.matcher(this.baseURL);

        while (matcher.find()) {

            props.put(matcher.group(1),matcher.group(2));

            matcher.appendReplacement(output, "");

        }

        matcher.appendTail(output);

        this.baseURL = output.toString();

    }

    @Override

    void fetch(WMSRequest request, int attempt) throws Exception{

        URL url = null;

        try {

            url = getURL(

                    b.minEast, b.minNorth,

                    b.maxEast, b.maxNorth,

                    width(), height());

            request.finish(State.IMAGE, grab(request, url, attempt));

        } catch(Exception e) {

            Main.error(e);

            throw new Exception(e.getMessage() + "\nImage couldn't be fetched: " + (url != null ? url.toString() : ""), e);

        }

    }

    public static final NumberFormat latLonFormat = new DecimalFormat("###0.0000000",

            new DecimalFormatSymbols(Locale.US));

    protected URL getURL(double w, double s,double e,double n,

            int wi, int ht) throws MalformedURLException {

        String myProj = Main.getProjection().toCode();

        if (!info.getServerProjections().contains(myProj) && "EPSG:3857".equals(Main.getProjection().toCode())) {

            LatLon sw = Main.getProjection().eastNorth2latlon(new EastNorth(w, s));

            LatLon ne = Main.getProjection().eastNorth2latlon(new EastNorth(e, n));

            myProj = "EPSG:4326";

            s = sw.lat();

            w = sw.lon();

            n = ne.lat();

            e = ne.lon();

        }

        if ("EPSG:4326".equals(myProj) && !info.getServerProjections().contains(myProj) && info.getServerProjections().contains("CRS:84")) {

            myProj = "CRS:84";

        }

        // Bounding box coordinates have to be switched for WMS 1.3.0 EPSG:4326.

        //

        // Background:

        //

        // bbox=x_min,y_min,x_max,y_max

        //

        //      SRS=... is WMS 1.1.1

        //      CRS=... is WMS 1.3.0

        //

        // The difference:

        //      For SRS x is east-west and y is north-south

        //      For CRS x and y are as specified by the EPSG

        //          E.g. [1] lists lat as first coordinate axis and lot as second, so it is switched for EPSG:4326.

        //          For most other EPSG code there seems to be no difference.

        // [1] https://www.epsg-registry.org/report.htm?type=selection&entity=urn:ogc:def:crs:EPSG::4326&reportDetail=short&style=urn:uuid:report-style:default-with-code&style_name=OGP%20Default%20With%20Code&title=EPSG:4326

        boolean switchLatLon = false;

        if (baseURL.toLowerCase().contains("crs=epsg:4326")) {

            switchLatLon = true;

        } else if (baseURL.toLowerCase().contains("crs=") && "EPSG:4326".equals(myProj)) {

            switchLatLon = true;

        }

        String bbox;

        if (switchLatLon) {

            bbox = String.format("%s,%s,%s,%s", latLonFormat.format(s), latLonFormat.format(w), latLonFormat.format(n), latLonFormat.format(e));

        } else {

            bbox = String.format("%s,%s,%s,%s", latLonFormat.format(w), latLonFormat.format(s), latLonFormat.format(e), latLonFormat.format(n));

        }

        return new URL(baseURL.replaceAll("\\{proj(\\([^})]+\\))?\\}", myProj)

                .replaceAll("\\{bbox\\}", bbox)

                .replaceAll("\\{w\\}", latLonFormat.format(w))

                .replaceAll("\\{s\\}", latLonFormat.format(s))

                .replaceAll("\\{e\\}", latLonFormat.format(e))

                .replaceAll("\\{n\\}", latLonFormat.format(n))

                .replaceAll("\\{width\\}", String.valueOf(wi))

                .replaceAll("\\{height\\}", String.valueOf(ht))

                .replace(" ", "%20"));

    }

    @Override

    public boolean loadFromCache(WMSRequest request) {

        BufferedImage cached = layer.cache.getExactMatch(

                Main.getProjection(), request.getPixelPerDegree(), b.minEast, b.minNorth);

        if (cached != null) {

            request.finish(State.IMAGE, cached);

            return true;

        } else if (request.isAllowPartialCacheMatch()) {

            BufferedImage partialMatch = layer.cache.getPartialMatch(

                    Main.getProjection(), request.getPixelPerDegree(), b.minEast, b.minNorth);

            if (partialMatch != null) {

                request.finish(State.PARTLY_IN_CACHE, partialMatch);

                return true;

            }

        }

        if((!request.isReal() && !layer.hasAutoDownload())){

            request.finish(State.NOT_IN_CACHE, null);

            return true;

        }

        return false;

    }

    protected BufferedImage grab(WMSRequest request, URL url, int attempt) throws IOException, OsmTransferException {

        Main.info("Grabbing WMS " + (attempt > 1? "(attempt " + attempt + ") ":"") + url);

        HttpURLConnection conn = Utils.openHttpConnection(url);

        for(Entry<String, String> e : props.entrySet()) {

            conn.setRequestProperty(e.getKey(), e.getValue());

        }

        conn.setConnectTimeout(Main.pref.getInteger("socket.timeout.connect",15) * 1000);

        conn.setReadTimeout(Main.pref.getInteger("socket.timeout.read", 30) * 1000);

        String contentType = conn.getHeaderField("Content-Type");

        if( conn.getResponseCode() != 200

                || contentType != null && !contentType.startsWith("image") )

            throw new IOException(readException(conn));

        ByteArrayOutputStream baos = new ByteArrayOutputStream();

        try (InputStream is = new ProgressInputStream(conn, null)) {

            Utils.copyStream(is, baos);

        }

        ByteArrayInputStream bais = new ByteArrayInputStream(baos.toByteArray());

        BufferedImage img = layer.normalizeImage(ImageProvider.read(bais, true, WMSLayer.PROP_ALPHA_CHANNEL.get()));

        bais.reset();

        layer.cache.saveToCache(layer.isOverlapEnabled()?img:null, bais, Main.getProjection(), request.getPixelPerDegree(), b.minEast, b.minNorth);

        return img;

    }

    protected String readException(URLConnection conn) throws IOException {

        StringBuilder exception = new StringBuilder();

        InputStream in = conn.getInputStream();

        try (BufferedReader br = new BufferedReader(new InputStreamReader(in, StandardCharsets.UTF_8))) {

            String line = null;

            while( (line = br.readLine()) != null) {

                // filter non-ASCII characters and control characters

                exception.append(line.replaceAll("[^\\p{Print}]", ""));

                exception.append('\n');

            }

            return exception.toString();

        }

    }

}