package org.geotools.map;
import java.awt.Color;
import java.awt.Rectangle;
import java.awt.geom.AffineTransform;
import java.awt.geom.Point2D;
import java.awt.image.BufferedImage;
import java.io.IOException;
import java.io.InputStream;
import java.util.ArrayList;
import java.util.Collections;
import java.util.HashSet;
import java.util.LinkedHashSet;
import java.util.List;
import java.util.Set;
import java.util.logging.Level;
import java.util.logging.Logger;
import javax.imageio.ImageIO;
import org.geotools.coverage.grid.GridCoverage2D;
import org.geotools.coverage.grid.GridCoverageFactory;
import org.geotools.coverage.grid.GridGeometry2D;
import org.geotools.coverage.grid.io.AbstractGridCoverage2DReader;
import org.geotools.coverage.grid.io.AbstractGridFormat;
import org.geotools.data.ows.Layer;
import org.geotools.data.wms.WebMapServer;
import org.geotools.data.wms.request.GetFeatureInfoRequest;
import org.geotools.data.wms.request.GetMapRequest;
import org.geotools.data.wms.response.GetFeatureInfoResponse;
import org.geotools.data.wms.response.GetMapResponse;
import org.geotools.geometry.DirectPosition2D;
import org.geotools.geometry.GeneralEnvelope;
import org.geotools.geometry.jts.ReferencedEnvelope;
import org.geotools.ows.ServiceException;
import org.geotools.referencing.CRS;
import org.geotools.referencing.CRS.AxisOrder;
import org.geotools.renderer.lite.RendererUtilities;
import org.geotools.util.Version;
import org.opengis.coverage.grid.Format;
import org.opengis.geometry.Envelope;
import org.opengis.parameter.GeneralParameterValue;
import org.opengis.parameter.ParameterValue;
import org.opengis.referencing.ReferenceIdentifier;
import org.opengis.referencing.crs.CoordinateReferenceSystem;
import org.opengis.referencing.crs.GeographicCRS;
/**
* A grid coverage readers backing onto a WMS server by issuing GetMap
*/
class WMSCoverageReader extends AbstractGridCoverage2DReader {
/** The logger for the map module. */
static public final Logger LOGGER = org.geotools.util.logging.Logging.getLogger("org.geotools.map");
static GridCoverageFactory gcf = new GridCoverageFactory();
/**
* The WMS server
*/
WebMapServer wms;
/**
* The layer
*/
List<Layer> layers = new ArrayList<Layer>();
/**
* The chosen SRS name
*/
String srsName;
/**
* The format to use for requests
*/
String format;
/**
* The last GetMap request
*/
GetMapRequest mapRequest;
/**
* The last GetMap response
*/
GridCoverage2D grid;
/**
* The set of SRS common to all layers
*/
Set<String> validSRS;
/**
* The cached layer bounds
*/
ReferencedEnvelope bounds;
/**
* The last request envelope
*/
ReferencedEnvelope requestedEnvelope;
/**
* Last request width
*/
int width;
/**
* Last request height
*/
int height;
/**
* Last request CRS (used for reprojected GetFeatureInfo)
*/
CoordinateReferenceSystem requestCRS;
/**
* Builds a new WMS coverage reader
*
* @param wms
* @param layer
*/
public WMSCoverageReader(WebMapServer wms, Layer layer) {
this.wms = wms;
// init the reader
addLayer(layer);
// best guess at the format with a preference for PNG (since it's normally transparent)
List<String> formats = wms.getCapabilities().getRequest().getGetMap().getFormats();
this.format = formats.iterator().next();
for (String format : formats) {
if ("image/png".equals(format) || "image/png24".equals(format)
|| "png".equals(format) || "png24".equals(format)
|| "image/png; mode=24bit".equals(format)) {
this.format = format;
break;
}
}
}
void addLayer(Layer layer) {
this.layers.add(layer);
if (srsName == null) {
// initialize from first layer
for(String srs : layer.getBoundingBoxes().keySet()) {
try {
// check it's valid, if not we crap out and move to the next
CRS.decode(srs);
srsName = srs;
break;
} catch(Exception e) {
// it's fine, we could not decode that code
}
}
if(srsName == null) {
if (layer.getSrs().contains("EPSG:4326")) {
// otherwise we try 4326
srsName = "EPSG:4326";
} else {
// if not even that works we just take the first...
srsName = (String) layer.getSrs().iterator().next();
}
}
validSRS = layer.getSrs();
} else {
Set<String> intersection = new HashSet<String>(validSRS);
intersection.retainAll(layer.getSrs());
// can we reuse what we have?
if (!intersection.contains(srsName)) {
if (intersection.size() == 0) {
throw new IllegalArgumentException("The layer being appended does "
+ "not have any SRS in common with the ones already "
+ "included in the WMS request, cannot be merged");
} else if (intersection.contains("EPSG:4326")) {
srsName = "EPSG:4326";
} else {
// if not even that works we just take the first...
srsName = (String) intersection.iterator().next();
}
this.validSRS = intersection;
}
}
CoordinateReferenceSystem crs = null;
try {
crs = CRS.decode(srsName);
} catch (Exception e) {
LOGGER.log(Level.FINE, "Bounds unavailable for layer" + layer);
}
this.crs = crs;
// update the cached bounds and the reader original envelope
updateBounds();
}
/**
* Issues GetFeatureInfo against a point using the params of the last GetMap request
*
* @param pos
* @return
* @throws IOException
*/
public InputStream getFeatureInfo(DirectPosition2D pos, String infoFormat, int featureCount, GetMapRequest getmap)
throws IOException {
GetFeatureInfoRequest request = wms.createGetFeatureInfoRequest(getmap);
request.setFeatureCount(1);
request.setQueryLayers(new LinkedHashSet<Layer>(layers));
request.setInfoFormat(infoFormat);
request.setFeatureCount(featureCount);
try {
AffineTransform tx = RendererUtilities.worldToScreenTransform(requestedEnvelope,
new Rectangle(width, height));
Point2D dest = new Point2D.Double();
Point2D src = new Point2D.Double(pos.x, pos.y);
tx.transform(src, dest);
request.setQueryPoint((int) dest.getX(), (int) dest.getY());
} catch (Exception e) {
throw (IOException) new IOException("Failed to grab feature info").initCause(e);
}
try {
if(LOGGER.isLoggable(Level.FINE)) {
LOGGER.fine("Issuing request: " + request.getFinalURL());
}
GetFeatureInfoResponse response = wms.issueRequest(request);
return response.getInputStream();
} catch (IOException e) {
throw e;
} catch (Throwable t) {
throw (IOException) new IOException("Failed to grab feature info").initCause(t);
}
}
@Override
public GridCoverage2D read(GeneralParameterValue[] parameters)
throws IllegalArgumentException, IOException {
// try to get request params from the request
Envelope requestedEnvelope = null;
int width = -1;
int height = -1;
Color backgroundColor = null;
if (parameters != null) {
for (GeneralParameterValue param : parameters) {
final ReferenceIdentifier name = param.getDescriptor().getName();
if (name.equals(AbstractGridFormat.READ_GRIDGEOMETRY2D.getName())) {
final GridGeometry2D gg = (GridGeometry2D) ((ParameterValue) param)
.getValue();
requestedEnvelope = gg.getEnvelope();
// the range high value is the highest pixel included in the raster,
// the actual width and height is one more than that
width = gg.getGridRange().getHigh(0) + 1;
height = gg.getGridRange().getHigh(1) + 1;
} else if(name.equals(AbstractGridFormat.BACKGROUND_COLOR.getName())) {
backgroundColor = (Color) ((ParameterValue) param).getValue();
}
}
}
// fill in a reasonable default if we did not manage to get the params
if (requestedEnvelope == null) {
requestedEnvelope = getOriginalEnvelope();
width = 640;
height = (int) Math.round(requestedEnvelope.getSpan(1)
/ requestedEnvelope.getSpan(0) * 640);
}
// if the structure did not change reuse the same response
if (grid != null && grid.getGridGeometry().getGridRange2D().getWidth() == width
&& grid.getGridGeometry().getGridRange2D().getHeight() == height
&& grid.getEnvelope().equals(requestedEnvelope))
return grid;
grid = getMap(reference(requestedEnvelope), width, height, backgroundColor);
return grid;
}
/**
* Execute the GetMap request
*/
GridCoverage2D getMap(ReferencedEnvelope requestedEnvelope, int width, int height, Color backgroundColor)
throws IOException {
// build the request
ReferencedEnvelope gridEnvelope = initMapRequest(requestedEnvelope, width, height, backgroundColor);
// issue the request and wrap response in a grid coverage
InputStream is = null;
try {
if(LOGGER.isLoggable(Level.FINE)) {
LOGGER.fine("Issuing request: " + mapRequest.getFinalURL());
}
GetMapResponse response = wms.issueRequest(mapRequest);
try {
is = response.getInputStream();
BufferedImage image = ImageIO.read(is);
if (image == null) {
throw (IOException) new IOException("GetMap failed: "
+ mapRequest.getFinalURL());
}
return gcf.create(layers.get(0).getTitle(), image, gridEnvelope);
} finally {
response.dispose();
}
} catch (ServiceException e) {
throw (IOException) new IOException("GetMap failed").initCause(e);
}
}
/**
* Sets up a max request with the provided parameters, making sure it is compatible with
* the layers own native SRS list
* @param bbox
* @param width
* @param height
* @return
* @throws IOException
*/
ReferencedEnvelope initMapRequest(ReferencedEnvelope bbox, int width, int height, Color backgroundColor)
throws IOException {
ReferencedEnvelope gridEnvelope = bbox;
String requestSrs = srsName;
try {
// first see if we can cascade the request in its native SRS
// we first look for an official epsg code
String code = null;
Integer epsgCode = CRS.lookupEpsgCode(bbox.getCoordinateReferenceSystem(), false);
if(epsgCode != null) {
code = "EPSG:" + epsgCode;
} else {
// otherwise let's make a fuller scan, but this method is more fragile...
code = CRS.lookupIdentifier(bbox.getCoordinateReferenceSystem(), false);
}
if (code != null && validSRS.contains(code)) {
requestSrs = code;
} else {
// first reproject to the map CRS
gridEnvelope = bbox.transform(getCrs(), true);
// then adjust the form factor
if (gridEnvelope.getWidth() < gridEnvelope.getHeight()) {
height = (int) Math.round(width * gridEnvelope.getHeight()
/ gridEnvelope.getWidth());
} else {
width = (int) Math.round(height * gridEnvelope.getWidth()
/ gridEnvelope.getHeight());
}
}
} catch (Exception e) {
throw new IOException("Could not reproject the request envelope", e);
}
GetMapRequest mapRequest = wms.createGetMapRequest();
// for some silly reason GetMapRequest will list the layers in the opposite order...
List<Layer> reversed = new ArrayList<Layer>(layers);
Collections.reverse(reversed);
for (Layer layer : reversed) {
mapRequest.addLayer(layer);
}
mapRequest.setDimensions(width, height);
mapRequest.setFormat(format);
if(backgroundColor == null) {
mapRequest.setTransparent(true);
} else {
String rgba = Integer.toHexString(backgroundColor.getRGB());
String rgb = rgba.substring(2, rgba.length());
mapRequest.setBGColour("0x" + rgb.toUpperCase());
mapRequest.setTransparent(backgroundColor.getAlpha() < 255);
}
try {
this.requestCRS = CRS.decode(requestSrs);
} catch(Exception e) {
throw new IOException("Could not decode request SRS " + requestSrs);
}
ReferencedEnvelope requestEnvelope = gridEnvelope;
mapRequest.setBBox(requestEnvelope);
mapRequest.setSRS(requestSrs);
this.mapRequest = mapRequest;
this.requestedEnvelope = gridEnvelope;
this.width = width;
this.height = height;
return gridEnvelope;
}
public Format getFormat() {
// this reader has not backing format
return null;
}
/**
* Returns the layer bounds
*
* @return
*/
public void updateBounds() {
ReferencedEnvelope result = reference(layers.get(0).getEnvelope(crs));
for (int i = 1; i < layers.size(); i++) {
ReferencedEnvelope layerEnvelope = reference(layers.get(i).getEnvelope(crs));
result.expandToInclude(layerEnvelope);
}
this.bounds = result;
this.originalEnvelope = new GeneralEnvelope(result);
}
/**
* Converts a {@link Envelope} into a {@link ReferencedEnvelope}
*
* @param envelope
* @return
*/
ReferencedEnvelope reference(Envelope envelope) {
ReferencedEnvelope env = new ReferencedEnvelope(envelope.getCoordinateReferenceSystem());
env.expandToInclude(envelope.getMinimum(0), envelope.getMinimum(1));
env.expandToInclude(envelope.getMaximum(0), envelope.getMaximum(1));
return env;
}
/**
* Converts a {@link GeneralEnvelope} into a {@link ReferencedEnvelope}
*
* @param ge
* @return
*/
ReferencedEnvelope reference(GeneralEnvelope ge) {
return new ReferencedEnvelope(ge.getMinimum(0), ge.getMaximum(0), ge.getMinimum(1), ge
.getMaximum(1), ge.getCoordinateReferenceSystem());
}
@Override
public String[] getMetadataNames() {
return new String[] { REPROJECTING_READER };
}
@Override
public String getMetadataValue(String name) {
if(REPROJECTING_READER.equals(name)) {
return "true";
}
return super.getMetadataValue(name);
}
}