/* Copyright (c) 2001 - 2007 TOPP - www.openplans.org. All rights reserved.
 * This code is licensed under the GPL 2.0 license, availible at the root
 * application directory.
 */
package org.geoserver.wfs.kvp;

import java.util.List;

import org.apache.commons.lang.StringUtils;
import org.geoserver.ows.KvpParser;
import org.geoserver.ows.util.KvpUtils;
import org.geoserver.platform.ServiceException;
import org.geotools.geometry.jts.ReferencedEnvelope;
import org.geotools.referencing.CRS;
import org.opengis.referencing.crs.CoordinateReferenceSystem;

import com.vividsolutions.jts.geom.Envelope;


public class BBoxKvpParser extends KvpParser {
    public BBoxKvpParser() {
        super("bbox", Envelope.class);
    }

    public Object parse(String value) throws Exception {
        List unparsed = KvpUtils.readFlat(value, KvpUtils.INNER_DELIMETER);

        // check to make sure that the bounding box has 4 coordinates
        if (unparsed.size() < 4) {
            throw new IllegalArgumentException("Requested bounding box contains wrong"
                + "number of coordinates (should have " + "4): " + unparsed.size());
        }

        //if it does, store them in an array of doubles
        double[] bbox = new double[4];

        for (int i = 0; i < 4; i++) {
            try {
                bbox[i] = Double.parseDouble((String) unparsed.get(i));
            } catch (NumberFormatException e) {
                throw new IllegalArgumentException("Bounding box coordinate " + i
                    + " is not parsable:" + unparsed.get(i));
            }
        }
        
        //ensure the values are sane
        double minx = bbox[0];
        double miny = bbox[1];
        double maxx = bbox[2];
        double maxy = bbox[3];
        
        if (minx > maxx) {
            throw new ServiceException("illegal bbox, minX: " + minx + " is "
                + "greater than maxX: " + maxx);
        }

        if (miny > maxy) {
            throw new ServiceException("illegal bbox, minY: " + miny + " is "
                + "greater than maxY: " + maxy);
        }

        //check for crs
        CoordinateReferenceSystem crs = null;

        if (unparsed.size() > 4) {
            // merge back the CRS definition, in case it is an AUTO one
            StringBuilder sb = new StringBuilder();
            for (int i = 4; i < unparsed.size(); i++) {
                sb.append(unparsed.get(i));
                if(i < (unparsed.size() - 1)) {
                    sb.append(",");
                }
            }
            crs = CRS.decode(sb.toString());
        } else {
            //TODO: use the default crs of the system
        }

        return new ReferencedEnvelope(minx,maxx,miny,maxy,crs);
    }
}