Centralize BoundingBox logic to a dedicated class

server/src/main/java/org/elasticsearch/common/geo/GeoBoundingBox.java

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+/*
+ * Licensed to Elasticsearch under one or more contributor
+ * license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright
+ * ownership. Elasticsearch licenses this file to you under
+ * the Apache License, Version 2.0 (the "License"); you may
+ * not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+package org.elasticsearch.common.geo;
+
+import org.elasticsearch.ElasticsearchParseException;
+import org.elasticsearch.common.ParseField;
+import org.elasticsearch.common.io.stream.StreamInput;
+import org.elasticsearch.common.io.stream.StreamOutput;
+import org.elasticsearch.common.io.stream.Writeable;
+import org.elasticsearch.common.xcontent.ToXContentObject;
+import org.elasticsearch.common.xcontent.XContentBuilder;
+import org.elasticsearch.common.xcontent.XContentParser;
+import org.elasticsearch.geometry.Geometry;
+import org.elasticsearch.geometry.Rectangle;
+import org.elasticsearch.geometry.ShapeType;
+import org.elasticsearch.geometry.utils.StandardValidator;
+import org.elasticsearch.geometry.utils.WellKnownText;
+
+import java.io.IOException;
+import java.text.ParseException;
+import java.util.Objects;
+
+/**
+ * A class representing a Geo-Bounding-Box for use by Geo queries and aggregations
+ * that deal with extents/rectangles representing rectangular areas of interest.
+ */
+public class GeoBoundingBox implements ToXContentObject, Writeable {
+    private static final WellKnownText WKT_PARSER = new WellKnownText(true, new StandardValidator(true));
+    static final ParseField TOP_RIGHT_FIELD = new ParseField("top_right");
+    static final ParseField BOTTOM_LEFT_FIELD = new ParseField("bottom_left");
+    static final ParseField TOP_FIELD = new ParseField("top");
+    static final ParseField BOTTOM_FIELD = new ParseField("bottom");
+    static final ParseField LEFT_FIELD = new ParseField("left");
+    static final ParseField RIGHT_FIELD = new ParseField("right");
+    static final ParseField WKT_FIELD = new ParseField("wkt");
+    public static final ParseField BOUNDS_FIELD = new ParseField("bounds");
+    public static final ParseField LAT_FIELD = new ParseField("lat");
+    public static final ParseField LON_FIELD = new ParseField("lon");
+    public static final ParseField TOP_LEFT_FIELD = new ParseField("top_left");
+    public static final ParseField BOTTOM_RIGHT_FIELD = new ParseField("bottom_right");
+
+    private final GeoPoint topLeft;
+    private final GeoPoint bottomRight;
+
+    public GeoBoundingBox(GeoPoint topLeft, GeoPoint bottomRight) {
+        this.topLeft = topLeft;
+        this.bottomRight = bottomRight;
+    }
+
+    public GeoBoundingBox(StreamInput input) throws IOException {
+        this.topLeft = input.readGeoPoint();
+        this.bottomRight = input.readGeoPoint();
+    }
+
+    public GeoPoint topLeft() {
+        return topLeft;
+    }
+
+    public GeoPoint bottomRight() {
+        return bottomRight;
+    }
+
+    public double top() {
+        return topLeft.lat();
+    }
+
+    public double bottom() {
+        return bottomRight.lat();
+    }
+
+    public double left() {
+        return topLeft.lon();
+    }
+
+    public double right() {
+        return bottomRight.lon();
+    }
+
+    @Override
+    public XContentBuilder toXContent(XContentBuilder builder, Params params) throws IOException {
+        builder.startObject(BOUNDS_FIELD.getPreferredName());
+        toXContentFragment(builder, true);
+        builder.endObject();
+        return builder;
+    }
+
+    public XContentBuilder toXContentFragment(XContentBuilder builder, boolean buildLatLonFields) throws IOException {
+        if (buildLatLonFields) {
+            builder.startObject(TOP_LEFT_FIELD.getPreferredName());
+            builder.field(LAT_FIELD.getPreferredName(), topLeft.lat());
+            builder.field(LON_FIELD.getPreferredName(), topLeft.lon());
+            builder.endObject();
+        } else {
+            builder.array(TOP_LEFT_FIELD.getPreferredName(), topLeft.lon(), topLeft.lat());
+        }
+        if (buildLatLonFields) {
+            builder.startObject(BOTTOM_RIGHT_FIELD.getPreferredName());
+            builder.field(LAT_FIELD.getPreferredName(), bottomRight.lat());
+            builder.field(LON_FIELD.getPreferredName(), bottomRight.lon());
+            builder.endObject();
+        } else {
+            builder.array(BOTTOM_RIGHT_FIELD.getPreferredName(), bottomRight.lon(), bottomRight.lat());
+        }
+        return builder;
+    }
+
+    @Override
+    public void writeTo(StreamOutput out) throws IOException {
+        out.writeGeoPoint(topLeft);
+        out.writeGeoPoint(bottomRight);
+    }
+
+    @Override
+    public boolean equals(Object o) {
+        if (this == o) return true;
+        if (o == null || getClass() != o.getClass()) return false;
+        GeoBoundingBox that = (GeoBoundingBox) o;
+        return topLeft.equals(that.topLeft) &&
+            bottomRight.equals(that.bottomRight);
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(topLeft, bottomRight);
+    }
+
+    @Override
+    public String toString() {
+        return "BBOX (" + topLeft.lon() + ", " + bottomRight.lon() + ", " + topLeft.lat() + ", " + bottomRight.lat() + ")";
+    }
+
+    /**
+     * Parses the bounding box and returns bottom, top, left, right coordinates
+     */
+    public static GeoBoundingBox parseBoundingBox(XContentParser parser) throws IOException, ElasticsearchParseException {
+        XContentParser.Token token = parser.currentToken();
+        if (token != XContentParser.Token.START_OBJECT) {
+            throw new ElasticsearchParseException("failed to parse bounding box. Expected start object but found [{}]", token);
+        }
+
+        double top = Double.NaN;
+        double bottom = Double.NaN;
+        double left = Double.NaN;
+        double right = Double.NaN;
+
+        String currentFieldName;
+        GeoPoint sparse = new GeoPoint();
+        Rectangle envelope = null;
+
+        while ((token = parser.nextToken()) != XContentParser.Token.END_OBJECT) {
+            if (token == XContentParser.Token.FIELD_NAME) {
+                currentFieldName = parser.currentName();
+                token = parser.nextToken();
+                if (WKT_FIELD.match(currentFieldName, parser.getDeprecationHandler())) {
+                    try {
+                        Geometry geometry = WKT_PARSER.fromWKT(parser.text());
+                        if (ShapeType.ENVELOPE.equals(geometry.type()) == false) {
+                            throw new ElasticsearchParseException("failed to parse WKT bounding box. ["
+                                + geometry.type() + "] found. expected [" + ShapeType.ENVELOPE + "]");
+                        }
+                        envelope = (Rectangle) geometry;
+                    } catch (ParseException|IllegalArgumentException e) {
+                        throw new ElasticsearchParseException("failed to parse WKT bounding box", e);
+                    }
+                } else if (TOP_FIELD.match(currentFieldName, parser.getDeprecationHandler())) {
+                    top = parser.doubleValue();
+                } else if (BOTTOM_FIELD.match(currentFieldName, parser.getDeprecationHandler())) {
+                    bottom = parser.doubleValue();
+                } else if (LEFT_FIELD.match(currentFieldName, parser.getDeprecationHandler())) {
+                    left = parser.doubleValue();
+                } else if (RIGHT_FIELD.match(currentFieldName, parser.getDeprecationHandler())) {
+                    right = parser.doubleValue();
+                } else {
+                    if (TOP_LEFT_FIELD.match(currentFieldName, parser.getDeprecationHandler())) {
+                        GeoUtils.parseGeoPoint(parser, sparse, false, GeoUtils.EffectivePoint.TOP_LEFT);
+                        top = sparse.getLat();
+                        left = sparse.getLon();
+                    } else if (BOTTOM_RIGHT_FIELD.match(currentFieldName, parser.getDeprecationHandler())) {
+                        GeoUtils.parseGeoPoint(parser, sparse, false, GeoUtils.EffectivePoint.BOTTOM_RIGHT);
+                        bottom = sparse.getLat();
+                        right = sparse.getLon();
+                    } else if (TOP_RIGHT_FIELD.match(currentFieldName, parser.getDeprecationHandler())) {
+                        GeoUtils.parseGeoPoint(parser, sparse, false, GeoUtils.EffectivePoint.TOP_RIGHT);
+                        top = sparse.getLat();
+                        right = sparse.getLon();
+                    } else if (BOTTOM_LEFT_FIELD.match(currentFieldName, parser.getDeprecationHandler())) {
+                        GeoUtils.parseGeoPoint(parser, sparse, false, GeoUtils.EffectivePoint.BOTTOM_LEFT);
+                        bottom = sparse.getLat();
+                        left = sparse.getLon();
+                    } else {
+                        throw new ElasticsearchParseException("failed to parse bounding box. unexpected field [{}]", currentFieldName);
+                    }
+                }
+            } else {
+                throw new ElasticsearchParseException("failed to parse bounding box. field name expected but [{}] found", token);
+            }
+        }
+        if (envelope != null) {
+            if (Double.isNaN(top) == false || Double.isNaN(bottom) == false || Double.isNaN(left) == false ||
+                Double.isNaN(right) == false) {
+                throw new ElasticsearchParseException("failed to parse bounding box. Conflicting definition found "
+                    + "using well-known text and explicit corners.");
+            }
+            GeoPoint topLeft = new GeoPoint(envelope.getMaxLat(), envelope.getMinLon());
+            GeoPoint bottomRight = new GeoPoint(envelope.getMinLat(), envelope.getMaxLon());
+            return new GeoBoundingBox(topLeft, bottomRight);
+        }
+        GeoPoint topLeft = new GeoPoint(top, left);
+        GeoPoint bottomRight = new GeoPoint(bottom, right);
+        return new GeoBoundingBox(topLeft, bottomRight);
+    }
+
+}