/*
 * Licensed to CRATE Technology GmbH ("Crate") under one or more contributor
 * license agreements.  See the NOTICE file distributed with this work for
 * additional information regarding copyright ownership.  Crate 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.
 *
 * However, if you have executed another commercial license agreement
 * with Crate these terms will supersede the license and you may use the
 * software solely pursuant to the terms of the relevant commercial agreement.
 */

package io.crate.types;

import com.google.common.base.Preconditions;
import org.locationtech.spatial4j.context.jts.JtsSpatialContext;
import org.locationtech.spatial4j.exception.InvalidShapeException;
import org.locationtech.spatial4j.io.WKTReader;
import org.locationtech.spatial4j.shape.Point;
import io.crate.Streamer;
import org.apache.lucene.util.BytesRef;
import org.elasticsearch.common.io.stream.StreamInput;
import org.elasticsearch.common.io.stream.StreamOutput;
import org.elasticsearch.common.lucene.BytesRefs;

import java.io.IOException;
import java.text.ParseException;
import java.util.List;
import java.util.Locale;

public class GeoPointType extends DataType<Double[]> implements Streamer<Double[]>, DataTypeFactory, FixedWidthType {

    public static final int ID = 13;
    public static final GeoPointType INSTANCE = new GeoPointType();

    private GeoPointType() {
    }

    public static final WKTReader WKT_READER = (WKTReader) JtsSpatialContext.GEO.getFormats().getWktReader();

    @Override
    public int id() {
        return ID;
    }

    @Override
    public String getName() {
        return "geo_point";
    }

    @Override
    public Streamer<?> streamer() {
        return this;
    }

    @Override
    public Double[] value(Object value) {
        if (value == null) {
            return null;
        }
        if (value instanceof Double[]) {
            Double[] doubles = (Double[]) value;
            checkLengthIs2(doubles.length);
            validate(doubles);
            return doubles;
        }
        if (value instanceof BytesRef) {
            return pointFromString(BytesRefs.toString(value));
        }
        if (value instanceof String) {
            return pointFromString((String) value);
        }
        if (value instanceof List) {
            List values = (List) value;
            checkLengthIs2(values.size());
            Double[] geoPoint = new Double[]{(Double) values.get(0), (Double) values.get(1)};
            validate(geoPoint);
            return geoPoint;
        }
        Object[] values = (Object[]) value;
        checkLengthIs2(values.length);
        Double[] geoPoint = new Double[]{
            ((Number) values[0]).doubleValue(),
            ((Number) values[1]).doubleValue()};
        validate(geoPoint);
        return geoPoint;
    }

    private void validate(Double[] doubles) {
        if (!isValid(doubles)) {
            throw new IllegalArgumentException(String.format(Locale.ENGLISH,
                "Failed to validate geo point [lon=%f, lat=%f], not a valid location.",
                doubles[0], doubles[1]));
        }
    }

    private static boolean isValid(Double[] geoPoint) {
        assert geoPoint.length == 2 : "Geo point array must contain 2 Double values.";
        return (geoPoint[0] >= -180.0d && geoPoint[0] <= 180.0d) && (geoPoint[1] >= -90.0d && geoPoint[1] <= 90.0d);
    }

    private static void checkLengthIs2(int actualLength) {
        Preconditions.checkArgument(actualLength == 2,
            "The value of a GeoPoint must be a double array with 2 items, not %s", actualLength);
    }

    private static Double[] pointFromString(String value) {
        try {
            Point point = (Point) WKT_READER.parse(value);
            return new Double[]{point.getX(), point.getY()};
        } catch (ParseException | InvalidShapeException e) {
            throw new IllegalArgumentException(String.format(Locale.ENGLISH,
                "Cannot convert \"%s\" to geo_point. %s", value, e.getLocalizedMessage()), e);
        }
    }

    @Override
    public int compareValueTo(Double[] val1, Double[] val2) {
        if (val1 == null) {
            return -1;
        }
        if (val2 == null) {
            return 1;
        }
        assert val1.length == 2 : "1st GeoPoint is empty";
        assert val2.length == 2 : "2nd GeoPoint is empty";

        // this is probably not really correct, but should be sufficient for the compareValueTo use case
        // (which is ordering and equality check)
        int latComp = Double.compare(val1[0], val2[0]);
        if (latComp != 0) {
            return latComp;
        }
        return Double.compare(val1[1], val2[1]);
    }

    @Override
    public DataType<?> create() {
        return INSTANCE;
    }

    @Override
    public Double[] readValueFrom(StreamInput in) throws IOException {
        if (in.readBoolean()) {
            return new Double[]{in.readDouble(), in.readDouble()};
        } else {
            return null;
        }
    }

    @Override
    public void writeValueTo(StreamOutput out, Object v) throws IOException {
        if (v == null) {
            out.writeBoolean(false);
        } else {
            out.writeBoolean(true);
            Double[] point = (Double[]) v;
            out.writeDouble(point[0]);
            out.writeDouble(point[1]);
        }
    }

    @Override
    public int fixedSize() {
        return 40; // 2x double + array overhead
    }
}