/*
 * Copyright (c) "Neo4j"
 * Neo4j Sweden AB [http://neo4j.com]
 *
 * This file is part of Neo4j.
 *
 * Neo4j is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
package org.neo4j.kernel.impl.index.schema.config;

import static org.assertj.core.api.Assertions.assertThat;

import java.util.Arrays;
import java.util.stream.Collectors;
import org.junit.jupiter.api.Test;
import org.neo4j.configuration.Config;
import org.neo4j.gis.spatial.index.Envelope;
import org.neo4j.values.storable.CoordinateReferenceSystem;

class SpaceFillingCurveSettingsFactoryTest {
    @Test
    void shouldGetDefaultSpaceFillingCurveSettingsForWGS84() {
        shouldGetSettingsFor(Config.defaults(), CoordinateReferenceSystem.WGS_84, 2, new Envelope(-180, 180, -90, 90));
    }

    @Test
    void shouldGetDefaultSpaceFillingCurveSettingsForWGS84_3D() {
        shouldGetSettingsFor(
                Config.defaults(),
                CoordinateReferenceSystem.WGS_84_3D,
                3,
                new Envelope(new double[] {-180, -90, -1000000}, new double[] {180, 90, 1000000}));
    }

    @Test
    void shouldGetDefaultSpaceFillingCurveSettingsForCartesian() {
        shouldGetSettingsFor(
                Config.defaults(),
                CoordinateReferenceSystem.CARTESIAN,
                2,
                new Envelope(-1000000, 1000000, -1000000, 1000000));
    }

    @Test
    void shouldGetDefaultSpaceFillingCurveSettingsForCartesian_3D() {
        shouldGetSettingsFor(
                Config.defaults(),
                CoordinateReferenceSystem.CARTESIAN_3D,
                3,
                new Envelope(new double[] {-1000000, -1000000, -1000000}, new double[] {1000000, 1000000, 1000000}));
    }

    @Test
    void shouldGetModifiedSpaceFillingCurveSettingsForWGS84() {
        CoordinateReferenceSystem crs = CoordinateReferenceSystem.WGS_84;
        for (int minx = -180; minx < 0; minx += 45) {
            for (int miny = -180; miny < 0; miny += 45) {
                for (int width = 10; width < 90; width += 40) {
                    for (int height = 10; height < 90; height += 40) {
                        shouldGetCustomSettingsFor(
                                crs, new double[] {minx, miny}, new double[] {minx + width, miny + height});
                    }
                }
            }
        }
    }

    @Test
    void shouldGetModifiedSpaceFillingCurveSettingsForWGS84_3D() {
        CoordinateReferenceSystem crs = CoordinateReferenceSystem.WGS_84_3D;
        shouldGetCustomSettingsFor(crs, new double[] {-180, -90, -1000000}, new double[] {180, 90, 1000000});
        shouldGetCustomSettingsFor(crs, new double[] {0, -90, -1000000}, new double[] {180, 0, 1000000});
        shouldGetCustomSettingsFor(crs, new double[] {-90, -45, -1000}, new double[] {90, 45, 1000});
        shouldGetCustomSettingsFor(crs, new double[] {-90, -90, -1000}, new double[] {90, 45, 1000});
        // invalid geographic limits should not affect settings or even the index, but will affect distance and bbox
        // calculations
        shouldGetCustomSettingsFor(crs, new double[] {-1000, -1000, -1000}, new double[] {1000, 1000, 1000});
    }

    @Test
    void shouldGetModifiedSpaceFillingCurveSettingsForCartesian() {
        CoordinateReferenceSystem crs = CoordinateReferenceSystem.CARTESIAN;
        for (int maxBits = 30; maxBits <= 60; maxBits += 10) {
            for (int minx = -1000000; minx < 0; minx += 200000) {
                for (int miny = -1000000; miny < 0; miny += 2000000) {
                    for (int width = 100000; width < 1000000; width += 200000) {
                        for (int height = 100000; height < 1000000; height += 200000) {
                            shouldGetCustomSettingsFor(
                                    crs, new double[] {minx, miny}, new double[] {minx + width, miny + height});
                        }
                    }
                }
            }
        }
    }

    @Test
    void shouldGetModifiedSpaceFillingCurveSettingsForCartesian_3D() {
        CoordinateReferenceSystem crs = CoordinateReferenceSystem.CARTESIAN_3D;
        shouldGetCustomSettingsFor(
                crs, new double[] {-1000000, -1000000, -1000000}, new double[] {1000000, 1000000, 1000000});
        shouldGetCustomSettingsFor(crs, new double[] {0, -1000000, -1000000}, new double[] {1000000, 0, 1000000});
        shouldGetCustomSettingsFor(crs, new double[] {-1000, -1000, -1000}, new double[] {1000, 1000, 1000});
        shouldGetCustomSettingsFor(crs, new double[] {-1000000000, -1000000000, -1000000000}, new double[] {
            1000000000, 1000000000, 1000000000
        });
    }

    private static void shouldGetCustomSettingsFor(CoordinateReferenceSystem crs, double[] min, double[] max) {
        CrsConfig crsConf = CrsConfig.group(crs);
        Config config = Config.newBuilder()
                .set(crsConf.min, Arrays.stream(min).boxed().collect(Collectors.toList()))
                .set(crsConf.max, Arrays.stream(max).boxed().collect(Collectors.toList()))
                .build();
        shouldGetSettingsFor(config, crs, min.length, new Envelope(min, max));
    }

    private static void shouldGetSettingsFor(
            Config config, CoordinateReferenceSystem crs, int dimensions, Envelope envelope) {
        ConfiguredSpaceFillingCurveSettingsCache configuredSettings =
                new ConfiguredSpaceFillingCurveSettingsCache(config);
        SpaceFillingCurveSettings settings = configuredSettings.forCRS(crs);
        assertThat(settings.getDimensions())
                .as("Expected " + dimensions + "D for " + crs.getName())
                .isEqualTo(dimensions);
        assertThat(settings.indexExtents())
                .as("Should have normal geographic 2D extents")
                .isEqualTo(envelope);
    }
}
