package com.moon.server.service.data;

import com.moon.server.entity.all.StaticData;
import com.moon.server.entity.data.MetaEntity;
import com.moon.server.helper.StringHelper;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.gdal.gdal.ColorTable;
import org.gdal.gdal.Dataset;
import org.gdal.gdal.gdal;
import org.gdal.ogr.Geometry;
import org.gdal.ogr.ogr;
import org.gdal.osr.SpatialReference;
import org.springframework.stereotype.Service;

import java.io.File;

/**
 * 栅格服务
 * @author WWW
 * @date 2023-08-25
 */
@Service
public class RasterService {
    private SpatialReference sr4326;

    private SpatialReference sr4490;

    private SpatialReference sr104903;

    private final static Log log = LogFactory.getLog(RasterService.class);

    /**
     * 初始化空间引用
     */
    private void initSpatialReference() {
        if (null == sr4326) {
            sr4326 = new SpatialReference();
            sr4326.ImportFromEPSG(StaticData.I4326);

            sr4490 = new SpatialReference();
            sr4490.ImportFromEPSG(StaticData.I4490);

            sr104903 = new SpatialReference(StaticData.MOON_2000_WKT);
        }
    }

    /**
     * 读取栅格信息
     */
    public void readRasterInfo(MetaEntity me, String file) {
        Dataset ds = null;
        try {
            File f = new File(file);
            if (!f.exists() || f.isDirectory()) {
                return;
            }

            ds = gdal.Open(file, 0);
            if (null == ds || ds.getRasterCount() == 0) {
                return;
            }

            // EPSG编码
            String epsg = getEpsg(ds);
            // 波段数
            String bands = "" + ds.getRasterCount();
            //vd.Meta.band_type = Enum.GetName(typeof(DataType), ds.GetRasterBand(1).DataType); // 数据类型
            ColorTable colorTable = ds.GetRasterBand(1).GetRasterColorTable();
            // 数据颜色表
            String ct = null == colorTable ? null : colorTable.toString();
            // 高程基准
            String hDatum = null;

            double[] transform = new double[6];
            ds.GetGeoTransform(transform);
            // 分辨率
            String resolution = String.format("%f,%f", transform[1], transform[5]);

            if (!StaticData.EPSGS.contains(epsg)) {
                return;
            }

            Geometry minPoint = getMinPoint(ds);
            Geometry maxPoint = getMaxPoint(ds);
            double xmin = minPoint.GetX(0);
            double ymin = minPoint.GetY(0);
            double xmax = maxPoint.GetX(0);
            double ymax = maxPoint.GetY(0);

            // 四至范围
            String geom = String.format("ST_GeomFromText('POLYGON ((%f %f,%f %f,%f %f,%f %f,%f %f))')", xmin, ymax, xmax, ymax, xmax, ymin, xmin, ymin, xmin, ymax);
        } catch (Exception ex) {
            log.error(ex.getMessage(), ex);
        } finally {
            if (null != ds) {
                ds.delete();
            }
        }
    }

    /**
     * 获取EPSG编码
     */
    private String getEpsg(Dataset ds) {
        SpatialReference sr = ds.GetSpatialRef();
        if (sr != null) {
            // 坐标系统
            String coorSys = sr.GetName();
            if (StaticData.MOON200.equals(coorSys)) {
                return "ESRI:" + StaticData.I104903;
            } else {
                String code = sr.GetAuthorityCode(null);
                return StringHelper.isEmpty(code) ? null : "EPSG:" + code;
            }
        }

        return null;
    }

    /**
     * 获取Dataset的最小点
     */
    private Geometry getMinPoint(Dataset ds) {
        double[] transform = new double[6];
        ds.GetGeoTransform(transform);

        String epsg = ds.GetSpatialRef().GetAuthorityCode(null);
        double xMin = transform[0];
        double yMin = transform[3] - ds.getRasterYSize() * transform[1];

        Geometry point = new Geometry(ogr.wkbPoint);
        point.AddPoint(xMin, yMin, 0);

        return transform(ds, point, epsg);
    }

    /**
     * 获取Dataset的最大点
     */
    private Geometry getMaxPoint(Dataset ds) {
        double[] transform = new double[6];
        ds.GetGeoTransform(transform);

        String epsg = ds.GetSpatialRef().GetAuthorityCode(null);
        double xMax = transform[0] + (ds.getRasterXSize() * transform[1]);
        double yMax = transform[3];

        Geometry point = new Geometry(ogr.wkbPoint);
        point.AddPoint(xMax, yMax, 0);

        return transform(ds, point, epsg);
    }

    /**
     * 坐标转换
     */
    private Geometry transform(Dataset ds, Geometry point, String epsg) {
        this.initSpatialReference();

        if (StringHelper.isEmpty(epsg)) {
            point.AssignSpatialReference(sr104903);
            return point;
        }
        if (String.valueOf(StaticData.I4326).equals(epsg)) {
            point.AssignSpatialReference(sr4326);
            return point;
        }
        if (String.valueOf(StaticData.I4490).equals(epsg)) {
            point.AssignSpatialReference(sr4490);
            return point;
        }

        point.AssignSpatialReference(ds.GetSpatialRef());
        if (ds.GetSpatialRef().GetName().contains(StaticData.CGCS2000)) {
            point.TransformTo(sr4490);
        } else {
            point.TransformTo(sr4326);
        }

        return point;
    }
}