package com.esri.hadoop.hive;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.hadoop.hive.ql.exec.Description;
import org.apache.hadoop.io.BytesWritable;
import org.apache.hadoop.io.IntWritable;
import org.apache.hive.pdk.HivePdkUnitTest;
import org.apache.hive.pdk.HivePdkUnitTests;
import com.esri.core.geometry.Geometry;
import com.esri.core.geometry.MultiPath;
import com.esri.core.geometry.MultiPoint;
import com.esri.core.geometry.Point;
import com.esri.core.geometry.ogc.OGCGeometry;
@Description(
name = "ST_PointN",
value = "_FUNC_(ST_Geometry, n) - returns the point that is the nth vertex in an ST_Linestring or ST_MultiPoint (1-based index)",
extended = "Example:\n"
+ " SELECT _FUNC_(ST_LineString(1.5,2.5, 3.0,2.2), 2) FROM src LIMIT 1; -- POINT(3.0 2.2)\n"
)
@HivePdkUnitTests(
cases = {
@HivePdkUnitTest(
query = "select ST_X(ST_PointN(ST_GeomFromText('multipoint ((10 40), (40 30), (20 20), (30 10))', 0), 2)) from onerow",
result = "40"
),
@HivePdkUnitTest(
query = "select ST_Y(ST_PointN(ST_GeomFromText('multipoint ((10 40), (40 30), (20 20), (30 10))', 0), 2)) from onerow",
result = "30"
),
@HivePdkUnitTest(
query = "select ST_X(ST_PointN(ST_GeomFromtext('linestring (10.02 20.01, 10.32 23.98, 11.92 25.64)'), 1)) from onerow",
result = "10.02"
),
@HivePdkUnitTest(
query = "select ST_Y(ST_PointN(ST_GeomFromtext('linestring (10.02 20.01, 10.32 23.98, 11.92 25.64)'), 1)) from onerow",
result = "20.01"
),
@HivePdkUnitTest(
query = "ST_PointN(ST_GeomFromText('multipoint ((10 40), (40 30), (20 20), (30 10))', 0), 5) from onerow",
result = "null"
)
}
)
public class ST_PointN extends ST_GeometryAccessor {
static final Log LOG = LogFactory.getLog(ST_PointN.class.getName());
public BytesWritable evaluate(BytesWritable geomref, IntWritable index) {
if (geomref == null || geomref.getLength() == 0 || index == null) {
LogUtils.Log_ArgumentsNull(LOG);
return null;
}
OGCGeometry ogcGeometry = GeometryUtils.geometryFromEsriShape(geomref);
if (ogcGeometry == null){
LogUtils.Log_ArgumentsNull(LOG);
return null;
}
Geometry esriGeom = ogcGeometry.getEsriGeometry();
Point pn = null;
int idx = index.get();
idx = (idx == 0) ? 0 : idx-1; // consistency with SDE ST_Geometry
switch(esriGeom.getType()) {
case Line:
case Polyline:
MultiPath lines = (MultiPath)(esriGeom);
try {
pn = lines.getPoint(idx);
} catch (Exception e) {
LogUtils.Log_InvalidIndex(LOG, idx+1, 1, lines.getPointCount());
return null;
}
break;
case MultiPoint:
MultiPoint mp = (MultiPoint)(esriGeom);
try {
pn = mp.getPoint(idx);
} catch (Exception e) {
LogUtils.Log_InvalidIndex(LOG, idx+1, 1, mp.getPointCount());
return null;
}
break;
default: // ST_Geometry ST_PointN gives ERROR on Point or Polygon (on PostgreSQL)
LogUtils.Log_InvalidType(LOG, GeometryUtils.OGCType.ST_LINESTRING, GeometryUtils.getType(geomref));
return null;
}
return GeometryUtils.geometryToEsriShapeBytesWritable(pn,
GeometryUtils.getWKID(geomref),
GeometryUtils.OGCType.ST_POINT);
}
}