fixed bug in function with single point values

database/src/migrations/release.0.8.0/fn_calculate_area_intersect.sql

@@ -1,6 +1,7 @@
 -- *******************************************************************
 -- Procedure: fn_calculate_area_intersect
 -- Purpose: returns true if both geometries intersect by the given tolerance amount (0.4 == 40% coverage)
+-- Assumptions: This function assumes that geom1 will always be a Polygon/ MultiPolygon provided by the system `region_lookup` table.
 --
 -- MODIFICATION HISTORY
 -- Person           Date        Comments
@@ -11,10 +12,24 @@
 CREATE OR REPLACE FUNCTION fn_calculate_area_intersect(geom1 geometry, geom2 geometry, tolerance float)
 RETURNS boolean AS $$
 DECLARE
-  intersection_area double precision;
+	intersection_area double precision;
+	geometry_1_area double precision;
+	geometry_2_area double precision;
+	results boolean;
 BEGIN
-  select ST_Area(ST_Intersection(geom1, geom2)) into intersection_area;
-  RETURN intersection_area / ST_Area(geom1) >= tolerance
-         OR intersection_area / ST_Area(geom2) >= tolerance;
+	-- special case to handle single point geometries
+	IF ST_GeometryType(geom2) = 'ST_Point' then 
+    -- ST_Area returns 0 for an area throwing off the calculation 
+    -- So checking ST_Point with ST_Intersects alone provides a more accurate results
+	  results := ST_Intersects(geom1, geom2);
+	ELSE 
+	  SELECT ST_Area(ST_Intersection(geom1, geom2)) INTO intersection_area;
+    SELECT ST_Area(geom1) INTO geometry_1_area;
+    SELECT ST_Area(geom2) INTO geometry_2_area;
+
+    results := intersection_area / geometry_1_area >= tolerance OR intersection_area / geometry_2_area >= tolerance;
+	END IF;
+
+  RETURN results;
 END;
 $$ LANGUAGE plpgsql;