+CREATE OR REPLACE FUNCTION reverse_place_diameter(rank_search SMALLINT)
+ RETURNS FLOAT
+ AS $$
+BEGIN
+ IF rank_search <= 4 THEN
+ RETURN 5.0;
+ ELSIF rank_search <= 8 THEN
+ RETURN 1.8;
+ ELSIF rank_search <= 12 THEN
+ RETURN 0.6;
+ ELSIF rank_search <= 17 THEN
+ RETURN 0.16;
+ ELSIF rank_search <= 18 THEN
+ RETURN 0.08;
+ ELSIF rank_search <= 19 THEN
+ RETURN 0.04;
+ END IF;
+
+ RETURN 0.02;
+END;
+$$
+LANGUAGE plpgsql IMMUTABLE;
+
+CREATE OR REPLACE FUNCTION get_postcode_rank(country_code VARCHAR(2), postcode TEXT,
+ OUT rank_search SMALLINT, OUT rank_address SMALLINT)
+AS $$
+DECLARE
+ part TEXT;
+BEGIN
+ rank_search := 30;
+ rank_address := 30;
+ postcode := upper(postcode);
+
+ IF country_code = 'gb' THEN
+ IF postcode ~ '^([A-Z][A-Z]?[0-9][0-9A-Z]? [0-9][A-Z][A-Z])$' THEN
+ rank_search := 25;
+ rank_address := 5;
+ ELSEIF postcode ~ '^([A-Z][A-Z]?[0-9][0-9A-Z]? [0-9])$' THEN
+ rank_search := 23;
+ rank_address := 5;
+ ELSEIF postcode ~ '^([A-Z][A-Z]?[0-9][0-9A-Z])$' THEN
+ rank_search := 21;
+ rank_address := 5;
+ END IF;
+
+ ELSEIF country_code = 'sg' THEN
+ IF postcode ~ '^([0-9]{6})$' THEN
+ rank_search := 25;
+ rank_address := 11;
+ END IF;
+
+ ELSEIF country_code = 'de' THEN
+ IF postcode ~ '^([0-9]{5})$' THEN
+ rank_search := 21;
+ rank_address := 11;
+ END IF;
+
+ ELSE
+ -- Guess at the postcode format and coverage (!)
+ IF postcode ~ '^[A-Z0-9]{1,5}$' THEN -- Probably too short to be very local
+ rank_search := 21;
+ rank_address := 11;
+ ELSE
+ -- Does it look splitable into and area and local code?
+ part := substring(postcode from '^([- :A-Z0-9]+)([- :][A-Z0-9]+)$');
+
+ IF part IS NOT NULL THEN
+ rank_search := 25;
+ rank_address := 11;
+ ELSEIF postcode ~ '^[- :A-Z0-9]{6,}$' THEN
+ rank_search := 21;
+ rank_address := 11;
+ END IF;
+ END IF;
+ END IF;
+
+END;
+$$
+LANGUAGE plpgsql IMMUTABLE;
+
+-- Find the nearest artificial postcode for the given geometry.
+-- TODO For areas there should not be more than two inside the geometry.
+CREATE OR REPLACE FUNCTION get_nearest_postcode(country VARCHAR(2), geom GEOMETRY) RETURNS TEXT
+ AS $$
+DECLARE
+ outcode TEXT;
+ cnt INTEGER;
+BEGIN
+ -- If the geometry is an area then only one postcode must be within
+ -- that area, otherwise consider the area as not having a postcode.
+ IF ST_GeometryType(geom) in ('ST_Polygon','ST_MultiPolygon') THEN
+ SELECT min(postcode), count(*) FROM
+ (SELECT postcode FROM location_postcode
+ WHERE ST_Contains(geom, location_postcode.geometry) LIMIT 2) sub
+ INTO outcode, cnt;
+
+ IF cnt = 1 THEN
+ RETURN outcode;
+ ELSE
+ RETURN null;
+ END IF;
+ END IF;
+
+ SELECT postcode FROM location_postcode
+ WHERE ST_DWithin(geom, location_postcode.geometry, 0.05)
+ AND location_postcode.country_code = country
+ ORDER BY ST_Distance(geom, location_postcode.geometry) LIMIT 1
+ INTO outcode;
+
+ RETURN outcode;
+END;
+$$
+LANGUAGE plpgsql;
+
+