Add agg_stop indicator to transit stations (POI)

layers/poi/layer.sql

@@ -3,7 +3,7 @@
 -- etldoc:     label="layer_poi | <z12> z12 | <z13> z13 | <z14_> z14+" ] ;
 
 CREATE OR REPLACE FUNCTION layer_poi(bbox geometry, zoom_level integer, pixel_width numeric)
-RETURNS TABLE(osm_id bigint, geometry geometry, name text, name_en text, name_de text, tags hstore, class text, subclass text, "rank" int) AS $$
+RETURNS TABLE(osm_id bigint, geometry geometry, name text, name_en text, name_de text, tags hstore, class text, subclass text, agg_stop integer, "rank" int) AS $$
     SELECT osm_id, geometry, NULLIF(name, '') AS name,
         COALESCE(NULLIF(name_en, ''), name) AS name_en,
         COALESCE(NULLIF(name_de, ''), name, name_en) AS name_de,
@@ -14,6 +14,7 @@ RETURNS TABLE(osm_id bigint, geometry geometry, name text, name_en text, name_de
                 THEN NULLIF(information, '')
             ELSE subclass
         END AS subclass,
+        agg_stop,
         row_number() OVER (
             PARTITION BY LabelGrid(geometry, 100 * pixel_width)
             ORDER BY CASE WHEN name = '' THEN 2000 ELSE poi_class_rank(poi_class(subclass, mapping_key)) END ASC
@@ -35,14 +36,18 @@ RETURNS TABLE(osm_id bigint, geometry geometry, name text, name_en text, name_de
         UNION ALL
         -- etldoc: osm_poi_polygon ->  layer_poi:z12
         -- etldoc: osm_poi_polygon ->  layer_poi:z13
-        SELECT * FROM osm_poi_polygon
+        SELECT *,
+            NULL::INTEGER AS agg_stop
+        FROM osm_poi_polygon
             WHERE geometry && bbox
                 AND zoom_level BETWEEN 12 AND 13
                 AND ((subclass='station' AND mapping_key = 'railway')
                     OR subclass IN ('halt', 'ferry_terminal'))
         UNION ALL
         -- etldoc: osm_poi_polygon ->  layer_poi:z14_
-        SELECT * FROM osm_poi_polygon
+        SELECT *,
+            NULL::INTEGER AS agg_stop
+        FROM osm_poi_polygon
             WHERE geometry && bbox
                 AND zoom_level >= 14
         ) as poi_union

layers/poi/mapping.yaml

@@ -333,6 +333,9 @@ tables:
     - name: information
       key: information
       type: string
+    - name: uic_ref
+      key: uic_ref
+      type: string
     mapping:
       aerialway: *poi_mapping_aerialway
       amenity: *poi_mapping_amenity
@@ -380,6 +383,9 @@ tables:
     - name: information
       key: information
       type: string
+    - name: uic_ref
+      key: uic_ref
+      type: string
     mapping:
       aerialway: *poi_mapping_aerialway
       amenity: *poi_mapping_amenity

layers/poi/poi.yaml

@@ -32,14 +32,24 @@ layer:
         local relative importance of a POI within it's cell in the grid. This can be used to reduce label density at *z14*.
         Since all POIs already need to be contained at *z14* you can use `less than rank=10` epxression to limit
         POIs. At some point like *z17* you can show all POIs.
+    agg_stop:
+      description: |
+          Experimental feature! Indicates main platform of public transport
+          stops (buses, trams, and subways). Grouping of platforms is
+          implemented using
+          [`uic_ref`](http://wiki.openstreetmap.org/wiki/Key:uic_ref) tag that
+           is not used worldwide.
+      values: [1]
   datasource:
     geometry_field: geometry
     srid: 900913
-    query: (SELECT geometry, name, name_en, name_de, {name_languages}, class, subclass, rank FROM layer_poi(!bbox!, z(!scale_denominator!), !pixel_width!)) AS t
+    query: (SELECT geometry, name, name_en, name_de, {name_languages}, class, subclass, agg_stop, rank FROM layer_poi(!bbox!, z(!scale_denominator!), !pixel_width!)) AS t
 schema:
+  - ./public_transport_stop_type.sql
   - ./update_poi_polygon.sql
   - ./update_poi_point.sql
   - ./class.sql
+  - ./poi_stop_agg.sql
   - ./layer.sql
 datasources:
   - type: imposm3

layers/poi/poi_stop_agg.sql

@@ -0,0 +1,39 @@
+DROP MATERIALIZED VIEW IF EXISTS osm_poi_stop_centroid CASCADE;
+CREATE MATERIALIZED VIEW osm_poi_stop_centroid AS (
+  SELECT
+      uic_ref,
+      count(*) as count,
+			CASE WHEN count(*) > 2 THEN ST_Centroid(ST_UNION(geometry))
+			ELSE NULL END AS centroid
+  FROM osm_poi_point
+	WHERE
+		nullif(uic_ref, '') IS NOT NULL
+		AND subclass IN ('bus_stop', 'bus_station', 'tram_stop', 'subway')
+	GROUP BY
+		uic_ref
+	HAVING
+		count(*) > 1
+);
+
+DROP MATERIALIZED VIEW IF EXISTS osm_poi_stop_rank CASCADE;
+CREATE MATERIALIZED VIEW osm_poi_stop_rank AS (
+	SELECT
+		p.osm_id,
+-- 		p.uic_ref,
+-- 		p.subclass,
+		ROW_NUMBER()
+		OVER (
+			PARTITION BY p.uic_ref
+			ORDER BY
+				p.subclass :: public_transport_stop_type NULLS LAST,
+				ST_Distance(c.centroid, p.geometry)
+		) AS rk
+	FROM osm_poi_point p
+		INNER JOIN osm_poi_stop_centroid c ON (p.uic_ref = c.uic_ref)
+	WHERE
+		subclass IN ('bus_stop', 'bus_station', 'tram_stop', 'subway')
+	ORDER BY p.uic_ref, rk
+);
+
+ALTER TABLE osm_poi_point ADD COLUMN IF NOT EXISTS agg_stop INTEGER DEFAULT NULL;
+SELECT update_osm_poi_point_agg();

layers/poi/public_transport_stop_type.sql

@@ -0,0 +1,11 @@
+DO $$
+BEGIN
+    IF NOT EXISTS (SELECT 1
+                   FROM pg_type
+                   WHERE typname = 'public_transport_stop_type') THEN
+        CREATE TYPE public_transport_stop_type AS ENUM (
+          'subway', 'tram_stop', 'bus_station', 'bus_stop'
+        );
+    END IF;
+END
+$$;

layers/poi/update_poi_point.sql

@@ -21,6 +21,30 @@ $$ LANGUAGE plpgsql;
 
 SELECT update_osm_poi_point();
 
+CREATE OR REPLACE FUNCTION update_osm_poi_point_agg() RETURNS VOID AS $$
+BEGIN
+  UPDATE osm_poi_point p
+  SET agg_stop = CASE
+      WHEN p.subclass IN ('bus_stop', 'bus_station', 'tram_stop', 'subway')
+        THEN 1
+      ELSE NULL
+  END;
+
+  UPDATE osm_poi_point p
+    SET agg_stop = (
+      CASE
+        WHEN p.subclass IN ('bus_stop', 'bus_station', 'tram_stop', 'subway')
+            AND r.rk IS NULL OR r.rk = 1
+          THEN 1
+        ELSE NULL
+      END)
+    FROM osm_poi_stop_rank r
+    WHERE p.osm_id = r.osm_id
+  ;
+
+END;
+$$ LANGUAGE plpgsql;
+
 -- Handle updates
 
 CREATE SCHEMA IF NOT EXISTS poi_point;
@@ -38,6 +62,9 @@ CREATE OR REPLACE FUNCTION poi_point.refresh() RETURNS trigger AS
   BEGIN
     RAISE LOG 'Refresh poi_point';
     PERFORM update_osm_poi_point();
+    REFRESH MATERIALIZED VIEW osm_poi_stop_centroid;
+    REFRESH MATERIALIZED VIEW osm_poi_stop_rank;
+    PERFORM update_osm_poi_point_agg();
     DELETE FROM poi_point.updates;
     RETURN null;
   END;