Add state from Natural Earth

data.yml

@@ -191,6 +191,34 @@ Layer:
       abbrev: String
       labelrank: Number
       name: String
+      postal: String
+      scalerank: Number
+    properties: 
+      "buffer-size": 64
+    srs: +proj=merc +a=6378137 +b=6378137 +lat_ts=0.0 +lon_0=0.0 +x_0=0.0 +y_0=0.0 +k=1.0 +units=m +nadgrids=@null +wktext +no_defs +over
+  - id: state
+    Datasource: 
+      dbname: osm
+      extent: -20037508.34,-20037508.34,20037508.34,20037508.34
+      geometry_field: geom
+      geometry_table: ''
+      host: db
+      key_field: ''
+      key_field_as_attribute: ''
+      max_size: 512
+      password: osm
+      port: 5432
+      srid: 900913
+      table: (SELECT * FROM layer_state(!bbox!, z(!scale_denominator!))) AS t
+      type: postgis
+      user: osm
+    description: Buildings
+    fields: 
+      abbrev: String
+      labelrank: Number
+      name: String
+      name_en: String
+      postal: String
       scalerank: Number
     properties: 
       "buffer-size": 64

schema/layers/state.sql

@@ -0,0 +1,44 @@
+CREATE TABLE IF NOT EXISTS state_label AS (
+    SELECT topoint(geom) AS geom,
+           name_local, fix_win1252_shp_encoding(name) AS name_en,
+           abbrev, postal,
+           scalerank, labelrank,
+           shape_area, datarank, type
+    FROM ne_10m_admin_1_states_provinces_shp
+    WHERE type IN ('State', 'Avtonomnyy Okrug', 'Sheng', 'Estado')
+    AND scalerank <= 3 AND labelrank <= 2
+);
+CREATE INDEX IF NOT EXISTS state_label_geom_idx ON state_label USING gist(geom);
+
+CREATE OR REPLACE FUNCTION fix_win1252_shp_encoding(str TEXT) RETURNS TEXT
+AS $$
+BEGIN
+    RETURN convert_from(convert_to(str, 'WIN1252'), 'UTF-8');
+    EXCEPTION WHEN others THEN RETURN str;
+END;
+$$ LANGUAGE plpgsql IMMUTABLE;
+
+CREATE OR REPLACE VIEW state_z3 AS (
+    SELECT * FROM state_label
+    WHERE (scalerank <= 2 AND labelrank <= 1) OR type = 'Avtonomnyy Okrug'
+);
+
+CREATE OR REPLACE VIEW state_z4 AS (
+    SELECT * FROM state_label
+);
+
+CREATE OR REPLACE FUNCTION layer_state(bbox geometry, zoom_level int)
+RETURNS TABLE(geom geometry, name text, name_en text, abbrev text, postal text, scalerank int, labelrank int) AS $$
+    WITH zoom_levels AS (
+        SELECT * FROM state_z3
+        WHERE zoom_level = 3
+        UNION ALL
+        SELECT * FROM state_z4
+        WHERE zoom_level >= 4
+    )
+    SELECT geom,
+    COALESCE(name_local, name_en) AS name_local, name_en,
+    abbrev, postal, scalerank::int, labelrank::int FROM zoom_levels
+    WHERE geom && bbox
+    ORDER BY scalerank ASC, labelrank ASC, shape_area DESC;
+$$ LANGUAGE SQL IMMUTABLE;