+"""
+Functions for importing, updating and otherwise maintaining the table
+of artificial postcode centroids.
+"""
+
+from nominatim.db.utils import execute_file
+from nominatim.db.connection import connect
+
+def import_postcodes(dsn, project_dir):
+ """ Set up the initial list of postcodes.
+ """
+
+ with connect(dsn) as conn:
+ conn.drop_table('gb_postcode')
+ conn.drop_table('us_postcode')
+
+ with conn.cursor() as cur:
+ cur.execute("""CREATE TABLE gb_postcode (
+ id integer,
+ postcode character varying(9),
+ geometry GEOMETRY(Point, 4326))""")
+
+ with conn.cursor() as cur:
+ cur.execute("""CREATE TABLE us_postcode (
+ postcode text,
+ x double precision,
+ y double precision)""")
+ conn.commit()
+
+ gb_postcodes = project_dir / 'gb_postcode_data.sql.gz'
+ if gb_postcodes.is_file():
+ execute_file(dsn, gb_postcodes)
+
+ us_postcodes = project_dir / 'us_postcode_data.sql.gz'
+ if us_postcodes.is_file():
+ execute_file(dsn, us_postcodes)
+
+ with conn.cursor() as cur:
+ cur.execute("TRUNCATE location_postcode")
+ cur.execute("""
+ INSERT INTO location_postcode
+ (place_id, indexed_status, country_code, postcode, geometry)
+ SELECT nextval('seq_place'), 1, country_code,
+ upper(trim (both ' ' from address->'postcode')) as pc,
+ ST_Centroid(ST_Collect(ST_Centroid(geometry)))
+ FROM placex
+ WHERE address ? 'postcode' AND address->'postcode' NOT SIMILAR TO '%(,|;)%'
+ AND geometry IS NOT null
+ GROUP BY country_code, pc
+ """)
+
+ cur.execute("""
+ INSERT INTO location_postcode
+ (place_id, indexed_status, country_code, postcode, geometry)
+ SELECT nextval('seq_place'), 1, 'us', postcode,
+ ST_SetSRID(ST_Point(x,y),4326)
+ FROM us_postcode WHERE postcode NOT IN
+ (SELECT postcode FROM location_postcode
+ WHERE country_code = 'us')
+ """)
+
+ cur.execute("""
+ INSERT INTO location_postcode
+ (place_id, indexed_status, country_code, postcode, geometry)
+ SELECT nextval('seq_place'), 1, 'gb', postcode, geometry
+ FROM gb_postcode WHERE postcode NOT IN
+ (SELECT postcode FROM location_postcode
+ WHERE country_code = 'gb')
+ """)
+
+ cur.execute("""
+ DELETE FROM word WHERE class='place' and type='postcode'
+ and word NOT IN (SELECT postcode FROM location_postcode)
+ """)
+
+ cur.execute("""
+ SELECT count(getorcreate_postcode_id(v)) FROM
+ (SELECT distinct(postcode) as v FROM location_postcode) p
+ """)
+ conn.commit()