"""
Functions for importing and managing static country information.
"""
import psycopg2.extras

from nominatim.db import utils as db_utils
from nominatim.db.connection import connect

def setup_country_tables(dsn, sql_dir, ignore_partitions=False):
    """ Create and populate the tables with basic static data that provides
        the background for geocoding. Data is assumed to not yet exist.
    """
    db_utils.execute_file(dsn, sql_dir / 'country_name.sql')
    db_utils.execute_file(dsn, sql_dir / 'country_osm_grid.sql.gz')

    if ignore_partitions:
        with connect(dsn) as conn:
            with conn.cursor() as cur:
                cur.execute('UPDATE country_name SET partition = 0')
            conn.commit()


def create_country_names(conn, tokenizer, languages=None):
    """ Add default country names to search index. `languages` is a comma-
        separated list of language codes as used in OSM. If `languages` is not
        empty then only name translations for the given languages are added
        to the index.
    """
    if languages:
        languages = languages.split(',')

    def _include_key(key):
        return key == 'name' or \
               (key.startswith('name:') and (not languages or key[5:] in languages))

    with conn.cursor() as cur:
        psycopg2.extras.register_hstore(cur)
        cur.execute("""SELECT country_code, name FROM country_name
                       WHERE country_code is not null""")

        with tokenizer.name_analyzer() as analyzer:
            for code, name in cur:
                names = {'countrycode': code}
                if code == 'gb':
                    names['short_name'] = 'UK'
                if code == 'us':
                    names['short_name'] = 'United States'

                # country names (only in languages as provided)
                if name:
                    names.update(((k, v) for k, v in name.items() if _include_key(k)))

                analyzer.add_country_names(code, names)

    conn.commit()