#!/usr/bin/env python3

"""Wrapper around US Census address geocoder API described here:
https://www2.census.gov/geo/pdfs/maps-data/data/Census_Geocoder_User_Guide.pdf"""

import logging
import re
from typing import Dict, Optional

import requests
from bs4 import BeautifulSoup
from requests.utils import requote_uri

logger = logging.getLogger(__name__)


def geocode_address(address: str) -> Optional[Dict[str, str]]:
    """Send a single address to the US Census geocoding API.

    >>> out = geocode_address('5 Shelbern Dr,,, 07738')
    >>> out['Matched Address']
    '5 SHELBERN DR, LINCROFT, NJ, 07738'

    """
    url = 'https://geocoding.geo.census.gov/geocoder/geographies/onelineaddress'
    url += f'?address={address}'
    url += '&layers=all&benchmark=4&vintage=4'
    url = requote_uri(url)
    logger.debug('GET: %s', url)
    r = requests.get(url)
    if r.status_code != 200:
        logger.error('Unexpected response code %d, wanted 200.  Fail.', r.status_code)
        return None
    else:
        soup = BeautifulSoup(r.text, 'html.parser')
        result = soup.find('div', id='pl_gov_census_geo_geocoder_domain_AddressResult')
        logger.debug('Unhelpful result blurb: "%s"', result)
        output = result.get_text('\n')
        label = None
        out = {}
        for line in output.split('\n'):
            if re.match(r'.*: *$', line):
                line = line.strip()
                label = line[:-1]
                logger.debug('Label is: "%s"', label)
            else:
                if label:
                    out[label] = line.strip()
                    logger.debug('Value is: "%s"', out[label])
    return out


if __name__ == '__main__':
    import doctest

    doctest.testmod()