--$Id: location_extract_place_fuzzy.sql 9324 2012-02-27 22:08:12Z pramsey $-
-- location_extract_place_fuzzy(string, stateAbbrev)
-- This function checks the place_lookup table to find a potential match to
-- the location described at the end of the given string.  If an exact match
-- fails, a fuzzy match is performed.  The location as found in the given
-- string is returned.
CREATE OR REPLACE FUNCTION location_extract_place_fuzzy(
    fullStreet VARCHAR,
    stateAbbrev VARCHAR
) RETURNS VARCHAR
AS $_$
DECLARE
  ws VARCHAR;
  tempString VARCHAR;
  location VARCHAR;
  tempInt INTEGER;
  word_count INTEGER;
  rec RECORD;
  test BOOLEAN;
  lstate VARCHAR;
BEGIN
--$Id: location_extract_place_fuzzy.sql 9324 2012-02-27 22:08:12Z pramsey $-
  ws := E'[ ,.\n\f\t]';

  tempString := substring(fullStreet, '(?i)' || ws
      || '([a-zA-Z0-9]+)$');
  IF tempString IS NULL THEN
      tempString := fullStreet;
  END IF;

  IF stateAbbrev IS NOT NULL THEN
    lstate := statefp FROM state WHERE stusps = stateAbbrev;
    SELECT into tempInt count(*) FROM place
        WHERE place.statefp = lstate
        AND soundex(tempString) = end_soundex(name);
  ELSE
    SELECT into tempInt count(*) FROM place
        WHERE soundex(tempString) = end_soundex(name);
  END IF;

  IF tempInt > 0 THEN
    -- Some potentials were found.  Begin a word-by-word soundex on each.
    tempInt := 50;
    IF stateAbbrev IS NOT NULL THEN
      FOR rec IN SELECT name FROM place
          WHERE place.statefp = lstate
          AND soundex(tempString) = end_soundex(name) LOOP
        word_count := count_words(rec.name);
        test := TRUE;
        tempString := get_last_words(fullStreet, word_count);
        FOR i IN 1..word_count LOOP
          IF soundex(split_part(tempString, ' ', i)) !=
            soundex(split_part(rec.name, ' ', i)) THEN
            test := FALSE;
          END IF;
        END LOOP;
          IF test THEN
            -- The soundex matched, determine if the distance is better.
            IF levenshtein_ignore_case(rec.name, tempString) < tempInt THEN
              location := tempString;
              tempInt := levenshtein_ignore_case(rec.name, tempString);
            END IF;
          END IF;
      END LOOP;
    ELSE
      FOR rec IN SELECT name FROM place
          WHERE soundex(tempString) = end_soundex(name) LOOP
        word_count := count_words(rec.name);
        test := TRUE;
        tempString := get_last_words(fullStreet, word_count);
        FOR i IN 1..word_count LOOP
          IF soundex(split_part(tempString, ' ', i)) !=
            soundex(split_part(rec.name, ' ', i)) THEN
            test := FALSE;
          END IF;
        END LOOP;
          IF test THEN
            -- The soundex matched, determine if the distance is better.
            IF levenshtein_ignore_case(rec.name, tempString) < tempInt THEN
              location := tempString;
            tempInt := levenshtein_ignore_case(rec.name, tempString);
          END IF;
        END IF;
      END LOOP;
    END IF;
  END IF;

  RETURN location;
END;
$_$ LANGUAGE plpgsql STABLE;
