Nominatim/lib/ReverseGeocode.php

<?php

namespace Nominatim;

class ReverseGeocode
{
    protected $oDB;
    protected $iMaxRank = 28;


    public function __construct(&$oDB)
    {
        $this->oDB =& $oDB;
    }


    public function setZoom($iZoom)
    {
        // Zoom to rank, this could probably be calculated but a lookup gives fine control
        $aZoomRank = array(
                      0 => 2, // Continent / Sea
                      1 => 2,
                      2 => 2,
                      3 => 4, // Country
                      4 => 4,
                      5 => 8, // State
                      6 => 10, // Region
                      7 => 10,
                      8 => 12, // County
                      9 => 12,
                      10 => 17, // City
                      11 => 17,
                      12 => 18, // Town / Village
                      13 => 18,
                      14 => 22, // Suburb
                      15 => 22,
                      16 => 26, // Street, TODO: major street?
                      17 => 26,
                      18 => 30, // or >, Building
                      19 => 30, // or >, Building
                     );
        $this->iMaxRank = (isset($iZoom) && isset($aZoomRank[$iZoom]))?$aZoomRank[$iZoom]:28;
    }

    /**
     * Find the closest interpolation with the given search diameter.
     *
     * @param string $sPointSQL   Reverse geocoding point as SQL
     * @param float  $fSearchDiam Search diameter
     *
     * @return Record of the interpolation or null.
     */
    protected function lookupInterpolation($sPointSQL, $fSearchDiam)
    {
        $sSQL = 'SELECT place_id, parent_place_id, 30 as rank_search,';
        $sSQL .= ' ST_LineLocatePoint(linegeo,'.$sPointSQL.') as fraction';
        $sSQL .= ' , ST_Distance(linegeo,'.$sPointSQL.') as distance';
        $sSQL .= ' FROM location_property_osmline';
        $sSQL .= ' WHERE ST_DWithin('.$sPointSQL.', linegeo, '.$fSearchDiam.')';
        $sSQL .= ' and indexed_status = 0 and startnumber is not NULL ';
        $sSQL .= ' ORDER BY ST_distance('.$sPointSQL.', linegeo) ASC limit 1';

        return chksql(
            $this->oDB->getRow($sSQL),
            "Could not determine closest housenumber on an osm interpolation line."
        );
    }

    /* lookup()
     * returns { place_id =>, type => '(osm|tiger)' }
     * fails if no place was found
     */


    public function lookup($fLat, $fLon, $bDoInterpolation = true)
    {
        $sPointSQL = 'ST_SetSRID(ST_Point('.$fLon.','.$fLat.'),4326)';
        $iMaxRank = $this->iMaxRank;

        // Find the nearest point
        $fSearchDiam = 0.0004;
        $iPlaceID = null;
        $fMaxAreaDistance = 1;
        $bIsInUnitedStates = false;
        $bPlaceIsTiger = false;
        $bPlaceIsLine = false;
        while (!$iPlaceID && $fSearchDiam < $fMaxAreaDistance) {
            $fSearchDiam = $fSearchDiam * 2;

            // If we have to expand the search area by a large amount then we need a larger feature
            // then there is a limit to how small the feature should be
            if ($fSearchDiam > 2 && $iMaxRank > 4) $iMaxRank = 4;
            if ($fSearchDiam > 1 && $iMaxRank > 9) $iMaxRank = 8;
            if ($fSearchDiam > 0.8 && $iMaxRank > 10) $iMaxRank = 10;
            if ($fSearchDiam > 0.6 && $iMaxRank > 12) $iMaxRank = 12;
            if ($fSearchDiam > 0.2 && $iMaxRank > 17) $iMaxRank = 17;
            if ($fSearchDiam > 0.1 && $iMaxRank > 18) $iMaxRank = 18;
            if ($fSearchDiam > 0.008 && $iMaxRank > 22) $iMaxRank = 22;
            if ($fSearchDiam > 0.001 && $iMaxRank > 26) {
                // try with interpolations before continuing
                if ($bDoInterpolation) {
                    // no house found, try with interpolations
                    $aPlaceLine = $this->lookupInterpolation($sPointSQL, $fSearchDiam/2);

                    if ($aPlaceLine) {
                        // interpolation is closer to point than placex house
                        $bPlaceIsLine = true;
                        $aPlace = $aPlaceLine;
                        $iPlaceID = $aPlaceLine['place_id'];
                        $iParentPlaceID = $aPlaceLine['parent_place_id']; // the street
                        $fFraction = $aPlaceLine['fraction'];
                        $iMaxRank = 30;

                        break;
                    }
                }
                // no interpolation found, continue search
                $iMaxRank = 26;
            }

            $sSQL = 'select place_id,parent_place_id,rank_search,country_code';
            $sSQL .= ' FROM placex';
            $sSQL .= ' WHERE ST_DWithin('.$sPointSQL.', geometry, '.$fSearchDiam.')';
            $sSQL .= ' and rank_search != 28 and rank_search >= '.$iMaxRank;
            $sSQL .= ' and (name is not null or housenumber is not null)';
            $sSQL .= ' and class not in (\'waterway\',\'railway\',\'tunnel\',\'bridge\',\'man_made\')';
            $sSQL .= ' and indexed_status = 0 ';
            $sSQL .= ' and (ST_GeometryType(geometry) not in (\'ST_Polygon\',\'ST_MultiPolygon\') ';
            $sSQL .= ' OR ST_DWithin('.$sPointSQL.', centroid, '.$fSearchDiam.'))';
            $sSQL .= ' ORDER BY ST_distance('.$sPointSQL.', geometry) ASC limit 1';
            if (CONST_Debug) var_dump($sSQL);
            $aPlace = chksql(
                $this->oDB->getRow($sSQL),
                "Could not determine closest place."
            );
            $iPlaceID = $aPlace['place_id'];
            $iParentPlaceID = $aPlace['parent_place_id'];
            $bIsInUnitedStates = ($aPlace['country_code'] == 'us');
        }

        // If a house was found make sure there isn't an interpolation line
        // that is closer
        if ($bDoInterpolation && !$bPlaceIsLine && $aPlace && $aPlace['rank_search'] == 30) {
            // get the distance of the house to the search point
            $sSQL = 'SELECT ST_distance('.$sPointSQL.', house.geometry)';
            $sSQL .= ' FROM placex as house WHERE house.place_id='.$iPlaceID;

            $fDistancePlacex = chksql(
                $this->oDB->getOne($sSQL),
                "Could not determine distance between searched point and placex house."
            );

            // look for an interpolation that is closer
            $aPlaceLine = $this->lookupInterpolation($sPointSQL, $fDistancePlacex);

            if ($aPlaceLine && (float) $aPlaceLine['distance'] < (float) $fDistancePlacex) {
                // interpolation is closer to point than placex house
                $bPlaceIsLine = true;
                $aPlace = $aPlaceLine;
                $iPlaceID = $aPlaceLine['place_id'];
                $iParentPlaceID = $aPlaceLine['parent_place_id']; // the street
                $fFraction = $aPlaceLine['fraction'];
            }
        }

        // Only street found? If it's in the US we can check TIGER data for nearest housenumber
        if (CONST_Use_US_Tiger_Data && $bDoInterpolation && $bIsInUnitedStates && $this->iMaxRank >= 28 && $iPlaceID && ($aPlace['rank_search'] == 26 || $aPlace['rank_search'] == 27 )) {
            $fSearchDiam = 0.001;
            $sSQL = 'SELECT place_id,parent_place_id,30 as rank_search, ST_LineLocatePoint(linegeo,'.$sPointSQL.') as fraction';
            //if (CONST_Debug) { $sSQL .= ', housenumber, ST_distance('.$sPointSQL.', centroid) as distance, st_y(centroid) as lat, st_x(centroid) as lon'; }
            $sSQL .= ' FROM location_property_tiger WHERE parent_place_id = '.$iPlaceID;
            $sSQL .= ' AND ST_DWithin('.$sPointSQL.', linegeo, '.$fSearchDiam.')';  //no centroid anymore in Tiger data, now we have lines
            $sSQL .= ' ORDER BY ST_distance('.$sPointSQL.', linegeo) ASC limit 1';

            if (CONST_Debug) {
                $sSQL = preg_replace('/limit 1/', 'limit 100', $sSQL);
                var_dump($sSQL);

                $aAllHouses = chksql($this->oDB->getAll($sSQL));
                foreach ($aAllHouses as $i) {
                    echo $i['housenumber'] . ' | ' . $i['distance'] * 1000 . ' | ' . $i['lat'] . ' | ' . $i['lon']. ' | '. "<br>\n";
                }
            }

            $aPlaceTiger = chksql(
                $this->oDB->getRow($sSQL),
                "Could not determine closest Tiger place."
            );
            if ($aPlaceTiger) {
                if (CONST_Debug) var_dump('found Tiger housenumber', $aPlaceTiger);
                $bPlaceIsTiger = true;
                $aPlace = $aPlaceTiger;
                $iPlaceID = $aPlaceTiger['place_id'];
                $iParentPlaceID = $aPlaceTiger['parent_place_id']; // the street
                $fFraction = $aPlaceTiger['fraction'];
                $iMaxRank = 30;
            }
        }

        // The point we found might be too small - use the address to find what it is a child of
        if ($iPlaceID && $iMaxRank < 28) {
            if (($aPlace['rank_search'] > 28 || $bPlaceIsTiger || $bPlaceIsLine) && $iParentPlaceID) {
                $iPlaceID = $iParentPlaceID;
                $bPlaceIsLine = false;
                $bPlaceIsTiger = false;
            }
            $sSQL  = 'select address_place_id';
            $sSQL .= ' FROM place_addressline';
            $sSQL .= " WHERE place_id = $iPlaceID";
            $sSQL .= " ORDER BY abs(cached_rank_address - $iMaxRank) asc,cached_rank_address desc,isaddress desc,distance desc";
            $sSQL .= ' LIMIT 1';
            $iPlaceID = chksql($this->oDB->getOne($sSQL), "Could not get parent for place.");
            if (!$iPlaceID) {
                $iPlaceID = $aPlace['place_id'];
            }
        }
        return array(
                'place_id' => $iPlaceID,
                'type' => $bPlaceIsTiger ? 'tiger' : ($bPlaceIsLine ? 'interpolation' : 'osm'),
                'fraction' => ($bPlaceIsTiger || $bPlaceIsLine) ? $fFraction : -1
               );
    }
}