<?php
/**
* SPDX-License-Identifier: GPL-2.0-only
*
* This file is part of Nominatim. (https://nominatim.org)
*
* Copyright (C) 2022 by the Nominatim developer community.
* For a full list of authors see the git log.
*/
namespace Nominatim;
require_once(CONST_LibDir.'/lib.php');
/**
* Collection of search constraints that are independent of the
* actual interpretation of the search query.
*
* The search context is shared between all SearchDescriptions. This
* object mainly serves as context provider for the database queries.
* Therefore most data is directly cached as SQL statements.
*/
class SearchContext
{
/// Search radius around a given Near reference point.
private $fNearRadius = false;
/// True if search must be restricted to viewbox only.
public $bViewboxBounded = false;
/// Reference point for search (as SQL).
public $sqlNear = '';
/// Viewbox selected for search (as SQL).
public $sqlViewboxSmall = '';
/// Viewbox with a larger buffer around (as SQL).
public $sqlViewboxLarge = '';
/// Reference along a route (as SQL).
public $sqlViewboxCentre = '';
/// List of countries to restrict search to (as array).
public $aCountryList = null;
/// List of countries to restrict search to (as SQL).
public $sqlCountryList = '';
/// List of place IDs to exclude (as SQL).
private $sqlExcludeList = '';
/// Subset of word ids of full words in the query.
private $aFullNameWords = array();
public function setFullNameWords($aWordList)
{
$this->aFullNameWords = $aWordList;
}
public function getFullNameTerms()
{
return $this->aFullNameWords;
}
/**
* Check if a reference point is defined.
*
* @return bool True if a reference point is defined.
*/
public function hasNearPoint()
{
return $this->fNearRadius !== false;
}
/**
* Get radius around reference point.
*
* @return float Search radius around reference point.
*/
public function nearRadius()
{
return $this->fNearRadius;
}
/**
* Set search reference point in WGS84.
*
* If set, then only places around this point will be taken into account.
*
* @param float $fLat Latitude of point.
* @param float $fLon Longitude of point.
* @param float $fRadius Search radius around point.
*
* @return void
*/
public function setNearPoint($fLat, $fLon, $fRadius = 0.1)
{
$this->fNearRadius = $fRadius;
$this->sqlNear = 'ST_SetSRID(ST_Point('.$fLon.','.$fLat.'),4326)';
}
/**
* Check if the search is geographically restricted.
*
* Searches are restricted if a reference point is given or if
* a bounded viewbox is set.
*
* @return bool True, if the search is geographically bounded.
*/
public function isBoundedSearch()
{
return $this->hasNearPoint() || ($this->sqlViewboxSmall && $this->bViewboxBounded);
}
/**
* Set rectangular viewbox.
*
* The viewbox may be bounded which means that no search results
* must be outside the viewbox.
*
* @param float[4] $aViewBox Coordinates of the viewbox.
* @param bool $bBounded True if the viewbox is bounded.
*
* @return void
*/
public function setViewboxFromBox(&$aViewBox, $bBounded)
{
$this->bViewboxBounded = $bBounded;
$this->sqlViewboxCentre = '';
$this->sqlViewboxSmall = sprintf(
'ST_SetSRID(ST_MakeBox2D(ST_Point(%F,%F),ST_Point(%F,%F)),4326)',
$aViewBox[0],
$aViewBox[1],
$aViewBox[2],
$aViewBox[3]
);
$fHeight = abs($aViewBox[0] - $aViewBox[2]);
$fWidth = abs($aViewBox[1] - $aViewBox[3]);
$this->sqlViewboxLarge = sprintf(
'ST_SetSRID(ST_MakeBox2D(ST_Point(%F,%F),ST_Point(%F,%F)),4326)',
max($aViewBox[0], $aViewBox[2]) + $fHeight,
max($aViewBox[1], $aViewBox[3]) + $fWidth,
min($aViewBox[0], $aViewBox[2]) - $fHeight,
min($aViewBox[1], $aViewBox[3]) - $fWidth
);
}
/**
* Set viewbox along a route.
*
* The viewbox may be bounded which means that no search results
* must be outside the viewbox.
*
* @param object $oDB Nominatim::DB instance to use for computing the box.
* @param string[] $aRoutePoints List of x,y coordinates along a route.
* @param float $fRouteWidth Buffer around the route to use.
* @param bool $bBounded True if the viewbox bounded.
*
* @return void
*/
public function setViewboxFromRoute(&$oDB, $aRoutePoints, $fRouteWidth, $bBounded)
{
$this->bViewboxBounded = $bBounded;
$this->sqlViewboxCentre = "ST_SetSRID('LINESTRING(";
$sSep = '';
foreach ($aRoutePoints as $aPoint) {
$fPoint = (float)$aPoint;
$this->sqlViewboxCentre .= $sSep.$fPoint;
$sSep = ($sSep == ' ') ? ',' : ' ';
}
$this->sqlViewboxCentre .= ")'::geometry,4326)";
$sSQL = 'ST_BUFFER('.$this->sqlViewboxCentre.','.($fRouteWidth/69).')';
$sGeom = $oDB->getOne('select '.$sSQL, null, 'Could not get small viewbox');
$this->sqlViewboxSmall = "'".$sGeom."'::geometry";
$sSQL = 'ST_BUFFER('.$this->sqlViewboxCentre.','.($fRouteWidth/30).')';
$sGeom = $oDB->getOne('select '.$sSQL, null, 'Could not get large viewbox');
$this->sqlViewboxLarge = "'".$sGeom."'::geometry";
}
/**
* Set list of excluded place IDs.
*
* @param integer[] $aExcluded List of IDs.
*
* @return void
*/
public function setExcludeList($aExcluded)
{
$this->sqlExcludeList = ' not in ('.join(',', $aExcluded).')';
}
/**
* Set list of countries to restrict search to.
*
* @param string[] $aCountries List of two-letter lower-case country codes.
*
* @return void
*/
public function setCountryList($aCountries)
{
$this->sqlCountryList = '('.join(',', array_map('addQuotes', $aCountries)).')';
$this->aCountryList = $aCountries;
}
/**
* Extract a reference point from a query string.
*
* @param string $sQuery Query to scan.
*
* @return string The remaining query string.
*/
public function setNearPointFromQuery($sQuery)
{
$aResult = parseLatLon($sQuery);
if ($aResult !== false
&& $aResult[1] <= 90.1
&& $aResult[1] >= -90.1
&& $aResult[2] <= 180.1
&& $aResult[2] >= -180.1
) {
$this->setNearPoint($aResult[1], $aResult[2]);
$sQuery = trim(str_replace($aResult[0], ' ', $sQuery));
}
return $sQuery;
}
/**
* Get an SQL snippet for computing the distance from the reference point.
*
* @param string $sObj SQL variable name to compute the distance from.
*
* @return string An SQL string.
*/
public function distanceSQL($sObj)
{
return 'ST_Distance('.$this->sqlNear.", $sObj)";
}
/**
* Get an SQL snippet for checking if something is within range of the
* reference point.
*
* @param string $sObj SQL variable name to compute if it is within range.
*
* @return string An SQL string.
*/
public function withinSQL($sObj)
{
return sprintf('ST_DWithin(%s, %s, %F)', $sObj, $this->sqlNear, $this->fNearRadius);
}
/**
* Get an SQL snippet of the importance factor of the viewbox.
*
* The importance factor is computed by checking if an object is within
* the viewbox and/or the extended version of the viewbox.
*
* @param string $sObj SQL variable name of object to weight the importance
*
* @return string SQL snippet of the factor with a leading multiply sign.
*/
public function viewboxImportanceSQL($sObj)
{
$sSQL = '';
if ($this->sqlViewboxSmall) {
$sSQL = " * CASE WHEN ST_Contains($this->sqlViewboxSmall, $sObj) THEN 1 ELSE 0.5 END";
}
if ($this->sqlViewboxLarge) {
$sSQL = " * CASE WHEN ST_Contains($this->sqlViewboxLarge, $sObj) THEN 1 ELSE 0.5 END";
}
return $sSQL;
}
/**
* SQL snippet checking if a place ID should be excluded.
*
* @param string $sVariable SQL variable name of place ID to check,
* potentially prefixed with more SQL.
*
* @return string SQL snippet.
*/
public function excludeSQL($sVariable)
{
if ($this->sqlExcludeList) {
return $sVariable.$this->sqlExcludeList;
}
return '';
}
/**
* Check if the given country is covered by the search context.
*
* @param string $sCountryCode Country code of the country to check.
*
* @return True, if no country code restrictions are set or the
* country is included in the country list.
*/
public function isCountryApplicable($sCountryCode)
{
return $this->aCountryList === null || in_array($sCountryCode, $this->aCountryList);
}
public function debugInfo()
{
return array(
'Near radius' => $this->fNearRadius,
'Near point (SQL)' => $this->sqlNear,
'Bounded viewbox' => $this->bViewboxBounded,
'Viewbox (SQL, small)' => $this->sqlViewboxSmall,
'Viewbox (SQL, large)' => $this->sqlViewboxLarge,
'Viewbox (SQL, centre)' => $this->sqlViewboxCentre,
'Countries (SQL)' => $this->sqlCountryList,
'Excluded IDs (SQL)' => $this->sqlExcludeList
);
}
}