mprins / dokuwiki-plugin-spatialhelper

helper/search.php

<?php
/*
 * Copyright (c) 2011-2014 Mark C. Prins <mprins@users.sf.net>
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

/**
 * DokuWiki Plugin spatialhelper (Search component).
 *
 * @license BSD license
 * @author  Mark Prins
 */
class helper_plugin_spatialhelper_search extends DokuWiki_Plugin {
    /**
     * spatial index.
     *
     * @var array
     */
    protected $spatial_idx = array();
    /**
     * handle to the geoPHP plugin.
     */
    protected $geophp;
    /**
     * Precision, Distance of Adjacent Cell in Meters.
     *
     * @see https://stackoverflow.com/questions/13836416/geohash-and-max-distance
     *
     * @var float
     */
    private $precision = array(
        5003530,
        625441,
        123264,
        19545,
        3803,
        610,
        118,
        19,
        3.7,
        0.6
    );

    /**
     * constructor; initialize/load spatial index.
     */
    public function __construct() {
        // parent::__construct ();
        global $conf;

        if(!$geophp = plugin_load('helper', 'geophp')) {
            $message = 'helper_plugin_spatialhelper_search::spatialhelper_search: geophp plugin is not available.';
            msg($message, -1);
        }

        $idx_dir = $conf ['indexdir'];
        if(!@file_exists($idx_dir . '/spatial.idx')) {
            $indexer = plugin_load('helper', 'spatialhelper_index');

$indexer is not used, you could remove the assignment.

        }

        $this->spatial_idx = unserialize(io_readFile($fn = $idx_dir . '/spatial.idx', false));
    }

    /**
     * Find locations based on the coordinate pair.
     *
     * @param float $lat
     *          The y coordinate (or latitude)
     * @param float $lon
     *          The x coordinate (or longitude)
     */
    public function findNearbyLatLon(float $lat, float $lon): array {
        $geometry = new Point($lon, $lat);
        return $this->findNearby($geometry->out('geohash'), $geometry);
    }

    /**
     * finds nearby elements in the index based on the geohash.
     * returns a list of documents and the bunding box.
     *
     * @param string $geohash
     * @param Point  $p
     *          optional point
     * @return array of ...
     */
    public function findNearby(string $geohash, Point $p = null): array {
        $_geohashClass = new Geohash();
        if(!$p) {
            $decodedPoint = $_geohashClass->read($geohash);
        } else {
            $decodedPoint = $p;
        }

        // find adjacent blocks
        $adjacent                 = array();
        $adjacent ['center']      = $geohash;
        $adjacent ['top']         = $_geohashClass->adjacent($adjacent ['center'], 'top');
        $adjacent ['bottom']      = $_geohashClass->adjacent($adjacent ['center'], 'bottom');
        $adjacent ['right']       = $_geohashClass->adjacent($adjacent ['center'], 'right');
        $adjacent ['left']        = $_geohashClass->adjacent($adjacent ['center'], 'left');
        $adjacent ['topleft']     = $_geohashClass->adjacent($adjacent ['left'], 'top');
        $adjacent ['topright']    = $_geohashClass->adjacent($adjacent ['right'], 'top');
        $adjacent ['bottomright'] = $_geohashClass->adjacent($adjacent ['right'], 'bottom');
        $adjacent ['bottomleft']  = $_geohashClass->adjacent($adjacent ['left'], 'bottom');
        dbglog($adjacent, "adjacent geo hashes:");

        // find all the pages in the index that overlap with the adjacent hashes
        $docIds = array();
        foreach($adjacent as $adjHash) {
            if(is_array($this->spatial_idx)) {
                foreach($this->spatial_idx as $_geohash => $_docIds) {
                    if(strpos($_geohash, $adjHash) !== false) {
                        // dbglog ( "Found adjacent geo hash: $adjHash in $_geohash" );
                        // if $adjHash similar to geohash
                        $docIds = array_merge($docIds, $_docIds);
                    }
                }
            }
        }
        $docIds = array_unique($docIds);
        dbglog($docIds, "found docIDs");

        // create associative array of pages + calculate distance
        $pages   = array();
        $media   = array();
        $indexer = plugin_load('helper', 'spatialhelper_index');

        foreach($docIds as $id) {
            if(strpos($id, 'media__', 0) === 0) {
                $id = substr($id, strlen('media__'));
                if(auth_quickaclcheck($id) >= /*AUTH_READ*/ 1) {
                    $point    = $indexer->getCoordsFromExif($id);
                    $line     = new LineString(
                        [
                            $decodedPoint,
                            $point
                        ]
                    );
                    $media [] = array(
                        'id'       => $id,
                        'distance' => (int) ($line->greatCircleLength()),
                        'lat'      => $point->y(),
                        'lon'      => $point->x()
                        // optionally add other meta such as tag, description...
                    );
                }
            } else {
                if(auth_quickaclcheck($id) >= /*AUTH_READ*/ 1) {
                    $geotags  = p_get_metadata($id, 'geo');
                    $point    = new Point($geotags ['lon'], $geotags ['lat']);
                    $line     = new LineString(
                        [
                            $decodedPoint,
                            $point
                        ]
                    );
                    $pages [] = array(
                        'id'          => $id,
                        'distance'    => (int) ($line->greatCircleLength()),
                        'description' => p_get_metadata($id, 'description')['abstract'],
                        'lat'         => $geotags ['lat'],
                        'lon'         => $geotags ['lon']
                        // optionally add other meta such as tag...
                    );
                }
            }
        }

        // sort all the pages/media using distance
        usort(
            $pages, static function ($a, $b) {
            return strnatcmp($a ['distance'], $b ['distance']);
        }
        );
        usort(
            $media, static function ($a, $b) {
            return strnatcmp($a ['distance'], $b ['distance']);
        }
        );

        return array(
            'pages'     => $pages,
            'media'     => $media,
            'lat'       => $decodedPoint->y(),
            'lon'       => $decodedPoint->x(),
            'geohash'   => $geohash,
            'precision' => $this->precision [strlen($geohash)]
        );
    }
}