Added "streets within" query to API

api/within.js

@@ -0,0 +1,75 @@
+const Database = require('better-sqlite3');
+const polyline = require('@mapbox/polyline');
+const query = { within: require('../query/within') };
+const project = require('../lib/project');
+const proximity = require('../lib/proximity');
+
+// polyline precision
+const PRECISION = 6;
+
+// export setup method
+function setup( streetDbPath ){
+
+  // connect to db
+  // @todo: this is required as the query uses the 'street.' prefix for tables
+  const db = new Database(':memory:');
+
+  // attach street database
+  db.exec(`ATTACH DATABASE '${streetDbPath}' as 'street'`);
+
+  // query method
+  var q = function( topLeftCoord, bottomRightCoord, cb ){
+
+    var topLeft = {
+      lat: parseFloat( topLeftCoord.lat ),
+      lon: parseFloat( topLeftCoord.lon )
+    };
+
+    var bottomRight = {
+      lat: parseFloat( bottomRightCoord.lat ),
+      lon: parseFloat( bottomRightCoord.lon )
+    };
+
+    // error checking
+    if( isNaN( topLeft.lat ) ){ return cb( 'invalid latitude' ); }
+    if( isNaN( topLeft.lon ) ){ return cb( 'invalid longitude' ); }
+
+    if( isNaN( bottomRight.lat ) ){ return cb( 'invalid latitude' ); }
+    if( isNaN( bottomRight.lon ) ){ return cb( 'invalid longitude' ); }
+
+    try {
+      // perform a db lookup for nearby streets
+      const res = query.within( db, topLeft, bottomRight );
+
+      // no results were found
+      if( !res || !res.length ){ return cb( null, null ); }
+
+      // decode polylines
+      res.forEach( function( street, i ){
+        res[i].coordinates = project.dedupe( polyline.toGeoJSON(street.line, PRECISION).coordinates );
+      });
+
+      var center = {
+          lat: (topLeft.lat + bottomRight.lat) / 2,
+          lon: (topLeft.lon + bottomRight.lon) / 2
+        };
+
+      // order streets by proximity from point (by projecting it on to each line string)
+      var ordered = proximity.nearest.street( res, [ center.lon, center.lat ] );
+
+      // return streets ordered ASC by distance from point
+      cb( null, ordered );
+    } catch (err) {
+      // an error occurred
+      return cb(err, null);
+    }
+  };
+
+  // return methods
+  return {
+    query: q,
+    close: db.close.bind( db ),
+  };
+}
+
+module.exports = setup;

cmd/server.js

@@ -4,6 +4,7 @@ const search = require('../api/search');
 const extract = require('../api/extract');
 const street = require('../api/street');
 const near = require('../api/near');
+const within= require('../api/within');
 const pretty = require('../lib/pretty');
 const analyze = require('../lib/analyze');
 
@@ -32,7 +33,8 @@ const conn = {
   search: search( process.argv[2], process.argv[3] ),
   extract: extract( process.argv[2], process.argv[3] ),
   street: street( process.argv[3] ),
-  near: near( process.argv[3] )
+  near: near( process.argv[3] ),
+  within: within( process.argv[3] )
 };
 
 function log() {
@@ -172,6 +174,41 @@ app.get('/street/near/geojson', function( req, res ){
   });
 });
 
+// get streets within bounding box
+// eg: http://localhost:3000/street/within/geojson
+app.get('/street/within/geojson', function( req, res ){
+
+  var topLeft = { lat: req.query.topLeftLat, lon: req.query.topLeftLon };
+  var bottomRight = { lat: req.query.bottomRightLat, lon: req.query.bottomRightLon };
+
+  conn.within.query( topLeft, bottomRight, function( err, ordered ){
+    if( err ){ return res.status(400).json( formatError( err ) ); }
+    if( !ordered || !ordered.length ){ return res.status(200).json({}); }
+
+    var geojson = {
+      'type': 'FeatureCollection',
+      'features': ordered.map( function( o ){
+        return {
+          'type': 'Feature',
+          'properties': {
+            'id': o.street.id,
+            'name': Array.isArray( o.street.name ) ? o.street.name[0] : o.street.name,
+            'polyline': o.street.line,
+            'distance': ( Math.floor(( o.proj.dist || 0 ) * 1000000 ) / 1000000 ),
+            'projection': o.proj.point
+          },
+          'geometry': {
+            'type': 'LineString',
+            'coordinates': o.street.coordinates
+          }
+        };
+      })
+    };
+
+    res.json( geojson );
+  });
+});
+
 // get street geometry as geojson
 // eg: http://localhost:3000/street/1/geojson
 app.get('/street/:id/geojson', function( req, res ){

query/within.js

@@ -0,0 +1,33 @@
+const DynamicQueryCache = require('./DynamicQueryCache');
+
+// Remove before PR.
+const logger = require('pelias-logger').get('interpolation');
+
+/**
+  find all streets which have a bbox which envelops the specified point; regardless of their names.
+**/
+
+const SQL = `
+  SELECT street.polyline.id, street.polyline.line, street.names.name FROM street.polyline
+  JOIN street.rtree ON street.rtree.id = street.polyline.id
+  JOIN street.names ON street.names.id = street.polyline.id
+  WHERE ((street.rtree.minX + street.rtree.maxX) / 2 BETWEEN $topLeftLon AND $bottomRightLon 
+  AND (street.rtree.minY + street.rtree.maxY) / 2 BETWEEN $bottomRightLat AND $topLeftLat )
+  GROUP BY street.polyline.id;
+`;
+
+const cache = new DynamicQueryCache(SQL);
+
+module.exports = ( db, topLeft, bottomRight) => {
+
+  // use a prepared statement from cache (or generate one if not yet cached)
+  const stmt = cache.getStatement(db);
+
+  // execute statement
+  return stmt.all({
+    topLeftLat: topLeft.lat,
+    topLeftLon: topLeft.lon,
+    bottomRightLat: bottomRight.lat,
+    bottomRightLon: bottomRight.lon,
+  });
+};

readme.md

@@ -253,6 +253,11 @@ The API supports additional environment variables that affect its operation:
 
 `geojson`: `/street/near/geojson?lat=-41.288788&lon=174.766843`
 
+### GET /street/within/geojson
+> Get all streets within a lat/lon bounding box, ordered by distance to the center, ASC. The top/left pair should contain the minimum longitude and the maximum latitude, and the bottom/left pair should contain the maximum longitude and the minimum latitude.
+
+`geojson`: `/street/within/geojson?topLeftLat=-41.28&topLeftLon=174.76&bottomRightLat=-41.38&bottomRightLon=174.86`
+
 ### GET /street/{id}/geojson
 > return the geometry for a specific street id