using multiple suggesters but one query

controller/suggest_nearby.js

@@ -1,15 +1,16 @@
 
 var service = {
-  suggest: require('../service/suggest'),
+  suggest: require('../service/suggest_multiple'),
   mget: require('../service/mget')
 };
 var geojsonify = require('../helper/geojsonify').search;
+var resultsHelper = require('../helper/results');
 
 function setup( backend, query ){
 
   // allow overriding of dependencies
   backend = backend || require('../src/backend');
-  query = query || require('../query/suggest');
+  query = query || require('../query/suggest_multiple');
 
   function controller( req, res, next ){
 
@@ -38,6 +39,9 @@ function setup( backend, query ){
       // error handler
       if( err ){ return next( err ); }
       
+      // pick the required number of results 
+      suggested = resultsHelper.picker(suggested, req.clean.size);
+      
       // no documents suggested, return empty array to avoid ActionRequestValidationException
       if( !Array.isArray( suggested ) || !suggested.length ){
         return reply([]);

helper/results.js

@@ -0,0 +1,48 @@
+
+var picker = function( results, size ){
+  var combined = [];
+  var num_results = 0;
+
+  for (var i=0; i<results.length && num_results<size; i++) {
+    if (results[i] && results[i].length) {
+      combined[i] = combined[i] || [];
+      combined[i].push(results[i][0]);
+      results[i].splice(0,1);
+      num_results++;
+    } else {
+      results.splice(i,1);
+      i--;
+    }
+    
+    if (i === results.length-1) {
+      i=0;
+    }
+  }
+  return (combined.length > 0) ? sort_by_score(combined) : combined;
+};
+
+var dedup = function(arr) {
+  var unique_ids = [];
+  return arr.filter(function(item, pos) {
+    if (unique_ids.indexOf(item.name.default) === -1) {
+      unique_ids.push(item.name.default);
+      return true;
+    }
+    return false;
+  });
+};
+
+var sort_by_score = function(arr) {
+  return arr.map(function(doc) {
+    return doc.sort(function(a,b) {
+      return b.score - a.score;
+    });
+  }).reduce(function(a,b) { //flatten
+    return a.concat(b);
+  });
+};
+
+module.exports = {
+  picker: picker,
+  dedup: dedup
+};

query/suggest_multiple.js

@@ -0,0 +1,97 @@
+
+var logger = require('../src/logger');
+
+// Build pelias suggest query
+function generate( params, precision ){
+
+  var getPrecision = function(zoom) {
+    switch (true) {
+      case (zoom > 15):
+        return 5; // zoom: >= 16
+      case (zoom > 9):
+        return 4; // zoom: 10-15
+      case (zoom > 5):
+        return 3; // zoom: 6-9
+      case (zoom > 3):
+        return 2; // zoom: 4-5
+      default:
+        return 1; // zoom: 1-3 or when zoom: undefined
+    }
+  };
+
+  var cmd = {
+    'text' : params.input,
+    'pelias_1' : {
+      'completion' : {
+        'size' : params.size,
+        'field' : 'suggest',
+        'context': {
+          'dataset': params.layers,
+          'location': {
+            'value': [ params.lon, params.lat ],
+            'precision': 5
+          }
+        }
+      }
+    },
+    'pelias_2' : {
+      'completion' : {
+        'size' : params.size,
+        'field' : 'suggest',
+        'context': {
+          'dataset': params.layers,
+          'location': {
+            'value': [ params.lon, params.lat ],
+            'precision': 3
+          }
+        }
+      }
+    },
+    'pelias_3' : {
+      'completion' : {
+        'size' : params.size,
+        'field' : 'suggest',
+        'context': {
+          'dataset': params.layers,
+          'location': {
+            'value': [ params.lon, params.lat ],
+            'precision': 1
+          }
+        }
+      }
+    },
+    'pelias_4' : {
+      'completion' : {
+        'size' : params.size,
+        'field' : 'suggest',
+        'context': {
+          'dataset': ['admin0', 'admin1', 'admin2'],
+          'location': {
+            'value': [ params.lon, params.lat ],
+            'precision': precision || getPrecision(params.zoom)
+          }
+        }
+      }
+    },
+    'pelias_5' : {
+      'completion' : {
+        'size' : params.size,
+        'field' : 'suggest',
+        'context': {
+          'dataset': params.layers,
+          'location': {
+            'value': [ params.lon, params.lat ],
+            'precision': 3
+          }
+        },
+        'fuzzy': {}
+      }
+    }
+  };
+
+  // logger.log( 'cmd', JSON.stringify( cmd, null, 2 ) );
+  return cmd;
+
+}
+
+module.exports = generate;

service/suggest_multiple.js

@@ -0,0 +1,44 @@
+
+/**
+
+  cmd can be any valid ES suggest command
+
+**/
+
+function service( backend, cmd, cb ){
+  // query new backend
+  backend().client.suggest( cmd, function( err, data ){
+    // handle backend errors
+    if( err ){ return cb( err ); }
+    
+    // map returned documents
+    
+    var docs = [];
+    var unique_ids = [];
+    var num_keys = Object.keys(data).length;
+    var has_docs = function(obj) {
+      return Array.isArray( obj ) && obj.length && obj[0].options && obj[0].options.length;
+    };
+    for (var i=1, j=0; i<num_keys && j<num_keys; i++) {
+      var keys = 'pelias_'+i;
+      if ( has_docs(data[keys]) ){
+        docs[i] = docs[i] || [];
+        var res = data[keys][0].options[0];
+        if (unique_ids.indexOf(res.text) === -1) {
+          docs[i].push(res);
+          unique_ids.push(res.text);
+        } 
+        data[keys][0].options.splice(0,1);
+      } else {
+        j++;
+      }
+      i = i === num_keys-1 ? 1 : i;
+    }
+
+    // fire callback
+    return cb( null, docs);
+  });
+
+}
+
+module.exports = service;