Fine-tune the admin boosting query.

query/search.js
	-Follow up on @hkrishna's work and fine-tune the admin-boosting
	query by:

		* not searching for `neighborhood` matches
		* assigning boost values to each `should` clause, with
		higher values for higher admin levels.

	-These changes fix the `West New York` in `New Jersey`
	regression pointed out in https://github.com/pelias/api/issues/91

query/search.js

@@ -33,22 +33,33 @@ function generate( params ){
     }
   };
   
+  /**
+   * If the query contained an administrative region name, boost results that
+   * contain a matching admin value, assigning higher values to higher admin
+   * levels (admin0 carries more weight than locality, for instance).
+   */
   if (params.input_admin) {
-    var admin_fields = get_layers(['admin','admin1_abbr','alpha3']);
-    query.query.filtered.query.bool.should = [];
-
-    admin_fields.forEach(function(admin_field) {
-      var match = {};
-      match[admin_field] = params.input_admin;
-      query.query.filtered.query.bool.should.push({
-         'match': match
-      });
+    var adminFieldWeights = {
+      admin0: 20,
+      alpha3: 20,
+      admin1: 10,
+      admin1_abbr: 10,
+      admin2: 5,
+      locality: 1,
+      local_admin: 1
+    };
+    query.query.filtered.query.bool.should = Object.keys( adminFieldWeights ).map( function ( field ){
+      var boostFactor = adminFieldWeights[ field ];
+      var shouldClause = { match: { } };
+      shouldClause.match[ field ] = {
+        query: params.input_admin,
+        boost: boostFactor
+      };
+      return shouldClause;
     });
   }
 
   query.sort = query.sort.concat(sort);
-  // console.log( JSON.stringify( query, null, 2 ) );
-
   return query;
 }
 

test/unit/query/search.js

@@ -238,42 +238,58 @@ module.exports.tests.query = function(test, common) {
               'should': [
                 {
                   'match': {
-                    'admin1_abbr': 'usa'
+                    'admin0': {
+                      'query': 'usa',
+                      'boost': 20
                     }
-                },
-                {
-                  'match': {
-                    'alpha3': 'usa'
                   }
                 },
                 {
                   'match': {
-                    'admin0': 'usa'
+                    'alpha3': {
+                      'query': 'usa',
+                      'boost': 20
+                    }
                   }
                 },
                 {
                   'match': {
-                    'admin1': 'usa'
+                    'admin1': {
+                      'query': 'usa',
+                      'boost': 10
+                    }
                   }
                 },
                 {
                   'match': {
-                    'admin2': 'usa'
+                    'admin1_abbr': {
+                      'query': 'usa',
+                      'boost': 10
+                    }
                   }
                 },
                 {
                   'match': {
-                    'neighborhood': 'usa'
+                    'admin2': {
+                      'query': 'usa',
+                      'boost': 5
+                    }
                   }
                 },
                 {
                   'match': {
-                    'locality': 'usa'
+                    'locality': {
+                      'query': 'usa',
+                      'boost': 1
+                    }
                   }
                 },
                 {
                   'match': {
-                    'local_admin': 'usa'
+                    'local_admin': {
+                      'query': 'usa',
+                      'boost': 1
+                    }
                   }
                 }
               ]