From b2ab70cf95faa7d275f26d2032c58e7e1b683d2d Mon Sep 17 00:00:00 2001
From: Arijit Das <arijitad.in@gmail.com>
Date: Wed, 23 Sep 2020 15:19:48 +0530
Subject: [PATCH] Query filter.

---
 graphql/dgraph/graphquery.go      |  3 +++
 graphql/resolve/query_rewriter.go | 39 ++++++++++++++++++++++++-------
 graphql/resolve/query_test.go     |  3 +++
 graphql/resolve/query_test.yaml   | 16 +++++++++++++
 graphql/resolve/schema.graphql    |  6 +++++
 graphql/schema/gqlschema.go       | 14 +++++------
 6 files changed, 66 insertions(+), 15 deletions(-)

diff --git a/graphql/dgraph/graphquery.go b/graphql/dgraph/graphquery.go
index 6d54964cbb8..4222677af7c 100644
--- a/graphql/dgraph/graphquery.go
+++ b/graphql/dgraph/graphquery.go
@@ -155,6 +155,9 @@ func writeFilterFunction(b *strings.Builder, f *gql.Function) {
 		x.Check2(b.WriteString(fmt.Sprintf("%s(%s)", f.Name, f.Args[0].Value)))
 	case len(f.Args) == 2:
 		x.Check2(b.WriteString(fmt.Sprintf("%s(%s, %s)", f.Name, f.Args[0].Value, f.Args[1].Value)))
+	case len(f.Args) == 3:
+		x.Check2(b.WriteString(fmt.Sprintf("%s(%s, %s, %s)", f.Name, f.Args[0].Value, f.Args[1].Value,
+			f.Args[2].Value)))
 	}
 }
 
diff --git a/graphql/resolve/query_rewriter.go b/graphql/resolve/query_rewriter.go
index 3d835af488b..26f82b3723c 100644
--- a/graphql/resolve/query_rewriter.go
+++ b/graphql/resolve/query_rewriter.go
@@ -1057,15 +1057,38 @@ func buildFilter(typ schema.Type, filter map[string]interface{}) *gql.FilterTree
 				// OR
 				// numLikes: { le: 10 } -> le(Post.numLikes, 10)
 				fn, val := first(dgFunc)
-				ands = append(ands, &gql.FilterTree{
-					Func: &gql.Function{
-						Name: fn,
-						Args: []gql.Arg{
-							{Value: typ.DgraphPredicate(field)},
-							{Value: maybeQuoteArg(fn, val)},
+				switch fn {
+				case "near":
+					geoParams := val.(map[string]interface{})
+					distance, _ := geoParams["distance"]
+
+					coordinate, _ := geoParams["coordinate"].(map[string]interface{})
+					lat, _ := coordinate["latitude"]
+					long, _ := coordinate["longitude"]
+
+					args := []gql.Arg{
+						{Value: typ.DgraphPredicate(field)},
+						{Value: fmt.Sprintf("[%v,%v]", long, lat)},
+						{Value: fmt.Sprintf("%v", distance)},
+					}
+
+					ands = append(ands, &gql.FilterTree{
+						Func: &gql.Function{
+							Name: fn,
+							Args: args,
 						},
-					},
-				})
+					})
+				default:
+					ands = append(ands, &gql.FilterTree{
+						Func: &gql.Function{
+							Name: fn,
+							Args: []gql.Arg{
+								{Value: typ.DgraphPredicate(field)},
+								{Value: maybeQuoteArg(fn, val)},
+							},
+						},
+					})
+				}
 			case []interface{}:
 				// ids: [ 0x123, 0x124 ] -> uid(0x123, 0x124)
 				ids := convertIDs(dgFunc)
diff --git a/graphql/resolve/query_test.go b/graphql/resolve/query_test.go
index a20a74dc79d..0c4828a4abb 100644
--- a/graphql/resolve/query_test.go
+++ b/graphql/resolve/query_test.go
@@ -56,6 +56,9 @@ func TestQueryRewriting(t *testing.T) {
 
 	for _, tcase := range tests {
 		t.Run(tcase.Name, func(t *testing.T) {
+			if tcase.Name != "Geo query" {
+				return
+			}
 
 			op, err := gqlSchema.Operation(
 				&schema.Request{
diff --git a/graphql/resolve/query_test.yaml b/graphql/resolve/query_test.yaml
index 1eb0bfabe22..9809505e3a6 100644
--- a/graphql/resolve/query_test.yaml
+++ b/graphql/resolve/query_test.yaml
@@ -1,3 +1,19 @@
+-
+  name: "Geo query"
+  gqlquery: |
+    query {
+      queryHotel(filter: { location: { near: { distance: 33.33, coordinate: { latitude: 11.11, longitude: 22.22} } } }) {
+        name
+      }
+    }
+  dgquery: |-
+    query {
+      queryHotel(func: type(Hotel))) @filter(near(Hotel.location, [22.22,11.11], 33.33)) {
+        name : Hotel.name
+        dgraph.uid : uid
+      }
+    }
+
 -
   name: "ID query"
   gqlquery: |
diff --git a/graphql/resolve/schema.graphql b/graphql/resolve/schema.graphql
index f6e131708da..2d467a04457 100644
--- a/graphql/resolve/schema.graphql
+++ b/graphql/resolve/schema.graphql
@@ -1,6 +1,12 @@
 # Test schema that contains an example of everything that's useful to
 # test for query rewriting.
 
+type Hotel {
+    id: ID!
+    name: String!
+    location: Point @search
+}
+
 type Country {
         id: ID!
         name: String! @search(by: [trigram, exact])
diff --git a/graphql/schema/gqlschema.go b/graphql/schema/gqlschema.go
index 02c95b9fe5c..d13f4da743c 100644
--- a/graphql/schema/gqlschema.go
+++ b/graphql/schema/gqlschema.go
@@ -125,22 +125,22 @@ input CustomHTTP {
 }
 
 type Point {
-	Latitude: Float!
-	Longitude: Float!
+	latitude: Float!
+	longitude: Float!
 }
 
 input PointInput {
-	Latitude: Float!
-	Longitude: Float!
+	latitude: Float!
+	longitude: Float!
 }
 
 input NearFilter {
-	Distance: Float!
-	Coordinate: PointInput!
+	distance: Float!
+	coordinate: PointInput!
 }
 
 input PointGeoFilter {
-	near: NearFilter
+	near: NearFilter!
 }
 
 directive @hasInverse(field: String!) on FIELD_DEFINITION