From 647bfd10add83d43e5f67afa256ecc298a46202a Mon Sep 17 00:00:00 2001
From: Marty Schoch <marty.schoch@gmail.com>
Date: Fri, 4 Nov 2016 14:02:01 -0400
Subject: [PATCH] fix date facets when using MultiSearch

changed date parsing to NOT update internal state of the date
range object (avoids races)

second, when marshaling a facet date range, we now use the
string version, if the time.Time is zero and the string version
is not ""
---
 index_impl.go |  4 ++--
 search.go     | 28 +++++++++++++++++++++++-----
 2 files changed, 25 insertions(+), 7 deletions(-)

diff --git a/index_impl.go b/index_impl.go
index 20808736..12e0fd35 100644
--- a/index_impl.go
+++ b/index_impl.go
@@ -395,8 +395,8 @@ func (i *indexImpl) SearchInContext(ctx context.Context, req *SearchRequest) (sr
 				facetBuilder := facet.NewDateTimeFacetBuilder(facetRequest.Field, facetRequest.Size)
 				dateTimeParser := i.m.DateTimeParserNamed("")
 				for _, dr := range facetRequest.DateTimeRanges {
-					dr.ParseDates(dateTimeParser)
-					facetBuilder.AddRange(dr.Name, dr.Start, dr.End)
+					start, end := dr.ParseDates(dateTimeParser)
+					facetBuilder.AddRange(dr.Name, start, end)
 				}
 				facetsBuilder.Add(facetName, facetBuilder)
 			} else {
diff --git a/search.go b/search.go
index b389cce1..f9467e0e 100644
--- a/search.go
+++ b/search.go
@@ -38,19 +38,22 @@ type dateTimeRange struct {
 	endString   *string
 }
 
-func (dr *dateTimeRange) ParseDates(dateTimeParser analysis.DateTimeParser) {
+func (dr *dateTimeRange) ParseDates(dateTimeParser analysis.DateTimeParser) (start, end time.Time) {
+	start = dr.Start
 	if dr.Start.IsZero() && dr.startString != nil {
-		start, err := dateTimeParser.ParseDateTime(*dr.startString)
+		s, err := dateTimeParser.ParseDateTime(*dr.startString)
 		if err == nil {
-			dr.Start = start
+			start = s
 		}
 	}
+	end = dr.End
 	if dr.End.IsZero() && dr.endString != nil {
-		end, err := dateTimeParser.ParseDateTime(*dr.endString)
+		e, err := dateTimeParser.ParseDateTime(*dr.endString)
 		if err == nil {
-			dr.End = end
+			end = e
 		}
 	}
+	return start, end
 }
 
 func (dr *dateTimeRange) UnmarshalJSON(input []byte) error {
@@ -76,6 +79,21 @@ func (dr *dateTimeRange) UnmarshalJSON(input []byte) error {
 	return nil
 }
 
+func (dr *dateTimeRange) MarshalJSON() ([]byte, error) {
+	rv := map[string]interface{}{
+		"name":  dr.Name,
+		"start": dr.Start,
+		"end":   dr.End,
+	}
+	if dr.Start.IsZero() && dr.startString != nil {
+		rv["start"] = dr.startString
+	}
+	if dr.End.IsZero() && dr.endString != nil {
+		rv["end"] = dr.endString
+	}
+	return json.Marshal(rv)
+}
+
 // A FacetRequest describes a facet or aggregation
 // of the result document set you would like to be
 // built.