From 74632b5e983281424d1fda0a9ca7eeda093a1df9 Mon Sep 17 00:00:00 2001
From: utkarshcmu <utkarsh.cmu@gmail.com>
Date: Mon, 7 Nov 2016 17:28:30 -0800
Subject: [PATCH 1/2] Added last function for alerting conditions

---
 pkg/services/alerting/conditions/reducer.go      | 7 +++++++
 pkg/services/alerting/conditions/reducer_test.go | 6 ++++++
 public/app/features/alerting/alert_def.ts        | 1 +
 3 files changed, 14 insertions(+)

diff --git a/pkg/services/alerting/conditions/reducer.go b/pkg/services/alerting/conditions/reducer.go
index a982fa63d33..5fbaeb18326 100644
--- a/pkg/services/alerting/conditions/reducer.go
+++ b/pkg/services/alerting/conditions/reducer.go
@@ -62,6 +62,13 @@ func (s *SimpleReducer) Reduce(series *tsdb.TimeSeries) null.Float {
 	case "count":
 		value = float64(len(series.Points))
 		allNull = false
+	case "last":
+		for _, point := range series.Points {
+			if point[0].Valid {
+				value = point[0].Float64
+				allNull = false
+			}
+		}
 	}
 
 	if allNull {
diff --git a/pkg/services/alerting/conditions/reducer_test.go b/pkg/services/alerting/conditions/reducer_test.go
index 198a52b746a..dfd229e1374 100644
--- a/pkg/services/alerting/conditions/reducer_test.go
+++ b/pkg/services/alerting/conditions/reducer_test.go
@@ -35,6 +35,12 @@ func TestSimpleReducer(t *testing.T) {
 			result := testReducer("count", 1, 2, 3000)
 			So(result, ShouldEqual, float64(3))
 		})
+
+		Convey("last", func() {
+			result := testReducer("last", 1, 2, 3000)
+			So(result, ShouldEqual, float64(3000))
+		})
+
 	})
 }
 
diff --git a/public/app/features/alerting/alert_def.ts b/public/app/features/alerting/alert_def.ts
index aaddb9e425f..8ee1981f3d8 100644
--- a/public/app/features/alerting/alert_def.ts
+++ b/public/app/features/alerting/alert_def.ts
@@ -34,6 +34,7 @@ var reducerTypes = [
   {text: 'max()', value: 'max'},
   {text: 'sum()' , value: 'sum'},
   {text: 'count()', value: 'count'},
+  {text: 'last()', value: 'last'},
 ];
 
 var noDataModes = [

From 841fb74b39736e85987389389c10a550543cc0fb Mon Sep 17 00:00:00 2001
From: utkarshcmu <utkarsh.cmu@gmail.com>
Date: Mon, 7 Nov 2016 23:15:47 -0800
Subject: [PATCH 2/2] Reversed loop for last function

---
 pkg/services/alerting/conditions/reducer.go | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/pkg/services/alerting/conditions/reducer.go b/pkg/services/alerting/conditions/reducer.go
index 5fbaeb18326..988a640591d 100644
--- a/pkg/services/alerting/conditions/reducer.go
+++ b/pkg/services/alerting/conditions/reducer.go
@@ -63,10 +63,12 @@ func (s *SimpleReducer) Reduce(series *tsdb.TimeSeries) null.Float {
 		value = float64(len(series.Points))
 		allNull = false
 	case "last":
-		for _, point := range series.Points {
-			if point[0].Valid {
-				value = point[0].Float64
+		points := series.Points
+		for i := len(points) - 1; i >= 0; i-- {
+			if points[i][0].Valid {
+				value = points[i][0].Float64
 				allNull = false
+				break
 			}
 		}
 	}