From 2aa1387b58bfcb54390b7449342ac29be5ac1120 Mon Sep 17 00:00:00 2001
From: DanB <danb@cgrates.org>
Date: Fri, 30 Oct 2020 13:37:29 +0100
Subject: [PATCH] Adding costWithRates skel to Rates

---
 rates/librates.go      | 24 +++++++++++++++++
 rates/librates_test.go | 61 ++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 85 insertions(+)

diff --git a/rates/librates.go b/rates/librates.go
index 2dfe08561..325d84647 100644
--- a/rates/librates.go
+++ b/rates/librates.go
@@ -132,6 +132,7 @@ func orderRatesOnIntervals(aRts []*engine.Rate, sTime time.Time, usage time.Dura
 			rWw.add(rIt)
 		}
 	}
+
 	// sort the activation times
 	sortedATimes := make([]time.Time, len(rtIdx))
 	idxATimes := 0
@@ -175,3 +176,26 @@ func orderRatesOnIntervals(aRts []*engine.Rate, sTime time.Time, usage time.Dura
 	}
 	return
 }
+
+// costWithRates will give out the cost projection for the given orderedRates and usage
+func costWithRates(rts []*orderedRate, usage time.Duration) (rtIvls []*engine.RateSInterval, err error) {
+	//var usageSIdx time.Duration // usageStart for one rate
+	for i, rt := range rts {
+		var usageEIdx time.Duration
+		if i != len(rts)-1 {
+			usageEIdx = rts[i+1].Duration
+		}
+		var iRts []*engine.IntervalRate
+		for _, iRt := range rt.IntervalRates {
+			if usageEIdx == 0 || iRt.IntervalStart < usageEIdx {
+				iRts = append(iRts, iRt)
+			}
+		}
+		//fmt.Printf("iRts: %+v\n", iRts)
+		if usageEIdx == 0 {
+			break
+		}
+		//usageSIdx = usageEIdx // continue for the next interval
+	}
+	return
+}
diff --git a/rates/librates_test.go b/rates/librates_test.go
index 1491c6760..bf5f5c81a 100644
--- a/rates/librates_test.go
+++ b/rates/librates_test.go
@@ -1574,3 +1574,64 @@ func TestOrderRatesOnIntervalStartLowerThanEndIdx(t *testing.T) {
 		t.Errorf("Expected %+v, received %+v", utils.ToJSON(expected), utils.ToJSON(ordRts))
 	}
 }
+
+func TestCostWithRates(t *testing.T) {
+	rt0 := &engine.Rate{
+		ID: "RATE0",
+		IntervalRates: []*engine.IntervalRate{
+			{
+				IntervalStart: time.Duration(0),
+				Unit:          time.Duration(1 * time.Minute),
+				Increment:     time.Duration(1 * time.Minute),
+				Value:         0.10,
+			},
+			{
+				IntervalStart: time.Duration(60 * time.Second),
+				Unit:          time.Duration(1 * time.Minute),
+				Increment:     time.Duration(1 * time.Second),
+				Value:         0.05,
+			},
+		},
+	}
+	rt0.Compile()
+
+	rt1 := &engine.Rate{
+		ID: "RATE1",
+		IntervalRates: []*engine.IntervalRate{
+			{
+
+				IntervalStart: time.Duration(0),
+				Unit:          time.Duration(1 * time.Minute),
+				Increment:     time.Duration(1 * time.Second),
+				Value:         0.20,
+			},
+			{
+
+				IntervalStart: time.Duration(2 * time.Minute),
+				Unit:          time.Duration(1 * time.Minute),
+				Increment:     time.Duration(1 * time.Second),
+				Value:         0.15,
+			},
+		},
+	}
+	rt1.Compile()
+
+	rts := []*orderedRate{
+		{
+			time.Duration(0),
+			rt0,
+		},
+		{
+			time.Duration(90 * time.Second),
+			rt1,
+		},
+	}
+
+	//eRtIvls := []*engine.RateSInterval{}
+	var eRtIvls []*engine.RateSInterval
+	if rtIvls, err := costWithRates(rts, time.Duration(130*time.Second)); err != nil {
+		t.Error(err)
+	} else if !reflect.DeepEqual(eRtIvls, rtIvls) {
+		t.Errorf("expecting: %+v, received: %+v", eRtIvls, rtIvls)
+	}
+}