Fix/implement distance

main.go

@@ -1,3 +1,4 @@
 package main
 
-func main() {}
+func main() {
+}

repository/distance/calculate.go

@@ -0,0 +1,40 @@
+package distance
+
+import (
+	"math"
+	"mock-shipping-provider/primitive"
+	"mock-shipping-provider/repository"
+)
+
+type CalculateDistance struct {
+	Radius             float64
+	ServicableDistance float64
+}
+
+func NewCalculateDistance() repository.DistanceCalculation {
+	return &CalculateDistance{
+		Radius:             6371.0,
+		ServicableDistance: 5245.0,
+	}
+}
+
+func (c *CalculateDistance) Calculate(from primitive.Coordinate, to primitive.Coordinate) (distance float64, serviceable bool) {
+	lat1Rad := from.Latitude * math.Pi / 180
+	lon1Rad := from.Longitude * math.Pi / 180
+	lat2Rad := to.Latitude * math.Pi / 180
+	lon2Rad := to.Longitude * math.Pi / 180
+
+	dlat := lat2Rad - lat1Rad
+	dlon := lon2Rad - lon1Rad
+
+	a := math.Sin(dlat/2)*math.Sin(dlat/2) + math.Cos(lat1Rad)*math.Cos(lat2Rad)*math.Sin(dlon/2)*math.Sin(dlon/2)
+	cal := 2 * math.Atan2(math.Sqrt(a), math.Sqrt(1-a))
+
+	distanceCalculation := c.Radius * cal
+
+	if distanceCalculation > c.ServicableDistance {
+		return distanceCalculation, false
+	}
+
+	return distanceCalculation, true
+}

repository/distance/calculate_test.go

@@ -0,0 +1,44 @@
+package distance_test
+
+import (
+	"mock-shipping-provider/primitive"
+	"mock-shipping-provider/repository/distance"
+	"testing"
+)
+
+func TestDistanceCalculation(t *testing.T) {
+	distanceCalculation := distance.NewCalculateDistance()
+
+	t.Run("test distance not service", func(t *testing.T) {
+		from := primitive.Coordinate{
+			Latitude:  -4.5387718,
+			Longitude: 120.3146973,
+		}
+
+		to := primitive.Coordinate{
+			Latitude:  40.7128,
+			Longitude: -74.0060,
+		}
+		distance, serviceable := distanceCalculation.Calculate(from, to)
+		if serviceable {
+			t.Errorf("must not servicable: %v", distance)
+		}
+	})
+
+	t.Run("test distance serviceable", func(t *testing.T) {
+		from := primitive.Coordinate{
+			Latitude:  -6.1601629,
+			Longitude: 106.6793193,
+		}
+
+		to := primitive.Coordinate{
+			Latitude:  -4.5387718,
+			Longitude: 120.3146973,
+		}
+		distance, serviceable := distanceCalculation.Calculate(from, to)
+		if !serviceable {
+			t.Errorf("must be servicable: %v", distance)
+		}
+	})
+
+}