started adding test for shared group and created utility methods for

getting shared balances

engine/sharedgroup.go

@@ -18,6 +18,18 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>
 
 package engine
 
+import (
+	"math"
+	"math/rand"
+	"time"
+)
+
+const (
+	STRATEGY_LOWEST_FIRST  = "*lowest_first"
+	STRATEGY_HIGHEST_FIRST = "*highest_first"
+	STRATEGY_RANDOM        = "*random"
+)
+
 type SharedGroup struct {
 	Id          string
 	Strategy    string
@@ -26,3 +38,46 @@ type SharedGroup struct {
 	Weight      float64
 	Members     []string
 }
+
+func (sg *SharedGroup) GetMembersExceptUser(ubId string) []string {
+	for i, m := range sg.Members {
+		if m == ubId {
+			a := make([]string, len(sg.Members))
+			copy(a, sg.Members)
+			a[i], a = a[len(a)-1], a[:len(a)-1]
+			return a
+		}
+	}
+	return sg.Members
+}
+
+func (sg *SharedGroup) PopBalanceByStrategy(balanceChain *BalanceChain) (bal *Balance) {
+	bc := *balanceChain
+	if len(bc) == 0 {
+		return
+	}
+	index := 0
+	switch sg.Strategy {
+	case STRATEGY_RANDOM:
+		rand.Seed(time.Now().Unix())
+		index = rand.Intn(len(bc))
+	case STRATEGY_LOWEST_FIRST:
+		minVal := math.MaxFloat64
+		for i, b := range bc {
+			if b.Value < minVal {
+				minVal = b.Value
+				index = i
+			}
+		}
+	case STRATEGY_HIGHEST_FIRST:
+		maxVal := math.SmallestNonzeroFloat64
+		for i, b := range bc {
+			if b.Value > maxVal {
+				maxVal = b.Value
+				index = i
+			}
+		}
+	}
+	bal, bc[index], *balanceChain = bc[index], bc[len(bc)-1], bc[:len(bc)-1]
+	return
+}