Initial QSfera import

Server/services/graph/pkg/service/v0/ordering.go

@@ -0,0 +1,32 @@
+package svc
+
+import (
+	"strings"
+
+	libregraph "github.com/opencloud-eu/libre-graph-api-go"
+)
+
+// lessSpacesByLastModifiedDateTime reports whether the element i
+// must sort before the element j.
+func lessSpacesByLastModifiedDateTime(i, j *libregraph.Drive) bool {
+	// compare the items when both dates are set
+	if i.LastModifiedDateTime != nil && j.LastModifiedDateTime != nil {
+		return i.LastModifiedDateTime.Before(*j.LastModifiedDateTime)
+	}
+	// an item without a timestamp is considered "less than" an item with a timestamp
+	if i.LastModifiedDateTime == nil && j.LastModifiedDateTime != nil {
+		return true
+	}
+	// an item without a timestamp is considered "less than" an item with a timestamp
+	if i.LastModifiedDateTime != nil && j.LastModifiedDateTime == nil {
+		return false
+	}
+	// fallback to name if no dateTime is set on both items
+	return strings.ToLower(i.Name) < strings.ToLower(j.Name)
+}
+
+func reverse(less func(i, j int) bool) func(i, j int) bool {
+	return func(i, j int) bool {
+		return !less(i, j)
+	}
+}