Import of https://github.com/ciena/voltctl at commit 40d61fbf3f910ed4017cf67c9c79e8e1f82a33a5
Change-Id: I8464c59e60d76cb8612891db3303878975b5416c
diff --git a/pkg/order/order.go b/pkg/order/order.go
new file mode 100644
index 0000000..715b302
--- /dev/null
+++ b/pkg/order/order.go
@@ -0,0 +1,172 @@
+/*
+ * Copyright 2019-present Ciena Corporation
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package order
+
+import (
+ "fmt"
+ "reflect"
+ "sort"
+ "strings"
+)
+
+type Operation int
+
+const (
+ ASC Operation = iota
+ DSC
+)
+
+type SortTerm struct {
+ Op Operation
+ Name string
+}
+
+func (o Operation) String() string {
+ switch o {
+ default:
+ fallthrough
+ case ASC:
+ return "ASC"
+ case DSC:
+ return "DSC"
+ }
+}
+
+type Sorter []SortTerm
+
+func split(term string) SortTerm {
+ st := SortTerm{}
+ if len(term) > 0 {
+ switch term[0] {
+ case '+':
+ fallthrough
+ case '>':
+ st.Op = ASC
+ st.Name = term[1:]
+ case '-':
+ fallthrough
+ case '<':
+ st.Op = DSC
+ st.Name = term[1:]
+ default:
+ st.Op = ASC
+ st.Name = term
+ }
+ } else {
+ st.Op = ASC
+ st.Name = term
+ }
+ return st
+}
+
+// Parse parses a comma separated list of filter terms
+func Parse(spec string) (Sorter, error) {
+ terms := strings.Split(spec, ",")
+ s := make([]SortTerm, 0)
+ for _, term := range terms {
+ s = append(s, split(term))
+ }
+
+ return s, nil
+}
+
+func (s Sorter) Process(data interface{}) (interface{}, error) {
+ slice := reflect.ValueOf(data)
+ if slice.Kind() != reflect.Slice {
+ return data, nil
+ }
+
+ sort.SliceStable(data, func(i, j int) bool {
+ left := reflect.ValueOf(slice.Index(i).Interface())
+ right := reflect.ValueOf(slice.Index(j).Interface())
+ for _, term := range s {
+ fleft := left.FieldByName(term.Name)
+ fright := right.FieldByName(term.Name)
+ switch fleft.Kind() {
+ case reflect.Uint:
+ fallthrough
+ case reflect.Uint8:
+ fallthrough
+ case reflect.Uint16:
+ fallthrough
+ case reflect.Uint32:
+ fallthrough
+ case reflect.Uint64:
+ ileft := fleft.Uint()
+ iright := fright.Uint()
+ switch term.Op {
+ case ASC:
+ if ileft < iright {
+ return true
+ } else if ileft > iright {
+ return false
+ }
+ case DSC:
+ if ileft > iright {
+ return true
+ } else if ileft < iright {
+ return false
+ }
+ }
+ case reflect.Int:
+ fallthrough
+ case reflect.Int8:
+ fallthrough
+ case reflect.Int16:
+ fallthrough
+ case reflect.Int32:
+ fallthrough
+ case reflect.Int64:
+ ileft := fleft.Int()
+ iright := fright.Int()
+ switch term.Op {
+ case ASC:
+ if ileft < iright {
+ return true
+ } else if ileft > iright {
+ return false
+ }
+ case DSC:
+ if ileft > iright {
+ return true
+ } else if ileft < iright {
+ return false
+ }
+ }
+ default:
+ sleft := fmt.Sprintf("%v", left.FieldByName(term.Name))
+ sright := fmt.Sprintf("%v", right.FieldByName(term.Name))
+ diff := strings.Compare(sleft, sright)
+ if term.Op != DSC {
+ if diff == -1 {
+ return true
+ } else if diff == 1 {
+ return false
+ }
+ } else {
+ if diff == 1 {
+ return true
+ } else if diff == -1 {
+ return false
+ }
+ }
+ }
+ }
+ return false
+ })
+
+ return data, nil
+}