From 7137b23d04c632c22097cebe11d067f3b18b4920 Mon Sep 17 00:00:00 2001
From: Darren Shepherd <darren@rancher.com>
Date: Sat, 16 Dec 2017 01:26:07 -0700
Subject: [PATCH] Conditions framework

---
 condition/condition.go | 149 +++++++++++++++++++++++++++++++++++++++++
 1 file changed, 149 insertions(+)
 create mode 100644 condition/condition.go

diff --git a/condition/condition.go b/condition/condition.go
new file mode 100644
index 00000000..85a5ef1c
--- /dev/null
+++ b/condition/condition.go
@@ -0,0 +1,149 @@
+package condition
+
+import (
+	"reflect"
+	"time"
+
+	"github.com/pkg/errors"
+	"github.com/rancher/norman/controller"
+	"k8s.io/apimachinery/pkg/runtime"
+)
+
+type Cond string
+
+func (c Cond) True(obj runtime.Object) {
+	setStatus(obj, string(c), "True")
+}
+
+func (c Cond) IsTrue(obj runtime.Object) bool {
+	return getStatus(obj, string(c)) == "True"
+}
+
+func (c Cond) False(obj runtime.Object) {
+	setStatus(obj, string(c), "False")
+}
+
+func (c Cond) IsFalse(obj runtime.Object) bool {
+	return getStatus(obj, string(c)) == "False"
+}
+
+func (c Cond) Unknown(obj runtime.Object) {
+	setStatus(obj, string(c), "Unknown")
+}
+
+func (c Cond) IsUnknown(obj runtime.Object) bool {
+	return getStatus(obj, string(c)) == "Unknown"
+}
+
+func (c Cond) Reason(obj runtime.Object, reason string) {
+	cond := findOrCreateCond(obj, string(c))
+	getFieldValue(cond, "Reason").SetString(reason)
+	touchTS(cond)
+}
+
+func (c Cond) GetReason(obj runtime.Object) string {
+	cond := findOrCreateCond(obj, string(c))
+	return getFieldValue(cond, "Reason").String()
+}
+
+func (c Cond) Once(obj runtime.Object, f func() (runtime.Object, error)) (runtime.Object, error) {
+	if c.IsFalse(obj) {
+		return obj, &controller.ForgetError{
+			Err: errors.New(c.GetReason(obj)),
+		}
+	}
+
+	if c.IsTrue(obj) {
+		return obj, nil
+	}
+
+	c.Unknown(obj)
+	newObj, err := f()
+	if newObj != nil {
+		obj = newObj
+	}
+
+	if err != nil {
+		c.False(obj)
+		c.Reason(obj, err.Error())
+		return obj, err
+	}
+	c.True(obj)
+	return obj, nil
+}
+
+func (c Cond) Do(obj runtime.Object, f func() error) error {
+	c.Unknown(obj)
+	if err := f(); err != nil {
+		c.False(obj)
+		c.Reason(obj, err.Error())
+		return err
+	}
+	c.True(obj)
+	return nil
+}
+
+func touchTS(value reflect.Value) {
+	now := time.Now().Format(time.RFC3339)
+	getFieldValue(value, "LastUpdateTime").SetString(now)
+}
+
+func getStatus(obj interface{}, condName string) string {
+	cond := findOrCreateCond(obj, condName)
+	return getFieldValue(cond, "Status").String()
+}
+
+func setStatus(obj interface{}, condName, status string) {
+	cond := findOrCreateCond(obj, condName)
+	getFieldValue(cond, "Status").SetString(status)
+	touchTS(cond)
+}
+
+func findOrCreateCond(obj interface{}, condName string) reflect.Value {
+	condSlice := getValue(obj, "Status", "Conditions")
+	cond := findCond(condSlice, condName)
+	if cond != nil {
+		return *cond
+	}
+
+	newCond := reflect.New(condSlice.Type().Elem()).Elem()
+	newCond.FieldByName("Type").SetString(condName)
+	newCond.FieldByName("Status").SetString("Unknown")
+	condSlice.Set(reflect.Append(condSlice, newCond))
+	return newCond
+}
+
+func findCond(val reflect.Value, name string) *reflect.Value {
+	for i := 0; i < val.Len(); i++ {
+		cond := val.Index(i)
+		typeVal := getFieldValue(cond, "Type")
+		if typeVal.String() == name {
+			return &cond
+		}
+	}
+
+	return nil
+}
+
+func getValue(obj interface{}, name ...string) reflect.Value {
+	v := reflect.ValueOf(obj)
+	t := v.Type()
+	if t.Kind() == reflect.Ptr {
+		v = v.Elem()
+		t = v.Type()
+	}
+
+	field := v.FieldByName(name[0])
+	if len(name) == 1 {
+		return field
+	}
+	return getFieldValue(field, name[1:]...)
+}
+
+func getFieldValue(v reflect.Value, name ...string) reflect.Value {
+	field := v.FieldByName(name[0])
+	if len(name) == 1 {
+		return field
+	}
+	return getFieldValue(field, name[1:]...)
+}