/*
Copyright 2016 The Kubernetes Authors.

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 testutil

import (
	"errors"
	"fmt"
	"sync"
	"time"

	apierrors "k8s.io/apimachinery/pkg/api/errors"
	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
	"k8s.io/apimachinery/pkg/runtime"
	"k8s.io/apimachinery/pkg/types"
	"k8s.io/apimachinery/pkg/util/sets"
	"k8s.io/apimachinery/pkg/watch"
	"k8s.io/client-go/util/clock"
	"k8s.io/kubernetes/pkg/api"
	"k8s.io/kubernetes/pkg/api/resource"
	"k8s.io/kubernetes/pkg/api/v1"
	"k8s.io/kubernetes/pkg/client/clientset_generated/clientset/fake"
	v1core "k8s.io/kubernetes/pkg/client/clientset_generated/clientset/typed/core/v1"
	utilnode "k8s.io/kubernetes/pkg/util/node"
)

// FakeNodeHandler is a fake implementation of NodesInterface and NodeInterface. It
// allows test cases to have fine-grained control over mock behaviors. We also need
// PodsInterface and PodInterface to test list & delet pods, which is implemented in
// the embedded client.Fake field.
type FakeNodeHandler struct {
	*fake.Clientset

	// Input: Hooks determine if request is valid or not
	CreateHook func(*FakeNodeHandler, *v1.Node) bool
	Existing   []*v1.Node

	// Output
	CreatedNodes        []*v1.Node
	DeletedNodes        []*v1.Node
	UpdatedNodes        []*v1.Node
	UpdatedNodeStatuses []*v1.Node
	RequestCount        int

	// Synchronization
	lock           sync.Mutex
	DeleteWaitChan chan struct{}
}

type FakeLegacyHandler struct {
	v1core.CoreV1Interface
	n *FakeNodeHandler
}

// GetUpdatedNodesCopy returns a slice of Nodes with updates applied.
func (c *FakeNodeHandler) GetUpdatedNodesCopy() []*v1.Node {
	c.lock.Lock()
	defer c.lock.Unlock()
	updatedNodesCopy := make([]*v1.Node, len(c.UpdatedNodes), len(c.UpdatedNodes))
	for i, ptr := range c.UpdatedNodes {
		updatedNodesCopy[i] = ptr
	}
	return updatedNodesCopy
}

// Core returns fake CoreInterface.
func (c *FakeNodeHandler) Core() v1core.CoreV1Interface {
	return &FakeLegacyHandler{c.Clientset.Core(), c}
}

// Nodes return fake NodeInterfaces.
func (m *FakeLegacyHandler) Nodes() v1core.NodeInterface {
	return m.n
}

// Create adds a new Node to the fake store.
func (m *FakeNodeHandler) Create(node *v1.Node) (*v1.Node, error) {
	m.lock.Lock()
	defer func() {
		m.RequestCount++
		m.lock.Unlock()
	}()
	for _, n := range m.Existing {
		if n.Name == node.Name {
			return nil, apierrors.NewAlreadyExists(api.Resource("nodes"), node.Name)
		}
	}
	if m.CreateHook == nil || m.CreateHook(m, node) {
		nodeCopy := *node
		m.CreatedNodes = append(m.CreatedNodes, &nodeCopy)
		return node, nil
	} else {
		return nil, errors.New("Create error.")
	}
}

// Get returns a Node from the fake store.
func (m *FakeNodeHandler) Get(name string, opts metav1.GetOptions) (*v1.Node, error) {
	m.lock.Lock()
	defer func() {
		m.RequestCount++
		m.lock.Unlock()
	}()
	for i := range m.UpdatedNodes {
		if m.UpdatedNodes[i].Name == name {
			nodeCopy := *m.UpdatedNodes[i]
			return &nodeCopy, nil
		}
	}
	for i := range m.Existing {
		if m.Existing[i].Name == name {
			nodeCopy := *m.Existing[i]
			return &nodeCopy, nil
		}
	}
	return nil, nil
}

// List returns a list of Nodes from the fake store.
func (m *FakeNodeHandler) List(opts metav1.ListOptions) (*v1.NodeList, error) {
	m.lock.Lock()
	defer func() {
		m.RequestCount++
		m.lock.Unlock()
	}()
	var nodes []*v1.Node
	for i := 0; i < len(m.UpdatedNodes); i++ {
		if !contains(m.UpdatedNodes[i], m.DeletedNodes) {
			nodes = append(nodes, m.UpdatedNodes[i])
		}
	}
	for i := 0; i < len(m.Existing); i++ {
		if !contains(m.Existing[i], m.DeletedNodes) && !contains(m.Existing[i], nodes) {
			nodes = append(nodes, m.Existing[i])
		}
	}
	for i := 0; i < len(m.CreatedNodes); i++ {
		if !contains(m.CreatedNodes[i], m.DeletedNodes) && !contains(m.CreatedNodes[i], nodes) {
			nodes = append(nodes, m.CreatedNodes[i])
		}
	}
	nodeList := &v1.NodeList{}
	for _, node := range nodes {
		nodeList.Items = append(nodeList.Items, *node)
	}
	return nodeList, nil
}

// Delete delets a Node from the fake store.
func (m *FakeNodeHandler) Delete(id string, opt *v1.DeleteOptions) error {
	m.lock.Lock()
	defer func() {
		m.RequestCount++
		if m.DeleteWaitChan != nil {
			m.DeleteWaitChan <- struct{}{}
		}
		m.lock.Unlock()
	}()
	m.DeletedNodes = append(m.DeletedNodes, NewNode(id))
	return nil
}

// DeleteCollection deletes a collection of Nodes from the fake store.
func (m *FakeNodeHandler) DeleteCollection(opt *v1.DeleteOptions, listOpts metav1.ListOptions) error {
	return nil
}

// Update updates a Node in the fake store.
func (m *FakeNodeHandler) Update(node *v1.Node) (*v1.Node, error) {
	m.lock.Lock()
	defer func() {
		m.RequestCount++
		m.lock.Unlock()
	}()
	nodeCopy := *node
	for i, updateNode := range m.UpdatedNodes {
		if updateNode.Name == nodeCopy.Name {
			m.UpdatedNodes[i] = &nodeCopy
			return node, nil
		}
	}
	m.UpdatedNodes = append(m.UpdatedNodes, &nodeCopy)
	return node, nil
}

// UpdateStatus updates a status of a Node in the fake store.
func (m *FakeNodeHandler) UpdateStatus(node *v1.Node) (*v1.Node, error) {
	m.lock.Lock()
	defer func() {
		m.RequestCount++
		m.lock.Unlock()
	}()
	nodeCopy := *node
	m.UpdatedNodeStatuses = append(m.UpdatedNodeStatuses, &nodeCopy)
	return node, nil
}

// PatchStatus patches a status of a Node in the fake store.
func (m *FakeNodeHandler) PatchStatus(nodeName string, data []byte) (*v1.Node, error) {
	m.RequestCount++
	return &v1.Node{}, nil
}

// Watch watches Nodes in a fake store.
func (m *FakeNodeHandler) Watch(opts metav1.ListOptions) (watch.Interface, error) {
	return watch.NewFake(), nil
}

// Patch patches a Node in the fake store.
func (m *FakeNodeHandler) Patch(name string, pt types.PatchType, data []byte, subresources ...string) (*v1.Node, error) {
	return nil, nil
}

// FakeRecorder is used as a fake during testing.
type FakeRecorder struct {
	source v1.EventSource
	Events []*v1.Event
	clock  clock.Clock
}

// Event emits a fake event to the fake recorder
func (f *FakeRecorder) Event(obj runtime.Object, eventtype, reason, message string) {
	f.generateEvent(obj, metav1.Now(), eventtype, reason, message)
}

// Eventf emits a fake formatted event to the fake recorder
func (f *FakeRecorder) Eventf(obj runtime.Object, eventtype, reason, messageFmt string, args ...interface{}) {
	f.Event(obj, eventtype, reason, fmt.Sprintf(messageFmt, args...))
}

// PastEventf is a no-op
func (f *FakeRecorder) PastEventf(obj runtime.Object, timestamp metav1.Time, eventtype, reason, messageFmt string, args ...interface{}) {
}

func (f *FakeRecorder) generateEvent(obj runtime.Object, timestamp metav1.Time, eventtype, reason, message string) {
	ref, err := v1.GetReference(obj)
	if err != nil {
		return
	}
	event := f.makeEvent(ref, eventtype, reason, message)
	event.Source = f.source
	if f.Events != nil {
		fmt.Println("write event")
		f.Events = append(f.Events, event)
	}
}

func (f *FakeRecorder) makeEvent(ref *v1.ObjectReference, eventtype, reason, message string) *v1.Event {
	fmt.Println("make event")
	t := metav1.Time{Time: f.clock.Now()}
	namespace := ref.Namespace
	if namespace == "" {
		namespace = metav1.NamespaceDefault
	}
	return &v1.Event{
		ObjectMeta: metav1.ObjectMeta{
			Name:      fmt.Sprintf("%v.%x", ref.Name, t.UnixNano()),
			Namespace: namespace,
		},
		InvolvedObject: *ref,
		Reason:         reason,
		Message:        message,
		FirstTimestamp: t,
		LastTimestamp:  t,
		Count:          1,
		Type:           eventtype,
	}
}

// NewFakeRecorder returns a pointer to a newly constructed FakeRecorder.
func NewFakeRecorder() *FakeRecorder {
	return &FakeRecorder{
		source: v1.EventSource{Component: "nodeControllerTest"},
		Events: []*v1.Event{},
		clock:  clock.NewFakeClock(time.Now()),
	}
}

// NewNode is a helper function for creating Nodes for testing.
func NewNode(name string) *v1.Node {
	return &v1.Node{
		ObjectMeta: metav1.ObjectMeta{Name: name},
		Spec: v1.NodeSpec{
			ExternalID: name,
		},
		Status: v1.NodeStatus{
			Capacity: v1.ResourceList{
				v1.ResourceName(v1.ResourceCPU):    resource.MustParse("10"),
				v1.ResourceName(v1.ResourceMemory): resource.MustParse("10G"),
			},
		},
	}
}

// NewPod is a helper function for creating Pods for testing.
func NewPod(name, host string) *v1.Pod {
	pod := &v1.Pod{
		ObjectMeta: metav1.ObjectMeta{
			Namespace: "default",
			Name:      name,
		},
		Spec: v1.PodSpec{
			NodeName: host,
		},
		Status: v1.PodStatus{
			Conditions: []v1.PodCondition{
				{
					Type:   v1.PodReady,
					Status: v1.ConditionTrue,
				},
			},
		},
	}

	return pod
}

func contains(node *v1.Node, nodes []*v1.Node) bool {
	for i := 0; i < len(nodes); i++ {
		if node.Name == nodes[i].Name {
			return true
		}
	}
	return false
}

// GetZones returns list of zones for all Nodes stored in FakeNodeHandler
func GetZones(nodeHandler *FakeNodeHandler) []string {
	nodes, _ := nodeHandler.List(metav1.ListOptions{})
	zones := sets.NewString()
	for _, node := range nodes.Items {
		zones.Insert(utilnode.GetZoneKey(&node))
	}
	return zones.List()
}

// CreateZoneID returns a single zoneID for a given region and zone.
func CreateZoneID(region, zone string) string {
	return region + ":\x00:" + zone
}