/*
Copyright 2014 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 fake

import (
	"context"
	"fmt"
	"net"
	"regexp"
	"sync"
	"time"

	"k8s.io/api/core/v1"
	"k8s.io/apimachinery/pkg/types"
	cloudprovider "k8s.io/cloud-provider"
)

const defaultProviderName = "fake"

// FakeBalancer is a fake storage of balancer information
type FakeBalancer struct {
	Name           string
	Region         string
	LoadBalancerIP string
	Ports          []v1.ServicePort
	Hosts          []*v1.Node
}

type FakeUpdateBalancerCall struct {
	Service *v1.Service
	Hosts   []*v1.Node
}

// FakeCloud is a test-double implementation of Interface, LoadBalancer, Instances, and Routes. It is useful for testing.
type FakeCloud struct {
	Exists bool
	Err    error

	ExistsByProviderID      bool
	ErrByProviderID         error
	NodeShutdown            bool
	ErrShutdownByProviderID error

	Calls         []string
	Addresses     []v1.NodeAddress
	addressesMux  sync.Mutex
	ExtID         map[types.NodeName]string
	InstanceTypes map[types.NodeName]string
	Machines      []types.NodeName
	NodeResources *v1.NodeResources
	ClusterList   []string
	MasterName    string
	ExternalIP    net.IP
	Balancers     map[string]FakeBalancer
	UpdateCalls   []FakeUpdateBalancerCall
	RouteMap      map[string]*FakeRoute
	Lock          sync.Mutex
	Provider      string
	addCallLock   sync.Mutex
	cloudprovider.Zone
	VolumeLabelMap map[string]map[string]string

	RequestDelay time.Duration
}

type FakeRoute struct {
	ClusterName string
	Route       cloudprovider.Route
}

func (f *FakeCloud) addCall(desc string) {
	f.addCallLock.Lock()
	defer f.addCallLock.Unlock()

	time.Sleep(f.RequestDelay)

	f.Calls = append(f.Calls, desc)
}

// ClearCalls clears internal record of method calls to this FakeCloud.
func (f *FakeCloud) ClearCalls() {
	f.Calls = []string{}
}

// Initialize passes a Kubernetes clientBuilder interface to the cloud provider
func (f *FakeCloud) Initialize(clientBuilder cloudprovider.ControllerClientBuilder) {}

func (f *FakeCloud) ListClusters(ctx context.Context) ([]string, error) {
	return f.ClusterList, f.Err
}

func (f *FakeCloud) Master(ctx context.Context, name string) (string, error) {
	return f.MasterName, f.Err
}

func (f *FakeCloud) Clusters() (cloudprovider.Clusters, bool) {
	return f, true
}

// ProviderName returns the cloud provider ID.
func (f *FakeCloud) ProviderName() string {
	if f.Provider == "" {
		return defaultProviderName
	}
	return f.Provider
}

// HasClusterID returns true if the cluster has a clusterID
func (f *FakeCloud) HasClusterID() bool {
	return true
}

// LoadBalancer returns a fake implementation of LoadBalancer.
// Actually it just returns f itself.
func (f *FakeCloud) LoadBalancer() (cloudprovider.LoadBalancer, bool) {
	return f, true
}

// Instances returns a fake implementation of Instances.
//
// Actually it just returns f itself.
func (f *FakeCloud) Instances() (cloudprovider.Instances, bool) {
	return f, true
}

func (f *FakeCloud) Zones() (cloudprovider.Zones, bool) {
	return f, true
}

func (f *FakeCloud) Routes() (cloudprovider.Routes, bool) {
	return f, true
}

// GetLoadBalancer is a stub implementation of LoadBalancer.GetLoadBalancer.
func (f *FakeCloud) GetLoadBalancer(ctx context.Context, clusterName string, service *v1.Service) (*v1.LoadBalancerStatus, bool, error) {
	status := &v1.LoadBalancerStatus{}
	status.Ingress = []v1.LoadBalancerIngress{{IP: f.ExternalIP.String()}}

	return status, f.Exists, f.Err
}

// GetLoadBalancerName is a stub implementation of LoadBalancer.GetLoadBalancerName.
func (f *FakeCloud) GetLoadBalancerName(ctx context.Context, clusterName string, service *v1.Service) string {
	// TODO: replace DefaultLoadBalancerName to generate more meaningful loadbalancer names.
	return cloudprovider.DefaultLoadBalancerName(service)
}

// EnsureLoadBalancer is a test-spy implementation of LoadBalancer.EnsureLoadBalancer.
// It adds an entry "create" into the internal method call record.
func (f *FakeCloud) EnsureLoadBalancer(ctx context.Context, clusterName string, service *v1.Service, nodes []*v1.Node) (*v1.LoadBalancerStatus, error) {
	f.addCall("create")
	if f.Balancers == nil {
		f.Balancers = make(map[string]FakeBalancer)
	}

	name := f.GetLoadBalancerName(ctx, clusterName, service)
	spec := service.Spec

	zone, err := f.GetZone(context.TODO())
	if err != nil {
		return nil, err
	}
	region := zone.Region

	f.Balancers[name] = FakeBalancer{name, region, spec.LoadBalancerIP, spec.Ports, nodes}

	status := &v1.LoadBalancerStatus{}
	status.Ingress = []v1.LoadBalancerIngress{{IP: f.ExternalIP.String()}}

	return status, f.Err
}

// UpdateLoadBalancer is a test-spy implementation of LoadBalancer.UpdateLoadBalancer.
// It adds an entry "update" into the internal method call record.
func (f *FakeCloud) UpdateLoadBalancer(ctx context.Context, clusterName string, service *v1.Service, nodes []*v1.Node) error {
	f.addCall("update")
	f.UpdateCalls = append(f.UpdateCalls, FakeUpdateBalancerCall{service, nodes})
	return f.Err
}

// EnsureLoadBalancerDeleted is a test-spy implementation of LoadBalancer.EnsureLoadBalancerDeleted.
// It adds an entry "delete" into the internal method call record.
func (f *FakeCloud) EnsureLoadBalancerDeleted(ctx context.Context, clusterName string, service *v1.Service) error {
	f.addCall("delete")
	return f.Err
}

func (f *FakeCloud) AddSSHKeyToAllInstances(ctx context.Context, user string, keyData []byte) error {
	return cloudprovider.NotImplemented
}

// Implementation of Instances.CurrentNodeName
func (f *FakeCloud) CurrentNodeName(ctx context.Context, hostname string) (types.NodeName, error) {
	return types.NodeName(hostname), nil
}

// NodeAddresses is a test-spy implementation of Instances.NodeAddresses.
// It adds an entry "node-addresses" into the internal method call record.
func (f *FakeCloud) NodeAddresses(ctx context.Context, instance types.NodeName) ([]v1.NodeAddress, error) {
	f.addCall("node-addresses")
	f.addressesMux.Lock()
	defer f.addressesMux.Unlock()
	return f.Addresses, f.Err
}

func (f *FakeCloud) SetNodeAddresses(nodeAddresses []v1.NodeAddress) {
	f.addressesMux.Lock()
	defer f.addressesMux.Unlock()
	f.Addresses = nodeAddresses
}

// NodeAddressesByProviderID is a test-spy implementation of Instances.NodeAddressesByProviderID.
// It adds an entry "node-addresses-by-provider-id" into the internal method call record.
func (f *FakeCloud) NodeAddressesByProviderID(ctx context.Context, providerID string) ([]v1.NodeAddress, error) {
	f.addCall("node-addresses-by-provider-id")
	return f.Addresses, f.Err
}

// InstanceID returns the cloud provider ID of the node with the specified Name.
func (f *FakeCloud) InstanceID(ctx context.Context, nodeName types.NodeName) (string, error) {
	f.addCall("instance-id")
	return f.ExtID[nodeName], nil
}

// InstanceType returns the type of the specified instance.
func (f *FakeCloud) InstanceType(ctx context.Context, instance types.NodeName) (string, error) {
	f.addCall("instance-type")
	return f.InstanceTypes[instance], nil
}

// InstanceTypeByProviderID returns the type of the specified instance.
func (f *FakeCloud) InstanceTypeByProviderID(ctx context.Context, providerID string) (string, error) {
	f.addCall("instance-type-by-provider-id")
	return f.InstanceTypes[types.NodeName(providerID)], nil
}

// InstanceExistsByProviderID returns true if the instance with the given provider id still exists and is running.
// If false is returned with no error, the instance will be immediately deleted by the cloud controller manager.
func (f *FakeCloud) InstanceExistsByProviderID(ctx context.Context, providerID string) (bool, error) {
	f.addCall("instance-exists-by-provider-id")
	return f.ExistsByProviderID, f.ErrByProviderID
}

// InstanceShutdownByProviderID returns true if the instances is in safe state to detach volumes
func (f *FakeCloud) InstanceShutdownByProviderID(ctx context.Context, providerID string) (bool, error) {
	f.addCall("instance-shutdown-by-provider-id")
	return f.NodeShutdown, f.ErrShutdownByProviderID
}

// List is a test-spy implementation of Instances.List.
// It adds an entry "list" into the internal method call record.
func (f *FakeCloud) List(filter string) ([]types.NodeName, error) {
	f.addCall("list")
	result := []types.NodeName{}
	for _, machine := range f.Machines {
		if match, _ := regexp.MatchString(filter, string(machine)); match {
			result = append(result, machine)
		}
	}
	return result, f.Err
}

func (f *FakeCloud) GetZone(ctx context.Context) (cloudprovider.Zone, error) {
	f.addCall("get-zone")
	return f.Zone, f.Err
}

// GetZoneByProviderID implements Zones.GetZoneByProviderID
// This is particularly useful in external cloud providers where the kubelet
// does not initialize node data.
func (f *FakeCloud) GetZoneByProviderID(ctx context.Context, providerID string) (cloudprovider.Zone, error) {
	f.addCall("get-zone-by-provider-id")
	return f.Zone, f.Err
}

// GetZoneByNodeName implements Zones.GetZoneByNodeName
// This is particularly useful in external cloud providers where the kubelet
// does not initialize node data.
func (f *FakeCloud) GetZoneByNodeName(ctx context.Context, nodeName types.NodeName) (cloudprovider.Zone, error) {
	f.addCall("get-zone-by-node-name")
	return f.Zone, f.Err
}

func (f *FakeCloud) ListRoutes(ctx context.Context, clusterName string) ([]*cloudprovider.Route, error) {
	f.Lock.Lock()
	defer f.Lock.Unlock()
	f.addCall("list-routes")
	var routes []*cloudprovider.Route
	for _, fakeRoute := range f.RouteMap {
		if clusterName == fakeRoute.ClusterName {
			routeCopy := fakeRoute.Route
			routes = append(routes, &routeCopy)
		}
	}
	return routes, f.Err
}

func (f *FakeCloud) CreateRoute(ctx context.Context, clusterName string, nameHint string, route *cloudprovider.Route) error {
	f.Lock.Lock()
	defer f.Lock.Unlock()
	f.addCall("create-route")
	name := clusterName + "-" + nameHint
	if _, exists := f.RouteMap[name]; exists {
		f.Err = fmt.Errorf("route %q already exists", name)
		return f.Err
	}
	fakeRoute := FakeRoute{}
	fakeRoute.Route = *route
	fakeRoute.Route.Name = name
	fakeRoute.ClusterName = clusterName
	f.RouteMap[name] = &fakeRoute
	return nil
}

func (f *FakeCloud) DeleteRoute(ctx context.Context, clusterName string, route *cloudprovider.Route) error {
	f.Lock.Lock()
	defer f.Lock.Unlock()
	f.addCall("delete-route")
	name := route.Name
	if _, exists := f.RouteMap[name]; !exists {
		f.Err = fmt.Errorf("no route found with name %q", name)
		return f.Err
	}
	delete(f.RouteMap, name)
	return nil
}

func (c *FakeCloud) GetLabelsForVolume(ctx context.Context, pv *v1.PersistentVolume) (map[string]string, error) {
	if val, ok := c.VolumeLabelMap[pv.Name]; ok {
		return val, nil
	}
	return nil, fmt.Errorf("label not found for volume")
}