// +build !providerless

/*
Copyright 2018 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 azure

import (
	"fmt"
	"strings"
	"sync"
	"time"

	"github.com/Azure/azure-sdk-for-go/services/compute/mgmt/2019-07-01/compute"
	"github.com/Azure/go-autorest/autorest/to"

	"k8s.io/apimachinery/pkg/util/sets"
	"k8s.io/klog"
)

var (
	vmssNameSeparator  = "_"
	vmssCacheSeparator = "#"

	vmssVirtualMachinesKey  = "k8svmssVirtualMachinesKey"
	availabilitySetNodesKey = "k8sAvailabilitySetNodesKey"

	availabilitySetNodesCacheTTL = 15 * time.Minute
	vmssVirtualMachinesTTL       = 10 * time.Minute
)

type vmssVirtualMachinesEntry struct {
	resourceGroup  string
	vmssName       string
	instanceID     string
	virtualMachine *compute.VirtualMachineScaleSetVM
	lastUpdate     time.Time
}

func (ss *scaleSet) makeVmssVMName(scaleSetName, instanceID string) string {
	return fmt.Sprintf("%s%s%s", scaleSetName, vmssNameSeparator, instanceID)
}

func extractVmssVMName(name string) (string, string, error) {
	split := strings.SplitAfter(name, vmssNameSeparator)
	if len(split) < 2 {
		klog.V(3).Infof("Failed to extract vmssVMName %q", name)
		return "", "", ErrorNotVmssInstance
	}

	ssName := strings.Join(split[0:len(split)-1], "")
	// removing the trailing `vmssNameSeparator` since we used SplitAfter
	ssName = ssName[:len(ssName)-1]
	instanceID := split[len(split)-1]
	return ssName, instanceID, nil
}

func (ss *scaleSet) newVMSSVirtualMachinesCache() (*timedCache, error) {
	getter := func(key string) (interface{}, error) {
		localCache := &sync.Map{} // [nodeName]*vmssVirtualMachinesEntry

		allResourceGroups, err := ss.GetResourceGroups()
		if err != nil {
			return nil, err
		}

		for _, resourceGroup := range allResourceGroups.List() {
			scaleSetNames, err := ss.listScaleSets(resourceGroup)
			if err != nil {
				return nil, err
			}

			for _, ssName := range scaleSetNames {
				vms, err := ss.listScaleSetVMs(ssName, resourceGroup)
				if err != nil {
					return nil, err
				}

				for i := range vms {
					vm := vms[i]
					if vm.OsProfile == nil || vm.OsProfile.ComputerName == nil {
						klog.Warningf("failed to get computerName for vmssVM (%q)", ssName)
						continue
					}

					computerName := strings.ToLower(*vm.OsProfile.ComputerName)
					localCache.Store(computerName, &vmssVirtualMachinesEntry{
						resourceGroup:  resourceGroup,
						vmssName:       ssName,
						instanceID:     to.String(vm.InstanceID),
						virtualMachine: &vm,
						lastUpdate:     time.Now().UTC(),
					})
				}
			}
		}

		return localCache, nil
	}

	return newTimedcache(vmssVirtualMachinesTTL, getter)
}

func (ss *scaleSet) deleteCacheForNode(nodeName string) error {
	cached, err := ss.vmssVMCache.Get(vmssVirtualMachinesKey, cacheReadTypeUnsafe)
	if err != nil {
		return err
	}

	virtualMachines := cached.(*sync.Map)
	virtualMachines.Delete(nodeName)
	return nil
}

func (ss *scaleSet) newAvailabilitySetNodesCache() (*timedCache, error) {
	getter := func(key string) (interface{}, error) {
		localCache := sets.NewString()
		resourceGroups, err := ss.GetResourceGroups()
		if err != nil {
			return nil, err
		}

		for _, resourceGroup := range resourceGroups.List() {
			vmList, err := ss.Cloud.ListVirtualMachines(resourceGroup)
			if err != nil {
				return nil, err
			}

			for _, vm := range vmList {
				if vm.Name != nil {
					localCache.Insert(*vm.Name)
				}
			}
		}

		return localCache, nil
	}

	return newTimedcache(availabilitySetNodesCacheTTL, getter)
}

func (ss *scaleSet) isNodeManagedByAvailabilitySet(nodeName string, crt cacheReadType) (bool, error) {
	cached, err := ss.availabilitySetNodesCache.Get(availabilitySetNodesKey, crt)
	if err != nil {
		return false, err
	}

	availabilitySetNodes := cached.(sets.String)
	return availabilitySetNodes.Has(nodeName), nil
}