/*
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 cloudstack

import (
	"context"
	"errors"
	"fmt"
	"regexp"

	"github.com/xanzy/go-cloudstack/cloudstack"
	"k8s.io/api/core/v1"
	"k8s.io/apimachinery/pkg/types"
	cloudprovider "k8s.io/cloud-provider"
	"k8s.io/klog"
)

var labelInvalidCharsRegex *regexp.Regexp = regexp.MustCompile(`([^A-Za-z0-9][^-A-Za-z0-9_.]*)?[^A-Za-z0-9]`)

// NodeAddresses returns the addresses of the specified instance.
func (cs *CSCloud) NodeAddresses(ctx context.Context, name types.NodeName) ([]v1.NodeAddress, error) {
	instance, count, err := cs.client.VirtualMachine.GetVirtualMachineByName(
		string(name),
		cloudstack.WithProject(cs.projectID),
	)
	if err != nil {
		if count == 0 {
			return nil, cloudprovider.InstanceNotFound
		}
		return nil, fmt.Errorf("error retrieving node addresses: %v", err)
	}

	return cs.nodeAddresses(instance)
}

// NodeAddressesByProviderID returns the addresses of the specified instance.
func (cs *CSCloud) NodeAddressesByProviderID(ctx context.Context, providerID string) ([]v1.NodeAddress, error) {
	instance, count, err := cs.client.VirtualMachine.GetVirtualMachineByID(
		providerID,
		cloudstack.WithProject(cs.projectID),
	)
	if err != nil {
		if count == 0 {
			return nil, cloudprovider.InstanceNotFound
		}
		return nil, fmt.Errorf("error retrieving node addresses: %v", err)
	}

	return cs.nodeAddresses(instance)
}

func (cs *CSCloud) nodeAddresses(instance *cloudstack.VirtualMachine) ([]v1.NodeAddress, error) {
	if len(instance.Nic) == 0 {
		return nil, errors.New("instance does not have an internal IP")
	}

	addresses := []v1.NodeAddress{
		{Type: v1.NodeInternalIP, Address: instance.Nic[0].Ipaddress},
	}

	if instance.Hostname != "" {
		addresses = append(addresses, v1.NodeAddress{Type: v1.NodeHostName, Address: instance.Hostname})
	}

	if instance.Publicip != "" {
		addresses = append(addresses, v1.NodeAddress{Type: v1.NodeExternalIP, Address: instance.Publicip})
	} else {
		// Since there is no sane way to determine the external IP if the host isn't
		// using static NAT, we will just fire a log message and omit the external IP.
		klog.V(4).Infof("Could not determine the public IP of host %v (%v)", instance.Name, instance.Id)
	}

	return addresses, nil
}

// InstanceID returns the cloud provider ID of the specified instance.
func (cs *CSCloud) InstanceID(ctx context.Context, name types.NodeName) (string, error) {
	instance, count, err := cs.client.VirtualMachine.GetVirtualMachineByName(
		string(name),
		cloudstack.WithProject(cs.projectID),
	)
	if err != nil {
		if count == 0 {
			return "", cloudprovider.InstanceNotFound
		}
		return "", fmt.Errorf("error retrieving instance ID: %v", err)
	}

	return instance.Id, nil
}

// InstanceType returns the type of the specified instance.
func (cs *CSCloud) InstanceType(ctx context.Context, name types.NodeName) (string, error) {
	instance, count, err := cs.client.VirtualMachine.GetVirtualMachineByName(
		string(name),
		cloudstack.WithProject(cs.projectID),
	)
	if err != nil {
		if count == 0 {
			return "", cloudprovider.InstanceNotFound
		}
		return "", fmt.Errorf("error retrieving instance type: %v", err)
	}

	return labelInvalidCharsRegex.ReplaceAllString(instance.Serviceofferingname, ``), nil
}

// InstanceTypeByProviderID returns the type of the specified instance.
func (cs *CSCloud) InstanceTypeByProviderID(ctx context.Context, providerID string) (string, error) {
	instance, count, err := cs.client.VirtualMachine.GetVirtualMachineByID(
		providerID,
		cloudstack.WithProject(cs.projectID),
	)
	if err != nil {
		if count == 0 {
			return "", cloudprovider.InstanceNotFound
		}
		return "", fmt.Errorf("error retrieving instance type: %v", err)
	}

	return labelInvalidCharsRegex.ReplaceAllString(instance.Serviceofferingname, ``), nil
}

// AddSSHKeyToAllInstances is currently not implemented.
func (cs *CSCloud) AddSSHKeyToAllInstances(ctx context.Context, user string, keyData []byte) error {
	return cloudprovider.NotImplemented
}

// CurrentNodeName returns the name of the node we are currently running on.
func (cs *CSCloud) CurrentNodeName(ctx context.Context, hostname string) (types.NodeName, error) {
	return types.NodeName(hostname), nil
}

// InstanceExistsByProviderID returns if the instance still exists.
func (cs *CSCloud) InstanceExistsByProviderID(ctx context.Context, providerID string) (bool, error) {
	_, count, err := cs.client.VirtualMachine.GetVirtualMachineByID(
		providerID,
		cloudstack.WithProject(cs.projectID),
	)
	if err != nil {
		if count == 0 {
			return false, nil
		}
		return false, fmt.Errorf("error retrieving instance: %v", err)
	}

	return true, nil
}

// InstanceShutdownByProviderID returns true if the instance is in safe state to detach volumes
func (cs *CSCloud) InstanceShutdownByProviderID(ctx context.Context, providerID string) (bool, error) {
	return false, cloudprovider.NotImplemented
}