/*
Copyright 2019 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 alitasks

import (
	"fmt"
	"strings"

	common "github.com/denverdino/aliyungo/common"
	ecs "github.com/denverdino/aliyungo/ecs"

	"k8s.io/klog/v2"
	"k8s.io/kops/pkg/pki"
	"k8s.io/kops/upup/pkg/fi"
	"k8s.io/kops/upup/pkg/fi/cloudup/aliup"
	"k8s.io/kops/upup/pkg/fi/cloudup/terraform"
)

// +kops:fitask
type SSHKey struct {
	Name               *string
	Lifecycle          *fi.Lifecycle
	PublicKey          *fi.ResourceHolder
	KeyPairFingerPrint *string
}

var _ fi.CompareWithID = &SSHKey{}

func (s *SSHKey) CompareWithID() *string {
	return s.Name
}

func (s *SSHKey) Find(c *fi.Context) (*SSHKey, error) {
	cloud := c.Cloud.(aliup.ALICloud)

	describeKeyPairsArgs := &ecs.DescribeKeyPairsArgs{
		RegionId:    common.Region(cloud.Region()),
		KeyPairName: fi.StringValue(s.Name),
	}
	keypairs, _, err := cloud.EcsClient().DescribeKeyPairs(describeKeyPairsArgs)
	if err != nil {
		return nil, fmt.Errorf("error listing SSHKeys: %v", err)
	}

	if len(keypairs) == 0 {
		return nil, nil
	}

	if len(keypairs) != 1 {
		return nil, fmt.Errorf("Found multiple SSHKeys with Name %q", *s.Name)
	}

	klog.V(2).Infof("found matching SSHKey with name: %q", *s.Name)
	k := keypairs[0]
	actual := &SSHKey{
		Name:               fi.String(k.KeyPairName),
		KeyPairFingerPrint: fi.String(k.KeyPairFingerPrint),
	}

	// Avoid spurious changes
	if fi.StringValue(actual.KeyPairFingerPrint) == compactKeyFingerprint(fi.StringValue(s.KeyPairFingerPrint)) {
		klog.V(2).Infof("SSH key fingerprints match; assuming public keys match")
		actual.PublicKey = s.PublicKey
		actual.KeyPairFingerPrint = s.KeyPairFingerPrint
	} else {
		klog.V(2).Infof("Computed SSH key fingerprint mismatch: %q %q", fi.StringValue(s.KeyPairFingerPrint), fi.StringValue(actual.KeyPairFingerPrint))
	}

	// Ignore "system" fields
	actual.Lifecycle = s.Lifecycle

	return actual, nil
}

func compactKeyFingerprint(k string) string {
	return strings.Replace(k, ":", "", -1)
}

func (s *SSHKey) Run(c *fi.Context) error {
	if s.KeyPairFingerPrint == nil && s.PublicKey != nil {
		publicKey, err := s.PublicKey.AsString()
		if err != nil {
			return fmt.Errorf("error reading SSH public key: %v", err)
		}

		keyPairFingerPrint, err := pki.ComputeOpenSSHKeyFingerprint(publicKey)
		if err != nil {
			return fmt.Errorf("error computing key fingerprint for SSH key: %v", err)
		}
		klog.V(2).Infof("Computed SSH key fingerprint as %q", keyPairFingerPrint)
		s.KeyPairFingerPrint = &keyPairFingerPrint
	}
	return fi.DefaultDeltaRunMethod(s, c)
}

func (s *SSHKey) CheckChanges(a, e, changes *SSHKey) error {
	if a != nil {
		if changes.Name != nil {
			return fi.CannotChangeField("Name")
		}
	}
	return nil
}

func (_ *SSHKey) RenderALI(t *aliup.ALIAPITarget, a, e, changes *SSHKey) error {
	if a == nil {
		klog.V(2).Infof("Creating SSHKey with Name:%q", fi.StringValue(e.Name))

		importKeyPairArgs := &ecs.ImportKeyPairArgs{
			RegionId:    common.Region(t.Cloud.Region()),
			KeyPairName: fi.StringValue(e.Name),
		}

		if e.PublicKey != nil {
			d, err := e.PublicKey.AsString()
			if err != nil {
				return fmt.Errorf("error rendering SSHKey PublicKey: %v", err)
			}
			importKeyPairArgs.PublicKeyBody = d
		}

		importKeyPairResponse, err := t.Cloud.EcsClient().ImportKeyPair(importKeyPairArgs)
		if err != nil {
			return fmt.Errorf("error creating SSHKey: %v", err)
		}
		e.KeyPairFingerPrint = fi.String(importKeyPairResponse.KeyPairFingerPrint)
		return nil
	}
	return nil
}

type terraformSSHKey struct {
	Name      *string `json:"key_name,omitempty" cty:"key_name"`
	PublicKey *string `json:"public_key,omitempty" cty:"public_key"`
}

func (_ *SSHKey) RenderTerraform(t *terraform.TerraformTarget, a, e, changes *SSHKey) error {

	keyString, err := e.PublicKey.AsString()
	if err != nil {
		return fmt.Errorf("error rendering SSHKey PublicKey: %v", err)
	}

	tf := &terraformSSHKey{
		Name:      e.Name,
		PublicKey: &keyString,
	}

	return t.RenderResource("alicloud_key_pair", *e.Name, tf)
}

func (s *SSHKey) TerraformLink() *terraform.Literal {
	return terraform.LiteralProperty("alicloud_key_pair", *s.Name, "name")
}
