/*
Copyright 2020 The Flux CD contributors.

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 helm

import (
	"fmt"
	"io/ioutil"
	"os"
	"path/filepath"

	"helm.sh/helm/v3/pkg/getter"
	corev1 "k8s.io/api/core/v1"
)

func ClientOptionsFromSecret(secret corev1.Secret) ([]getter.Option, func(), error) {
	var opts []getter.Option
	basicAuth, err := BasicAuthFromSecret(secret)
	if err != nil {
		return opts, nil, err
	}
	if basicAuth != nil {
		opts = append(opts, basicAuth)
	}
	tlsClientConfig, cleanup, err := TLSClientConfigFromSecret(secret)
	if err != nil {
		return opts, nil, err
	}
	if tlsClientConfig != nil {
		opts = append(opts, tlsClientConfig)
	}
	return opts, cleanup, nil
}

func BasicAuthFromSecret(secret corev1.Secret) (getter.Option, error) {
	username, password := string(secret.Data["username"]), string(secret.Data["password"])
	switch {
	case username == "" && password == "":
		return nil, nil
	case username == "" || password == "":
		return nil, fmt.Errorf("invalid '%s' secret data: required fields 'username' and 'password'", secret.Name)
	}
	return getter.WithBasicAuth(username, password), nil
}

func TLSClientConfigFromSecret(secret corev1.Secret) (getter.Option, func(), error) {
	certBytes, keyBytes, caBytes := secret.Data["certFile"], secret.Data["keyFile"], secret.Data["caFile"]
	switch {
	case len(certBytes)+len(keyBytes)+len(caBytes) == 0:
		return nil, nil, nil
	case (len(certBytes) > 0 && len(keyBytes) == 0) || (len(keyBytes) > 0 && len(certBytes) == 0):
		return nil, nil, fmt.Errorf("invalid '%s' secret data: fields 'certFile' and 'keyFile' require each other's presence",
			secret.Name)
	}

	// create tmp dir for TLS files
	tmp, err := ioutil.TempDir("", "helm-tls-"+secret.Name)
	if err != nil {
		return nil, nil, err
	}
	cleanup := func() { os.RemoveAll(tmp) }

	var certFile, keyFile, caFile string

	if len(certBytes) > 0 && len(keyBytes) > 0 {
		certFile = filepath.Join(tmp, "cert.crt")
		if err := ioutil.WriteFile(certFile, certBytes, 0644); err != nil {
			cleanup()
			return nil, nil, err
		}
		keyFile = filepath.Join(tmp, "key.crt")
		if err := ioutil.WriteFile(keyFile, keyBytes, 0644); err != nil {
			cleanup()
			return nil, nil, err
		}
	}

	if len(caBytes) > 0 {
		caFile = filepath.Join(tmp, "ca.pem")
		if err := ioutil.WriteFile(caFile, caBytes, 0644); err != nil {
			cleanup()
			return nil, nil, err
		}
	}

	return getter.WithTLSClientConfig(certFile, keyFile, caFile), cleanup, nil
}