/*
Copyright 2021 The Flux 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 bootstrap

import (
	"fmt"
	"os"

	"k8s.io/cli-runtime/pkg/genericclioptions"

	"github.com/ProtonMail/go-crypto/openpgp"
	"github.com/fluxcd/pkg/git"
	runclient "github.com/fluxcd/pkg/runtime/client"

	"github.com/fluxcd/flux2/v2/pkg/log"
)

type Option interface {
	GitOption
	GitProviderOption
}

func WithBranch(branch string) Option {
	return branchOption(branch)
}

type branchOption string

func (o branchOption) applyGit(b *PlainGitBootstrapper) {
	b.branch = string(o)
}

func (o branchOption) applyGitProvider(b *GitProviderBootstrapper) {
	o.applyGit(b.PlainGitBootstrapper)
}

func WithSignature(name, email string) Option {
	return signatureOption{
		Name:  name,
		Email: email,
	}
}

type signatureOption git.Signature

func (o signatureOption) applyGit(b *PlainGitBootstrapper) {
	if o.Name != "" {
		b.signature.Name = o.Name
	}
	if o.Email != "" {
		b.signature.Email = o.Email
	}
}

func (o signatureOption) applyGitProvider(b *GitProviderBootstrapper) {
	o.applyGit(b.PlainGitBootstrapper)
}

func WithCommitMessageAppendix(appendix string) Option {
	return commitMessageAppendixOption(appendix)
}

type commitMessageAppendixOption string

func (o commitMessageAppendixOption) applyGit(b *PlainGitBootstrapper) {
	b.commitMessageAppendix = string(o)
}

func (o commitMessageAppendixOption) applyGitProvider(b *GitProviderBootstrapper) {
	o.applyGit(b.PlainGitBootstrapper)
}

func WithKubeconfig(rcg genericclioptions.RESTClientGetter, opts *runclient.Options) Option {
	return kubeconfigOption{
		rcg:  rcg,
		opts: opts,
	}
}

type kubeconfigOption struct {
	rcg  genericclioptions.RESTClientGetter
	opts *runclient.Options
}

func (o kubeconfigOption) applyGit(b *PlainGitBootstrapper) {
	b.restClientGetter = o.rcg
	b.restClientOptions = o.opts
}

func (o kubeconfigOption) applyGitProvider(b *GitProviderBootstrapper) {
	o.applyGit(b.PlainGitBootstrapper)
}

func WithLogger(logger log.Logger) Option {
	return loggerOption{logger}
}

type loggerOption struct {
	logger log.Logger
}

func (o loggerOption) applyGit(b *PlainGitBootstrapper) {
	b.logger = o.logger
}

func (o loggerOption) applyGitProvider(b *GitProviderBootstrapper) {
	b.logger = o.logger
}

func WithGitCommitSigning(gpgKeyRing openpgp.EntityList, passphrase, keyID string) Option {
	return gitCommitSigningOption{
		gpgKeyRing:    gpgKeyRing,
		gpgPassphrase: passphrase,
		gpgKeyID:      keyID,
	}
}

type gitCommitSigningOption struct {
	gpgKeyRing    openpgp.EntityList
	gpgPassphrase string
	gpgKeyID      string
}

func (o gitCommitSigningOption) applyGit(b *PlainGitBootstrapper) {
	b.gpgKeyRing = o.gpgKeyRing
	b.gpgPassphrase = o.gpgPassphrase
	b.gpgKeyID = o.gpgKeyID
}

func (o gitCommitSigningOption) applyGitProvider(b *GitProviderBootstrapper) {
	o.applyGit(b.PlainGitBootstrapper)
}

// WithSSHCommitSigning configures the bootstrapper to sign commits with
// an SSH private key. pem is the PEM-encoded private key (typically the
// OpenSSH "-----BEGIN OPENSSH PRIVATE KEY-----" format produced by
// ssh-keygen). password is the optional passphrase for the key; pass
// nil for an unencrypted key.
//
// WithSSHCommitSigning and WithGitCommitSigning are mutually exclusive;
// calling both is undefined behavior. The caller is responsible for
// rejecting that combination before constructing the bootstrapper (the
// flux CLI does this in bootstrapValidate).
func WithSSHCommitSigning(pem, password []byte) Option {
	return sshCommitSigningOption{pem: pem, password: password}
}

type sshCommitSigningOption struct {
	pem      []byte
	password []byte
}

func (o sshCommitSigningOption) applyGit(b *PlainGitBootstrapper) {
	b.sshSigningKey = o.pem
	b.sshSigningPassword = o.password
}

func (o sshCommitSigningOption) applyGitProvider(b *GitProviderBootstrapper) {
	o.applyGit(b.PlainGitBootstrapper)
}

func LoadEntityListFromPath(path string) (openpgp.EntityList, error) {
	if path == "" {
		return nil, nil
	}
	r, err := os.Open(path)
	if err != nil {
		return nil, fmt.Errorf("unable to open GPG key ring: %w", err)
	}
	entityList, err := openpgp.ReadKeyRing(r)
	if err != nil {
		return nil, fmt.Errorf("unable to read GPG key ring: %w", err)
	}
	return entityList, nil
}
