/*
Copyright © The ESO 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

    https://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 keepersecurity implements a provider for Keeper Security secrets management service
package keepersecurity

import (
	"context"
	"errors"
	"fmt"

	ksm "github.com/keeper-security/secrets-manager-go/core"
	"github.com/keeper-security/secrets-manager-go/core/logger"
	kclient "sigs.k8s.io/controller-runtime/pkg/client"
	"sigs.k8s.io/controller-runtime/pkg/webhook/admission"

	esv1 "github.com/external-secrets/external-secrets/apis/externalsecrets/v1"
	"github.com/external-secrets/external-secrets/runtime/esutils"
	"github.com/external-secrets/external-secrets/runtime/esutils/resolvers"
)

const (
	errKeeperSecurityUnableToCreateConfig          = "unable to create valid KeeperSecurity config: %w"
	errKeeperSecurityStore                         = "received invalid KeeperSecurity SecretStore resource: %s"
	errKeeperSecurityNilSpec                       = "nil spec"
	errKeeperSecurityNilSpecProvider               = "nil spec.provider"
	errKeeperSecurityNilSpecProviderKeeperSecurity = "nil spec.provider.keepersecurity"
	errKeeperSecurityStoreMissingFolderID          = "missing: spec.provider.keepersecurity.folderID"
)

// Provider implements the necessary NewClient() and ValidateStore() funcs for Keeper Security.
type Provider struct{}

// https://github.com/external-secrets/external-secrets/issues/644
var _ esv1.SecretsClient = &Client{}
var _ esv1.Provider = &Provider{}

// Capabilities returns the provider's supported capabilities (ReadWrite).
func (p *Provider) Capabilities() esv1.SecretStoreCapabilities {
	return esv1.SecretStoreReadWrite
}

// NewClient constructs a new Keeper Security client with the provided store configuration.
func (p *Provider) NewClient(ctx context.Context, store esv1.GenericStore, kube kclient.Client, namespace string) (esv1.SecretsClient, error) {
	storeSpec := store.GetSpec()
	if storeSpec == nil || storeSpec.Provider == nil || storeSpec.Provider.KeeperSecurity == nil {
		return nil, fmt.Errorf(errKeeperSecurityStore, store)
	}

	keeperStore := storeSpec.Provider.KeeperSecurity

	clientConfig, err := getKeeperSecurityAuth(ctx, keeperStore, kube, store.GetKind(), namespace)
	if err != nil {
		return nil, fmt.Errorf(errKeeperSecurityUnableToCreateConfig, err)
	}
	ksmClientOptions := &ksm.ClientOptions{
		Config:   ksm.NewMemoryKeyValueStorage(clientConfig),
		LogLevel: logger.ErrorLevel,
	}
	ksmClient := ksm.NewSecretsManager(ksmClientOptions)
	client := &Client{
		folderID:           keeperStore.FolderID,
		ksmClient:          ksmClient,
		getByTitleFallback: keeperStore.GetByTitleFallback,
	}

	return client, nil
}

// ValidateStore validates the Keeper Security SecretStore configuration.
func (p *Provider) ValidateStore(store esv1.GenericStore) (admission.Warnings, error) {
	if store == nil {
		return nil, fmt.Errorf(errKeeperSecurityStore, store)
	}
	spc := store.GetSpec()
	if spc == nil {
		return nil, errors.New(errKeeperSecurityNilSpec)
	}
	if spc.Provider == nil {
		return nil, errors.New(errKeeperSecurityNilSpecProvider)
	}
	if spc.Provider.KeeperSecurity == nil {
		return nil, errors.New(errKeeperSecurityNilSpecProviderKeeperSecurity)
	}

	// check mandatory fields
	config := spc.Provider.KeeperSecurity

	if err := esutils.ValidateSecretSelector(store, config.Auth); err != nil {
		return nil, fmt.Errorf("error validating secret selector: %w", err)
	}
	if config.FolderID == "" {
		return nil, errors.New(errKeeperSecurityStoreMissingFolderID)
	}

	return nil, nil
}

func getKeeperSecurityAuth(ctx context.Context, store *esv1.KeeperSecurityProvider, kube kclient.Client, storeKind, namespace string) (string, error) {
	return resolvers.SecretKeyRef(
		ctx,
		kube,
		storeKind,
		namespace,
		&store.Auth)
}

// NewProvider creates a new Provider instance.
func NewProvider() esv1.Provider {
	return &Provider{}
}

// ProviderSpec returns the provider specification for registration.
func ProviderSpec() *esv1.SecretStoreProvider {
	return &esv1.SecretStoreProvider{
		KeeperSecurity: &esv1.KeeperSecurityProvider{},
	}
}

// MaintenanceStatus returns the maintenance status of the provider.
func MaintenanceStatus() esv1.MaintenanceStatus {
	return esv1.MaintenanceStatusMaintained
}
