/*
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 vault

import (
	"context"
	"errors"
	"strings"

	"github.com/hashicorp/vault/api/auth/approle"

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

const (
	errInvalidAppRoleID = "invalid Auth.AppRole: neither `roleId` nor `roleRef` was supplied"
)

func setAppRoleToken(ctx context.Context, v *client) (bool, error) {
	appRole := v.store.Auth.AppRole
	if appRole != nil {
		err := v.requestTokenWithAppRoleRef(ctx, appRole)
		if err != nil {
			return true, err
		}
		return true, nil
	}
	return false, nil
}

func (c *client) requestTokenWithAppRoleRef(ctx context.Context, appRole *esv1.VaultAppRole) error {
	var err error
	var roleID string // becomes the RoleID used to authenticate with HashiCorp Vault

	// prefer .auth.appRole.roleId, fallback to .auth.appRole.roleRef, give up after that.
	if appRole.RoleID != "" { // use roleId from CRD, if configured
		roleID = strings.TrimSpace(appRole.RoleID)
	} else if appRole.RoleRef != nil { // use RoleID from Secret, if configured
		roleID, err = resolvers.SecretKeyRef(ctx, c.kube, c.storeKind, c.namespace, appRole.RoleRef)
		if err != nil {
			return err
		}
	} else { // we ran out of ways to get RoleID. return an appropriate error
		return errors.New(errInvalidAppRoleID)
	}

	secretID, err := resolvers.SecretKeyRef(ctx, c.kube, c.storeKind, c.namespace, &appRole.SecretRef)
	if err != nil {
		return err
	}
	secret := approle.SecretID{FromString: secretID}
	appRoleClient, err := approle.NewAppRoleAuth(roleID, &secret, approle.WithMountPath(appRole.Path))
	if err != nil {
		return err
	}
	_, err = c.auth.Login(ctx, appRoleClient)
	metrics.ObserveAPICall(constants.ProviderHCVault, constants.CallHCVaultLogin, err)
	if err != nil {
		return err
	}
	return nil
}