/*
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 v1beta1

import (
	esmeta "github.com/external-secrets/external-secrets/apis/meta/v1"
)

// VaultKVStoreVersion defines the version of the KV store in Vault.
type VaultKVStoreVersion string

const (
	// VaultKVStoreV1 represents version 1 of the Vault KV store.
	VaultKVStoreV1 VaultKVStoreVersion = "v1"
	// VaultKVStoreV2 represents version 2 of the Vault KV store.
	VaultKVStoreV2 VaultKVStoreVersion = "v2"
)

// VaultProvider configures a store to sync secrets using a HashiCorp Vault KV backend.
type VaultProvider struct {
	// Auth configures how secret-manager authenticates with the Vault server.
	Auth *VaultAuth `json:"auth,omitempty"`

	// Server is the connection address for the Vault server, e.g: "https://vault.example.com:8200".
	Server string `json:"server"`

	// Path is the mount path of the Vault KV backend endpoint, e.g:
	// "secret". The v2 KV secret engine version specific "/data" path suffix
	// for fetching secrets from Vault is optional and will be appended
	// if not present in specified path.
	// +optional
	Path *string `json:"path,omitempty"`

	// Version is the Vault KV secret engine version. This can be either "v1" or
	// "v2". Version defaults to "v2".
	// +kubebuilder:validation:Optional
	// +kubebuilder:validation:Enum="v1";"v2"
	// +kubebuilder:default:="v2"
	Version VaultKVStoreVersion `json:"version"`

	// Name of the vault namespace. Namespaces is a set of features within Vault Enterprise that allows
	// Vault environments to support Secure Multi-tenancy. e.g: "ns1".
	// More about namespaces can be found here https://www.vaultproject.io/docs/enterprise/namespaces
	// +optional
	Namespace *string `json:"namespace,omitempty"`

	// PEM encoded CA bundle used to validate Vault server certificate. Only used
	// if the Server URL is using HTTPS protocol. This parameter is ignored for
	// plain HTTP protocol connection. If not set the system root certificates
	// are used to validate the TLS connection.
	// +optional
	CABundle []byte `json:"caBundle,omitempty"`

	// The configuration used for client side related TLS communication, when the Vault server
	// requires mutual authentication. Only used if the Server URL is using HTTPS protocol.
	// This parameter is ignored for plain HTTP protocol connection.
	// It's worth noting this configuration is different from the "TLS certificates auth method",
	// which is available under the `auth.cert` section.
	// +optional
	ClientTLS VaultClientTLS `json:"tls,omitempty"`

	// The provider for the CA bundle to use to validate Vault server certificate.
	// +optional
	CAProvider *CAProvider `json:"caProvider,omitempty"`

	// ReadYourWrites ensures isolated read-after-write semantics by
	// providing discovered cluster replication states in each request.
	// More information about eventual consistency in Vault can be found here
	// https://www.vaultproject.io/docs/enterprise/consistency
	// +optional
	ReadYourWrites bool `json:"readYourWrites,omitempty"`

	// ForwardInconsistent tells Vault to forward read-after-write requests to the Vault
	// leader instead of simply retrying within a loop. This can increase performance if
	// the option is enabled serverside.
	// https://www.vaultproject.io/docs/configuration/replication#allow_forwarding_via_header
	// +optional
	ForwardInconsistent bool `json:"forwardInconsistent,omitempty"`

	// Headers to be added in Vault request
	// +optional
	Headers map[string]string `json:"headers,omitempty"`
}

// VaultClientTLS is the configuration used for client side related TLS communication,
// when the Vault server requires mutual authentication.
type VaultClientTLS struct {
	// CertSecretRef is a certificate added to the transport layer
	// when communicating with the Vault server.
	// If no key for the Secret is specified, external-secret will default to 'tls.crt'.
	// +optional
	CertSecretRef *esmeta.SecretKeySelector `json:"certSecretRef,omitempty"`

	// KeySecretRef to a key in a Secret resource containing client private key
	// added to the transport layer when communicating with the Vault server.
	// If no key for the Secret is specified, external-secret will default to 'tls.key'.
	// +optional
	KeySecretRef *esmeta.SecretKeySelector `json:"keySecretRef,omitempty"`
}

// VaultAuth is the configuration used to authenticate with a Vault server.
// Only one of `tokenSecretRef`, `appRole`,  `kubernetes`, `ldap`, `userPass`, `jwt` or `cert`
// can be specified. A namespace to authenticate against can optionally be specified.
type VaultAuth struct {
	// Name of the vault namespace to authenticate to. This can be different than the namespace your secret is in.
	// Namespaces is a set of features within Vault Enterprise that allows
	// Vault environments to support Secure Multi-tenancy. e.g: "ns1".
	// More about namespaces can be found here https://www.vaultproject.io/docs/enterprise/namespaces
	// This will default to Vault.Namespace field if set, or empty otherwise
	// +optional
	Namespace *string `json:"namespace,omitempty"`

	// TokenSecretRef authenticates with Vault by presenting a token.
	// +optional
	TokenSecretRef *esmeta.SecretKeySelector `json:"tokenSecretRef,omitempty"`

	// AppRole authenticates with Vault using the App Role auth mechanism,
	// with the role and secret stored in a Kubernetes Secret resource.
	// +optional
	AppRole *VaultAppRole `json:"appRole,omitempty"`

	// Kubernetes authenticates with Vault by passing the ServiceAccount
	// token stored in the named Secret resource to the Vault server.
	// +optional
	Kubernetes *VaultKubernetesAuth `json:"kubernetes,omitempty"`

	// Ldap authenticates with Vault by passing username/password pair using
	// the LDAP authentication method
	// +optional
	Ldap *VaultLdapAuth `json:"ldap,omitempty"`

	// Jwt authenticates with Vault by passing role and JWT token using the
	// JWT/OIDC authentication method
	// +optional
	Jwt *VaultJwtAuth `json:"jwt,omitempty"`

	// Cert authenticates with TLS Certificates by passing client certificate, private key and ca certificate
	// Cert authentication method
	// +optional
	Cert *VaultCertAuth `json:"cert,omitempty"`

	// Iam authenticates with vault by passing a special AWS request signed with AWS IAM credentials
	// AWS IAM authentication method
	// +optional
	Iam *VaultIamAuth `json:"iam,omitempty"`

	// UserPass authenticates with Vault by passing username/password pair
	// +optional
	UserPass *VaultUserPassAuth `json:"userPass,omitempty"`
}

// VaultAppRole authenticates with Vault using the App Role auth mechanism,
// with the role and secret stored in a Kubernetes Secret resource.
type VaultAppRole struct {
	// Path where the App Role authentication backend is mounted
	// in Vault, e.g: "approle"
	// +kubebuilder:default=approle
	Path string `json:"path"`

	// RoleID configured in the App Role authentication backend when setting
	// up the authentication backend in Vault.
	//+optional
	RoleID string `json:"roleId,omitempty"`

	// Reference to a key in a Secret that contains the App Role ID used
	// to authenticate with Vault.
	// The `key` field must be specified and denotes which entry within the Secret
	// resource is used as the app role id.
	//+optional
	RoleRef *esmeta.SecretKeySelector `json:"roleRef,omitempty"`

	// Reference to a key in a Secret that contains the App Role secret used
	// to authenticate with Vault.
	// The `key` field must be specified and denotes which entry within the Secret
	// resource is used as the app role secret.
	SecretRef esmeta.SecretKeySelector `json:"secretRef"`
}

// VaultKubernetesAuth authenticates against Vault using a Kubernetes ServiceAccount token stored in a Secret.
type VaultKubernetesAuth struct {
	// Path where the Kubernetes authentication backend is mounted in Vault, e.g:
	// "kubernetes"
	// +kubebuilder:default=kubernetes
	Path string `json:"mountPath"`

	// Optional service account field containing the name of a kubernetes ServiceAccount.
	// If the service account is specified, the service account secret token JWT will be used
	// for authenticating with Vault. If the service account selector is not supplied,
	// the secretRef will be used instead.
	// +optional
	ServiceAccountRef *esmeta.ServiceAccountSelector `json:"serviceAccountRef,omitempty"`

	// Optional secret field containing a Kubernetes ServiceAccount JWT used
	// for authenticating with Vault. If a name is specified without a key,
	// `token` is the default. If one is not specified, the one bound to
	// the controller will be used.
	// +optional
	SecretRef *esmeta.SecretKeySelector `json:"secretRef,omitempty"`

	// A required field containing the Vault Role to assume. A Role binds a
	// Kubernetes ServiceAccount with a set of Vault policies.
	Role string `json:"role"`
}

// VaultLdapAuth authenticates with Vault using the LDAP authentication method,
// with the username and password stored in a Kubernetes Secret resource.
type VaultLdapAuth struct {
	// Path where the LDAP authentication backend is mounted
	// in Vault, e.g: "ldap"
	// +kubebuilder:default=ldap
	Path string `json:"path"`

	// Username is an LDAP username used to authenticate using the LDAP Vault
	// authentication method
	Username string `json:"username"`

	// SecretRef to a key in a Secret resource containing password for the LDAP
	// user used to authenticate with Vault using the LDAP authentication
	// method
	// +optional
	SecretRef esmeta.SecretKeySelector `json:"secretRef,omitempty"`
}

// VaultAwsAuth tells the controller how to do authentication with aws.
// Only one of secretRef or jwt can be specified.
// if none is specified the controller will try to load credentials from its own service account assuming it is IRSA enabled.
type VaultAwsAuth struct {
	// +optional
	SecretRef *VaultAwsAuthSecretRef `json:"secretRef,omitempty"`
	// +optional
	JWTAuth *VaultAwsJWTAuth `json:"jwt,omitempty"`
}

// VaultAwsAuthSecretRef holds secret references for AWS credentials
// both AccessKeyID and SecretAccessKey must be defined in order to properly authenticate.
type VaultAwsAuthSecretRef struct {
	// The AccessKeyID is used for authentication
	// +optional
	AccessKeyID esmeta.SecretKeySelector `json:"accessKeyIDSecretRef,omitempty"`

	// The SecretAccessKey is used for authentication
	// +optional
	SecretAccessKey esmeta.SecretKeySelector `json:"secretAccessKeySecretRef,omitempty"`

	// The SessionToken used for authentication
	// This must be defined if AccessKeyID and SecretAccessKey are temporary credentials
	// see: https://docs.aws.amazon.com/IAM/latest/UserGuide/id_credentials_temp_use-resources.html
	// +optional
	SessionToken *esmeta.SecretKeySelector `json:"sessionTokenSecretRef,omitempty"`
}

// VaultAwsJWTAuth Authenticate against AWS using service account tokens.
type VaultAwsJWTAuth struct {
	// +optional
	ServiceAccountRef *esmeta.ServiceAccountSelector `json:"serviceAccountRef,omitempty"`
}

// VaultKubernetesServiceAccountTokenAuth authenticates with Vault using a temporary
// Kubernetes service account token retrieved by the `TokenRequest` API.
type VaultKubernetesServiceAccountTokenAuth struct {
	// Service account field containing the name of a kubernetes ServiceAccount.
	ServiceAccountRef esmeta.ServiceAccountSelector `json:"serviceAccountRef"`

	// Optional audiences field that will be used to request a temporary Kubernetes service
	// account token for the service account referenced by `serviceAccountRef`.
	// Defaults to a single audience `vault` it not specified.
	//
	// Deprecated: use serviceAccountRef.Audiences instead
	// +optional
	Audiences *[]string `json:"audiences,omitempty"`

	// Optional expiration time in seconds that will be used to request a temporary
	// Kubernetes service account token for the service account referenced by
	// `serviceAccountRef`.
	//
	// Deprecated: this will be removed in the future.
	// Defaults to 10 minutes.
	// +optional
	ExpirationSeconds *int64 `json:"expirationSeconds,omitempty"`
}

// VaultJwtAuth authenticates with Vault using the JWT/OIDC authentication
// method, with the role name and a token stored in a Kubernetes Secret resource or
// a Kubernetes service account token retrieved via `TokenRequest`.
type VaultJwtAuth struct {
	// Path where the JWT authentication backend is mounted
	// in Vault, e.g: "jwt"
	// +kubebuilder:default=jwt
	Path string `json:"path"`

	// Role is a JWT role to authenticate using the JWT/OIDC Vault
	// authentication method
	// +optional
	Role string `json:"role,omitempty"`

	// Optional SecretRef that refers to a key in a Secret resource containing JWT token to
	// authenticate with Vault using the JWT/OIDC authentication method.
	// +optional
	SecretRef *esmeta.SecretKeySelector `json:"secretRef,omitempty"`

	// Optional ServiceAccountToken specifies the Kubernetes service account for which to request
	// a token for with the `TokenRequest` API.
	// +optional
	KubernetesServiceAccountToken *VaultKubernetesServiceAccountTokenAuth `json:"kubernetesServiceAccountToken,omitempty"`
}

// VaultCertAuth authenticates with Vault using the JWT/OIDC authentication
// method, with the role name and token stored in a Kubernetes Secret resource.
type VaultCertAuth struct {
	// ClientCert is a certificate to authenticate using the Cert Vault
	// authentication method
	// +optional
	ClientCert esmeta.SecretKeySelector `json:"clientCert,omitempty"`

	// SecretRef to a key in a Secret resource containing client private key to
	// authenticate with Vault using the Cert authentication method
	// +optional
	SecretRef esmeta.SecretKeySelector `json:"secretRef,omitempty"`
}

// VaultIamAuth authenticates with Vault using the Vault's AWS IAM authentication method. Refer: https://developer.hashicorp.com/vault/docs/auth/aws
type VaultIamAuth struct {
	// Path where the AWS auth method is enabled in Vault, e.g: "aws"
	// +optional
	Path string `json:"path,omitempty"`
	// AWS region
	// +optional
	Region string `json:"region,omitempty"`
	// This is the AWS role to be assumed before talking to vault
	// +optional
	AWSIAMRole string `json:"role,omitempty"`
	// Vault Role. In vault, a role describes an identity with a set of permissions, groups, or policies you want to attach a user of the secrets engine
	Role string `json:"vaultRole"`
	// AWS External ID set on assumed IAM roles
	ExternalID string `json:"externalID,omitempty"`
	// X-Vault-AWS-IAM-Server-ID is an additional header used by Vault IAM auth method to mitigate against different types of replay attacks. More details here: https://developer.hashicorp.com/vault/docs/auth/aws
	// +optional
	VaultAWSIAMServerID string `json:"vaultAwsIamServerID,omitempty"`
	// Specify credentials in a Secret object
	// +optional
	SecretRef *VaultAwsAuthSecretRef `json:"secretRef,omitempty"`
	// Specify a service account with IRSA enabled
	// +optional
	JWTAuth *VaultAwsJWTAuth `json:"jwt,omitempty"`
}

// VaultUserPassAuth authenticates with Vault using UserPass authentication method,
// with the username and password stored in a Kubernetes Secret resource.
type VaultUserPassAuth struct {
	// Path where the UserPassword authentication backend is mounted
	// in Vault, e.g: "userpass"
	// +kubebuilder:default=userpass
	Path string `json:"path"`

	// Username is a username used to authenticate using the UserPass Vault
	// authentication method
	Username string `json:"username"`

	// SecretRef to a key in a Secret resource containing password for the
	// user used to authenticate with Vault using the UserPass authentication
	// method
	// +optional
	SecretRef esmeta.SecretKeySelector `json:"secretRef,omitempty"`
}
