// Copyright 2020 Google LLC.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

// Package internaloption contains options used internally by Google client code.
package internaloption

import (
	"golang.org/x/oauth2/google"
	"google.golang.org/api/internal"
	"google.golang.org/api/option"
)

type defaultEndpointOption string

func (o defaultEndpointOption) Apply(settings *internal.DialSettings) {
	settings.DefaultEndpoint = string(o)
}

// WithDefaultEndpoint is an option that indicates the default endpoint.
//
// It should only be used internally by generated clients.
//
// This is similar to WithEndpoint, but allows us to determine whether the user has overridden the default endpoint.
func WithDefaultEndpoint(url string) option.ClientOption {
	return defaultEndpointOption(url)
}

type defaultMTLSEndpointOption string

func (o defaultMTLSEndpointOption) Apply(settings *internal.DialSettings) {
	settings.DefaultMTLSEndpoint = string(o)
}

// WithDefaultMTLSEndpoint is an option that indicates the default mTLS endpoint.
//
// It should only be used internally by generated clients.
func WithDefaultMTLSEndpoint(url string) option.ClientOption {
	return defaultMTLSEndpointOption(url)
}

// SkipDialSettingsValidation bypasses validation on ClientOptions.
//
// It should only be used internally.
func SkipDialSettingsValidation() option.ClientOption {
	return skipDialSettingsValidation{}
}

type skipDialSettingsValidation struct{}

func (s skipDialSettingsValidation) Apply(settings *internal.DialSettings) {
	settings.SkipValidation = true
}

// EnableDirectPath returns a ClientOption that overrides the default
// attempt to use DirectPath.
//
// It should only be used internally by generated clients.
// This is an EXPERIMENTAL API and may be changed or removed in the future.
func EnableDirectPath(dp bool) option.ClientOption {
	return enableDirectPath(dp)
}

type enableDirectPath bool

func (e enableDirectPath) Apply(o *internal.DialSettings) {
	o.EnableDirectPath = bool(e)
}

// EnableDirectPathXds returns a ClientOption that overrides the default
// DirectPath type. It is only valid when DirectPath is enabled.
//
// It should only be used internally by generated clients.
// This is an EXPERIMENTAL API and may be changed or removed in the future.
func EnableDirectPathXds() option.ClientOption {
	return enableDirectPathXds(true)
}

type enableDirectPathXds bool

func (x enableDirectPathXds) Apply(o *internal.DialSettings) {
	o.EnableDirectPathXds = bool(x)
}

// AllowNonDefaultServiceAccount returns a ClientOption that overrides the default
// requirement for using the default service account for DirectPath.
//
// It should only be used internally by generated clients.
// This is an EXPERIMENTAL API and may be changed or removed in the future.
func AllowNonDefaultServiceAccount(nd bool) option.ClientOption {
	return allowNonDefaultServiceAccount(nd)
}

type allowNonDefaultServiceAccount bool

func (a allowNonDefaultServiceAccount) Apply(o *internal.DialSettings) {
	o.AllowNonDefaultServiceAccount = bool(a)
}

// WithDefaultAudience returns a ClientOption that specifies a default audience
// to be used as the audience field ("aud") for the JWT token authentication.
//
// It should only be used internally by generated clients.
func WithDefaultAudience(audience string) option.ClientOption {
	return withDefaultAudience(audience)
}

type withDefaultAudience string

func (w withDefaultAudience) Apply(o *internal.DialSettings) {
	o.DefaultAudience = string(w)
}

// WithDefaultScopes returns a ClientOption that overrides the default OAuth2
// scopes to be used for a service.
//
// It should only be used internally by generated clients.
func WithDefaultScopes(scope ...string) option.ClientOption {
	return withDefaultScopes(scope)
}

type withDefaultScopes []string

func (w withDefaultScopes) Apply(o *internal.DialSettings) {
	o.DefaultScopes = make([]string, len(w))
	copy(o.DefaultScopes, w)
}

// EnableJwtWithScope returns a ClientOption that specifies if scope can be used
// with self-signed JWT.
func EnableJwtWithScope() option.ClientOption {
	return enableJwtWithScope(true)
}

type enableJwtWithScope bool

func (w enableJwtWithScope) Apply(o *internal.DialSettings) {
	o.EnableJwtWithScope = bool(w)
}

// WithCredentials returns a client option to specify credentials which will be used to authenticate API calls.
// This credential takes precedence over all other credential options.
func WithCredentials(creds *google.Credentials) option.ClientOption {
	return (*withCreds)(creds)
}

type withCreds google.Credentials

func (w *withCreds) Apply(o *internal.DialSettings) {
	o.InternalCredentials = (*google.Credentials)(w)
}

// EnableNewAuthLibrary returns a ClientOption that specifies if libraries in this
// module to delegate auth to our new library. This option will be removed in
// the future once all clients have been moved to the new auth layer.
func EnableNewAuthLibrary() option.ClientOption {
	return enableNewAuthLibrary(true)
}

type enableNewAuthLibrary bool

func (w enableNewAuthLibrary) Apply(o *internal.DialSettings) {
	o.EnableNewAuthLibrary = bool(w)
}

// EmbeddableAdapter is a no-op option.ClientOption that allow libraries to
// create their own client options by embedding this type into their own
// client-specific option wrapper. See example for usage.
type EmbeddableAdapter struct{}

func (*EmbeddableAdapter) Apply(_ *internal.DialSettings) {}
