oauthserver

type ExternalService struct {
	ID               int64  `xorm:"id pk autoincr"`
	Name             string `xorm:"name"`
	ClientID         string `xorm:"client_id"`
	Secret           string `xorm:"secret"`
	RedirectURI      string `xorm:"redirect_uri"` // Not used yet (code flow)
	GrantTypes       string `xorm:"grant_types"`  // CSV value
	Audiences        string `xorm:"audiences"`    // CSV value
	PublicPem        []byte `xorm:"public_pem"`
	ServiceAccountID int64  `xorm:"service_account_id"`
	// SelfPermissions are the registered service account permissions (registered and managed permissions)
	SelfPermissions []ac.Permission
	// ImpersonatePermissions is the restriction set of permissions while impersonating
	ImpersonatePermissions []ac.Permission

	// SignedInUser refers to the current Service Account identity/user
	SignedInUser      *user.SignedInUser
	Scopes            []string
	ImpersonateScopes []string
}

type ExternalServiceDTO struct {
	Name        string     `json:"name"`
	ID          string     `json:"clientId"`
	Secret      string     `json:"clientSecret"`
	RedirectURI string     `json:"redirectUri,omitempty"` // Not used yet (code flow)
	GrantTypes  string     `json:"grantTypes"`            // CSV value
	Audiences   string     `json:"audiences"`             // CSV value
	KeyResult   *KeyResult `json:"key,omitempty"`
}

type ExternalServiceRegistration struct {
	Name string `json:"name"`
	// RedirectURI is the URI that is used in the code flow.
	// Note that this is not used yet.
	RedirectURI *string `json:"redirectUri,omitempty"`
	// Impersonation access configuration
	Impersonation ImpersonationCfg `json:"impersonation"`
	// Self access configuration
	Self SelfCfg `json:"self"`
	// Key is the option to specify a public key or ask the server to generate a crypto key pair.
	Key *KeyOption `json:"key,omitempty"`
}

type ImpersonationCfg struct {
	// Enabled allows the service to request access tokens to impersonate users using the jwtbearer grant
	Enabled bool `json:"enabled"`
	// Groups allows the service to list the impersonated user's teams
	Groups bool `json:"groups"`
	// Permissions are the permissions that the external service needs when impersonating a user.
	// The intersection of this set with the impersonated user's permission guarantees that the client will not
	// gain more privileges than the impersonated user has.
	Permissions []accesscontrol.Permission `json:"permissions,omitempty"`
}

type KeyOption struct {
	// URL       string `json:"url,omitempty"` // TODO allow specifying a URL (to a .jwks file) to fetch the key from
	// PublicPEM contains the Base64 encoded public key in PEM format
	PublicPEM string `json:"public_pem,omitempty"`
	Generate  bool   `json:"generate,omitempty"`
}

type KeyResult struct {
	URL        string `json:"url,omitempty"`
	PrivatePem string `json:"private,omitempty"`
	PublicPem  string `json:"public,omitempty"`
	Generated  bool   `json:"generated,omitempty"`
}

type OAuth2Server interface {
	// SaveExternalService creates or updates an external service in the database, it generates client_id and secrets and
	// it ensures that the associated service account has the correct permissions.
	SaveExternalService(ctx context.Context, cmd *ExternalServiceRegistration) (*ExternalServiceDTO, error)
	// GetExternalService retrieves an external service from store by client_id. It populates the SelfPermissions and
	// SignedInUser from the associated service account.
	GetExternalService(ctx context.Context, id string) (*ExternalService, error)

	// HandleTokenRequest handles the client's OAuth2 query to obtain an access_token by presenting its authorization
	// grant (ex: client_credentials, jwtbearer).
	HandleTokenRequest(rw http.ResponseWriter, req *http.Request)
	// HandleIntrospectionRequest handles the OAuth2 query to determine the active state of an OAuth 2.0 token and
	// to determine meta-information about this token.
	HandleIntrospectionRequest(rw http.ResponseWriter, req *http.Request)
}

type SelfCfg struct {
	// Enabled allows the service to request access tokens for itself using the client_credentials grant
	Enabled bool `json:"enabled"`
	// Permissions are the permissions that the external service needs its associated service account to have.
	Permissions []accesscontrol.Permission `json:"permissions,omitempty"`
}

type Store interface {
	RegisterExternalService(ctx context.Context, client *ExternalService) error
	SaveExternalService(ctx context.Context, client *ExternalService) error
	GetExternalService(ctx context.Context, id string) (*ExternalService, error)
	GetExternalServiceByName(ctx context.Context, name string) (*ExternalService, error)
	GetExternalServicePublicKey(ctx context.Context, clientID string) (*jose.JSONWebKey, error)
}