oauth

type AuthorizationCode struct {
	ID            string         `json:"id"`
	Code          string         `json:"code"`
	ClientID      string         `json:"client_id"`
	UserID        string         `json:"user_id"`
	UserClaims    map[string]any `json:"user_claims"`
	CodeChallenge string         `json:"code_challenge"`
	RedirectURI   string         `json:"redirect_uri"`
	Scope         string         `json:"scope"`
	ExpiresAt     time.Time      `json:"expires_at"`
	Used          bool           `json:"used"`
	CreatedAt     time.Time      `json:"created_at"`
}

type AuthorizationRequest struct {
	ResponseType        string
	ClientID            string
	RedirectURI         string
	Scope               string
	State               string
	CodeChallenge       string
	CodeChallengeMethod string
}

type AuthorizationState struct {
	// ClientID is the OAuth client's client_id (e.g., Claude Desktop).
	ClientID string

	// RedirectURI is where to send the client after authentication.
	RedirectURI string

	// State is the client's original state parameter.
	State string

	// CodeChallenge is the PKCE challenge from the client.
	CodeChallenge string

	// CodeChallengeMethod is the PKCE method (S256 or plain).
	CodeChallengeMethod string

	// Scope is the requested scope.
	Scope string

	// UpstreamState is the state for the upstream IdP (e.g., Keycloak).
	UpstreamState string

	// CreatedAt is when this state was created.
	CreatedAt time.Time
}

type Client struct {
	ID           string    `json:"id"`
	ClientID     string    `json:"client_id"`
	ClientSecret string    `json:"client_secret"` // bcrypt hashed
	Name         string    `json:"name"`
	RedirectURIs []string  `json:"redirect_uris"`
	GrantTypes   []string  `json:"grant_types"`
	RequirePKCE  bool      `json:"require_pkce"`
	CreatedAt    time.Time `json:"created_at"`
	Active       bool      `json:"active"`
}

type DCRConfig struct {
	// Enabled enables DCR.
	Enabled bool

	// AllowedRedirectPatterns are regex patterns for allowed redirect URIs.
	AllowedRedirectPatterns []string

	// DefaultGrantTypes are the default grant types for new clients.
	DefaultGrantTypes []string

	// RequirePKCE requires PKCE for all clients.
	RequirePKCE bool
}

type DCRRequest struct {
	ClientName              string   `json:"client_name"`
	RedirectURIs            []string `json:"redirect_uris"`
	GrantTypes              []string `json:"grant_types,omitempty"`
	TokenEndpointAuthMethod string   `json:"token_endpoint_auth_method,omitempty"`
}

type DCRResponse struct {
	ClientID              string   `json:"client_id"`
	ClientSecret          string   `json:"client_secret,omitempty"`
	ClientName            string   `json:"client_name"`
	RedirectURIs          []string `json:"redirect_uris"`
	GrantTypes            []string `json:"grant_types"`
	ClientSecretExpiresAt int      `json:"client_secret_expires_at"` // 0 means never
}

type DCRService struct {
	// contains filtered or unexported fields
}

type ErrorResponse struct {
	Error            string `json:"error"`
	ErrorDescription string `json:"error_description,omitempty"`
}

type MemoryStateStore struct {
	// contains filtered or unexported fields
}

type MemoryStorage struct {
	// contains filtered or unexported fields
}

type PKCEMethod string

type RefreshToken struct {
	ID         string         `json:"id"`
	Token      string         `json:"token"`
	ClientID   string         `json:"client_id"`
	UserID     string         `json:"user_id"`
	UserClaims map[string]any `json:"user_claims"`
	Scope      string         `json:"scope"`
	ExpiresAt  time.Time      `json:"expires_at"`
	CreatedAt  time.Time      `json:"created_at"`
}

type Server struct {
	// contains filtered or unexported fields
}

type ServerConfig struct {
	// Issuer is the OAuth issuer URL.
	Issuer string

	// AccessTokenTTL is the access token lifetime.
	AccessTokenTTL time.Duration

	// RefreshTokenTTL is the refresh token lifetime.
	RefreshTokenTTL time.Duration

	// AuthCodeTTL is the authorization code lifetime.
	AuthCodeTTL time.Duration

	// SigningKey is the HMAC key used to sign JWT access tokens.
	// If not provided, tokens will be opaque (not recommended for production).
	// Generate with: openssl rand -base64 32
	SigningKey []byte

	// DCR configures Dynamic Client Registration.
	DCR DCRConfig

	// Upstream configures the upstream identity provider (e.g., Keycloak).
	Upstream *UpstreamConfig
}

type StateStore interface {
	// Save stores an authorization state.
	Save(key string, state *AuthorizationState) error

	// Get retrieves an authorization state.
	Get(key string) (*AuthorizationState, error)

	// Delete removes an authorization state.
	Delete(key string) error

	// Cleanup removes expired states.
	Cleanup(maxAge time.Duration) error
}

type Storage interface {
	// Client management
	CreateClient(ctx context.Context, client *Client) error
	GetClient(ctx context.Context, clientID string) (*Client, error)
	UpdateClient(ctx context.Context, client *Client) error
	DeleteClient(ctx context.Context, clientID string) error
	ListClients(ctx context.Context) ([]*Client, error)

	// Authorization code management
	SaveAuthorizationCode(ctx context.Context, code *AuthorizationCode) error
	GetAuthorizationCode(ctx context.Context, code string) (*AuthorizationCode, error)
	DeleteAuthorizationCode(ctx context.Context, code string) error
	CleanupExpiredCodes(ctx context.Context) error

	// Token management
	SaveRefreshToken(ctx context.Context, token *RefreshToken) error
	GetRefreshToken(ctx context.Context, token string) (*RefreshToken, error)
	DeleteRefreshToken(ctx context.Context, token string) error
	DeleteRefreshTokensForClient(ctx context.Context, clientID string) error
	CleanupExpiredTokens(ctx context.Context) error
}

type TokenRequest struct {
	GrantType    string
	Code         string
	RedirectURI  string
	ClientID     string
	ClientSecret string
	CodeVerifier string
	RefreshToken string
	Scope        string
}

type TokenResponse struct {
	AccessToken  string `json:"access_token"`
	TokenType    string `json:"token_type"`
	ExpiresIn    int    `json:"expires_in"`
	RefreshToken string `json:"refresh_token,omitempty"`
	Scope        string `json:"scope,omitempty"`
}

type UpstreamConfig struct {
	// Issuer is the upstream IdP issuer URL (e.g., Keycloak realm URL).
	Issuer string

	// ClientID is the MCP server's client ID in the upstream IdP.
	ClientID string

	// ClientSecret is the MCP server's client secret.
	ClientSecret string

	// RedirectURI is the callback URL for the upstream IdP.
	RedirectURI string
}