package auth

import (
	"context"
	"errors"
)

var (
	ErrTokenExpired     = errors.New("token has expired")
	ErrInvalidToken     = errors.New("token is invalid")
	ErrTokenBlacklisted = errors.New("token has been revoked")
)

// Service defines the interface for authentication operations
type Service interface {
	// GenerateToken creates a new authentication token for a user
	GenerateToken(ctx context.Context, clientID string) (string, error)

	// ValidateToken verifies a token and returns the client ID if valid
	ValidateToken(ctx context.Context, token string) (string, error)

	// RefreshToken creates a new token based on an existing valid token
	RefreshToken(ctx context.Context, token string) (string, error)

	// Logout invalidates a token
	Logout(ctx context.Context, token string) error
}