using Inversion;

namespace Spry.Authentication {

    /**
     * UserIdentityProvider implements the IdentityProvider interface from the
     * Authorisation system, bridging Authentication.User to Authorisation.Identity.
     * 
     * This allows the Authorisation system to retrieve Identity objects using
     * the UserService for storage operations.
     * 
     * Usage:
     * Register this as the IdentityProvider implementation in your IoC container:
     *   container.register<Authorisation.IdentityProvider, UserIdentityProvider>();
     * 
     * Or use directly:
     *   var provider = new UserIdentityProvider();
     *   var identity = yield provider.get_identity_by_id("user-123");
     */
    public class UserIdentityProvider : GLib.Object, Authorisation.IdentityProvider {

        private UserService _user_service = inject<UserService>();

        /**
         * Creates a new UserIdentityProvider.
         * Dependencies are injected via inject<>() pattern.
         */
        public UserIdentityProvider() {
            // Dependencies injected via field initializers
        }

        /**
         * Retrieves an Identity by its unique ID.
         * 
         * This method looks up a User by ID and returns it as an Identity.
         * Since User implements Identity, no conversion is needed.
         * 
         * @param id The user's unique identifier
         * @return The User as Identity, or null if not found
         * @throws Error on retrieval failure
         */
        public async Authorisation.Identity? get_identity_by_id(string id) throws Error {
            var user = yield _user_service.get_user_async(id);
            return user; // User implements Identity
        }

        /**
         * Retrieves an Identity by its username.
         * 
         * This method looks up a User by username and returns it as an Identity.
         * Since User implements Identity, no conversion is needed.
         * 
         * @param username The username to look up
         * @return The User as Identity, or null if not found
         * @throws Error on retrieval failure
         */
        public async Authorisation.Identity? get_identity_by_username(string username) throws Error {
            var user = yield _user_service.get_user_by_username_async(username);
            return user; // User implements Identity
        }
    }
}