@0x9a05e95f65f2edda;

using CSharp = import "programming_language/csharp.capnp";
$CSharp.namespace("FabAccessAPI.Schema");

using import "user.capnp".User;

interface Users {
    list @0 () -> ( users :List(User) );

    addUser @1 ( username :Text ) -> ( user :User, initialPassword :Text, error :Error );
    # Add a new user.  If adding the user succeeds then the newly created user is returned and
    # `error` is NULL / set to Error::ok.  If adding the user fails `user` is NULL and `error`
    # contains the reason for the failure.

    removeUser @2 ( user :User ) -> Fallible(Void, Void);
}

struct Error {
    union {
        ok @0 :Void;
        # This error is not actually set, i.e. the operation completed successfully.
        # This field is necessary because a NULL struct pointer may be interpreted as a struct with
        # default values.  In that case this will appear as an `Error` with the `ok` field set.

        exists @1 :Void;
        # There is already an user with the requested username

        usernameInvalid @2 :Void;
        # The provided username is not usable, e.g. contains invalid characters, is too long, or too
        # short.

        passwordInvalid @3 :Void;
        # The provided password is not usable, e.g. it's zero-length.
    }
}