// PUT /cms/admin/users/:id/roles — grant/revoke roles (admin only).
// body: { "add": ["author"], "remove": ["reader"] }
import "auth" as auth;
let g = auth::guard(ctx, ["admin"]);
if !g.ok { return g.response; }

let id = ctx.request.params.id;
let target = users::get(id);
if target == () { return #{ statusCode: 404, body: #{ error: "no such user" } }; }

let valid = ["admin", "author", "reader"];
let b = ctx.request.body;
if b != () {
    if b.add != () { for r in b.add { if valid.contains(r) { users::add_role(id, r); } } }
    if b.remove != () { for r in b.remove { if valid.contains(r) { users::remove_role(id, r); } } }
}
#{ statusCode: 200, body: #{ id: id, roles: auth::roles_of(target) } }