using System;
using System.Collections.Generic;
using System.Linq;

namespace LaDOSE.Entity
{
    /// <summary>
    /// The role names the API knows about. They must exist as rows in
    /// <c>applicationrole</c> — see Sql/2026-08-05_roles.sql.
    /// </summary>
    public static class Roles
    {
        /// <summary>May manage user accounts.</summary>
        public const string Admin = "Admin";

        /// <summary>May use everything else. The absence of a role means the same thing.</summary>
        public const string User = "User";

        public static readonly string[] All = { Admin, User };

        /// <summary>Case-insensitive, so 'admin' typed into the SQL seed still counts.</summary>
        public static bool IsAdmin(this ApplicationUser user)
        {
            return user.Names().Any(name => Admin.Equals(name, StringComparison.OrdinalIgnoreCase));
        }

        /// <summary>
        /// The user's role names. Empty when the user holds no role, and also when the
        /// query did not include them — callers that authorize must load them.
        /// </summary>
        public static List<string> Names(this ApplicationUser user)
        {
            return user?.UserRoles?
                       .Select(userRole => userRole.Role?.Name)
                       .Where(name => !string.IsNullOrWhiteSpace(name))
                       .OrderBy(name => name)
                       .ToList()
                   ?? new List<string>();
        }
    }
}