using System.Security.Claims;
using adas_core.Domain.Enums;
using Microsoft.AspNetCore.Mvc;
using Microsoft.AspNetCore.Mvc.Filters;

namespace adas_core.Authentication.Attributes;

/// <summary>
/// Specifies an authorization filter attribute that restricts access to decorated methods based on a required role of type <see cref="PermissionEnum.RolesType"/>.
/// Inherits from <see cref="Attribute"/> and implements <see cref="IAuthorizationFilter"/> to participate in the authorization pipeline.
/// </summary>
/// <remarks>
/// Constrained by <see cref="System.AttributeUsageAttribute"/> to <see cref="AttributeTargets.Method"/>, the attribute is configured at construction with the required <paramref name="type"/>.
/// </remarks>
/// <!-- aidoc:v1 sig=b5093e9 -->
/// <!-- aidoc-review:v1 severity=medium kind=missing_param
///      "The primary constructor parameter 'type' is referenced via <paramref> in remarks but lacks a formal <param> tag describing its purpose." -->
[AttributeUsage(AttributeTargets.Method)]
public class AuthorizeRolesAttribute(PermissionEnum.RolesType type) : Attribute, IAuthorizationFilter
{
    /// <summary>
    /// Performs authorization by ensuring the current user is authenticated and has a role matching the required permission type.
    /// Responds with an unauthorized result when no user is authenticated, bypasses role checking for the AuthSome permission type,
    /// and otherwise responds with a forbid result when no user role starts with the permission type value.
    /// </summary>
    /// <param name="context">The authorization filter context providing access to the HTTP context and where the authorization result is assigned.</param>
    /// <!-- aidoc:v1 sig=6368c5d body=ab6a306 -->
    public void OnAuthorization(AuthorizationFilterContext context)
        {
            var user = context.HttpContext.User;
    
            if (user.Identity?.IsAuthenticated != true)
            {
                context.Result = new UnauthorizedResult();
                return;
            }
    
            var roles = user.Claims.Where(c => c.Type == ClaimTypes.Role);
    
            if (type == PermissionEnum.RolesType.AuthSome) return;
    
            var hasRequiredRole = roles.Any(r => r.Value.StartsWith(type.ToString()));
            if (!hasRequiredRole) context.Result = new ForbidResult();
        }
}