using System.Security.Claims;
using SurveyBackend.Core.Contexts;
using SurveyBackend.Services.Exceptions;

namespace SurveyBackend.Contexts;

/// <summary>
/// Упрощает получение UserId из JWT-токена
/// </summary>
public class UserContext : IUserContext
{
    private readonly IHttpContextAccessor _httpContextAccessor;

    /// <summary>
    /// Добавьте HttpContextAccessor в DI и будет счастье
    /// </summary>
    /// <param name="httpContextAccessor"></param>
    public UserContext(IHttpContextAccessor httpContextAccessor)
    {
        _httpContextAccessor = httpContextAccessor;
    }

    /// <summary>
    /// Возвращает UserId из токена, при отсуствии кидает Unauthorized
    /// </summary>
    /// <exception cref="UnauthorizedAccessException"></exception>
    public int UserId =>
        int.Parse(
            _httpContextAccessor.HttpContext?.User.Claims.FirstOrDefault(c => c.Type == ClaimTypes.NameIdentifier)
                ?.Value ?? throw new UnauthorizedException("Where's your token mister"));
}