social-media/backend/src/Web/Common/Security/ClaimsPrincipalExtensions.cs

using System.Security.Claims;

namespace Hutopy.Web.Common.Security;

public static class ClaimsPrincipalExtensions
{
    public static Guid GetUserId(this ClaimsPrincipal claims)
    {
        return (Guid)claims.GetRequiredClaim<Guid>(ClaimTypes.NameIdentifier);
    }
    
    public static string GetName(this ClaimsPrincipal claims)
    {
        return (string)claims.GetRequiredClaim<string>(ClaimTypes.Name);
    }
    
    public static string? GetAlias(this ClaimsPrincipal claims)
    {
        return (string?)claims.GetClaim<string?>(KnownClaims.Alias);
    } 
    
    public static string? GetPortraitUrl(this ClaimsPrincipal claims)
    {
        return (string?)claims.GetClaim<string?>(KnownClaims.PortraitUrl);
    } 
    
    public static string GetFirstName(this ClaimsPrincipal claims)
    {
        return (string)claims.GetRequiredClaim<string>(ClaimTypes.GivenName);
    }

    public static string GetLastName(this ClaimsPrincipal claims)
    {
        return (string)claims.GetRequiredClaim<string>(ClaimTypes.Surname);
    }

    public static string GetEmail(this ClaimsPrincipal claims)
    {
        return (string)claims.GetRequiredClaim<string>(ClaimTypes.Email);
    }

    private static object? GetClaim<TValue>(this ClaimsPrincipal claims, string key)
    {
        var claim = claims.FindFirst(key);

        if (claim is null) return default;
        return claims.GetRequiredClaim<TValue>(key);
    }

    private static object GetRequiredClaim<TValue>(this ClaimsPrincipal claims, string key)
    {
        var claim = claims.FindFirst(key);

        if (claim is null) throw new MissingClaimException(key);

        if (typeof(TValue) == typeof(Guid))
        {
            return Guid.Parse(claim.Value);
        }

        return Convert.ChangeType(claim.Value, typeof(TValue));
    }
}