using Microsoft.AspNetCore.Authentication;
using Microsoft.Extensions.Options;
using System.Security.Claims;
using System.Text.Encodings.Web;

namespace BlackRock.Reporting.API.Jwt
{
    public class BasicAuthenticationOptions : AuthenticationSchemeOptions
    {
    }

    public class CustomAuthenticationHandler : AuthenticationHandler<BasicAuthenticationOptions>
    {
        public CustomAuthenticationHandler(IOptionsMonitor<BasicAuthenticationOptions> options, 
            ILoggerFactory logger, UrlEncoder encoder, ISystemClock clock) : base(options, logger, encoder, clock)
        {
        }

        protected override async Task<AuthenticateResult> HandleAuthenticateAsync()
        {
            //return AuthenticateResult.Success(new AuthenticationTicket
            //    Principal = new System.Security.Claims.ClaimsPrincipal(),
            //    AuthenticationScheme = Scheme.Name
            //});
            if (!Request.Headers.ContainsKey("Authorization"))
                return AuthenticateResult.Fail("unauthorized");

            string authorizationHeader = Request.Headers["Authorization"];

            if (string.IsNullOrEmpty(authorizationHeader))
                return AuthenticateResult.Fail("unauthorized");

            if (!authorizationHeader.StartsWith("bearer", StringComparison.OrdinalIgnoreCase))
                return AuthenticateResult.Fail("unauthorized");

            string token = authorizationHeader.Substring("bearer".Length).Trim();
            if (string.IsNullOrEmpty(token))
                return AuthenticateResult.Fail("unauthorized");
            try
            {
                return ValidateToken(token);
            }
            catch (Exception ex)
            {
                return AuthenticateResult.Fail("unauthorize");
            }
        }

        private AuthenticateResult ValidateToken(string token)
        {
            var principal = new ClaimsPrincipal();//JwtManager.GetPrincipal(token);
            if (principal == null)
                return AuthenticateResult.Fail("unauthorized");

            AuthenticationTicket ticket = new AuthenticationTicket(principal, Scheme.Name);
            return AuthenticateResult.Success(ticket);
        }
    }
}