using System.Security.Claims;
using System.Security.Cryptography;
using System.Text;
using System.Text.Encodings.Web;
using MareSynchronosServer;
using MareSynchronosShared.Data;
using MareSynchronosShared.Metrics;
using MareSynchronosShared.Protos;
using Microsoft.AspNetCore.Authentication;
using Microsoft.AspNetCore.Http;
using Microsoft.EntityFrameworkCore;
using Microsoft.Extensions.Logging;
using Microsoft.Extensions.Options;
using ISystemClock = Microsoft.AspNetCore.Authentication.ISystemClock;

namespace MareSynchronosShared.Authentication
{

    public class SecretKeyGrpcAuthenticationHandler : AuthenticationHandler<AuthenticationSchemeOptions>
    {
        public const string AuthScheme = "SecretKeyGrpcAuth";

        private readonly AuthService.AuthServiceClient _authClient;
        private readonly IHttpContextAccessor _accessor;

        public SecretKeyGrpcAuthenticationHandler(IHttpContextAccessor accessor, AuthService.AuthServiceClient authClient, 
            IOptionsMonitor<AuthenticationSchemeOptions> options, ILoggerFactory logger, UrlEncoder encoder, ISystemClock clock) : base(options, logger, encoder, clock)
        {
            this._authClient = authClient;
            _accessor = accessor;
        }

        protected override async Task<AuthenticateResult> HandleAuthenticateAsync()
        {
            if(!Request.Headers.TryGetValue("Authorization", out var authHeader))
            {
                authHeader = string.Empty;
            }
            var ip = _accessor.GetIpAddress();

            var authResult = await _authClient.AuthorizeAsync(new AuthRequest() {Ip = ip, SecretKey = authHeader}).ConfigureAwait(false);

            if (!authResult.Success)
            {
                return AuthenticateResult.Fail("Failed Authorization");
            }

            string uid = authResult.Uid;

            var claims = new List<Claim>
            {
                new(ClaimTypes.NameIdentifier, uid),
                new(ClaimTypes.Authentication, authHeader)
            };

            var identity = new ClaimsIdentity(claims, nameof(SecretKeyGrpcAuthenticationHandler));
            var principal = new ClaimsPrincipal(identity);
            var ticket = new AuthenticationTicket(principal, Scheme.Name);

            return AuthenticateResult.Success(ticket);
        }
    }
}