using ManagerService.Data;
using ManagerService.Service;
using ManagerService.Service.Services;
using Microsoft.AspNetCore.Authentication;
using Microsoft.EntityFrameworkCore;
using Microsoft.Extensions.Logging;
using Microsoft.Extensions.Options;
using System.Security.Claims;
using System.Text.Encodings.Web;
using System.Threading.Tasks;

namespace ManagerService.Security
{
    public class ApiKeyAuthenticationHandler : AuthenticationHandler<AuthenticationSchemeOptions>
    {
        private const string HeaderName = "X-Api-Key";
        private readonly MyInfoMateDbContext _db;

        public ApiKeyAuthenticationHandler(
            IOptionsMonitor<AuthenticationSchemeOptions> options,
            ILoggerFactory logger,
            UrlEncoder encoder,
            MyInfoMateDbContext db)
            : base(options, logger, encoder)
        {
            _db = db;
        }

        protected override async Task<AuthenticateResult> HandleAuthenticateAsync()
        {
            if (!Request.Headers.TryGetValue(HeaderName, out var keyValue))
                return AuthenticateResult.NoResult();

            var value = keyValue.ToString();
            var keyHash = TokensService.GenerateSHA256String(value);

            var apiKey = await _db.ApiKeys.FirstOrDefaultAsync(k =>
                k.IsActive &&
                (k.DateExpiration == null || k.DateExpiration > System.DateTime.UtcNow) &&
                (k.Key == value || k.KeyHash == keyHash));

            if (apiKey == null)
                return AuthenticateResult.Fail("Invalid API Key");

            var claims = new[]
            {
                new Claim(Service.Security.ClaimTypes.InstanceId, apiKey.InstanceId),
                new Claim(Service.Security.ClaimTypes.AppType, apiKey.AppType.ToString()),
                new Claim(Service.Security.ClaimTypes.Permission, Service.Security.Permissions.AppRead),
                new Claim(Service.Security.ClaimTypes.Permission, Service.Security.Permissions.Viewer),
            };

            var principal = new ClaimsPrincipal(new ClaimsIdentity(claims, Scheme.Name));
            return AuthenticateResult.Success(new AuthenticationTicket(principal, Scheme.Name));
        }
    }
}