using Hangfire.Common;
using Hangfire.Server;
using Strata.CoreLib.Claims;
using System;
using System.Collections.Generic;
using System.Globalization;
using System.Linq;
using System.Security.Claims;
using System.Threading;

namespace Strata.RxNorm.Biz.Hangfire
{
    /// <summary>
    /// Captures Job parameters as Claims on the ThreadPrincipal running the job
    /// </summary>
    [AttributeUsage(AttributeTargets.Class | AttributeTargets.Interface | AttributeTargets.Method)]
    public class CaptureJobParameterAttribute : JobFilterAttribute, IServerFilter
    {
        public int DatabaseGuidArgumentPosition { get; set; } = -1;
        public int StrataIdArgumentPosition { get; set; } = -1;

        // server filters
        public void OnPerforming(PerformingContext filterContext)
        {
            var claims = new List<Claim>();
            var args = filterContext.BackgroundJob.Job.Args.ToArray();

            if (StrataIdArgumentPosition >= 0)
            {
                var strataIdValue = string.Format(CultureInfo.CurrentCulture, $"{{{StrataIdArgumentPosition}}}", args);
                if (int.TryParse(strataIdValue, out var strataId))
                {
                    claims.Add(new Claim(StrataClaims.StrataId, strataId.ToString()));
                }
            }

            if (DatabaseGuidArgumentPosition >= 0)
            {
                var databaseGuidValue = string.Format(CultureInfo.CurrentCulture, $"{{{DatabaseGuidArgumentPosition}}}", args);
                if (Guid.TryParse(databaseGuidValue, out var databaseGuid))
                {
                    claims.Add(new Claim(StrataClaims.DatabaseGuid, databaseGuid.ToString()));
                }
            }

            if (claims.Count == 0)
            {
                return;
            }

            var principal = new ClaimsPrincipal(new ClaimsIdentity(claims, "hangfire_impersonation"));
            Thread.CurrentPrincipal = principal;
        }

        public void OnPerformed(PerformedContext filterContext)
        {
            Thread.CurrentPrincipal = null;
        }
    }
}