using System;
using System.Threading.Tasks;

using Microsoft.Extensions.Caching.Memory;
using Microsoft.Owin.Security;
using Microsoft.Owin.Security.Cookies;

namespace IwbZero.Zero.Configuration
{
    public class IwbAuthenticationSessionStore : IAuthenticationSessionStore
    {
        private const string KeyPrefix = "IWB-";
        private readonly IMemoryCache _cache;

        public IwbAuthenticationSessionStore()
        {
            _cache = new MemoryCache(new MemoryCacheOptions());
        }

        public async Task<string> StoreAsync(AuthenticationTicket ticket)
        {
            var key = KeyPrefix + Guid.NewGuid().ToString("N");
            await RenewAsync(key, ticket);
            return key;
        }

        public Task RenewAsync(string key, AuthenticationTicket ticket)
        {
            var options = new MemoryCacheEntryOptions();
            var expiresUtc = ticket.Properties.ExpiresUtc;
            if (expiresUtc.HasValue)
            {
                options.SetAbsoluteExpiration(expiresUtc.Value);
            }
            options.SetSlidingExpiration(TimeSpan.FromHours(1));
            _cache.Set(key, ticket, options);
            return Task.FromResult(0);
        }

        public Task<AuthenticationTicket> RetrieveAsync(string key)
        {
            _cache.TryGetValue(key, out AuthenticationTicket ticket);
            return Task.FromResult(ticket);
        }

        public Task RemoveAsync(string key)
        {
            _cache.Remove(key);
            return Task.FromResult(0);
        }
    }
}