using System;
using System.Collections.Generic;
using System.Linq;
using ChaosBot.Services;

namespace ChaosBot.WebServer
{
    public class AccessTokenCache : ICache<string, string>
    {
        private Dictionary<string, Tuple<string, DateTime>> _cache = new Dictionary<string, Tuple<string, DateTime>>();
        
        public void Invalidate()
        {
            DateTime now = DateTime.Now;

            _cache = _cache
                .Where(v => v.Value.Item2 > now)
                .ToDictionary(x => x.Key, x => x.Value);
        }

        public void Add(string key, string value, DateTime expires)
        {
            _cache.Add(key, new Tuple<string, DateTime>(value, expires));
        }

        public void Remove(string key)
        {
            _cache.Remove(key);
        }

        public string Get(string key)
        {
            if (!_cache.TryGetValue(key, out Tuple<string, DateTime> data))
                throw new KeyNotFoundException();

            return data.Item1;
        }

        public bool HasKey(string key)
        {
            return _cache.ContainsKey(key);
        }

        public List<string> GetKeys()
        {
            return _cache.Keys.ToList();
        }
    }
}