using Microsoft.EntityFrameworkCore;
using System;
using System.Collections.Concurrent;
using System.Collections.Generic;

namespace AsbCloudInfrastructure.Services.Cache
{

    public class CacheDb
    {
        private readonly ConcurrentDictionary<string, (DateTime, IEnumerable<object>)> cache = new ConcurrentDictionary<string, (DateTime, IEnumerable<object>)>();
        private readonly TimeSpan obsolesenceTime = TimeSpan.FromMinutes(15);

        public CacheTable<TEntity> GetCachedTable<TEntity>(DbContext context)
            where TEntity : class
        {
            var entityTypeName = typeof(TEntity).FullName;

            if (!cache.ContainsKey(entityTypeName))
                cache[entityTypeName] = (DateTime.Now, new List<TEntity>(8));

            bool isCachedDataObsolete = DateTime.Now - cache[entityTypeName].Item1 > obsolesenceTime;

            var tableCache = new CacheTable<TEntity>(context, cache[entityTypeName]);

            if (isCachedDataObsolete)
                tableCache.Refresh();

            return tableCache;
        }

        public void DropAll() => cache.Clear();

        public void Drop<TEntity>() => cache.Remove(typeof(TEntity).FullName, out _);
    }
}