using System;
using System.Runtime.CompilerServices;
using System.Threading.Tasks;
using Newtonsoft.Json;
using Sony.Filtr.DistributedCaching.ETW;
using StackExchange.Redis;

namespace Sony.Filtr.DistributedCaching
{
    public class RedisGenericCacheProvider : IGenericCacheProvider
    {
        private readonly IDatabase _db;

        public RedisGenericCacheProvider(IDatabase db)
        {
            this._db = db;
        }

        public T Get<T>(string cacheKey)
        {
            var value = this._db.StringGet(cacheKey);

            return value.IsNull ? default(T) : JsonConvert.DeserializeObject<T>(value);
        }

        public T GetOrAdd<T>(string cacheKey, Func<T> loadData, [CallerMemberName]string caller = "")
        {
            //T data = this.Get<T>(cacheKey);
            //if (data == null)
            //{
            //    data = this.LoadData(loadData, caller);
            //    this.Set(cacheKey, data);
            //}

            //return data;

            return this.GetOrAddAsync<T>(cacheKey, () => Task.Run(() => loadData()), caller).Result;
        }

        public async Task<T> GetOrAddAsync<T>(string cacheKey, Func<Task<T>> loadData, [CallerMemberName]string caller = "")
        {
            T data = this.Get<T>(cacheKey);
            if (data == null)
            {
                data = await this.LoadDataAsync(loadData, caller);
                this.Set(cacheKey, data);
            }

            return data;
        }

        public void Set(string cacheKey, object value)
        {
            bool setResult = this._db.StringSet(cacheKey, JsonConvert.SerializeObject(value));
        }

        public bool Remove(string cacheKey)
        {
            return this._db.KeyDelete(cacheKey);
        }

        public bool Clear()
        {
            return false;
        }

        private async Task<T> LoadDataAsync<T>(Func<Task<T>> loadData, string caller)
        {
            ApolloRedisCacheProviderEventSource.Log.LoadDataStart(caller);
            T data = await loadData();
            ApolloRedisCacheProviderEventSource.Log.LoadDataStop();

            return data;
        }
    }
}