using Microsoft.Extensions.Caching.Distributed;
using Microsoft.Extensions.Caching.StackExchangeRedis;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.Options;
using StackExchange.Redis;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using Volo.Abp.Caching;
using Volo.Abp.DependencyInjection;

namespace Syc.Abp.Caching.Redis
{
    public partial class RedisCacheProvide : IRedisCacheProvide, ITransientDependency
    {
        private readonly IServiceProvider serviceProvider;
        private readonly AbpDistributedCacheOptions abpDistributedCacheOptions;
        private readonly RedisCacheOptions redisCacheOptions;

        public RedisCacheProvide(IServiceProvider serviceProvider,IOptions<AbpDistributedCacheOptions> options,IOptions<RedisCacheOptions> redisCachOptions)
        {
            this.serviceProvider = serviceProvider;
            this.abpDistributedCacheOptions = options.Value;
            this.redisCacheOptions = redisCachOptions.Value;
        }

        private IDistributedCache<CacheItem<T>> GetDistributedCache<T>()
           => serviceProvider.GetService<IDistributedCache<CacheItem<T>>>();

        #region ICacheProvide 实现

        /// <summary>
        /// 获取
        /// </summary>
        /// <typeparam name="T"></typeparam>
        /// <param name="key"></param>
        /// <returns></returns>
        /// <exception cref="ArgumentNullException"></exception>
        public async Task<T> GetAsync<T>(string key)
        {
            if (string.IsNullOrWhiteSpace(key))
                throw new ArgumentNullException(nameof(key));

            var cache = GetDistributedCache<T>();
            var result = await cache.GetAsync(key);

            return result is null ? default : result.Value ?? default;
        }

        /// <summary>
        /// 获取缓存过期配置
        /// </summary>
        /// <param name="absExpiration">绝对过期</param>
        /// <param name="relativeExpiration">相对过期</param>
        /// <param name="slidExpiration">滑动过期</param>
        /// <returns></returns>
        private DistributedCacheEntryOptions GetDistributedCacheEntryOptions(int? absExpiration = null, int? relativeExpiration = null, int? slidExpiration = null)
        {
            DateTimeOffset? absoluteExpiration = null;
            if (absExpiration.HasValue)
                absoluteExpiration = DateTimeOffset.Now.AddSeconds(absExpiration.Value);

            TimeSpan? absoluteExpirationRelativeToNow = null;
            if (relativeExpiration.HasValue)
                absoluteExpirationRelativeToNow = TimeSpan.FromSeconds(relativeExpiration.Value);

            TimeSpan? slidingExpiration = null;
            if (slidExpiration.HasValue)
                slidingExpiration = TimeSpan.FromSeconds(slidExpiration.Value);

            return new DistributedCacheEntryOptions()
            {
                AbsoluteExpiration = absoluteExpiration,
                AbsoluteExpirationRelativeToNow = absoluteExpirationRelativeToNow,
                SlidingExpiration = slidingExpiration,
            };
        }

        /// <summary>
        /// 获取
        /// </summary>
        /// <typeparam name="T"></typeparam>
        /// <param name="key"></param>
        /// <param name="func"></param>
        /// <param name="relativeExpiration"></param>
        /// <returns></returns>
        /// <exception cref="ArgumentNullException"></exception>
        public async Task<T> GetAsync<T>(string key, Func<T> func, int relativeExpiration)
        {
            if (string.IsNullOrWhiteSpace(key))
                throw new ArgumentNullException(nameof(key));

            var result = await GetAsync<T>(key);
            if (result is null)
                result = func();
            await SaveAsync(key, result, relativeExpiration);
            return result;
        }

        /// <summary>
        /// 删除key
        /// </summary>
        /// <param name="key"></param>
        /// <returns></returns>
        /// <exception cref="ArgumentNullException"></exception>
        public async Task RemoveAsync(string key)
        {
            if (string.IsNullOrWhiteSpace(key))
                throw new ArgumentNullException(nameof(key));
            var cache = serviceProvider.GetService<IDistributedCache>();
            await cache.RemoveAsync(key);
        }

        /// <summary>
        /// 添加/保存
        /// </summary>
        /// <typeparam name="T"></typeparam>
        /// <param name="key"></param>
        /// <param name="value"></param>
        /// <param name="relativeExpiration"></param>
        /// <returns></returns>
        /// <exception cref="ArgumentNullException"></exception>
        public async Task SaveAsync<T>(string key, T value, int? relativeExpiration = null)
        {
            if (string.IsNullOrWhiteSpace(key))
                throw new ArgumentNullException(nameof(key));
            var option = GetDistributedCacheEntryOptions(relativeExpiration: relativeExpiration);
            var cache = GetDistributedCache<T>();
            await cache.SetAsync(key, new CacheItem<T>(value, option), option);
        }

        #endregion
    }
}