using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;
using Microsoft.Extensions.Caching.Distributed;
using Volo.Abp.Caching;

namespace Win_in.Sfs.Shared.Application;

/// <summary>
///
/// </summary>
public static class CachingExtensions
{
    /// <summary>
    /// 获取或添加缓存
    /// </summary>
    /// <typeparam name="TCacheItem"></typeparam>
    /// <param name="cache"></param>
    /// <param name="key"></param>
    /// <param name="factory"></param>
    /// <param name="minutes"></param>
    /// <returns></returns>
    public static async Task<TCacheItem> GetOrAddItemAsync<TCacheItem>(
        this IDistributedCache<TCacheItem> cache, string key, Func<Task<TCacheItem>> factory, int minutes)
        where TCacheItem : class
    {
        TCacheItem cacheItem;

        var result = await cache.GetAsync(key).ConfigureAwait(false);
        if (result == null)
        {
            cacheItem = await factory.Invoke().ConfigureAwait(false);
            await cache.SetItemAsync(key, cacheItem, minutes).ConfigureAwait(false);
        }
        else
        {
            cacheItem = result;
        }

        return cacheItem;
    }

    /// <summary>
    ///
    /// </summary>
    /// <param name="cache"></param>
    /// <param name="keys"></param>
    /// <typeparam name="TCacheItem"></typeparam>
    /// <returns></returns>
    public static async Task<IEnumerable<TCacheItem>> GetItemsAsync<TCacheItem>(
        this IDistributedCache<TCacheItem> cache, IEnumerable<string> keys) where TCacheItem : class
    {
        var cacheItems = await cache.GetManyAsync(keys, null, true).ConfigureAwait(false);
        return cacheItems.Select(p => p.Value);
    }

    /// <summary>
    ///
    /// </summary>
    /// <param name="cache"></param>
    /// <param name="key"></param>
    /// <param name="cacheItem"></param>
    /// <param name="minutes"></param>
    /// <typeparam name="TCacheItem"></typeparam>
    public static async Task SetItemAsync<TCacheItem>(
        this IDistributedCache<TCacheItem> cache, string key, TCacheItem cacheItem, int minutes) where TCacheItem : class
    {
        var options = CreateDistributedCacheEntryOptions<TCacheItem>(minutes);
        await cache.SetAsync(key, cacheItem, options, null, true).ConfigureAwait(false);
    }

    /// <summary>
    ///
    /// </summary>
    /// <param name="cache"></param>
    /// <param name="cacheItems"></param>
    /// <param name="minutes"></param>
    /// <typeparam name="TCacheItem"></typeparam>
    public static async Task SetItemsAsync<TCacheItem>(
        this IDistributedCache<TCacheItem> cache, IEnumerable<KeyValuePair<string, TCacheItem>> cacheItems, int minutes) where TCacheItem : class
    {
        var options = CreateDistributedCacheEntryOptions<TCacheItem>(minutes);
        await cache.SetManyAsync(cacheItems, options).ConfigureAwait(false);
    }

    /// <summary>
    ///
    /// </summary>
    /// <param name="cache"></param>
    /// <param name="key"></param>
    /// <typeparam name="TCacheItem"></typeparam>
    public static async Task DeleteItemAsync<TCacheItem>(
        this IDistributedCache<TCacheItem> cache, string key)
        where TCacheItem : class
    {
        var result = await cache.GetAsync(key).ConfigureAwait(false);
        if (result != null)
        {
            await cache.RemoveAsync(key).ConfigureAwait(false);
        }
    }

    private static DistributedCacheEntryOptions CreateDistributedCacheEntryOptions<TCacheItem>(int minutes)
    {
        var options = new DistributedCacheEntryOptions();
        if (minutes != SfsCacheConst.Never)
        {
            options.AbsoluteExpiration = DateTimeOffset.Now.AddMinutes(minutes);
        }

        return options;
    }
}