EnvelopeGenerator/EnvelopeGenerator.Application/Extensions/CacheExtensions.cs

using Microsoft.Extensions.Caching.Distributed;

namespace EnvelopeGenerator.Application.Extensions
{
    public static class CacheExtensions
    {
        public static Task SetLongAsync(this IDistributedCache cache, string key, long value, DistributedCacheEntryOptions? options = null)
            => options is null
                ? cache.SetAsync(key, BitConverter.GetBytes(value))
                : cache.SetAsync(key, BitConverter.GetBytes(value), options: options);

        public static async Task<long?> GetLongAsync(this IDistributedCache cache, string key)
        {
            var value = await cache.GetAsync(key);
            return value is null ? null : BitConverter.ToInt64(value, 0);
        }

        public static Task SetDateTimeAsync(this IDistributedCache cache, string key, DateTime value, DistributedCacheEntryOptions? options = null)
            => cache.SetLongAsync(key: key, value: value.Ticks, options: options);

        public static async Task<DateTime?> GetDateTimeAsync(this IDistributedCache cache, string key)
        {
            var value = await cache.GetAsync(key);
            return value is null ? null : new(BitConverter.ToInt64(value, 0));
        }

        public static Task SetTimeSpanAsync(this IDistributedCache cache, string key, TimeSpan value, DistributedCacheEntryOptions? options = null)
            => cache.SetLongAsync(key: key, value: value.Ticks, options: options);

        public static async Task<TimeSpan?> GetTimeSpanAsync(this IDistributedCache cache, string key)
        {
            var value = await cache.GetAsync(key);
            return value is null ? null : new(BitConverter.ToInt64(value, 0));
        }

        public static string GetOrSet(this IDistributedCache cache, string key, Func<string> factory, DistributedCacheEntryOptions? options = null, bool cacheInBackground = false, CancellationToken token = default)
        {
            var value = cache.GetString(key);
            if (value is null)
            {
                // create new and save
                value = factory();

                void Cache()
                {
                    if (options is null)
                        cache.SetString(key: key, value: value);
                    else
                        cache.SetString(key: key, value: value, options: options);
                }

                if (cacheInBackground)
                    _ = Task.Run(() => Cache(), token);
                else
                    Cache();
            }

            return value;
        }

        public static async Task<string> GetOrSetAsync(this IDistributedCache cache, string key, Func<Task<string>> factory, DistributedCacheEntryOptions? options = null, bool cacheInBackground = false, CancellationToken token = default)
        {
            var value = await cache.GetStringAsync(key, token: token);
            if(value is null)
            {
                // create new and save
                value = await factory();

                Task CacheAsync() => options is null
                    ? cache.SetStringAsync(key: key, value: value, token: token)
                    : cache.SetStringAsync(key: key, value: value, options: options, token: token);

                if (cacheInBackground)
                    _ = Task.Run(async () => await CacheAsync(), token);
                else
                    await CacheAsync();
            }

            return value;
        }
    }
}