IM/backend/IM_API/Services/RedisCacheService.cs

using IM_API.Interface.Services;
using IM_API.Models;
using IM_API.Tools;
using Microsoft.Extensions.Caching.Distributed;
using System.Text.Json;

namespace IM_API.Services
{
    public class RedisCacheService:ICacheService
    {
        private readonly IDistributedCache _cache;
        public RedisCacheService(IDistributedCache cache)
        {
            _cache = cache;
        }

        public async Task<T?> GetAsync<T>(string key)
        {
            var valueBytes= await _cache.GetAsync(key);
            if (valueBytes is null || valueBytes.Length == 0) return default;
            return JsonSerializer.Deserialize<T>(valueBytes);
        }

        public async Task<User?> GetUserCacheAsync(string username)
        {
            var usernameKey = RedisKeys.GetUserinfoKeyByUsername(username);
            var userid = await GetAsync<string>(usernameKey);
            if (userid is null) return default;
            var key = RedisKeys.GetUserinfoKey(userid);
            return await GetAsync<User>(key);
        }

        public async Task RemoveAsync(string key) => await _cache.RemoveAsync(key);

        public async Task RemoveUserCacheAsync(string username)
        {
            var usernameKey = RedisKeys.GetUserinfoKeyByUsername(username);
            var userid = await GetAsync<string>(usernameKey);
            if (userid is null) return;
            var key = RedisKeys.GetUserinfoKey(userid);
            await RemoveAsync(key);
        }

        public async Task SetAsync<T>(string key, T value, TimeSpan? expiration = null)
        {
            var options = new DistributedCacheEntryOptions
            {
                AbsoluteExpirationRelativeToNow = expiration ?? TimeSpan.FromHours(1)
            };
            var valueBytes = JsonSerializer.SerializeToUtf8Bytes(value);
            await _cache.SetAsync(key, valueBytes, options);
        }

        public async Task SetUserCacheAsync(User user)
        {
            var idKey = RedisKeys.GetUserinfoKey(user.Id.ToString());
            await SetAsync(idKey, user);
            var usernameKey = RedisKeys.GetUserinfoKeyByUsername(user.Username);
            await SetAsync(usernameKey, user.Id.ToString());
        }
    }
}