Core.Blueprint.DAL/Core.Blueprint.DAL.Redis/CacheService.cs

using Azure.Identity;
using Core.Blueprint.DAL.Redis.Contracts;
using Microsoft.Extensions.Logging;
using StackExchange.Redis;
using System.Text.Json;


namespace Core.Blueprint.DAL.Redis
{
    public class CacheService : ICacheService
    {
        private IDatabase _cacheDatabase = null!;
        private readonly ILogger<CacheService> _logger;


        public CacheService(string connectionString, ILogger<CacheService> logger)
        {
            _logger = logger;
            Task.Run(async () =>
            {
                _cacheDatabase = await GetRedisDatabase(connectionString);
            }).Wait();
        }

        private async Task<IDatabase> GetRedisDatabase(string connectionString)
        {
            try
            {
                var configurationOptions = await ConfigurationOptions.Parse($"{connectionString}")
                    .ConfigureForAzureWithTokenCredentialAsync(new DefaultAzureCredential());

                configurationOptions.AbortOnConnectFail = false;
                var connectionMultiplexer = await ConnectionMultiplexer.ConnectAsync(configurationOptions);

                _logger.LogInformation("Successfully connected to Redis.");

                return connectionMultiplexer.GetDatabase();
            }
            catch (Exception ex)
            {
                _logger.LogError(ex, "Error establishing Redis connection.");
                throw;
            }
        }


        public async Task<T> GetAsync<T>(string key)
        {
            try
            {
                var value = await _cacheDatabase.StringGetAsync(key);
                if (value.IsNullOrEmpty)
                {
                    _logger.LogInformation($"Cache miss for key: {key}");
                    return default;
                }

                _logger.LogInformation($"Cache hit for key: {key}");
                return JsonSerializer.Deserialize<T>(value);
            }
            catch (Exception ex)
            {
                _logger.LogError(ex, $"Error getting cache item with key {key}");
                throw;
            }
        }

        public async Task SetAsync<T>(string key, T value, TimeSpan? expiry = null)
        {
            try
            {
                var json = JsonSerializer.Serialize(value);
                await _cacheDatabase.StringSetAsync(key, json, expiry);
                _logger.LogInformation($"Cache item set with key: {key}");
            }
            catch (Exception ex)
            {
                _logger.LogError(ex, $"Error setting cache item with key {key}");
                throw;
            }
        }

        public async Task RemoveAsync(string key)
        {
            try
            {
                await _cacheDatabase.KeyDeleteAsync(key);
                _logger.LogInformation($"Cache item removed with key: {key}");
            }
            catch (Exception ex)
            {
                _logger.LogError(ex, $"Error removing cache item with key {key}");
                throw;
            }
        }

        public async Task<bool> ExistsAsync(string key)
        {
            try
            {
                var exists = await _cacheDatabase.KeyExistsAsync(key);
                _logger.LogInformation($"Cache item exists check for key: {key} - {exists}");
                return exists;
            }
            catch (Exception ex)
            {
                _logger.LogError(ex, $"Error checking existence of cache item with key {key}");
                throw;
            }
        }

        public async Task RefreshAsync(string key, TimeSpan? expiry = null)
        {
            try
            {
                var value = await _cacheDatabase.StringGetAsync(key);
                if (!value.IsNullOrEmpty)
                {
                    await _cacheDatabase.StringSetAsync(key, value, expiry);
                    _logger.LogInformation($"Cache item refreshed with key: {key}");
                }
                else
                {
                    _logger.LogWarning($"Cache item with key: {key} does not exist, cannot refresh");
                }
            }
            catch (Exception ex)
            {
                _logger.LogError(ex, $"Error refreshing cache item with key {key}");
                throw;
            }
        }
    }
}