using Kit.Helpers.Postgres;

namespace Kit.Helpers;

/// <summary>
/// Провайдер кэша через самописную схему (и её элементы) distributed. <br />
/// </summary>
public class PgTableDistributedCacheService : IDistributedCacheService
{
    private readonly IDistributedLockService _distributedLockService;
    private readonly string _connectionString;

    private const string _lockType = "PgTableDistributedCacheService";

    public PgTableDistributedCacheService(
        IConfigurationDistributedPg configuration,
        IDistributedLockService distributedLockService)
    {
        _distributedLockService = distributedLockService;
        _connectionString = configuration.DistributedConnectionString;
    }

    public void ExecuteOnLock(string key, Action action)
    {
        _distributedLockService.ExecuteOnLock(_lockType, key, action);
    }

    public TResult ExecuteOnLock<TResult>(string key, Func<TResult> action)
    {
        return _distributedLockService.ExecuteOnLock(_lockType, key, action);
    }

    public void SetCacheData<TObject>(string cacheName, TObject data, DistributedCacheOptions setProperties)
    {
        this.ExecuteOnLock(cacheName, () =>
        {
            var parameters = new List<KeyValuePair<string, object>>
            {
                new KeyValuePair<string, object>("_key", cacheName),
                new KeyValuePair<string, object>("_value", data.JsonSerialize())
            };
            if (setProperties.AbsoluteExpirationRelativeToNow.HasValue)
            {
                parameters.Add(new KeyValuePair<string, object>("_absolute_expiration_seconds", (int)setProperties.AbsoluteExpirationRelativeToNow.Value.TotalSeconds));
            }
            if (setProperties.SlidingExpiration.HasValue)
            {
                parameters.Add(new KeyValuePair<string, object>("_sliding_expiration_seconds", (int)setProperties.SlidingExpiration.Value.TotalSeconds));
            }

            _connectionString.ExecuteNonQuery("distributed.cache_insert", isStoredProcedure: true, parameters);
        });
    }

    public TResult? GetCacheData<TResult>(string cacheName)
    {
        return this.ExecuteOnLock(cacheName, () =>
        {
            var parameters = new List<KeyValuePair<string, object>>
            {
                new KeyValuePair<string, object>("_key", cacheName)
            };
            object? result = _connectionString.ExecuteScalar<object>("distributed.cache_select", isStoredProcedure: true, parameters:parameters);

            if (result is not string jsonString)
            {
                return default;
            }

            try
            {
                return jsonString.JsonDeserialize<TResult>();
            }
            catch (Exception ex)
            {
                throw new InvalidOperationException($"Error while deserializing json value of cache. cacheName: {cacheName}", ex);
            }
        });
    }
}