using System;
using System.Collections.Generic;
using System.Text;
using System.Threading;

namespace Pole.Orleans.Provider.EntityframeworkCore
{
    public static class GrainStorageContext<TEntity>
           where TEntity : class
    {
        // ReSharper disable once StaticMemberInGenericType
        private static readonly AsyncLocal<bool> IsConfiguredLocal
            = new AsyncLocal<bool>();

        private static readonly AsyncLocal<ConfigureEntryStateDelegate<TEntity>>
            ConfigureStateDelegateLocal
                = new AsyncLocal<ConfigureEntryStateDelegate<TEntity>>();

        internal static bool IsConfigured => IsConfiguredLocal.Value;

        internal static ConfigureEntryStateDelegate<TEntity> ConfigureStateDelegate
            => ConfigureStateDelegateLocal.Value;

        /// <summary>
        /// Configures the entry state. 
        /// Use it to modify what gets changed during the write operations.
        /// </summary>
        /// <param name="configureState">The delegate to be called before saving context's state.</param>
        public static void ConfigureEntryState(ConfigureEntryStateDelegate<TEntity> configureState)
        {
            ConfigureStateDelegateLocal.Value = configureState;
            IsConfiguredLocal.Value = true;
        }

        public static void Clear()
        {
            ConfigureStateDelegateLocal.Value = null;
            IsConfiguredLocal.Value = false;
        }
    }
}