using System.Collections;
using System.Threading;

using FrostFS.Refs;

namespace FrostFS.SDK.ClientV2.Mappers.GRPC;

public static class VersionMapper
{
    private static readonly Hashtable _cacheMessages = [];
    private static readonly Hashtable _cacheModels = [];
    private static SpinLock _spinlock = new();

    public static Version ToMessage(this FrostFsVersion model)
    {
        var key = model.Major << 16 + model.Minor;

        if (!_cacheMessages.ContainsKey(key))
        {
            bool lockTaken = false;
            try
            {
                _spinlock.Enter(ref lockTaken);
                var message = new Version
                {
                    Major = (uint)model.Major,
                    Minor = (uint)model.Minor
                };

                _cacheMessages.Add(key, message);
                return message;
            }
            catch (System.ArgumentException)
            {
                // ignore attempt to add duplicate
            }
            finally
            {
                if (lockTaken)
                    _spinlock.Exit(false);
            }
        }

        return (Version)_cacheMessages[key];
    }

    public static FrostFsVersion ToModel(this Version message)
    {
        var key = (int)message.Major << 16 + (int)message.Minor;

        if (!_cacheModels.ContainsKey(key))
        {
            bool lockTaken = false;
            try
            {
                _spinlock.Enter(ref lockTaken);
                var model = new FrostFsVersion((int)message.Major, (int)message.Minor);

                _cacheModels.Add(key, model);
                return model;
            }
            catch (System.ArgumentException)
            {
                // ignore attempt to add duplicate
            }
            finally
            {
                if (lockTaken)
                    _spinlock.Exit(false);
            }
        }

        return (FrostFsVersion)_cacheModels[key];
    }
}