// Copyright (c) .NET Foundation. All rights reserved.
// Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.

using System;
using System.Diagnostics;
using System.Threading;

namespace Libuv.Internal
{
  public abstract class UvHandle : UvMemory
  {
    private static readonly LibuvFunctions.uv_close_cb _destroyMemory = DestroyMemory;
    private Action<Action<IntPtr>, IntPtr> _queueCloseHandle;

    protected UvHandle(ILibuvTrace logger) : base (logger)
    {
    }

    protected void CreateHandle(
      LibuvFunctions uv,
      int threadId,
      int size,
      Action<Action<IntPtr>, IntPtr> queueCloseHandle)
    {
      _queueCloseHandle = queueCloseHandle;
      CreateMemory(uv, threadId, size);
    }

    protected override bool ReleaseHandle()
    {
      IntPtr memory = handle;
      if (memory != IntPtr.Zero)
      {
        handle = IntPtr.Zero;

        if (Thread.CurrentThread.ManagedThreadId == ThreadId)
        {
          _uv.close(memory, _destroyMemory);
        }
        else if (_queueCloseHandle != null)
        {
          // This can be called from the finalizer.
          // Ensure the closure doesn't reference "this".
          LibuvFunctions uv = _uv;
          _queueCloseHandle(memory2 => uv.close(memory2, _destroyMemory), memory);
        }
        else
        {
          Debug.Assert(false, "UvHandle not initialized with queueCloseHandle action");
          return false;
        }
      }
      return true;
    }

    public void Reference()
    {
      _uv.@ref(this);
    }

    public void Unreference()
    {
      _uv.unref(this);
    }
  }
}