using System;
using System.Runtime.InteropServices;
using Microsoft.Win32.SafeHandles;

namespace CeresSharp.Native.SafeHandles;

/// <summary>
/// Base class for all Ceres native resource handles.
/// </summary>
public abstract class BaseSafeHandle : SafeHandleZeroOrMinusOneIsInvalid
{
    protected BaseSafeHandle() : base(true)
    {
    }

    protected BaseSafeHandle(IntPtr handle, bool ownsHandle) : base(ownsHandle)
    {
        SetHandle(handle);
    }

    private volatile bool _released = false;

    protected override bool ReleaseHandle()
    {
        // Prevent double-free by checking if already released
        // Use volatile read/write for thread safety in finalizer
        if (_released || IsInvalid)
            return true; // Already released or invalid

        try
        {
            // Add try-catch to prevent crash in finalizer thread
            // If native handle is already freed or invalid, this will fail gracefully
            ReleaseNativeHandle(handle);
            _released = true;
            return true;
        }
        catch
        {
            // Ignore errors in finalizer - native handle may already be freed
            // Mark as released to prevent retry
            _released = true;
            // Return true to indicate handle was "released" (even if it failed)
            return true;
        }
    }

    /// <summary>
    /// Releases the native handle. Must be implemented by derived classes.
    /// </summary>
    protected abstract void ReleaseNativeHandle(IntPtr handle);
}