// Copyright (C) 2026 SharpEmu Emulator Project
// SPDX-License-Identifier: GPL-2.0-or-later

using SharpEmu.HLE;

namespace SharpEmu.Core.Cpu;

public sealed class TrackedCpuMemory : ICpuMemory, ITrackedCpuMemory, IGuestMemoryAllocator, ICpuMemoryWrapper
{
    private readonly ICpuMemory _inner;

    public TrackedCpuMemory(ICpuMemory inner)
    {
        _inner = inner ?? throw new ArgumentNullException(nameof(inner));
    }

    public CpuMemoryAccessFailure? LastFailure { get; private set; }

    public ICpuMemory Inner => _inner;

    public string DescribeReadRange(ulong address, ulong size) => _inner.DescribeReadRange(address, size);

    public bool TryRead(ulong virtualAddress, Span<byte> destination)
    {
        var result = _inner.TryRead(virtualAddress, destination);
        if (!result)
        {
            LastFailure = new CpuMemoryAccessFailure(virtualAddress, destination.Length, isWrite: false);
        }

        return result;
    }

    public bool TryWrite(ulong virtualAddress, ReadOnlySpan<byte> source)
    {
        var result = _inner.TryWrite(virtualAddress, source);
        if (!result)
        {
            LastFailure = new CpuMemoryAccessFailure(virtualAddress, source.Length, isWrite: true);
        }

        return result;
    }

    public bool TryCompare(
        ulong virtualAddress,
        ReadOnlySpan<byte> expected,
        out bool equal) =>
        _inner.TryCompare(virtualAddress, expected, out equal);

    public bool TryCopy(ulong destinationAddress, ulong sourceAddress, ulong length) =>
        _inner.TryCopy(destinationAddress, sourceAddress, length);

    public bool CanRead(ulong address, ulong size) => _inner.CanRead(address, size);

    public bool TryAllocateGuestMemory(ulong size, ulong alignment, out ulong address)
    {
        if (_inner is IGuestMemoryAllocator allocator)
        {
            return allocator.TryAllocateGuestMemory(size, alignment, out address);
        }

        address = 0;
        return false;
    }

    public bool TryFreeGuestMemory(ulong address)
    {
        return _inner is IGuestMemoryAllocator allocator && allocator.TryFreeGuestMemory(address);
    }
}