/*

 * Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>

 * Copyright (c) 2022, the SerenityOS developers.

 *

 * SPDX-License-Identifier: BSD-2-Clause

 */

#pragma once

#include <AK/Error.h>

#include <AK/RefCounted.h>

#include <AK/RefPtr.h>

#include <AK/Vector.h>

#include <LibCore/Forward.h>

#include <unistd.h>

namespace IPC {

class AutoCloseFileDescriptor : public RefCounted<AutoCloseFileDescriptor> {

public:

    AutoCloseFileDescriptor(int fd)

        : m_fd(fd)

    {

    }

    ~AutoCloseFileDescriptor()

    {

        if (m_fd != -1)

            close(m_fd);

    }

    int value() const { return m_fd; }

private:

    int m_fd;

};

class MessageBuffer {

public:

    MessageBuffer();

    ErrorOr<void> extend_data_capacity(size_t capacity);

    ErrorOr<void> append_data(u8 const* values, size_t count);

    ErrorOr<void> append_file_descriptor(int fd);

    ErrorOr<void> transfer_message(Core::LocalSocket& socket, bool block_event_loop = false);

private:

    Vector<u8, 1024> m_data;

    Vector<NonnullRefPtr<AutoCloseFileDescriptor>, 1> m_fds;

};

enum class ErrorCode : u32 {

    PeerDisconnected

};

template<typename Value>

using IPCErrorOr = ErrorOr<Value, ErrorCode>;

class Message {

public:

    virtual ~Message() = default;

    virtual u32 endpoint_magic() const = 0;

    virtual int message_id() const = 0;

    virtual char const* message_name() const = 0;

    virtual bool valid() const = 0;

    virtual ErrorOr<MessageBuffer> encode() const = 0;

protected:

    Message() = default;

};

}