/* -------------------------------------------

  Copyright (C) 2024-2025, Amlal El Mahrouss, all rights reserved..

  File: IPC.h.
  Purpose: IPC protocol.

------------------------------------------- */

#ifndef INC_IPC_H
#define INC_IPC_H

#include <NeKit/Defines.h>
#include <NeKit/KString.h>
#include <hint/CompilerHint.h>

/// @file IPC.h
/// @brief IPC comm. protocol.

/// IA separator.
#define kIPCRemoteSeparator ":"

/// Interchange address, consists of ProcessID:TEAM.
#define kIPCRemoteInvalid "00:00"

#define kIPCHeaderMagic (0x4950434)

namespace Kernel {
struct IPC_ADDR;
struct IPC_MSG;

/// @brief 128-bit IPC address.
struct PACKED IPC_ADDR final {
  UInt64 UserProcessID;
  UInt64 UserProcessTeam;

  ////////////////////////////////////
  // some operators.
  ////////////////////////////////////

  bool operator==(const IPC_ADDR& addr) noexcept;

  bool operator==(IPC_ADDR& addr) noexcept;

  bool operator!=(const IPC_ADDR& addr) noexcept;

  bool operator!=(IPC_ADDR& addr) noexcept;
};

typedef struct IPC_ADDR IPC_ADDR;

enum {
  kIPCLittleEndian = 0,
  kIPCBigEndian    = 1,
  kIPCMixedEndian  = 2,
};

constexpr inline auto kIPCMsgSize = 6094U;

enum {
  kIPCLockInvalid,
  kIPCLockFree = 1,
  kIPCLockUsed = 2,
};

/// @brief IPC connection header, message cannot be greater than 6K.
typedef struct IPC_MSG final {
  UInt32   IpcHeaderMagic;  // cRemoteHeaderMagic
  UInt8    IpcEndianess;    // 0 : LE, 1 : BE
  SizeT    IpcPacketSize;
  IPC_ADDR IpcFrom;
  IPC_ADDR IpcTo;
  UInt32   IpcCRC32;
  UInt32   IpcMsg;
  UInt32   IpcMsgSz;
  UInt8    IpcData[kIPCMsgSize];
  UInt32   IpcLock;
  /// @brief Passes the message to target, could be anything, HTTP packet, JSON or whatever.
  static Bool Pass(IPC_MSG* self, IPC_MSG* target) noexcept;
} PACKED IPC_MSG;

/// @brief Sanitize packet function
/// @retval true packet is correct.
/// @retval false packet is incorrect and process has crashed.
Bool ipc_sanitize_packet(_Input IPC_MSG* pckt_in);

/// @brief Construct packet function
/// @retval true packet is correct.
/// @retval false packet is incorrect and process has crashed.
Bool ipc_construct_packet(_Output _Input IPC_MSG** pckt_in);
}  // namespace Kernel

#endif  // INC_IPC_H