#pragma once

#include "types.h"

#ifdef __cplusplus
extern "C" {
#endif

/* IPC Protocol Flags */
#define IPC_FLAG_FAST_REGISTERS (1 << 0)  /* Message fits entirely in registers */
#define IPC_FLAG_SHM_ATTACHED   (1 << 1)  /* Attached shared memory buffer */
#define IPC_FLAG_CAP_TRANSFER   (1 << 2)  /* Delegating capability in message */
#define IPC_FLAG_NONBLOCKING    (1 << 3)  /* Return immediately if receiver not ready */

/* Shared Memory Descriptor for Zero-Copy Transfers */
typedef struct ipc_shm_desc {
    cap_t    shm_cap;       /* Capability to shared memory region */
    uint64_t offset;        /* Offset within SHM buffer */
    uint64_t length;        /* Length of data payload */
    uint32_t permissions;   /* Read/Write flags */
    uint32_t _reserved;
} __attribute__((packed)) ipc_shm_desc_t;

/* IPC Message Payload Representation */
typedef struct ipc_msg {
    uint64_t badge;         /* Sender authentication badge (injected by kernel) */
    uint32_t opcode;        /* Interface Method / Function ID */
    uint32_t flags;         /* IPC_FLAG_* */
    
    /* Fast-Path Register Payload (4 x 64-bit = 32 bytes directly passed) */
    uint64_t args[4];

    /* Zero-Copy Extended Descriptor */
    ipc_shm_desc_t shm;
} __attribute__((aligned(16))) ipc_msg_t;

/* Standard Common IPC Opcodes */
#define IPC_OP_PING             0x0001
#define IPC_OP_PONG             0x0002
#define IPC_OP_REGISTER_SERVER  0x0010
#define IPC_OP_LOOKUP_SERVER    0x0011
#define IPC_OP_NOTIFY_EVENT     0x0020
#define IPC_OP_READ             0x0100
#define IPC_OP_WRITE            0x0101
#define IPC_OP_IOCTL            0x0102

#ifdef __cplusplus
}
#endif