/*
 * SPDX-License-Identifier: LicenseRef-CSSL-1.0
 */

#ifndef TLV_DECODER_H_
#define TLV_DECODER_H_

#include <arpa/inet.h>  // ntohl, ntohs
#include "nas_log.h"

#ifndef NAS_DEBUG
//# define NAS_DEBUG 1
#endif

#define DECODE_U8(bUFFER, vALUE, sIZE)    \
    vALUE = *(uint8_t*)(bUFFER);    \
    sIZE += sizeof(uint8_t)

#define DECODE_U16(bUFFER, vALUE, sIZE)   \
    vALUE = ntohs(*(uint16_t*)(bUFFER));  \
    sIZE += sizeof(uint16_t)

#define DECODE_U24(bUFFER, vALUE, sIZE)   \
    vALUE = ntohl(*(uint32_t*)(bUFFER)) >> 8; \
    sIZE += sizeof(uint8_t) + sizeof(uint16_t)

#define DECODE_U32(bUFFER, vALUE, sIZE) \
  {                                     \
    uint32_t v;                         \
    memcpy(&v, bUFFER, sizeof(v));      \
    vALUE = ntohl(v);                   \
  }                                     \
  sIZE += sizeof(uint32_t)

#if (BYTE_ORDER == LITTLE_ENDIAN)
# define DECODE_LENGTH_U16(bUFFER, vALUE, sIZE)          \
    vALUE = ((*(bUFFER)) << 8) | (*((bUFFER) + 1));      \
    sIZE += sizeof(uint16_t)
#else
# define DECODE_LENGTH_U16(bUFFER, vALUE, sIZE)          \
    vALUE = (*(bUFFER)) | (*((bUFFER) + 1) << 8);        \
    sIZE += sizeof(uint16_t)
#endif

#define IES_DECODE_U8(bUFFER, dECODED, vALUE) \
    DECODE_U8(bUFFER + dECODED, vALUE, dECODED)

#define IES_DECODE_U16(bUFFER, dECODED, vALUE)   \
  do {                                           \
    uint16_t val;                                \
    memcpy(&val, bUFFER + dECODED, sizeof(val)); \
    DECODE_U16(&val, vALUE, dECODED);            \
  } while (0)

#define IES_DECODE_U24(bUFFER, dECODED, vALUE)  \
    DECODE_U24(bUFFER + dECODED, vALUE, dECODED)

#define IES_DECODE_U32(bUFFER, dECODED, vALUE)  \
    DECODE_U32(bUFFER + dECODED, vALUE, dECODED)

typedef enum {
  TLV_DECODE_ERROR_OK                     =  0,
  TLV_DECODE_UNEXPECTED_IEI               = -1,
  TLV_DECODE_MANDATORY_FIELD_NOT_PRESENT  = -2,
  TLV_DECODE_VALUE_DOESNT_MATCH           = -3,

  /* Fatal errors - received message should not be processed */
  TLV_DECODE_WRONG_MESSAGE_TYPE           = -10,
  TLV_DECODE_PROTOCOL_NOT_SUPPORTED       = -11,
  TLV_DECODE_BUFFER_TOO_SHORT             = -12,
  TLV_DECODE_BUFFER_NULL                  = -13,
  TLV_DECODE_MAC_MISMATCH                 = -14,
} tlv_decoder_error_code;

/* Defines error code limit below which received message should be discarded
 * because it cannot be further processed */
#define TLV_DECODE_FATAL_ERROR  (TLV_DECODE_VALUE_DOESNT_MATCH)

extern int errorCodeDecoder;

#ifdef ENABLE_TESTS
#define TLV_DEC_ERROR(...) fprintf(stderr, "TLV Decoder: " __VA_ARGS__)
#else
#define TLV_DEC_ERROR(...) // Do nothing
#endif

#define CHECK_PDU_POINTER_AND_LENGTH_DECODER(bUFFER, mINIMUMlENGTH, lENGTH)                                          \
  do {                                                                                                               \
    if ((bUFFER) == NULL) {                                                                                          \
      TLV_DEC_ERROR("(%s:%d) Got NULL pointer for the payload\n", __FILE__, __LINE__);                               \
      return TLV_DECODE_BUFFER_NULL;                                                                                 \
    }                                                                                                                \
    if ((lENGTH) < (mINIMUMlENGTH)) {                                                                                \
      TLV_DEC_ERROR("(%s:%d) Expecting at least %d bytes, got %u\n", __FILE__, __LINE__, (mINIMUMlENGTH), (lENGTH)); \
      return TLV_DECODE_BUFFER_TOO_SHORT;                                                                            \
    }                                                                                                                \
  } while (0)

#define CHECK_LENGTH_DECODER(bUFFERlENGTH, lENGTH)                                      \
  do {                                                                                  \
    if ((bUFFERlENGTH) < (lENGTH)) {                                                    \
      TLV_DEC_ERROR("(%s:%d) Buffer is too short, length (%u) is less than the required length (%u)\n", \
                  __FILE__,                                                             \
                  __LINE__,                                                             \
                  (bUFFERlENGTH),                                                       \
                  (lENGTH));                                                            \
      return TLV_DECODE_BUFFER_TOO_SHORT;                                               \
    }                                                                                   \
  } while (0)

#define CHECK_MESSAGE_TYPE(mESSAGE_TYPE, BUFFER)                                                                          \
  do {                                                                                                                    \
    if ((MESSAGE_TYPE) != (BUFFER)) {                                                                                     \
      TLV_DEC_ERROR("(%s:%d) Wrong message type: Got: %u, Expected: %u\n", __FILE__, __LINE__, (BUFFER), (MESSAGE_TYPE)); \
      return TLV_DECODE_WRONG_MESSAGE_TYPE;                                                                               \
    }                                                                                                                     \
  } while (0)

#define CHECK_IEI_DECODER(iEI, bUFFER)                                         \
  do {                                                                         \
    if ((iEI) != (bUFFER)) {                                                   \
      TLV_DEC_ERROR(                                                           \
          "IEI check failure: %s:%d: IEI is different than the one expected: " \
          "(Got: 0x%x, expecting: 0x%x)\n",                                    \
          __FILE__,                                                            \
          __LINE__,                                                            \
          (bUFFER),                                                            \
          (iEI));                                                              \
      return TLV_DECODE_UNEXPECTED_IEI;                                        \
    }                                                                          \
  } while (0)

#endif /* define (TLV_DECODER_H_) */
