/*
 * Licensed to the OpenAirInterface (OAI) Software Alliance under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The OpenAirInterface Software Alliance licenses this file to You under
 * the OAI Public License, Version 1.0  (the "License"); you may not use this file
 * except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.openairinterface.org/?page_id=698
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 *-------------------------------------------------------------------------------
 * For more information about the OpenAirInterface (OAI) Software Alliance:
 *      contact@openairinterface.org
 */

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <stdint.h>

#include "nas_log.h"

#include "TLVEncoder.h"
#include "TLVDecoder.h"
#include "AttachRequest.h"

int decode_attach_request(attach_request_msg *attach_request, uint8_t *buffer, uint32_t len)
{
  uint32_t decoded = 0;
  int decoded_result = 0;

  LOG_FUNC_IN;
  LOG_TRACE(INFO, "EMM  - attach_request len = %d",
            len);
  // Check if we got a NULL pointer and if buffer length is >= minimum length expected for the message.
  CHECK_PDU_POINTER_AND_LENGTH_DECODER(buffer, ATTACH_REQUEST_MINIMUM_LENGTH, len);

  /* Decoding mandatory fields */
  if ((decoded_result = decode_u8_eps_attach_type(&attach_request->epsattachtype, 0, *(buffer + decoded)  & 0x0f, len - decoded)) < 0) {
    //         return decoded_result;
    LOG_FUNC_RETURN(decoded_result);
  }

  if ((decoded_result = decode_u8_nas_key_set_identifier(&attach_request->naskeysetidentifier, 0, *(buffer + decoded) >> 4, len - decoded)) < 0) {
    //         return decoded_result;
    LOG_FUNC_RETURN(decoded_result);
  }

  decoded++;

  if ((decoded_result = decode_eps_mobile_identity(&attach_request->oldgutiorimsi, 0, buffer + decoded, len - decoded)) < 0) {
    //         return decoded_result;
    LOG_FUNC_RETURN(decoded_result);
  } else
    decoded += decoded_result;

  if ((decoded_result = decode_ue_network_capability(&attach_request->uenetworkcapability, 0, buffer + decoded, len - decoded)) < 0) {
    //         return decoded_result;
    LOG_FUNC_RETURN(decoded_result);
  } else
    decoded += decoded_result;

  if ((decoded_result = decode_esm_message_container(&attach_request->esmmessagecontainer, 0, buffer + decoded, len - decoded)) < 0) {
    //         return decoded_result;
    LOG_FUNC_RETURN(decoded_result);
  } else
    decoded += decoded_result;

  /* Decoding optional fields */
  while(len - decoded > 0) {
    uint8_t ieiDecoded = *(buffer + decoded);

    /* Type | value iei are below 0x80 so just return the first 4 bits */
    if (ieiDecoded >= 0x80)
      ieiDecoded = ieiDecoded & 0xf0;

    switch(ieiDecoded) {
    case ATTACH_REQUEST_OLD_PTMSI_SIGNATURE_IEI:
      if ((decoded_result =
             decode_p_tmsi_signature(&attach_request->oldptmsisignature,
                                     ATTACH_REQUEST_OLD_PTMSI_SIGNATURE_IEI, buffer + decoded,
                                     len - decoded)) <= 0) {
        //         return decoded_result;
        LOG_FUNC_RETURN(decoded_result);
      }

      decoded += decoded_result;
      /* Set corresponding mask to 1 in presencemask */
      attach_request->presencemask |= ATTACH_REQUEST_OLD_PTMSI_SIGNATURE_PRESENT;
      break;

    case ATTACH_REQUEST_ADDITIONAL_GUTI_IEI:
      if ((decoded_result =
             decode_eps_mobile_identity(&attach_request->additionalguti,
                                        ATTACH_REQUEST_ADDITIONAL_GUTI_IEI, buffer + decoded, len -
                                        decoded)) <= 0) {
        //         return decoded_result;
        LOG_FUNC_RETURN(decoded_result);
      }

      decoded += decoded_result;
      /* Set corresponding mask to 1 in presencemask */
      attach_request->presencemask |= ATTACH_REQUEST_ADDITIONAL_GUTI_PRESENT;
      break;

    case ATTACH_REQUEST_LAST_VISITED_REGISTERED_TAI_IEI:
      if ((decoded_result =
             decode_tracking_area_identity(&attach_request->lastvisitedregisteredtai,
                                           ATTACH_REQUEST_LAST_VISITED_REGISTERED_TAI_IEI, buffer +
                                           decoded, len - decoded)) <= 0) {
        //         return decoded_result;
        LOG_FUNC_RETURN(decoded_result);
      }

      decoded += decoded_result;
      /* Set corresponding mask to 1 in presencemask */
      attach_request->presencemask |= ATTACH_REQUEST_LAST_VISITED_REGISTERED_TAI_PRESENT;
      break;

    case ATTACH_REQUEST_DRX_PARAMETER_IEI:
      if ((decoded_result =
             decode_drx_parameter(&attach_request->drxparameter,
                                  ATTACH_REQUEST_DRX_PARAMETER_IEI, buffer + decoded, len -
                                  decoded)) <= 0) {
        //         return decoded_result;
        LOG_FUNC_RETURN(decoded_result);
      }

      decoded += decoded_result;
      /* Set corresponding mask to 1 in presencemask */
      attach_request->presencemask |= ATTACH_REQUEST_DRX_PARAMETER_PRESENT;
      break;

    case ATTACH_REQUEST_MS_NETWORK_CAPABILITY_IEI:
      if ((decoded_result =
             decode_ms_network_capability(&attach_request->msnetworkcapability,
                                          ATTACH_REQUEST_MS_NETWORK_CAPABILITY_IEI, buffer + decoded,
                                          len - decoded)) <= 0) {
        //         return decoded_result;
        LOG_FUNC_RETURN(decoded_result);
      }

      decoded += decoded_result;
      /* Set corresponding mask to 1 in presencemask */
      attach_request->presencemask |= ATTACH_REQUEST_MS_NETWORK_CAPABILITY_PRESENT;
      break;

    case ATTACH_REQUEST_OLD_LOCATION_AREA_IDENTIFICATION_IEI:
      if ((decoded_result =
             decode_location_area_identification(&attach_request->oldlocationareaidentification,
                 ATTACH_REQUEST_OLD_LOCATION_AREA_IDENTIFICATION_IEI, buffer
                 + decoded, len - decoded)) <= 0) {
        //         return decoded_result;
        LOG_FUNC_RETURN(decoded_result);
      }

      decoded += decoded_result;
      /* Set corresponding mask to 1 in presencemask */
      attach_request->presencemask |= ATTACH_REQUEST_OLD_LOCATION_AREA_IDENTIFICATION_PRESENT;
      break;

    case ATTACH_REQUEST_TMSI_STATUS_IEI:
      if ((decoded_result =
             decode_tmsi_status(&attach_request->tmsistatus,
                                ATTACH_REQUEST_TMSI_STATUS_IEI, buffer + decoded, len -
                                decoded)) <= 0) {
        //         return decoded_result;
        LOG_FUNC_RETURN(decoded_result);
      }

      decoded += decoded_result;
      /* Set corresponding mask to 1 in presencemask */
      attach_request->presencemask |= ATTACH_REQUEST_TMSI_STATUS_PRESENT;
      break;

    case ATTACH_REQUEST_MOBILE_STATION_CLASSMARK_2_IEI:
      if ((decoded_result =
             decode_mobile_station_classmark_2(&attach_request->mobilestationclassmark2,
                 ATTACH_REQUEST_MOBILE_STATION_CLASSMARK_2_IEI, buffer +
                 decoded, len - decoded)) <= 0) {
        //         return decoded_result;
        LOG_FUNC_RETURN(decoded_result);
      }

      decoded += decoded_result;
      /* Set corresponding mask to 1 in presencemask */
      attach_request->presencemask |= ATTACH_REQUEST_MOBILE_STATION_CLASSMARK_2_PRESENT;
      break;

    case ATTACH_REQUEST_MOBILE_STATION_CLASSMARK_3_IEI:
      if ((decoded_result =
             decode_mobile_station_classmark_3(&attach_request->mobilestationclassmark3,
                 ATTACH_REQUEST_MOBILE_STATION_CLASSMARK_3_IEI, buffer +
                 decoded, len - decoded)) <= 0) {
        //         return decoded_result;
        LOG_FUNC_RETURN(decoded_result);
      }

      decoded += decoded_result;
      /* Set corresponding mask to 1 in presencemask */
      attach_request->presencemask |= ATTACH_REQUEST_MOBILE_STATION_CLASSMARK_3_PRESENT;
      break;

    case ATTACH_REQUEST_SUPPORTED_CODECS_IEI:
      if ((decoded_result =
             decode_supported_codec_list(&attach_request->supportedcodecs,
                                         ATTACH_REQUEST_SUPPORTED_CODECS_IEI, 
					 buffer + decoded, 
					 len   - decoded)) <= 0) {
        //         return decoded_result;
        LOG_FUNC_RETURN(decoded_result);
      }

      decoded += decoded_result;
      /* Set corresponding mask to 1 in presencemask */
      attach_request->presencemask |= ATTACH_REQUEST_SUPPORTED_CODECS_PRESENT;
      break;

    case ATTACH_REQUEST_ADDITIONAL_UPDATE_TYPE_IEI:
      if ((decoded_result =
             decode_additional_update_type(&attach_request->additionalupdatetype,
                                           ATTACH_REQUEST_ADDITIONAL_UPDATE_TYPE_IEI, buffer +
                                           decoded, len - decoded)) <= 0) {
        //         return decoded_result;
        LOG_FUNC_RETURN(decoded_result);
      }

      decoded += decoded_result;
      /* Set corresponding mask to 1 in presencemask */
      attach_request->presencemask |= ATTACH_REQUEST_ADDITIONAL_UPDATE_TYPE_PRESENT;
      break;

    case ATTACH_REQUEST_OLD_GUTI_TYPE_IEI:
      if ((decoded_result =
             decode_guti_type(&attach_request->oldgutitype,
                              ATTACH_REQUEST_OLD_GUTI_TYPE_IEI,
                              buffer + decoded, len - decoded)) <= 0) {
        //         return decoded_result;
        LOG_FUNC_RETURN(decoded_result);
      }

      decoded += decoded_result;
      /* Set corresponding mask to 1 in presencemask */
      attach_request->presencemask |= ATTACH_REQUEST_OLD_GUTI_TYPE_PRESENT;
      break;

    case ATTACH_REQUEST_VOICE_DOMAIN_PREFERENCE_AND_UE_USAGE_SETTING_IEI:
      if ((decoded_result =
             decode_voice_domain_preference_and_ue_usage_setting(&attach_request->voicedomainpreferenceandueusagesetting,
                 ATTACH_REQUEST_VOICE_DOMAIN_PREFERENCE_AND_UE_USAGE_SETTING_IEI,
                 buffer + decoded, len - decoded)) <= 0) {
        //         return decoded_result;
        LOG_FUNC_RETURN(decoded_result);
      }

      decoded += decoded_result;
      /* Set corresponding mask to 1 in presencemask */
      attach_request->presencemask |= ATTACH_REQUEST_VOICE_DOMAIN_PREFERENCE_AND_UE_USAGE_SETTING_PRESENT;
      break;

    case ATTACH_REQUEST_MS_NETWORK_FEATURE_SUPPORT_IEI: 
      if ((decoded_result =
	   decode_ms_network_feature_support(&attach_request->msnetworkfeaturesupport,
					     ATTACH_REQUEST_MS_NETWORK_FEATURE_SUPPORT_IEI,
					     buffer + decoded, len - decoded)) <= 0) {
        //         return decoded_result;
	LOG_FUNC_RETURN(decoded_result);
      }
      
      decoded += decoded_result;
      /* Set corresponding mask to 1 in presencemask */
      attach_request->presencemask |= ATTACH_REQUEST_MS_NETWORK_FEATURE_SUPPORT_PRESENT;
      break;
    default:
     
      errorCodeDecoder = TLV_DECODE_UNEXPECTED_IEI;
      {
        //                     return TLV_DECODE_UNEXPECTED_IEI;
        LOG_TRACE(INFO,"EMM: Can't decode the message with iei %d\n",ieiDecoded);
	LOG_FUNC_RETURN(TLV_DECODE_UNEXPECTED_IEI);
      }
    }
  }

  LOG_FUNC_RETURN(decoded);
}

int encode_attach_request(attach_request_msg *attach_request, uint8_t *buffer, uint32_t len)
{
  int encoded = 0;
  int encode_result = 0;

  /* Checking IEI and pointer */
  CHECK_PDU_POINTER_AND_LENGTH_ENCODER(buffer, ATTACH_REQUEST_MINIMUM_LENGTH, len);

  *(buffer + encoded) = ((encode_u8_nas_key_set_identifier(&attach_request->naskeysetidentifier) & 0x0f) << 4) | (encode_u8_eps_attach_type(&attach_request->epsattachtype) & 0x0f);
  encoded++;

  if ((encode_result =
         encode_eps_mobile_identity(&attach_request->oldgutiorimsi, 0, buffer +
                                    encoded, len - encoded)) < 0)        //Return in case of error
    return encode_result;
  else
    encoded += encode_result;

  if ((encode_result =
         encode_ue_network_capability(&attach_request->uenetworkcapability, 0,
                                      buffer + encoded, len - encoded)) < 0)        //Return in case of error
    return encode_result;
  else
    encoded += encode_result;

  if ((encode_result =
         encode_esm_message_container(&attach_request->esmmessagecontainer, 0,
                                      buffer + encoded, len - encoded)) < 0)        //Return in case of error
    return encode_result;
  else
    encoded += encode_result;

  if ((attach_request->presencemask & ATTACH_REQUEST_OLD_PTMSI_SIGNATURE_PRESENT)
      == ATTACH_REQUEST_OLD_PTMSI_SIGNATURE_PRESENT) {
    if ((encode_result =
           encode_p_tmsi_signature(&attach_request->oldptmsisignature,
                                   ATTACH_REQUEST_OLD_PTMSI_SIGNATURE_IEI, buffer + encoded, len -
                                   encoded)) < 0)
      // Return in case of error
      return encode_result;
    else
      encoded += encode_result;
  }

  if ((attach_request->presencemask & ATTACH_REQUEST_ADDITIONAL_GUTI_PRESENT)
      == ATTACH_REQUEST_ADDITIONAL_GUTI_PRESENT) {
    if ((encode_result =
           encode_eps_mobile_identity(&attach_request->additionalguti,
                                      ATTACH_REQUEST_ADDITIONAL_GUTI_IEI, buffer + encoded, len -
                                      encoded)) < 0)
      // Return in case of error
      return encode_result;
    else
      encoded += encode_result;
  }

  if ((attach_request->presencemask & ATTACH_REQUEST_LAST_VISITED_REGISTERED_TAI_PRESENT)
      == ATTACH_REQUEST_LAST_VISITED_REGISTERED_TAI_PRESENT) {
    if ((encode_result =
           encode_tracking_area_identity(&attach_request->lastvisitedregisteredtai,
                                         ATTACH_REQUEST_LAST_VISITED_REGISTERED_TAI_IEI, buffer + encoded,
                                         len - encoded)) < 0)
      // Return in case of error
      return encode_result;
    else
      encoded += encode_result;
  }

  if ((attach_request->presencemask & ATTACH_REQUEST_DRX_PARAMETER_PRESENT)
      == ATTACH_REQUEST_DRX_PARAMETER_PRESENT) {
    if ((encode_result = encode_drx_parameter(&attach_request->drxparameter,
                         ATTACH_REQUEST_DRX_PARAMETER_IEI, buffer + encoded, len -
                         encoded)) < 0)
      // Return in case of error
      return encode_result;
    else
      encoded += encode_result;
  }

  if ((attach_request->presencemask & ATTACH_REQUEST_MS_NETWORK_CAPABILITY_PRESENT)
      == ATTACH_REQUEST_MS_NETWORK_CAPABILITY_PRESENT) {
    if ((encode_result =
           encode_ms_network_capability(&attach_request->msnetworkcapability,
                                        ATTACH_REQUEST_MS_NETWORK_CAPABILITY_IEI, buffer + encoded, len -
                                        encoded)) < 0)
      // Return in case of error
      return encode_result;
    else
      encoded += encode_result;
  }

  if ((attach_request->presencemask & ATTACH_REQUEST_OLD_LOCATION_AREA_IDENTIFICATION_PRESENT)
      == ATTACH_REQUEST_OLD_LOCATION_AREA_IDENTIFICATION_PRESENT) {
    if ((encode_result =
           encode_location_area_identification(&attach_request->oldlocationareaidentification,
               ATTACH_REQUEST_OLD_LOCATION_AREA_IDENTIFICATION_IEI, buffer +
               encoded, len - encoded)) < 0)
      // Return in case of error
      return encode_result;
    else
      encoded += encode_result;
  }

  if ((attach_request->presencemask & ATTACH_REQUEST_TMSI_STATUS_PRESENT)
      == ATTACH_REQUEST_TMSI_STATUS_PRESENT) {
    if ((encode_result = encode_tmsi_status(&attach_request->tmsistatus,
                                            ATTACH_REQUEST_TMSI_STATUS_IEI, buffer + encoded, len - encoded))
        < 0)
      // Return in case of error
      return encode_result;
    else
      encoded += encode_result;
  }

  if ((attach_request->presencemask & ATTACH_REQUEST_MOBILE_STATION_CLASSMARK_2_PRESENT)
      == ATTACH_REQUEST_MOBILE_STATION_CLASSMARK_2_PRESENT) {
    if ((encode_result =
           encode_mobile_station_classmark_2(&attach_request->mobilestationclassmark2,
               ATTACH_REQUEST_MOBILE_STATION_CLASSMARK_2_IEI, buffer + encoded,
               len - encoded)) < 0)
      // Return in case of error
      return encode_result;
    else
      encoded += encode_result;
  }

  if ((attach_request->presencemask & ATTACH_REQUEST_MOBILE_STATION_CLASSMARK_3_PRESENT)
      == ATTACH_REQUEST_MOBILE_STATION_CLASSMARK_3_PRESENT) {
    if ((encode_result =
           encode_mobile_station_classmark_3(&attach_request->mobilestationclassmark3,
               ATTACH_REQUEST_MOBILE_STATION_CLASSMARK_3_IEI, buffer + encoded,
               len - encoded)) < 0)
      // Return in case of error
      return encode_result;
    else
      encoded += encode_result;
  }

  if ((attach_request->presencemask & ATTACH_REQUEST_SUPPORTED_CODECS_PRESENT)
      == ATTACH_REQUEST_SUPPORTED_CODECS_PRESENT) {
    if ((encode_result =
           encode_supported_codec_list(&attach_request->supportedcodecs,
                                       ATTACH_REQUEST_SUPPORTED_CODECS_IEI, buffer + encoded, len -
                                       encoded)) < 0)
      // Return in case of error
      return encode_result;
    else
      encoded += encode_result;
  }

  if ((attach_request->presencemask & ATTACH_REQUEST_ADDITIONAL_UPDATE_TYPE_PRESENT)
      == ATTACH_REQUEST_ADDITIONAL_UPDATE_TYPE_PRESENT) {
    if ((encode_result =
           encode_additional_update_type(&attach_request->additionalupdatetype,
                                         ATTACH_REQUEST_ADDITIONAL_UPDATE_TYPE_IEI, buffer + encoded, len -
                                         encoded)) < 0)
      // Return in case of error
      return encode_result;
    else
      encoded += encode_result;
  }

  if ((attach_request->presencemask & ATTACH_REQUEST_OLD_GUTI_TYPE_PRESENT)
      == ATTACH_REQUEST_OLD_GUTI_TYPE_PRESENT) {
    if ((encode_result =
           encode_guti_type(&attach_request->oldgutitype,
                            ATTACH_REQUEST_OLD_GUTI_TYPE_IEI,
                            buffer + encoded, len - encoded)) < 0)
      // Return in case of error
      return encode_result;
    else
      encoded += encode_result;
  }

  if ((attach_request->presencemask & ATTACH_REQUEST_VOICE_DOMAIN_PREFERENCE_AND_UE_USAGE_SETTING_PRESENT)
      == ATTACH_REQUEST_VOICE_DOMAIN_PREFERENCE_AND_UE_USAGE_SETTING_PRESENT) {
    if ((encode_result =
           encode_voice_domain_preference_and_ue_usage_setting(&attach_request->voicedomainpreferenceandueusagesetting,
               ATTACH_REQUEST_VOICE_DOMAIN_PREFERENCE_AND_UE_USAGE_SETTING_IEI,
               buffer + encoded, len - encoded)) < 0)
      // Return in case of error
      return encode_result;
    else
      encoded += encode_result;
  }

  if ((attach_request->presencemask & ATTACH_REQUEST_MS_NETWORK_FEATURE_SUPPORT_PRESENT)
      == ATTACH_REQUEST_MS_NETWORK_FEATURE_SUPPORT_PRESENT) {
    if ((encode_result =
	 encode_ms_network_feature_support(&attach_request->msnetworkfeaturesupport,
					   ATTACH_REQUEST_MS_NETWORK_FEATURE_SUPPORT_IEI, 
					   buffer + encoded, 
					   len -  encoded)) < 0)
      // Return in case of error
      return encode_result;
    else
      encoded += encode_result;
  }
  
  return encoded;
}

