/*******************************************************************************
    OpenAirInterface
    Copyright(c) 1999 - 2014 Eurecom

    OpenAirInterface is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation, either version 3 of the License, or
    (at your option) any later version.


    OpenAirInterface is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with OpenAirInterface.The full GNU General Public License is
   included in this distribution in the file called "COPYING". If not,
   see <http://www.gnu.org/licenses/>.

  Contact Information
  OpenAirInterface Admin: openair_admin@eurecom.fr
  OpenAirInterface Tech : openair_tech@eurecom.fr
  OpenAirInterface Dev  : openair4g-devel@eurecom.fr

  Address      : Eurecom, Compus SophiaTech 450, route des chappes, 06451 Biot, France.

 *******************************************************************************/
#include <stdio.h>
#include <string.h>
#include <unistd.h>
#include <pthread.h>

#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <netinet/sctp.h>
#include <arpa/inet.h>

#include "sctp_primitives_client.h"

#include "s1ap_common.h"
#include "s1ap_eNB.h"
#include "s1ap_mme.h"
#include "s1ap_ies_defs.h"

#include "s1ap_eNB_encoder.h"
#include "s1ap_eNB_decoder.h"

#define NB_OF_ENB 10
#define NB_OF_UES 100

static int connected_eNB = 0;
static char ip_addr[] = "127.0.0.1";
uint32_t ipv4_local = 0x7F000001;
static uint8_t id[] = { 0x03, 0x56, 0xf0, 0xd8 };
static char identity[] = { 0x02, 0x08, 0x34 };
static char tac[] = { 0x00, 0x01 };
static char infoNAS[] = { 0x07, 0x42, 0x01, 0xE0, 0x06, 0x00, 0x00, 0xF1, 0x10, 0x00, 0x01, 0x00, 0x2C,
                          0x52, 0x01, 0xC1, 0x01, 0x09, 0x10, 0x03, 0x77, 0x77, 0x77, 0x07, 0x61, 0x6E, 0x72, 0x69, 0x74,
                          0x73, 0x75, 0x03, 0x63, 0x6F, 0x6D, 0x05, 0x01, 0x0A, 0x01, 0x20, 0x37, 0x27, 0x0E, 0x80, 0x80,
                          0x21, 0x0A, 0x03, 0x00, 0x00, 0x0A, 0x81, 0x06, 0x0A, 0x00, 0x00, 0x01, 0x50, 0x0B, 0xF6,
                          0x00, 0xF1, 0x10, 0x80, 0x01, 0x01, 0x00, 0x00, 0x00, 0x01
                        };
uint32_t nb_eNB = NB_OF_ENB;
uint32_t nb_ue  = NB_OF_UES;

void s1ap_test_generate_s1_setup_request(uint32_t eNB_id, uint8_t **buffer,
        uint32_t *length);
int s1ap_test_generate_initial_ue_message(uint32_t eNB_UE_S1AP_ID,
        uint8_t **buffer,
        uint32_t *length);
int recv_callback(uint32_t assocId,
                  uint32_t stream,
                  uint8_t *buffer,
                  uint32_t length);
int sctp_connected(void *args,
                   uint32_t assocId,
                   uint32_t instreams,
                   uint32_t outstreams);

void s1ap_test_generate_s1_setup_request(uint32_t eNB_id, uint8_t **buffer,
        uint32_t *length)
{
    S1SetupRequestIEs_t s1SetupRequest;
    SupportedTAs_Item_t ta;
    PLMNidentity_t plmnIdentity;
    uint8_t *id_p = (uint8_t *)(&eNB_id + 1);

    memset(&s1SetupRequest, 0, sizeof(S1SetupRequestIEs_t));
    s1SetupRequest.global_ENB_ID.eNB_ID.present = ENB_ID_PR_macroENB_ID;
    s1SetupRequest.global_ENB_ID.eNB_ID.choice.macroENB_ID.buf = id_p;
    s1SetupRequest.global_ENB_ID.eNB_ID.choice.macroENB_ID.size = 3;
    s1SetupRequest.global_ENB_ID.eNB_ID.choice.macroENB_ID.bits_unused = 4;
    OCTET_STRING_fromBuf(&s1SetupRequest.global_ENB_ID.pLMNidentity, identity, 3);

    s1SetupRequest.presenceMask |= S1SETUPREQUESTIES_ENBNAME_PRESENT;
    OCTET_STRING_fromBuf(&s1SetupRequest.eNBname, "ENB 1 eurecom",
                         strlen("ENB 1 eurecom"));

    memset(&ta, 0, sizeof(SupportedTAs_Item_t));
    memset(&plmnIdentity, 0, sizeof(PLMNidentity_t));
    OCTET_STRING_fromBuf(&ta.tAC, tac, 2);
    OCTET_STRING_fromBuf(&plmnIdentity, identity, 3);
    ASN_SEQUENCE_ADD(&ta.broadcastPLMNs, &plmnIdentity);
    ASN_SEQUENCE_ADD(&s1SetupRequest.supportedTAs, &ta);

    s1SetupRequest.defaultPagingDRX = PagingDRX_v64;

    s1ap_eNB_encode_s1_setup_request(&s1SetupRequest, buffer, length);
}

int s1ap_test_generate_initial_ue_message(uint32_t eNB_UE_S1AP_ID,
        uint8_t **buffer,
        uint32_t *length)
{
    InitialUEMessageIEs_t  initialUEmessageIEs;
    InitialUEMessageIEs_t *initialUEmessageIEs_p = &initialUEmessageIEs;

    memset(initialUEmessageIEs_p, 0, sizeof(InitialUEMessageIEs_t));

    initialUEmessageIEs.eNB_UE_S1AP_ID = eNB_UE_S1AP_ID & 0x00ffffff;
    initialUEmessageIEs.nas_pdu.buf = (uint8_t *)infoNAS;
    initialUEmessageIEs.nas_pdu.size = sizeof(infoNAS);

    initialUEmessageIEs.tai.tAC.buf = (uint8_t *)tac;
    initialUEmessageIEs.tai.tAC.size = 2;
    initialUEmessageIEs.tai.pLMNidentity.buf = (uint8_t *)identity;
    initialUEmessageIEs.tai.pLMNidentity.size = 3;
    initialUEmessageIEs.eutran_cgi.pLMNidentity.buf = (uint8_t *)identity;
    initialUEmessageIEs.eutran_cgi.pLMNidentity.size = 3;
    initialUEmessageIEs.eutran_cgi.cell_ID.buf = (uint8_t *)id;
    initialUEmessageIEs.eutran_cgi.cell_ID.size = 4;
    initialUEmessageIEs.eutran_cgi.cell_ID.bits_unused = 4;

    initialUEmessageIEs.rrC_Establishment_Cause = RRC_Establishment_Cause_mo_Data;

    return s1ap_eNB_encode_initial_ue_message(initialUEmessageIEs_p, buffer, length);
}

int s1ap_test_generate_initial_setup_resp(uint32_t eNB_UE_S1AP_ID,
        uint32_t mme_UE_S1AP_ID,
        uint8_t  eRAB_id,
        uint32_t teid,
        uint8_t **buffer,
        uint32_t *length)
{
    InitialContextSetupResponseIEs_t  initialResponseIEs;
    InitialContextSetupResponseIEs_t *initialResponseIEs_p = &initialResponseIEs;

    E_RABSetupItemCtxtSURes_t e_RABSetupItemCtxtSURes;

    memset(initialResponseIEs_p, 0, sizeof(InitialContextSetupResponseIEs_t));
    memset(&e_RABSetupItemCtxtSURes, 0, sizeof(E_RABSetupItemCtxtSURes_t));

    initialResponseIEs_p->mme_ue_s1ap_id = mme_UE_S1AP_ID;
    initialResponseIEs_p->eNB_UE_S1AP_ID = eNB_UE_S1AP_ID;

    e_RABSetupItemCtxtSURes.e_RAB_ID = eRAB_id;
    e_RABSetupItemCtxtSURes.transportLayerAddress.buf = (uint8_t *)&ipv4_local;
    e_RABSetupItemCtxtSURes.transportLayerAddress.size = 4;

    e_RABSetupItemCtxtSURes.gTP_TEID.buf = (uint8_t *)&teid;
    e_RABSetupItemCtxtSURes.gTP_TEID.size = 4;

    ASN_SEQUENCE_ADD(
        &initialResponseIEs_p->e_RABSetupListCtxtSURes.e_RABSetupItemCtxtSURes,
        &e_RABSetupItemCtxtSURes);

    return s1ap_eNB_encode_initial_context_setup_response(initialResponseIEs_p,
            buffer, length);
}

int recv_callback(uint32_t  assocId,
                  uint32_t  stream,
                  uint8_t  *buffer,
                  uint32_t  length)
{
    s1ap_message message;
    uint8_t *buffer2;
    uint32_t len;
    int j;

    if (s1ap_eNB_decode_pdu(&message, buffer, length) < 0) {
        fprintf(stderr, "s1ap_eNB_decode_pdu returned status < 0\n");
        free(buffer);
        return -1;
    }

    if (message.procedureCode == ProcedureCode_id_S1Setup
            && message.direction == S1AP_PDU_PR_successfulOutcome) {
        for (j = 0; j < nb_ue; j++) {
            s1ap_test_generate_initial_ue_message(j, &buffer2, &len);
            if (sctp_send_msg(assocId, j % 64 + 1, buffer2, len) < 0) {
                fprintf(stderr,
                        "sctp_send_msg returned status < 0\nSomething bad happened on SCTP layer\n");
                free(buffer2);
                break;
            }
            free(buffer2);
        }
    } else if (message.procedureCode == ProcedureCode_id_InitialContextSetup
               && message.direction == S1AP_PDU_PR_initiatingMessage) {
        fprintf(stdout, "Received InitialContextSetup request\n");
        s1ap_test_generate_initial_setup_resp(
            message.msg.initialContextSetupRequestIEs.eNB_UE_S1AP_ID,
            message.msg.initialContextSetupRequestIEs.mme_ue_s1ap_id,
            0x5,
            0x1,
            &buffer2,
            &len);
        if (sctp_send_msg(assocId, stream, buffer2, len) < 0) {
            fprintf(stderr,
                    "sctp_send_msg returned status < 0\nSomething bad happened on SCTP layer\n");
            free(buffer2);
        }
        free(buffer2);
    } else {
        fprintf(stderr, "Received unexpected message %d %d\n", message.procedureCode,
                message.direction);
        free(buffer);
        return -1;
    }

    free(buffer);

    return 0;
}

int sctp_connected(void     *args,
                   uint32_t  assocId,
                   uint32_t  instreams,
                   uint32_t  outstreams)
{
    uint8_t *buffer;
    uint32_t len;

    fprintf(stdout, "New association %d\n", assocId);

    s1ap_test_generate_s1_setup_request(assocId * nb_eNB, &buffer, &len);

    if (sctp_send_msg(assocId, 0, buffer, len) < 0) {
        free(buffer);
        fprintf(stderr,
                "sctp_send_msg returned status < 0. Something bad happened on SCTP layer\n");
        exit(0);
    }
    free(buffer);

    connected_eNB++;
    return 0;
}

int main(int argc, char *argv[])
{
    asn_enc_rval_t retVal;

    int i;

    SupportedTAs_Item_t ta;
    PLMNidentity_t plmnIdentity;

    asn_debug = 0;
    asn1_xer_print = 0;

    if (argc > 1) {
        nb_eNB = atoi(argv[1]);
        if (argc > 2) {
            nb_ue = atoi(argv[2]);
        }
    }

    for (i = 0; i < nb_eNB; i++) {
        sctp_connect_to_remote_host(ip_addr, 36412, 18, NULL, sctp_connected,
                                    recv_callback);
    }
    while (1) {
        sleep(1);
    }


//     generateUplinkNASTransport(&buffer, &len);
//     sctp_send_msg(assoc[0], 0, buffer, len);
//     s1ap_mme_decode_pdu(buffer, len);

    sctp_terminate();

    return(0);
}
