/*
 * Copyright (c) 2006, Swedish Institute of Computer Science.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the Institute nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 * $Id: radio-arch.c,v 1.3 2006/10/05 07:46:53 fros4943 Exp $
 */

#include "dev/radio-arch.h"
#include "dev/radio.h"

#include "lib/simEnvChange.h"

#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include "net/uip.h"
#include "net/uip-fw.h"
#include "sys/etimer.h"
#include "sys/cooja_mt.h"

#include "sys/log.h"

const struct simInterface radio_interface;

// COOJA variables
char simTransmitting;
char simReceiving;

char simInDataBuffer[UIP_BUFSIZE];
int simInSize;
char simOutDataBuffer[UIP_BUFSIZE];
int simOutSize;

char simRadioHWOn = 1;
int simSignalStrength;

/*-----------------------------------------------------------------------------------*/
static void
doInterfaceActionsBeforeTick(void)
{
  // If radio is turned off, do nothing
  if (!simRadioHWOn) {
    simInSize = 0;
    return;
  }
  
  // Busy-wait while receiving (in main file)
  if (simReceiving) {
    busyWaitNext = 1;
    return;
  }
  
  // If no incoming radio data, do nothing
  if (simInSize == 0) {
    return;
  }
  
  // Check size of received packet
  if (simInSize > UIP_BUFSIZE) {
    // Drop packet by not delivering
    return;
  }
  
  // Hand over new packet to uIP
  uip_len = simInSize;
  memcpy(&uip_buf[UIP_LLH_LEN], &simInDataBuffer[0], simInSize);
  tcpip_input();
  simInSize = 0;
}

/*-----------------------------------------------------------------------------------*/
static void
doInterfaceActionsAfterTick(void)
{
  // Nothing to do
}
/*-----------------------------------------------------------------------------------*/
u8_t
simDoSend(void)
{
  // If radio is turned off, do nothing
  if (!simRadioHWOn) {
    // TODO Should we reset uip_len if radio is off?
    uip_len = 0;
    return UIP_FW_DROPPED;
  }
  
  // Drop packet if data size too large
  if(uip_len > UIP_BUFSIZE) {
    uip_len = 0;
    return UIP_FW_TOOLARGE;
  }
  
  // Drop packet if no data length
  if (uip_len <= 0) {
    return UIP_FW_ZEROLEN;
  }
  
  // - Initiate transmission -
  simTransmitting = 1;
  
  // Copy packet data to temporary storage
  memcpy(&simOutDataBuffer[0], &uip_buf[UIP_LLH_LEN], uip_len);
  simOutSize = uip_len;
  
  // Busy-wait while we are receiving
  while (simReceiving) {
    cooja_mt_yield();
  }
	
  // Busy-wait until ether is ready, or die (MAC imitation)
  int retries=0;
  /*	while (retries < 5 && simSignalStrength > -80) {
  // TODO Retry and signal strength threshold values?
  retries++;
  printf("WAITING FOR ETHER! (null)\n");
  cooja_mt_yield();
  }
  if (simSignalStrength > -80) {
  return UIP_FW_DROPPED;
  }
  */	
  // Busy-wait while transmitting
  while (simTransmitting) {
    cooja_mt_yield();
  }
  
  return UIP_FW_OK;
}
/*-----------------------------------------------------------------------------------*/
/**
 * \brief      Turn radio on.
 *
 *             This function turns the radio hardware on.
 */
void
radio_on(void) {
  simRadioHWOn = 1;
}
/*-----------------------------------------------------------------------------------*/
/**
 * \brief      Turn radio off.
 *
 *             This function turns the radio hardware off.
 */
void radio_off(void) {
  simRadioHWOn = 0;
}
/*-----------------------------------------------------------------------------------*/
SIM_INTERFACE(radio_interface,
	      doInterfaceActionsBeforeTick,
	      doInterfaceActionsAfterTick);