/****************************************************************
 * 
 * Set of utility routines fir the level 2p processing
 *
 * byteSwapInt   :  Routine to do the byte swapping on an int variable
 * byteSwapShort :  Routine to do the byte swapping on a short variable
 * byteSwapFloat :  Routine to do the byte swapping on a float variable
 * printError    :  Program wide error reporting including time of error
 * 
 *
 * Version History:
 *
 * Origjnal version
 * 20 March 2006  -  Author : Jonathan Mittaz
 *
 * 17 April 2006  -  Tidy up of code : Jonathan Mittaz
 *
 */

/* Include files */
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <time.h>
#include <utils.h>
#include <sys/time.h>

/* Union structures to enable the correct byte swapping of idfferent 
 * variable types */
union char_to_int {
  unsigned char charval[4];
  int intval;
};

union char_to_long {
  unsigned char charval[4];
  long intval;
};

union char_to_short {
  unsigned char charval[2];
  short intval;
};

union char_to_float {
  unsigned char charval[4];
  float floatval;
};

/* Routines to do byte swapping */
/* Byte swap an int variable */
int byteSwapInt( int inValue )
{
  union char_to_int intUnion;
  union char_to_int intUnion2;
 
#ifdef BIG_ENDIAN_MACHINE
  return inValue;
#else  
  intUnion.intval = inValue;

  intUnion2.charval[0] = intUnion.charval[3];
  intUnion2.charval[1] = intUnion.charval[2];
  intUnion2.charval[2] = intUnion.charval[1];
  intUnion2.charval[3] = intUnion.charval[0];

  return intUnion2.intval;
#endif
}

/* Byte swap an long variable */
long byteSwapLong( long inValue )
{
  union char_to_long intUnion;
  union char_to_long intUnion2;
 
#ifdef BIG_ENDIAN_MACHINE
  return inValue;
#else
  intUnion.intval = inValue;

  intUnion2.charval[0] = intUnion.charval[3];
  intUnion2.charval[1] = intUnion.charval[2];
  intUnion2.charval[2] = intUnion.charval[1];
  intUnion2.charval[3] = intUnion.charval[0];

  return intUnion2.intval;
#endif
}

/* Byte swap a short variable */
short byteSwapShort( short inValue )
{
  union char_to_short intUnion;
  union char_to_short intUnion2;
 
#ifdef BIG_ENDIAN_MACHINE
  return inValue;
#else  
  intUnion.intval = inValue;

  intUnion2.charval[0] = intUnion.charval[1];
  intUnion2.charval[1] = intUnion.charval[0];

  return intUnion2.intval;
#endif
}

/* Byte swap a float variable */
float byteSwapFlt( float inValue )
{
  union char_to_float fltUnion;
  union char_to_float fltUnion2;
 
#ifdef BIG_ENDIAN_MACHINE
  return inValue;
#else  
  fltUnion.floatval = inValue;

  fltUnion2.charval[0] = fltUnion.charval[3];
  fltUnion2.charval[1] = fltUnion.charval[2];
  fltUnion2.charval[2] = fltUnion.charval[1];
  fltUnion2.charval[3] = fltUnion.charval[0];

  return fltUnion2.floatval;
#endif
}

/* Generic routine for error reporting - outputs an error string of the 
 * form :
 *
 *         L2P : ERROR : YYYY-MM-DD:hh:ss : Some error string 
 * 
 * where YYYY-MM-DD:hh:ss is the time at which the error is trapped
 *
 */
/*
 * Arguments:
 *
 *   pStr1     :  Program identifuer (in this case this will be L2P
 *   pStr2     :  Description of error trapped
 *   pFloat    :  Input floating point variable to be included in the
 *                description string
 *   pInString :  Input string variable to be included in the description
 *                string
 */
#define MAX_ERROR_STRING 1000
void printError( char *pStr1, char *pStr2, float_fp_kind *pFloat,
                 char *pInString )
{
  /* Temporary storage strings for output */
  char tempString[MAX_ERROR_STRING];
  char errorString[MAX_ERROR_STRING];
  char timeString[MAX_ERROR_STRING];

  /* Structures needed to get the current time */
  struct timeval tv;
  struct timezone tz;
  struct tm result;

  /* Get time */
  gettimeofday(&tv,&tz);

  /* Reformat time to output format */
  gmtime_r(&tv.tv_sec,&result);
  sprintf(timeString,"%4.4d-%2.2d-%2.2d:%2.2d:%2.2d",
	  1900+result.tm_year,result.tm_mon,result.tm_mday,result.tm_hour,
	  result.tm_min);

  /* Make output string */
  /* Add program stem (in our case L2P) */
  strcpy(errorString,pStr1);

  strcat(errorString," : ERROR : ");
  
  /* Add in time string */
  strcat(errorString,timeString);
  strcat(errorString," : ");
  
  if( NULL != pFloat ){
    /* If a floating point number is output - format will be included in the 
     * pStr2 string */
    sprintf(tempString,pStr2,*pFloat);
  } else if( NULL != pInString ) {
    /* If a filename or string is output - format will be included in the 
     * pStr2 string */
    sprintf(tempString,pStr2,pInString);
  } else {
    /* Just copy the input error string */
    strcpy(tempString,pStr2);
  }

  /* concatenate error description string to error message */
  strcat(errorString,tempString);

  /* Output error string to stderr and exit with code -1 */
  fprintf(stderr,"%s\n",errorString);
  exit(-1); 
}