/*  datedif - calculates the difference in days between two dates
 *  Copyright (C) 2000 Micael Widell     contact: xeniac@linux.nu
 *
 *  This program 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 2 of the License, or
 *  (at your option) any later version.
 *
 *  This program 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 this program; if not, write to the Free Software
 *  Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
 */

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
#include "checkargs.c" /* Check that the arguments are valid */
#include "datecalc.c"  /* Date calculations */

const char VERSION[] = "0.9.1-4";

void printVersion();
void printUsageHelp();
int printArgumentError(char*);

int main(int argc, char *argv[])
{  
  int args_ok;
  int printMore = 0;
  double dayDifference;
  
  /* Check for 'help' and 'version' arguments */
  if (2 == argc) {
    if (0 == strcmp(argv[1], "--version") || 0 == strcmp(argv[1], "-v")) {
      printVersion();
      return 0;
    } else if (0 == strcmp(argv[1], "--help") || 0 == strcmp(argv[1], "-h")) {
      printUsageHelp();
      return 0;
    }

  }

  /* Check for 'more' argument */
  if (4 == argc) {
    if (0 == strcmp(argv[1], "--more") || 0 == strcmp(argv[1], "-m")) {
      printMore = 1;
      argv[1] = argv[2];
      argv[2] = argv[3];
      argc = 3;
    }
  }
  
  if (3 != argc) /* If too few/many arguments, display usage help */
    {
      printUsageHelp();
      return 0;
    }
  
  /* Check if the user has used the -m argument with only one date */
  if (0 == strcmp(argv[1], "--more") || 0 == strcmp(argv[1], "-m")) {
    printf("You must supply two dates.\n");
    return 0;
  }

  /* Check if the dates are valid */
  args_ok = 1;
  if (!isDateArgument(argv[1]))
     args_ok = printArgumentError(argv[1]);
  if (!isDateArgument(argv[2]))
    args_ok = printArgumentError(argv[2]);
  
  if (!args_ok)
    return 0;
  
  /* Send the arguments to dateCalc() to do the actual calculations, and get 
     the difference in days stored in dayDifference */                   
  dayDifference = dateCalc(argv[1], argv[2]);
  
  /* Print the output */
  if(!printMore)
    printf("%.f", dayDifference);
  else
    printf("Date difference: %.f days.\n", dayDifference);
  
  return 0;
}

void printVersion() {
  printf("datedif %s\n", VERSION);
}

void printUsageHelp() {
  printf("Datedif calculates the difference in days between two dates.\n\n");
  printf("Usage: datedif [option] date1 date2\n\n");
  printf(" -m  --more        print nicer output, for non-script use\n");
  printf(" -h  --help        print this help and quit\n");
  printf(" -v  --version     print version information and quit\n\n");
  printf("Dates must be given in YYYYMMDD format. You can also use 'today' as a date.\n\n");
}

int printArgumentError(char* d) {
  printf("'%s' is not a valid date\n", d);
  return 0;
}