/* vi: set sw=4 ts=4:
 *
 * touch.c : change timestamp of a file
 * Copyright 2012 Choubey Ji <warior.linux@gmail.com>
 *
 * See http://pubs.opengroup.org/onlinepubs/9699919799/utilities/touch.html 

USE_TOUCH(NEWTOY(touch, "mrt", TOYFLAG_BIN))

config TOUCH
  bool "th"
  default y
  help
    Usage: Usage: touch [OPTION]... FILE...
    Update the access and modification times of each FILE to the current time.
    -m                     change only the modification time
    -r, --reference=FILE   use this file's times instead of current time
    -t STAMP               use [[CC]YY]MMDDhhmm[.ss] instead of current time
*/

#include "toys.h"

int check_date_format(char *date_input)
{
  int count_date_digit = 0;
  unsigned long long flag_b4_sec;
  int  flag_af_sec;
  char *date_store = (char *)malloc(12 * sizeof(char));

  while(date_input[count_date_digit] != '.') {
    date_store[count_date_digit] = date_input[count_date_digit];
    count_date_digit++;
  }
  date_store[count_date_digit++] = '\0';
  flag_b4_sec = atoll(date_store);
  date_store[0] = date_input[count_date_digit++];
  date_store[1] = date_input[count_date_digit];
  date_store[2] = '\0';
  flag_af_sec = atoi(date_store);
  if(date_store[0] == '0' && date_store[1] == '0') flag_af_sec = 1;
  if(flag_b4_sec && flag_af_sec) return 0;
  else return -1;
}

/* function to return number of seconds since epoch till the given date */
time_t get_time_sec(char *date_input)
{
  int count_date_digit = 0;
  char mm[3];
  char year[5];
  time_t time_of_modify;
  struct tm t_yyyymmddhhss;

  while(date_input[count_date_digit] != '.') {
    if(count_date_digit < 4) 
      year[count_date_digit] = date_input[count_date_digit];
    count_date_digit++;
    if(count_date_digit == 4) {
      year[count_date_digit] = '\0';
      t_yyyymmddhhss.tm_year = atoi(year)-1900;
      break;
    }
  }
  mm[0] = date_input[4];
  mm[1] = date_input[5];
  mm[2] = '\0';
  t_yyyymmddhhss.tm_mon = (atoi(mm) - 1);
  mm[0] = date_input[6];
  mm[1] = date_input[7];
  mm[2] = '\0';
  t_yyyymmddhhss.tm_mday = atoi(mm);
  mm[0] = date_input[8];
  mm[1] = date_input[9];
  mm[2] = '\0';
  t_yyyymmddhhss.tm_hour = atoi(mm);
  mm[0] = date_input[10];
  mm[1] = date_input[11];
  mm[2] = '\0';
  t_yyyymmddhhss.tm_min = atoi(mm);
  mm[0] = date_input[13];
  mm[1] = date_input[14];
  mm[2] = '\0';
  t_yyyymmddhhss.tm_sec = atoi(mm);
  time_of_modify = mktime(&t_yyyymmddhhss);
  return time_of_modify;
}

void touch_main(void)
{
  int fd, touch_flag_t = 0, touch_flag_m = 0, touch_flag_r = 0;
  time_t now;
  struct utimbuf modinfo;
  struct stat filestat;

  if (!toys.optflags) {
    time(&now);
    modinfo.modtime = now;
    modinfo.actime = now;
  } else {
    if (toys.optflags & 1) {
      touch_flag_t = 1;
      if ((toys.optflags >> 2) & 1) touch_flag_m = 1;
    }

    if ((toys.optflags >> 1) & 1) touch_flag_r = 1;

    if (toys.optflags >> 2) touch_flag_m = 1;
  }

  if (touch_flag_t) {
    if (!check_date_format(toys.optargs[0])) {
      modinfo.modtime = get_time_sec((char *)toys.optargs[0]);
      modinfo.actime = get_time_sec(toys.optargs[0]);
    } else {
      perror_msg("Invalid date format, -t [yyyyMMddhhmm.ss]");
      toys.exitval = EXIT_FAILURE;
    }
  }
  if(touch_flag_r) {
    if(stat(toys.optargs[0], &filestat) < 0) {
      printf("Error : unable to get information for file %s\n", toys.optargs[0]);
      toys.exitval = EXIT_FAILURE;
    }
    modinfo.modtime = filestat.st_mtime;
    modinfo.actime = filestat.st_atime;
  }
  if(touch_flag_m) {
    if(stat(toys.optargs[toys.optc - 1], &filestat) < 0) {
      toys.exitval = EXIT_FAILURE;
      return;
    }
    modinfo.actime = filestat.st_atime;
    if(!(touch_flag_r | touch_flag_t)) {
      time(&now);
      modinfo.modtime = now;
    }
  }
  if (utime(toys.optargs[toys.optc - 1], &modinfo) == -1) {
    if ((fd = open(toys.optargs[toys.optc - 1],O_CREAT |O_RDWR, 0644)) != -1) {
      close(fd);
      utime(toys.optargs[toys.optc - 1], &modinfo);
    } else {
      perror("unable to create the file");
      toys.exitval = EXIT_FAILURE;
    }
  }
}