#include "mess822.h"
#include "scan.h"

static stralloc tokens = {0};
static struct caltime ct;

int mess822_when(out,in)
mess822_time *out;
char *in;
{
  int state;
  int pos;
  int flagnumeric;
  long number;
  char *x;
  int known;

  if (!mess822_token(&tokens,in)) return 0;

  for (pos = tokens.len;pos > 0;--pos)
    if (pos >= 3)
      if (!tokens.s[pos - 1] && !tokens.s[pos - 3])
        if ((tokens.s[pos - 2] == ';') || (tokens.s[pos - 2] == ','))
	  break;

  /*          29 Aug 1996 14 : 04 : 52 CDT   */
  /* states: 1  2   3    4  5 6  7 8  9   10 */

  state = 1;
  known = 0;

  while (pos < tokens.len) {
    x = tokens.s + pos;
    pos += str_len(x) + 1;

    if (*x == ':') {
      if (state == 5) state = 6;
      if (state == 7) state = 8;
    }

    if (*x == '=') {
      ++x;
      flagnumeric = !x[scan_long(x,&number)];
      switch(state) {
	case 1:
	  if (!flagnumeric) return 1;
	  ct.date.day = number;
	  break;
	case 2:
	  if (!case_diffs(x,"Jan")) { ct.date.month = 1; break; }
	  if (!case_diffs(x,"Feb")) { ct.date.month = 2; break; }
	  if (!case_diffs(x,"Mar")) { ct.date.month = 3; break; }
	  if (!case_diffs(x,"Apr")) { ct.date.month = 4; break; }
	  if (!case_diffs(x,"May")) { ct.date.month = 5; break; }
	  if (!case_diffs(x,"Jun")) { ct.date.month = 6; break; }
	  if (!case_diffs(x,"Jul")) { ct.date.month = 7; break; }
	  if (!case_diffs(x,"Aug")) { ct.date.month = 8; break; }
	  if (!case_diffs(x,"Sep")) { ct.date.month = 9; break; }
	  if (!case_diffs(x,"Oct")) { ct.date.month = 10; break; }
	  if (!case_diffs(x,"Nov")) { ct.date.month = 11; break; }
	  if (!case_diffs(x,"Dec")) { ct.date.month = 12; break; }
	  return 1;
	case 3:
	  if (!flagnumeric) return 1;
	  if (number < 50) number += 2000;
	  if (number < 999) number += 1900;
	  ct.date.year = number;
	  break;
	case 4:
	  if (!flagnumeric) return 1;
	  ct.hour = number;
	  break;
	case 5:
	  return 1;
	case 6:
	  if (!flagnumeric) return 1;
	  ct.minute = number;
	  break;
	case 8:
	  if (!flagnumeric) return 1;
	  ct.second = number;
	  break;
	case 7:
	  ct.second = 0;
	  state = 9;
	case 9:
	  known = 2;
	  if (flagnumeric) { /* happiness */
	    if (number >= 0)
	      ct.offset = (number / 100) * 60 + (number % 100);
	    else
	      ct.offset = -(((-number) / 100) * 60 + ((-number) % 100));
	    if (!case_diffs(x,"-0000")) known = 1;
	    break;
	  }
	  if (!case_diffs(x,"UT")) { ct.offset = 0; break; }
	  if (!case_diffs(x,"GMT")) { ct.offset = 0; break; }
	  /* XXX: GMT+nnnn? */

	  if (!case_diffs(x,"BST")) { ct.offset = 60; break; }
	  if (!case_diffs(x,"CDT")) { ct.offset = -300; break; }
	  if (!case_diffs(x,"CET")) { ct.offset = 60; break; }
	  if (!case_diffs(x,"CST")) { ct.offset = -360; break; }
	  if (!case_diffs(x,"EDT")) { ct.offset = -240; break; }
	  if (!case_diffs(x,"EET")) { ct.offset = 120; break; }
	  if (!case_diffs(x,"EST")) { ct.offset = -300; break; }
	  if (!case_diffs(x,"HKT")) { ct.offset = 480; break; }
	  if (!case_diffs(x,"IST")) { ct.offset = 120; break; }
	  if (!case_diffs(x,"JST")) { ct.offset = 540; break; }
	  if (!case_diffs(x,"MDT")) { ct.offset = -360; break; }
	  if (!case_diffs(x,"MET")) { ct.offset = 60; break; }
	  if (!case_diffs(x,"METDST")) { ct.offset = 120; break; }
	  if (!case_diffs(x,"MST")) { ct.offset = -420; break; }
	  if (!case_diffs(x,"PDT")) { ct.offset = -420; break; }
	  if (!case_diffs(x,"PST")) { ct.offset = -480; break; }
	  return 1;
	case 10:
	  if (!case_diffs(x,"DST")) ct.offset += 60;
	  break;
      }
      if (state < 10) ++state;
    }
  }

  if (known) {
    out->known = known;
    out->ct = ct;
  }
  return 1;
}