#!/usr/local/bin/perl
#
# calrh -- a calendar utility
#
# Copyright (C) 1998, Robert Harlander. All rights reserved.
#
# Comments, bug reports, and suggestions to 
# rh@particle.physik.uni-karlsruhe.de
#
# 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, 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 GNU Emacs; see the file COPYING.  If not, write to
# the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
#
# ----------------------------------------------------------------------
$help = argproc("h(elp)?",0);
$edit = argproc("e(dit)?",0);
$termin = argproc("t(ermin)?",0);
$weekly = argproc("w(eekly)?",0);
$quiet = argproc("q(uiet)?",0);
$all = argproc("a(ll)?",0);
$only = argproc("o(nly)?",0);
($messkey,$message) = argproc("m(essage)?",1);

#
# $Id: calrh,v 1.5 2004/01/27 14:11:06 rharland Exp $
# $Log: calrh,v $
# Revision 1.5  2004/01/27 14:11:06  rharland
# bug fix.
#
# Revision 1.4  2004/01/26 18:08:41  rharland
# bug fixes
#
# Revision 1.3  2004/01/26 17:15:17  rharland
# Id and Log introduced.
#
#
# ----------------------------------------------------------------------
# 
# Last changes:
#
# - Jan  26, 2004 (rh, v2.23): breakstring introduced, and ">>>>" removed
# - Jan  26, 2004 (rh, v2.22): dayname appears in front of message
# - Oct  10, 2003 (rh, v2.21): -o and -m option added
# - Oct  10, 2001 (rh): bug fix ('calrh 0' now looks at only TODAY)
# - May   5, 1998 (rh): -a and -w option added
# - Nov. 10, 1997 (rh): -e and -t option added
#
# ----------------------------------------------------------------------

if($help) {
    print(
	  "   \n",
	  "   \n",
	  "         calrh  ---   Version 2.23 by rh\n",
	  "   \n",
	  "   \n",
	  "   USAGE:  calrh [-options] [n]\n",
	  "   \n",
	  "   DESCRIPTION:\n",
	  "   Works approximately like the command 'calendar' in UNIX\n",
	  "   so type 'man calendar' for more information.\n",
	  "   Note the options below\!\n",
	  "   For comments send email to robert.harlander\@cern.ch.\n",
	  "   \n",
	  "    Possible formats for date:\n",
	  "     December 7\n",
	  "     December/7\n",
	  "     12/7\n",
	  "     12 7\n",
	  "   \n",
	  "    You may also wildcard the month:\n",
	  "     * 7\n",
	  "   \n",
	  "    Possible formats for weekly events:\n",
	  "     Fr        Seminar\n",
          "     Freitag   Seminar\n",
          "     Friday    Seminar\n",
	  "   NOTE: Options \-w or \-a must be given to read weekly ",
	  "events!\n", 
	  "   \n",
	  "    Where there is a blank, you may also use several blanks or tabs.\n",
	  "   \n",
	  "   ARGUMENTS:\n",
	  "   n   the number of days to look ahead\n",
	  "       Default is 1. If n < 0, it is set to 0.\n\n",
	  "   OPTIONS:\n",
	  "   -h ............. show these help pages\n",
	  "   -e ............. edit the calendar file\n",
	  "   -t ............. insert new item to calendar file\n",
	  "   -w ............. show ONLY weekly events\n",
	  "   -a ............. show ALL events within \'n\' days\n",
	  "   -o ............. show ONLY the events \'n\' days ahead\n",
	  "   -m <message> ... print \'message\' before event",
	  "   \n",
	  "   NOTE: \n",
	  "   - the format 'Dec. 7' is not implemented\n",
#	  "   - the date need not be the first entry in the line\n",
#	  "     (this might be changed somewhen, so avoid to use it)\n",
	  "   - the date must be the first entry in the line\n",
	  "   - each option must be preceded by a '-'",
	  "   \n");
    exit;
}
# ----------------------------------------------------------------------
$home = $ENV{HOME};

if ($#ARGV != -1) {$offset = $ARGV[0]}
else {$offset = 1}

$offsetp = $offset;

if (!$messkey) {$message=""};

;# if ($offset < 0) {$offset = 0}


if (-e "$home/calendar") {push(@calfiles,"$home/calendar")}
if (-e "$home/.calendar") {push(@calfiles,"$home/.calendar")}
unless (@calfiles) {print "You don't have a calendar file.\n"}

@monthnames = ("January","February","March","April","May","June","July",
	       "August","September","October","November","December");

if ($edit) {system("$ENV{'EDITOR'} $calfiles[0]"); exit}

if ($termin) {print("Monat: "); chop($tmonth = <STDIN>);
	      print("Tag: "); chop($tday = <STDIN>);
	      print("Subject: "); chop($tsubject = <STDIN>);
	      if((grep(/^$tmonth$/,@monthnames) ||
		  grep(/^$tmonth$/,(1..12)) || $tmonth =~ /^\*$/) &&
		 grep(/^$tday$/,(1..31))) {
		  termin($calfiles[0],$tmonth,$tday,$tsubject)}
	      else {print "Wrong format.\n"; exit}
	  }


chop($dayname = `date +%A`);


chop($year = `date +%Y`);
chop($monthnum = `date +%m`);
chop($day = `date +%d`);

$monthnum =~ s/0(\d)/$1/;
$day =~ s/0(\d)/$1/;
$month = $monthnames[$monthnum-1];

if (dayname($dayname,$offsetp,"english") eq "Saturday") {$offsetp += 2}
elsif (dayname($dayname,$offsetp,"english") eq "Sunday") {$offsetp += 1}

foreach $calfile (@calfiles) {
unless (open(FILE,$calfile)) {print "You don't have a calendar file.\n";
				   exit};

if ($only) {@range = ($offset)}
else {
    if ($offsetp < 0) {@range = reverse($offsetp..-1)}
    else {@range = (0..$offsetp)}
}

for $i (@range) {
    ($daynew,$monthnumnew) = makedate($day+$i,$monthnum,$year);
    $month = $monthnames[$monthnumnew-1];
    $daygerman = dayname($dayname,$i,"german");
    $dayenglish = dayname($dayname,$i,"english");
    $daygermanshort = substr($daygerman,0,2);
    $dayenglishshort = substr($dayenglish,0,2);

    while (<FILE>) {
	if (!$weekly || $all) {
	    if (
		(/^[\t\/\ ]*$month[\t\/\ ]+$daynew[\s\:]/) ||
		(/^[\t\/\ ]*$monthnumnew[\t\/\ ]+$daynew[\s\:]/) ||
		(/^[\t\/\ ]+\*[\t\/\ ]+$daynew[\s\:]/)
		)
	    {
		chop($_);
		$outstring = "";
		$outday = $daygerman;
		$outstring .= $message." ".$outday.", ".$_;
		$outstring = breakstring(80,$outstring);
		unless ($quiet) {print("\a")}
		print($outstring,"\n");
	    }
	}
	if ($weekly || $all) {
	    if ((/^[\t\/\ ]*$daygerman[\s\:]/) ||
		   (/^[\t\/\ ]*$daygermanshort[\s\:]/) ||
		   (/^[\t\/\ ]*$dayenglish[\s\:]/) ||
		   (/^[\t\/\ ]*$dayenglishshort[\s\:]/))
	    {
		chop($_);
 		print("$message $_");
 		print("    ($daynew. $month)\n");
	    }
	}
    }
    seek(FILE,1,0);
}
close(FILE)
}

sub breakstring {
#
# breakstring($maxlength,$string)
#
# Returns $string with lines shorther than maxlength.
#
    my($string,$newstring,@strings,$maxlength);
    $maxlength = shift;
    $string = shift;
    $string =~ s/ *$//;
    @strings = split(/ /,$string);
    $newstring = shift(@strings);
    $settled = 0;
    $breaks=0;
    foreach $s (@strings) {
 	if (length($s) >= $maxlength) {
	    $newstring .= "\n"."    $s";
	    $breaks += length($newstring) % 80;
	    $settled = length("$newstring")-$breaks;
	}
 	elsif (length("$newstring"." $s")-$settled > $maxlength) {
	    $settled = length("$newstring")-$breaks;
	    $newstring .= "\n    "."$s";
	    $breaks++;
	}
	else {
	    $newstring .= " $s";
	}
    }
    return($newstring);
}

sub termin {
    my($file,$tmonth,$tday,$tsubject);
    ($file,$tmonth,$tday,$tsubject) = @_;
    open(FILE,">>$file");
    print {FILE} ("$tmonth $tday     $tsubject\n");
    close(FILE)
}


;# ----------------------------------------------------------------------
sub makedate {
    my($day,$month,$year);
    $day = shift;
    $month = shift;
    $year = shift;
    while ($day < 0) {
	if (($year % 400 == 0) || (($year % 4 == 0) && ($year % 100 != 0))) {
	    $day += 366;
	}
	else {$day += 365}
	$year -= 1;
    }

  DLOOP: while ($day > 28) {
      if (($day > 28) && ($month == 2)) {
	  if (($year % 400 == 0) || (($year % 4 == 0) && ($year % 100 != 0))) {
	      if ($day > 29) {
		  $day -= 29;
		  $month += 1;
	      }
	      else {last DLOOP}
	  }
	  else {
	      $day -= 28;
	      $month += 1;
	  }
      }
      elsif (($day > 30) && ("$month" =~ /^0?(4|6|9|11)$/)) {
	  $day -= 30;
	  $month += 1;
      }
      elsif ($day > 31) {
	  $day -= 31;
	  $month += 1;
      }
      else {last DLOOP}
      while ($month > 12) {
	  $month -= 12;
	  $year += 1;
      }
  }
    return($day,$month,$year);
}

sub dayname {
    #
    # dayname($dayname,$offset)
    #
    # Returns the name of the day $offset days from $dayname
    # Examples:  dayname("Monday",2) -> "Wednesday"
    #            dayname("Tuesday",8) -> "Wednesday"
    #            dayname("Tuesday",8,"german") -> "Mittwoch"
    #
    my(@daynames,$dayname,%daynums);
    unless ($language = $_[2]) {$language = "german"};
    %daynums = (Monday => 1, Tuesday => 2, Wednesday => 3, Thursday => 4,
		 Friday => 5, Saturday => 6, Sunday => 7);
    %daynames = (english => ["Monday", "Tuesday", "Wednesday", 
			      "Thursday", "Friday", "Saturday", "Sunday"],
		 german => ["Montag", "Dienstag", "Mittwoch", "Donnerstag",
			    "Freitag", "Samstag", "Sonntag"],
		 french => ["Lundi", "Mardi", "Mercredi", "Jeudi", "Vendredi",
			    "Samedi", "Dimanche"]);
    $dayname = ${$daynames{$language}}[($daynums{"$_[0]"} + $_[1] - 1) % 7];
    return($dayname)
}



sub argproc {
    #
    # by rh
    #
    # get the options from the argument list
    # (more flexible than PERL-builtin options management)
    #
    # Usage: argproc($optkey,$optnum)
    #
    #  $optkey is the name of the option (may be a pattern)
    #  $optnum is the number of arguments for the option
    #
    # Example: argproc("d(efault)?",1) together with the program call
    #          'program -d test1 test2'  returns the list (-d,test1).
    #          @ARGV is (test2) afterwards.
    #
    my($optkey,$optnum,$val,@optlist);
    $optkey = $_[0];
    $optnum = $_[1];
    
    foreach $val (0..$#ARGV) {
	if ($ARGV[$val] =~ m/^-$optkey$/) {
	    @optlist = splice(@ARGV,$val,$optnum+1);
	    last;
	}
    }
    return(@optlist);
}

sub min { ;#; min(ARRAY) returns minimum of ARRAY
    my($OUT,@IN);
    $OUT = $_[0];
    @IN = @_;
    for (@IN) {
        if ($_ < $OUT) {
            $OUT = $_}
    }
    return($OUT);
}