#!/usr/bin/perl

# 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, published at
# http://www.gnu.org/copyleft/gpl.html

use Date::Parse;
use Getopt::Long;
use HTTP::Request::Common qw(GET);
use Getopt::Long;
use Date::Calc;
use Data::Dumper;

# We make our own specialization of LWP::UserAgent that asks for
# user/password if document is protected.
{
  use LWP::UserAgent;
  package WikiRequestAgent;

  @ISA = qw(LWP::UserAgent);

  my ($password, $userid);

  sub new {
    $password = pop;
    $userid = pop;
    my $self = LWP::UserAgent::new(@_);
    $self->agent("lwp-request/$main::VERSION");
    $self;
  }

  sub get_basic_credentials {
    return ($userid, $password);
  }
}

my %opts; # parsed options
my $securityFilter     = "[\\\*\?\~\^\$\@\%\`\"\'\&\;\|\<\>\x00-\x1F]";

my %options = (
	       "password" => ["s", undef, "TheBazaar password"],
	       "userid" => ["s", undef, "TheBazaar userid"],
	       "zone|web" => ["s", undef, "zone (ie. TWiki web) to read calendar events from"],
	       "topic" => ["s", undef, "topic to read calendar events from"],
	       "fetchurl" => ["s", "http://wiki.sh.mvista.com/thebazaar/data/%ZONE/\%TOPIC.txt", "URL to open topic text with"],
	       "getalarms" => ["s", "atq", "command used to fetch existing alarms"],
	       "setalarm" => ["s", "at \"%HH:%MM %MO/%DD/%YY\"", "command to set an alarm"],
	       "rmalarm" => ["s", "atrm %JOB", "command used to delete existing alarm"],
	       "getalarmsregex" => ["s", '(\d+)\s+([^\s]+\s[^\s]+)', "regex to parse alarm string"],
	       "tz" => ["s", "-5", "GMT offset"],
	       "preset" => ["s", "5", "minutes to preset alarm by before event"],
	       "alarmjob" => ["s", "\$HOME/bin/bong 'Alarm: %DESC'", "Job to run when alarm expires" ],

	       "help" => [undef, undef, "Ask for help"],
);


my %sched;

print STDERR "WikiCalendar2alarm version 1.3, <wikical.20.bdixon@xoxy.net>\n";

&readOptions;
if ($opts{help}) {
  &displayHelp;
  exit;
}
my ($zone, $topic);
if ($ARGV[0] ne "") {
    ($zone, $topic) = split /\./, shift @ARGV;
}
$zone = $zone || $opts{zone};
$topic = $topic || $opts{topic};

print STDERR "Downloading calendar from to $zone.$topic\n";
&getatq();
&parseCalendar(getCalendar($zone, $topic));

exit;

sub parseCalendar {
  my ($text) = @_;

  # keep only bullet lines
  my @bullets = grep { /^\s+\*/ } split( /[\n\r]+/, $text );

  # bail out early if no events
  unless( @bullets ) {
    return;
  }

  &fetchDateParseDays( \@bullets, %options );
  &schedAlarms();

}

sub schedAlarms {
  my @now = Date::Calc::Localtime();
  my $now = Date::Calc::Mktime(@now[0,1,2,3,4,5]);
  foreach my $key (keys %sched) {
    # delete existing alarm
    if (defined $sched{$key}{at}) {
      my $cmd = $opts{rmalarm};
      $cmd =~ s/\%JOB/$sched{$key}{at}/;
      `$cmd`;
    }
    # create new alarms
    if (defined $sched{$key}{cal}) {

      # get and format the time
      my ($mm, $hh, $dd, $mo, $yy) = split ",", $key;

      # Don't set an alarm for the past
      $yy+=1900;
      next if ($now > Date::Calc::Mktime($yy,$mo,$dd,$hh,$mm,0));

      # back the alarm off by preset
      ($yy,$mo,$dd,$hh,$mm,undef) = Date::Calc::Add_Delta_DHMS($yy,$mo,$dd,$hh,$mm,0, 0, 0, -$opts{preset}, 0);
      $mm = sprintf("%02d",$mm);
      $hh = sprintf("%02d",$hh);

      # Get the alarm set command
      my $cmd = $opts{setalarm};
      $cmd =~ s/\%HH/$hh/;
      $cmd =~ s/\%MM/$mm/;
      $cmd =~ s/\%DD/$dd/;
      $cmd =~ s/\%MO/$mo/;
      $cmd =~ s/\%YY/$yy/;

      # get the alarm job command
      my $job = $opts{alarmjob};
      $job =~ s/\%DESC/$sched{$key}{cal}/;
      $job =~ s/\%HH/$hh/;
      $job =~ s/\%MM/$mm/;
      $job =~ s/\%DD/$dd/;
      $job =~ s/\%MO/$mo/;
      $job =~ s/\%YY/$yy/;

      # Set the alarm!
      `echo "$job" | $cmd`;
    }

  }
}

sub fetchDateParseDays
{
  if (defined $Date::Parse::VERSION) {
    my( $refBullets, %options) = @_;

    my @localBullets = @{$refBullets};
    @{$refBullets} = ();
    my @res;

    foreach my $bullet ( @localBullets ) {
      my ($timedescr) = ( $bullet =~ /^\s+\*\s([^|]*)/ );
      my @timedescr = split "-", $timedescr;
      my $text = pop @timedescr;
      my $date1 = join "-", @timedescr;
      my ($ss1,$mm1,$hh1,$day1,$month1,$year1,$zone1) = &Date::Parse::strptime ( $date1 );
      # minimal requirements are a valid hour and minute
      if (
	  (defined $hh1)
	  and
	  (defined $mm1)
	 ) {

	# fixup the month
	$month1++;

	# Correct for timezone of requested calendar
	my $zone2 = $opts{tz};
	$zone2 = $zone2 * 3600;
	my $offset = -$zone1+$zone2;

	# If someone sends really bogus info from a calendar we just want to silently ignore
	eval {
	    ($year1, $month1, $day1, $hh1, $mm1, $ss1) = Date::Calc::Add_Delta_YMDHMS($year1, $month1, $day1, $hh1, $mm1, $ss1, 0, 0, 0, 0, 0, $offset);
	};
	warn "$@ from line \"$bullet\" (" . join(",", $year1, $month1, $day1, $hh1, $mm1, $ss1, 0, 0, 0, 0, 0, $offset) . ")" if $@;

	# valid
	my $datestr = join ",", ($mm1, $hh1, $day1, $month1, $year1);
	$datestr =~ s/00/0/g;
	$datestr =~ s/,0(\d)/,$1/g;
	$text =~ s/$securityFilter//go;
	$sched{$datestr}{cal} = $text;
      }
    }
  }
}


sub getCalendar {
  my ($zone, $topic) = @_;
  my $ua = WikiRequestAgent->new($opts{userid}, $opts{password});
  my $url = $opts{fetchurl};
  $url =~ s/\%ZONE/$zone/g;
  $url =~ s/\%TOPIC/$topic/g;

  print STDERR "$url\n";

  my $req = GET "$url";
  my $content = $ua->request($req)->content;

  # Fixup formatting
  $content =~ s/\t/   /g;
  $content =~ tr/
//d;

  # Parse out any EVENTS variables
  my ($events) = ($content =~ m/\* Set EVENTS = ([^\n]+)/);
  print STDERR "EVENTS = $events\n";
  foreach my $zt ( split ",", $events ) {
    $zt =~ tr/ //d;
    my ($z, $t) = split /\./, $zt;
    if ("$z.$t" ne "$zone.$topic") {
      $content .= getCalendar($z, $t);
    }
  }

  return $content;
}

sub getatq {
  open GETALARMS, "$opts{getalarms}|" || die "Could not execute $opts{getalarms}";
  while (<GETALARMS>) {
    my ($atnum, $datestr) = ($_ =~ /$opts{getalarmsregex}/);
    my @date = strptime($datestr);
    shift @date;
    pop @date;
    my $datestr = join ",", @date;
    $datestr =~ s/00/0/g;
    $datestr =~ s/,0(\d)/,$1/g;
    $sched{$datestr}{at}=$atnum;
  }
}

sub displayHelp {
  print STDERR "\nUsage: WikiCalendar2Alarm Zone.TopicName\n\n";
  print STDERR "Options:\n";
  foreach my $opt (sort keys %options) {
    print STDERR " --$opt: " . $options{$opt}[2] . " (" . $options{$opt}[1] . ")\n";
  }
}

sub readOptions {
  my @optdef;
  foreach my $opt (sort keys %options) {
    if (defined $options{$opt}[0]) {
      push @optdef, "$opt=" . $options{$opt}[0];
    } else {
      push @optdef, "$opt";
    }
  }

  GetOptions(\%opts, @optdef);

  foreach my $opt (sort keys %options) {
    push @optdef, "$opt=" . $options{$opt}[0];
    $opts{$opt} = $opts{$opt} || $options{$opt}[1];
  }
}