#!/usr/bin/perl -w
#
# Copyright (c) 1999 by Bennet Yee <bsy@cs.ucsd.edu>
#
# 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., 675 Mass Ave, Cambridge, MA 02139, USA.
#
#
# mail_page, bsy@cs.ucsd.edu, 6/22/99.  cleaned up and made available
# for public consumption.  this is intended for use in .procmailrc
# to automatically transform some email into shorter messages that are
# sent to an email-to-paging/SMS gateway.  for example, i match email
# from my girlfriend so i'll get the gist of the email... or at least
# know to read the email in its uncompressed form.
#
# in my .procmailrc, i have an entry of the form:
#
# :0 c
# *^From:EMAIL-ADDR
# | /home/bsy/bin/mail_page SMS-NUMBER@PAGER-COMPANY.COM
#
# BUGS
#
# this program doesn't handle MIME data at all
#
$in_header = 1;
$lines_sent = 0;
$chars_sent = 0;
$line_limit = 32;
$char_limit = 256;
$compress = 1;
$discard_quoted = 1;
$debug = 0;
$english_compress_orig_word_lower_bound = 3;
$english_compress_result_word_lower_bound = 3;
$prefix_line = "";

$keephdr{"Subject:"} = undef;
$to_body{"Subject:"} = "S:";

$intro_lines = "";
$stdout = 0;

sub usage {
    print STDERR "usage: $0 [-kbBcCsulLpqQiod]\n";
    print STDERR "        [--keep header-tag]\n";
    print STDERR "        [--body header-tag-to-move-to-body]\n";
    print STDERR "        [--body-as header-tag short-form]\n";
    print STDERR "        [--compress] [--no-compress]\n";
    print STDERR "        [--short-threshold no-compress-char-count]\n";
    print STDERR "        [--unrecognized-threshold too-short-result-char-count]\n";
    print STDERR "        [--limit-char n] [--limit-line n] [-prefix str]\n";
    print STDERR "        [--keep-quoted] [--discard-quoted]\n";
    print STDERR "        [--intro-line str] [--stdout] [--debug]\n";
}

arg:
for ($i = 0; $i < @ARGV; $i++) {
    if ($ARGV[$i] eq "-k" || $ARGV[$i] eq "--keep") {
	++$i < @ARGV || die "$ARGV[$i-1] requires header tag argument\n";
	$keephdr{$ARGV[$i]} = $ARGV[$i];
    } elsif ($ARGV[$i] eq "-b" || $ARGV[$i] eq "--body") {
	++$i < @ARGV || die "$ARGV[$i-1] requires header tag argument\n";
	$to_body{$ARGV[$i]} = $ARGV[$i];
    } elsif ($ARGV[$i] eq "-B" || $ARGV[$i] eq "--body-as") {
	++$i < @ARGV || die "$ARGV[$i-1] requires header tag argument\n";
	++$i < @ARGV || die "$ARGV[$i-1] requires short-form tag argument\n";
	$to_body{$ARGV[$i-1]} = $ARGV[$i];
    } elsif ($ARGV[$i] eq "-c" || $ARGV[$i] eq "--compress") {
	$compress = 1;
    } elsif ($ARGV[$i] eq "-C" || $ARGV[$i] eq "--no-compress") {
	$compress = 0;
    } elsif ($ARGV[$i] eq "-d" || $ARGV[$i] eq "--debug") {
	++$debug;
    } elsif ($ARGV[$i] eq "-s" || $ARGV[$i] eq "--short-threshold") {
	++$i < @ARGV || die "$ARGV[$i-1] requires numeric argument\n";
	$ARGV[$i] =~ /^\d+$/ || die "$ARGV[$i-1] requires numeric argument\n";
	$english_compress_orig_word_lower_bound = $ARGV[$i];
    } elsif ($ARGV[$i] eq "-u" || $ARGV[$i] eq "--unrecognizable-threshold") {
	++$i < @ARGV || die "$ARGV[$i-1] requires numeric argument\n";
	$ARGV[$i] =~ /^\d+$/ || die "$ARGV[$i-1] requires numeric argument\n";
	$english_compress_result_word_lower_bound = $ARGV[$i];
    } elsif ($ARGV[$i] eq "-l" || $ARGV[$i] eq "--limit-char") {
	++$i < @ARGV || die "$ARGV[$i-1] requires numeric argument\n";
	$ARGV[$i] =~ /^\d+$/ || die "$ARGV[$i-1] requires numeric argument\n";
	$char_limit = $ARGV[$i];
    } elsif ($ARGV[$i] eq "-L" || $ARGV[$i] eq "--limit-line") {
	++$i < @ARGV || die "$ARGV[$i-1] requires numeric argument\n";
	$ARGV[$i] =~ /^\d+$/ || die "$ARGV[$i-1] requires numeric argument\n";
	$line_limit = $ARGV[$i];
    } elsif ($ARGV[$i] eq "-p" || $ARGV[$i] eq "--prefix") {
	++$i < @ARGV || die "$ARGV[$i-1] requires prefix argument\n";
	$prefix_line = $ARGV[$i];
    } elsif ($ARGV[$i] eq "-q" || $ARGV[$i] eq "--keep-quoted") {
	$discard_quoted = 0;
    } elsif ($ARGV[$i] eq "-Q" || $ARGV[$i] eq "--discard-quoted") {
	$discard_quoted = 1;
    } elsif ($ARGV[$i] eq "-i" || $ARGV[$i] eq "--intro-line") {
	++$i < @ARGV || die "$ARGV[$i-1] requires intro string argument\n";
	$intro_lines = $intro_lines . $ARGV[$i] . "\n";
    } elsif ($ARGV[$i] eq "-o" || $ARGV[$i] eq "--stdout") {
	$stdout = 1;
    } elsif ($ARGV[$i] =~ /^-/) {
	&usage(); exit 0;
    } else {
	last arg;
    }
}

die "at least one email addr argument required\n" unless $i < @ARGV || $stdout == 1;

$email_addr = "";

for (; $i < @ARGV; $i++) {
    ($addr = $ARGV[$i]) =~ s/'/'"'"'/g; # ' <-- 4 xemacs font-lock mode.
    $email_addr = $email_addr . "'". $addr . "' ";
}

@ARGV = ();

$pager = "PAGER";

if ($debug == 0) {
    if ($stdout == 0) {
	open $pager, "|/usr/sbin/sendmail $email_addr";
    } else {
	$pager = \*STDOUT;
    }
} else {
    if (defined $ENV{"TMPDIR"}) {
	$dir = $ENV{"TMPDIR"};
    } else {
	$dir = "/tmp";
    }
    open $pager, "> $dir/pager.txt";
    print $pager "email addr list $email_addr\n"; # testing
}

$body_hdr = "";

sub compress_addr {
    my($addr) = @_;
    
    $addr =~ s/^\s+//;
    $addr =~ s/\s+$//;
    if ($addr =~ /<([^@]+@[^>]+)>/) {
	return $1;
    }
    return $addr;
}

sub compress_english {
    my($line) = @_;
    my($w,$sw,$outl,$sep);

    $line =~ s/^\s+//;
    $line =~ s/\s+$//;
    $outl = ""; $sep = "";

    # do standard per-word substitutions

    foreach $w (split /\s+/, $line) {
	print "Debug: word $w\n" if $debug > 1;
	if ($w =~ /^http:/) {
	    $sw = $w; # do not compress URLs
	} else {
	    $sw = $w;
	    if (length($w) >= $english_compress_orig_word_lower_bound) {
		$sw =~ s/[aeiou]//g;
	    }
	    if (length($sw) < $english_compress_result_word_lower_bound) {
		$sw = $w;
	    }
	}
	$outl = $outl . $sep . $sw;
	$sep = " ";
    }
    return $outl;
}

sub send_text {
    my($line) = @_;

    print $pager $line;
    print STDERR "Sent $line\n" if $debug;
    $chars_sent += length($line);
    $lines_sent += length($line =~ s/[^\n]//g);
}

$fr = (getpwuid($<))[0] || "auto-reply daemon <nobody>";

LINE:
while (defined($line = <>)) {
    chop $line;
    if ($in_header) {
	if ($line eq "") {
	    $in_header = 0;
	    if (defined($to_body{"From:"})) {
		&send_text("\n".$to_body{"From:"}.&compress_addr($fr)."\n");
	    } else {
		&send_text("From: ".&compress_addr($fr)."\n\n");
	    }
	    &send_text($intro_lines) if ($intro_lines ne "");
	    &send_text($body_hdr);
	    next LINE;
	} elsif ($line =~ /^From:/) {
	    ($fr = $line) =~ s/^From://;
	} else {
	    ($tag = $line) =~ s/^([^:]*:)\W*(.*)/$1/;
	    if (defined($keephdr{$tag})) {
		&send_text($line."\n");
	    } elsif (defined($to_body{$tag})) {
		if ($to_body{$tag} ne $tag) {
		    $body_hdr = $body_hdr . $to_body{$tag} . &compress_english($2) . "\n";
		} else {
		    $body_hdr = $body_hdr . $line . "\n";
		}
	    }
	}
    } else {
	if ($line ne "") {
	    if ($line =~ /^\s*>/ && $discard_quoted == 1) {
		&send_text($prefix_line . ">\n");
		next LINE;
	    }
	    if ($chars_sent < $char_limit && $lines_sent < $line_limit) {
		&send_text($prefix_line . &compress_english($line)."\n");
	    }
	}
    }
}