#!/usr/bin/perl -wT

# Copyright (c) 2005, 2006, 2007, 2008 Peter Palfrader <peter@palfrader.org>
#
# Permission is hereby granted, free of charge, to any person obtaining
# a copy of this software and associated documentation files (the
# "Software"), to deal in the Software without restriction, including
# without limitation the rights to use, copy, modify, merge, publish,
# distribute, sublicense, and/or sell copies of the Software, and to
# permit persons to whom the Software is furnished to do so, subject to
# the following conditions:
#
# The above copyright notice and this permission notice shall be
# included in all copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
# EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
# MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
# NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
# LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
# OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
# WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

use strict;
use English;
use File::Basename;

my $HOME = '/home/commit/';
my $MAX_LINES = 4;
my $ENVELOPE_FROM = 'nobody@commit.noreply.org';
my $HEADER_FROM = 'nobody@commit.noreply.org';
my $BOT_ADDRESS = 'commit@commit.noreply.org';
my $SENDMAIL = '/usr/sbin/sendmail';
my $UNPARSEABLE = $HOME.'/Maildir.unparseable';

$ENV{'PATH'} = '/bin:/usr/bin';
delete @ENV{'IFS', 'CDPATH', 'ENV', 'BASH_ENV'};

die ("Usage: $PROGRAM_NAME <project> <mailfile>\n") unless (scalar @ARGV == 2);
my $project = $ARGV[0];

umask 077;

my $TMPDIR = "$HOME/cvs-tmp/";
-d $TMPDIR or
	mkdir $TMPDIR or
		die ("Cannot mkdir $TMPDIR: $0\n");

$project =~ m/^([a-zA-Z-]+(\.[a-zA-Z-]+)*)+$/;
$project = $1;
die ("Project is not a nice name.\n") unless defined $project;

sub whine_and_store_away($) {
	my ($complaint) = @_;

	$ARGV[1] =~ m#(Maildir.[a-z]+/new/[0-9]+\.[0-9_]+\.[a-z]+)#;
	my $clean_filename = $1;
	die ("Unable to clean filename '$ARGV[1]' for taint mode.") unless defined $clean_filename;

	my $newname = $UNPARSEABLE.'/new/'.basename($clean_filename);
	link ($clean_filename, $newname) or die ("Cannot link $clean_filename to $newname: $!\n");
	unlink ($clean_filename) or die ("Cannot unlink $clean_filename: $!\n");
	print $complaint;
	exit (1);
};

my $from;
my $message;
my $in_msg;
my $found_update_of;
my $tag;
my $cvs_mailcommit_directory;

open (MAIL, $ARGV[1]) || die ("Cannot open $ARGV[1]: $!\n");
my @mail = <MAIL>;
close(MAIL);

my $line;
while (defined($line = shift @mail)) {
	if ($line =~ m/^From:.*CVS User ([a-zA-Z0-9-.]*)/ && !defined $from) {
		$from = $1;
	} elsif ($line =~ m/^From:.*<(\S*?)@/ && !defined $from) {
		$from = $1;
	} elsif ($line =~ m/^From:\s*(\S*?)@/ && !defined $from) {
		$from = $1;
	#          Subject: [oftc-cvs-commits] CVS oftc-hybrid
	} elsif ($line =~ m/^Subject: (?:\[\S*\] )?CVS\s*(.*)/) {
		$cvs_mailcommit_directory = $1;
	} elsif ($line =~ m/^Update of /) {
		$found_update_of = 1;
	} elsif ($line =~ m/^\s*Tag:\s*(.*)$/) {
		$tag = $1;
	} elsif ($line =~ m/^Log Message:/) {
		$in_msg = 1;
		last;
	}
};
die ("$PROGRAM_NAME - $project: No author found.\n") unless defined $from;
whine_and_store_away("$PROGRAM_NAME - $project: 'Update of ' not found.\n") unless defined $found_update_of;

my $cur_line = 0;
my $last_line = '';
if ($in_msg) {
	while (defined($line = shift @mail)) {
		if ($line =~ m/^Index: / ||
		    $line =~ m/^--- NEW FILE/ ||
		    $line =~ m/^--/ ||
		    $line =~ m/^\*\*\*\*\*\*\*\*/
		    ) {
			last;
		}
		next if ($line =~ m/^\s*$/);
		if ($cur_line == $MAX_LINES) {
			$last_line = $_;
		} elsif ($cur_line > $MAX_LINES) {
			$last_line = "...\n";
			last;
		} else {
			$message .= $_;
		};
		$cur_line++;
	}
}
$message .= $last_line;

die ("No message found.\n") unless defined $message;
my $notice = "commit by $from: $message";

my $old_notice = '';
my $filename = $TMPDIR.'/'.$project;
if (-e $filename) {
	open(F, $filename) or die ("cannot open $filename: $!\n");
	local $/ = undef;
	$old_notice = <F>;
	close(F);
}
if ($notice eq $old_notice) {
	exit(0);
}
open(F, ">".$filename) or die ("cannot open $filename for writing: $!\n");
print F $notice;
close(F);

#open(MAIL, "|cat") or
open(MAIL, "|$SENDMAIL -t -oi -f $ENVELOPE_FROM") or
	die ("Cannot exec sendmail: $!\n");
print MAIL "From: $HEADER_FROM\n";
print MAIL "To: $BOT_ADDRESS\n";
print MAIL "Subject: Announce $project\n";
print MAIL "Precedence: junk\n";
print MAIL "\n";
print MAIL (defined $tag ? "[$tag] " : '') . (defined $cvs_mailcommit_directory && length ($cvs_mailcommit_directory) ? "[$cvs_mailcommit_directory] " : ''). $notice;
close(MAIL);