#! /usr/bin/perl -w
#
# $FreeBSD$
# 
# This hack is to sanitise the results of what the user may have
# "done" while editing the commit log message.. :-)   Peter Wemm.
#
# Note: this uses an enhancement to cvs's verifymsg functionality.
# Normally, the check is advisory only, the FreeBSD version reads
# back the file after the verifymsg file so that this script can
# make changes.
#

use strict;


############################################################
#
# Configurable options
#
############################################################

# These are the optional headers that can be filled at the end of
# each commit message.  The associated value is a regular-expression
# that is used to type-check the entered value.  If the match failed
# then the commit is rejected.  (See rcstemplate).
my %HEADERS = (
	"Reviewed by"		=> '.*',
	"Submitted by"		=> '.*',
	"Obtained from"		=> '.*',
	"Approved by"		=> '.*',
	"PR"			=> '.*',
	"MFC after"		=> '\d+(?:\s+(?:days?|weeks?|months?))?'
);



#############################################################
#
# Main Body
#
############################################################

my $filename = shift;
die "Usage: logcheck filename\n" unless $filename;




# Read the log file in, stripping 'CVS:' lines and removing trailing
# white spaces.
open IN, "< $filename" or
    die "logcheck: Cannot open for reading: $filename: $!\n";
my @log_in = map { s/^(.*?)\s*$/$1/; $1 } grep { !/^CVS:/ } <IN>;
close IN;

# Remove duplicate blank lines.
my $i = 0;
while ($i < scalar(@log_in) - 1) {
	if ($log_in[$i] eq "" && $log_in[$i + 1] eq "") {
		splice(@log_in, $i, 1);
		next;
        }
        ++$i;
}

# Remove leading and trailing blank lines.  (There will be at most
# one because of the duplicate removal above).
shift @log_in if $log_in[0] eq "";
pop @log_in if $log_in[-1] eq "";

# Scan through the commit message looking for templated headers
# as defined in the configuration file, and rcstemplate.
# Assume that these only exist in the last paragraph.
# Filter out blank entries, and type check if necessary.
my $j = $#log_in;	# The index of the last entry in the commit msg.
my $error = 0;
while ($j >= 0) {
	my $logline = $log_in[$j];

	--$j;

	# Hitting a blank line means that we've seen all of the last paragraph.
	last if $logline eq "";

	unless ($logline =~ /^(.*?):\s*(.*)$/) {
		### XXX
		# We're here because we saw a line that didn't match
		# a template header (no ':').  This could be a continuation
		# line from the previous header, or the log message proper.
		# We don't know, so run the risk of checking the last paragraph
		# of the log message for headers.
		next;
	}

	my $header = $1;
	my $value = $2;
	my $pattern = $HEADERS{$header};

	# Ignore unrecognised headers.
	unless (defined($pattern)) {
	### 	print "Warning: unknown template header: $header\n";
		next;
	}

	# Filter out the template header if it's blank.
	if ($value eq "") {
		splice(@log_in, $j + 1, 1);
		next;
	}

	# Type check the header
	unless ($value =~ /^$pattern$/) {
		print "Error: $header: should match '$pattern'.\n";
		++$error;
		next;
	}
}


# Write the modified log file back out.
my $tmpfile = $filename . "tmp";
open OUT, "> $tmpfile" or
    die "logcheck: Cannot open for writing: $tmpfile: $!\n";
print OUT map { "$_\n" } @log_in;
close OUT;


# Stop the commit if there was a problem with the template headers.
if ($error) {
	print "There were $error errors in the template headers.\n";
	print "Please fix the log message and commit again.\n";
	print "A copy of your log message was saved in $tmpfile.\n";
	exit 1;
}



# Nuke likely editor backups.
unlink "$filename.~";
unlink "$filename.bak";


# Overwrite the log message with our sanitised one.  (See the comment
# block at the top of this script for an explaination of why.)
rename($tmpfile, $filename) or
    die "logcheck: Could not rename $tmpfile to $filename: $!";

exit 0;