#!/usr/bin/perl -W
# SPDX-License-Identifier: GPL-2.0
#
# convert git commit id to a pretty patch we can apply to the stable tree
#
# Written in perl because the bash version is broken, it doesn't pass
# through the patch correctly :(
#

my $base_id = "";
my $line;
my $firstline = "true";
my $git_id;
my $header_complete = "false";
my $signed_off_by_seen = "false";
my $signed_off_by_complete = "false";
my $eat_subject_trailer = "false";
my $tmpfile;
#my $kernel_version;


$SIG{__DIE__} = sub
{
	# what usually happens is we don't have the git version, so clean up
	# the temp file we created.
	if ($tmpfile ne "") {
		unlink $tmpfile;
	}
};

$numArgs = $#ARGV + 1;
if ($numArgs < 1) {
	print "must provide git id\n";
	exit;
}

$base_id = shift;

if ($base_id eq "") {
	print "must provide git id\n";
	exit;
}

#$kernel_version = shift;
#if (!defined($kernel_version)) {
#	$kernel_version = "";
#}

#print "handing commit id $base_id\n";

$tmpfile = `mktemp patch.XXXXX` || die "Failed to run mktemp";
chomp($tmpfile);

# if we were smart, we could just reconstruct the header the way we want to
# with a format: string, but we are not, so let's parse the thing out...
$from = `git show --pretty=format:"%aN <%ae>" $base_id | head -n 1` || die "Failed to run git to get from";
$subj = `git show --pretty=format:"Subject: %s" $base_id | head -n 1` || die "Failed to run git to get subject";

open FILE, ">$tmpfile" || die "Failed to create $tmpfile";
#open GIT, "git show --pretty=email $base_id |" || die "Failed to run git";
open GIT, "git format-patch -n1 --no-numbered -k --stdout $base_id |" || die "Failed to run git";

while ($line = <GIT>) {

	# subjects have the fun ability to line-wrap, but we handled that above
	# when we grabbed the "raw" subject, so just ignore trailing subject
	# lines.
	if ($eat_subject_trailer eq "true") {
		$eat_subject_trailer = "false";
		if ($line =~m/^ /) {
			# eat this line
			next;
		}
	}

	# If this is the subject line, use our own.
	if ($line =~m/^Subject: /) {
		$line = $subj;
		$eat_subject_trailer = "true";
	}

	if ($line =~m/^Signed-off-by:/) {
		$signed_off_by_seen = "true";
	}

	if ($signed_off_by_seen eq "true") {
		if ($signed_off_by_complete eq "false") {
			if ($line eq "\n" || $line eq "---\n") {
				print FILE "Signed-off-by: Greg Kroah-Hartman <gregkh\@linuxfoundation.org>\n";
				$signed_off_by_complete = "true";
				$signed_off_by_seen = "false";
			}
		}
	}

	print FILE $line;

	if ($firstline eq "true") {
		my @from = split(/ /, $line);
		$git_id = $from[1];
		#print "git_id = $git_id\n";
		$firstline = "false";
	}
	if ($header_complete eq "false") {
		if ($line eq "\n") {
			print FILE "From: $from\n";
			print FILE "commit $git_id upstream.\n\n";
			$header_complete = "true";
		}
	}
}
close GIT;
close FILE;

#print "$tmpfile\n";

system "vim -c \":set syntax=mail\" $tmpfile";
system "reset";
$new_file = `rename-patch $tmpfile`;
chomp($new_file);
system "mv $new_file ~/linux/stable/";
#print "moved $new_file to ~/linux/stable/\n";

print "cd ~/linux/stable && ./apply_it $new_file @ARGV\n";
system "cd ~/linux/stable && ./apply_it $new_file @ARGV";
#system "cp ~/linux/stable/$new_file ~/linux/longterm";
#system "cd ~/linux/longterm && ./apply_it $new_file";

#TMPFILE1=`mktemp patch.XXXXXX` || exit 1
#TMPFILE2=`mktemp patch.XXXXXX` || exit 1
#
#GIT_ID=`git show $COMMIT_ID | head -n 1 | cut -f 2 -d ' '`
#FROM=`git show --pretty=email $COMMIT_ID | head -n 2 | grep "From: "`
#
#git show --pretty=email $COMMIT_ID > $TMPFILE1
#
#HEADER_COMPLETE=false
#while read line
#do
#	# Strip out the [PATCH] portion of the subject line, it's annoying.
#	new=`echo "$line" | sed -e 's/^Subject: \[PATCH\]/Subject:/g'`
#
#	# copy the line out to the new file
#	echo "$new" >> $TMPFILE2
#
#	# add our special text (author and git id) right before
#	# the changelog text happens.
#	if [ "$line" == "" ] ; then
#		if [ $HEADER_COMPLETE == false ] ; then
#			echo "$FROM" >> $TMPFILE2
#			echo "" >> $TMPFILE2
#			echo "commit $GIT_ID upstream." >> $TMPFILE2
#			echo "" >> $TMPFILE2
#			HEADER_COMPLETE=true
#		fi
#	fi
#done < $TMPFILE1
#rm $TMPFILE1
#vim $TMPFILE2
#PATCH=`rename-patch $TMPFILE2`
#mv $PATCH ~/linux/stable/
#
#echo "moved $PATCH to ~/linux/stable/"
#