#!/bin/sh
#
# Copyright (c) 2005 Junio C Hamano
#

USAGE='[-n | -k] [-o <dir> | --stdout] [--signoff] [--check] [--mbox] [--diff-options] <upstream> [<our-head>]'
LONG_USAGE='Prepare each commit with its patch since our-head forked from upstream,
one file per patch, for e-mail submission.  Each output file is
numbered sequentially from 1, and uses the first line of the commit
message (massaged for pathname safety) as the filename.

There are three output modes.  By default, output files are created in
the current working directory; when -o is specified, they are created
in that directory instead; when --stdout is specified, they are spit
on standard output, and can be piped to git-am.

When -n is specified, instead of "[PATCH] Subject", the first line is formatted
as "[PATCH N/M] Subject", unless you have only one patch.

When --mbox is specified, the output is formatted to resemble
UNIX mailbox format, and can be concatenated together for processing
with applymbox.'
. git-sh-setup

# Force diff to run in C locale.
LANG=C LC_ALL=C
export LANG LC_ALL

diff_opts=
LF='
'

outdir=./
while case "$#" in 0) break;; esac
do
    case "$1" in
    -c|--c|--ch|--che|--chec|--check)
    check=t ;;
    -a|--a|--au|--aut|--auth|--autho|--author|\
    -d|--d|--da|--dat|--date|\
    -m|--m|--mb|--mbo|--mbox) # now noop
    ;;
    -k|--k|--ke|--kee|--keep|--keep-|--keep-s|--keep-su|--keep-sub|\
    --keep-subj|--keep-subje|--keep-subjec|--keep-subject)
    keep_subject=t ;;
    -n|--n|--nu|--num|--numb|--numbe|--number|--numbere|--numbered)
    numbered=t ;;
    -s|--s|--si|--sig|--sign|--signo|--signof|--signoff)
    signoff=t ;;
    --st|--std|--stdo|--stdou|--stdout)
    stdout=t mbox=t date=t author=t ;;
    -o=*|--o=*|--ou=*|--out=*|--outp=*|--outpu=*|--output=*|--output-=*|\
    --output-d=*|--output-di=*|--output-dir=*|--output-dire=*|\
    --output-direc=*|--output-direct=*|--output-directo=*|\
    --output-director=*|--output-directory=*)
    outdir=`expr "$1" : '-[^=]*=\(.*\)'` ;;
    -o|--o|--ou|--out|--outp|--outpu|--output|--output-|--output-d|\
    --output-di|--output-dir|--output-dire|--output-direc|--output-direct|\
    --output-directo|--output-director|--output-directory)
    case "$#" in 1) usage ;; esac; shift
    outdir="$1" ;;
    -h|--h|--he|--hel|--help)
        usage
	;;
    -*' '* | -*"$LF"* | -*'	'*)
	# Ignore diff option that has whitespace for now.
	;;
    -*)	diff_opts="$diff_opts$1 " ;;
    *) break ;;
    esac
    shift
done

case "$keep_subject$numbered" in
tt)
	die '--keep-subject and --numbered are incompatible.' ;;
esac

tmp=.tmp-series$$
trap 'rm -f $tmp-*' 0 1 2 3 15

series=$tmp-series
commsg=$tmp-commsg
filelist=$tmp-files

# Backward compatible argument parsing hack.
#
# Historically, we supported:
# 1. "rev1"		is equivalent to "rev1..HEAD"
# 2. "rev1..rev2"
# 3. "rev1" "rev2	is equivalent to "rev1..rev2"
#
# We want to take a sequence of "rev1..rev2" in general.
# Also, "rev1.." should mean "rev1..HEAD"; git-diff users are
# familiar with that syntax.

case "$#,$1$2" in
1,?*..?*)
	# single "rev1..rev2"
	;;
1,?*..)
	# single "rev1.." should mean "rev1..HEAD"
	set x "$1"HEAD
	shift
	;;
1,*)
	# single rev1
	set x "$1..HEAD"
	shift
	;;
2,?*..?*)
	# not traditional "rev1" "rev2"
	;;
2,*)
	set x "$1..$2"
	shift
	;;
esac

# Now we have what we want in $@
for revpair
do
	case "$revpair" in
	?*..?*)
		rev1=`expr "$revpair" : '\(.*\)\.\.'`
		rev2=`expr "$revpair" : '.*\.\.\(.*\)'`
		;;
	*)
		rev1="$revpair^"
		rev2="$revpair"
		;;
	esac
	git-rev-parse --verify "$rev1^0" >/dev/null 2>&1 ||
		die "Not a valid rev $rev1 ($revpair)"
	git-rev-parse --verify "$rev2^0" >/dev/null 2>&1 ||
		die "Not a valid rev $rev2 ($revpair)"
	git-cherry -v "$rev1" "$rev2" |
	while read sign rev comment
	do
		case "$sign" in
		'-')
			echo >&2 "Merged already: $comment"
			;;
		*)
			echo $rev
			;;
		esac
	done
done >$series

me=`git-var GIT_AUTHOR_IDENT | sed -e 's/>.*/>/'`

case "$outdir" in
*/) ;;
*) outdir="$outdir/" ;;
esac
test -d "$outdir" || mkdir -p "$outdir" || exit

titleScript='
	/./d
	/^$/n
	s/^\[PATCH[^]]*\] *//
	s/[^-a-z.A-Z_0-9]/-/g
        s/\.\.\.*/\./g
	s/\.*$//
	s/--*/-/g
	s/^-//
	s/-$//
	s/$/./
	p
	q
'

process_one () {
	perl -w -e '
my ($keep_subject, $num, $signoff, $commsg) = @ARGV;
my ($signoff_pattern, $done_header, $done_subject, $signoff_seen,
    $last_was_signoff);

if ($signoff) {
	$signoff = "Signed-off-by: " . `git-var GIT_COMMITTER_IDENT`;
	$signoff =~ s/>.*/>/;
	$signoff_pattern = quotemeta($signoff);
}

my @weekday_names = qw(Sun Mon Tue Wed Thu Fri Sat);
my @month_names = qw(Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec);

sub show_date {
    my ($time, $tz) = @_;
    my $minutes = abs($tz);
    $minutes = ($minutes / 100) * 60 + ($minutes % 100);
    if ($tz < 0) {
        $minutes = -$minutes;
    }
    my $t = $time + $minutes * 60;
    my ($sec,$min,$hour,$mday,$mon,$year,$wday,$yday) = gmtime($t);
    return sprintf("%s %s %d %02d:%02d:%02d %d %+05d",
		   $weekday_names[$wday],
		   $month_names[$mon],
		   $mday, $hour, $min, $sec,
		   $year+1900, $tz);
}

print "From nobody Mon Sep 17 00:00:00 2001\n";
open FH, "git stripspace <$commsg |" or die "open $commsg pipe";
while (<FH>) {
    unless ($done_header) {
	if (/^$/) {
	    $done_header = 1;
	}
	elsif (/^author (.*>) (.*)$/) {
	    my ($author_ident, $author_date) = ($1, $2);
	    my ($utc, $off) = ($author_date =~ /^(\d+) ([-+]?\d+)$/);
	    $author_date = show_date($utc, $off);

	    print "From: $author_ident\n";
	    print "Date: $author_date\n";
	}
	next;
    }
    unless ($done_subject) {
	unless ($keep_subject) {
	    s/^\[PATCH[^]]*\]\s*//;
	    s/^/[PATCH$num] /;
	}
        print "Subject: $_";
	$done_subject = 1;
	next;
    }

    $last_was_signoff = 0;
    if (/Signed-off-by:/i) {
        if ($signoff ne "" && /Signed-off-by:\s*$signoff_pattern$/i) {
	    $signoff_seen = 1;
	}
    }
    print $_;
}
if (!$signoff_seen && $signoff ne "") {
    if (!$last_was_signoff) {
        print "\n";
    }
    print "$signoff\n";
}
print "\n---\n\n";
close FH or die "close $commsg pipe";
' "$keep_subject" "$num" "$signoff" $commsg

	git-diff-tree -p $diff_opts "$commit" | git-apply --stat --summary
	echo
	git-diff-tree -p $diff_opts "$commit"
	echo "-- "
	echo "@@GIT_VERSION@@"

	echo
}

total=`wc -l <$series | tr -dc "[0-9]"`
case "$total,$numbered" in
1,*)
	numfmt='' ;;
*,t)
	numfmt=`echo "$total" | wc -c`
	numfmt=$(($numfmt-1))
	numfmt=" %0${numfmt}d/$total"
esac

i=1
while read commit
do
    git-cat-file commit "$commit" | git-stripspace >$commsg
    title=`sed -ne "$titleScript" <$commsg`
    case "$numbered" in
    '') num= ;;
    *)
        num=`printf "$numfmt" $i` ;;
    esac

    file=`printf '%04d-%stxt' $i "$title"`
    if test '' = "$stdout"
    then
	    echo "$file"
	    process_one >"$outdir$file"
	    if test t = "$check"
	    then
		# This is slightly modified from Andrew Morton's Perfect Patch.
		# Lines you introduce should not have trailing whitespace.
		# Also check for an indentation that has SP before a TAB.
		grep -n '^+\([ 	]* 	.*\|.*[ 	]\)$' "$outdir$file"
		:
	    fi
    else
	    echo >&2 "$file"
	    process_one
    fi
    i=`expr "$i" + 1`
done <$series