#!/bin/sh
# Copyright 2005, Ryan Anderson <ryan@michonline.com>
#
# This file is licensed under the GPL v2, or a later version
# at the discretion of Linus Torvalds.

setglobal USAGE = ''<start> <url> [<end>]''
setglobal LONG_USAGE = ''Summarizes the changes between two commits to the standard output,
and includes the given URL in the generated summary.''
setglobal SUBDIRECTORY_OK = ''Yes''
setglobal OPTIONS_KEEPDASHDASH = ''
setglobal OPTIONS_STUCKLONG = ''
setglobal OPTIONS_SPEC = ''git request-pull [options] start url [end]
--
p    show patch text as well
''

source git-sh-setup

setglobal GIT_PAGER = ''
export GIT_PAGER

setglobal patch = ''
while	case "$#" in 0) break ;; esac
{
	match $1 {
	with -p
		setglobal patch = '-p' 
	with --
		shift; break 
	with -*
		usage 
	with *
		break 
	}
	shift
}

setglobal base = $1, url = $2, status = '0'

test -n $base && test -n $url || usage

setglobal baserev = $[git rev-parse --verify --quiet "$base"^0]
if test -z $baserev
{
    die "fatal: Not a valid revision: $base"
}

#
# $3 must be a symbolic ref, a unique ref, or
# a SHA object expression. It can also be of
# the format 'local-name:remote-name'.
#
setglobal local = $(3%:*)
setglobal local = $(local:-HEAD)
setglobal remote = $(3#*:)
setglobal pretty_remote = $(remote#refs/)
setglobal pretty_remote = $(pretty_remote#heads/)
setglobal head = $[git symbolic-ref -q $local]
setglobal head = $(head:-$(git show-ref --heads --tags "$local" | cut -d' ' -f2))
setglobal head = $(head:-$(git rev-parse --quiet --verify "$local"))

# None of the above? Bad.
test -z $head && die "fatal: Not a valid revision: $local"

# This also verifies that the resulting head is unique:
# "git show-ref" could have shown multiple matching refs..
setglobal headrev = $[git rev-parse --verify --quiet "$head"^0]
test -z $headrev && die "fatal: Ambiguous revision: $local"

# Was it a branch with a description?
setglobal branch_name = $(head#refs/heads/)
if test "z$branch_name" = "z$headref" ||
	! git config "branch.$branch_name.description" >/dev/null
{
	setglobal branch_name = ''
}

setglobal merge_base = $[git merge-base $baserev $headrev] ||
die "fatal: No commits in common between $base and $head"

# $head is the refname from the command line.
# If a ref with the same name as $head exists at the remote
# and their values match, use that.
#
# Otherwise find a random ref that matches $headrev.
setglobal find_matching_ref = ''
	my ($head,$headrev) = (@ARGV);
	my ($found);

	while (<STDIN>) {
		chomp;
		my ($sha1, $ref, $deref) = /^(\S+)\s+([^^]+)(\S*)$/;
		my ($pattern);
		next unless ($sha1 eq $headrev);

		$pattern="/$head\$";
		if ($ref eq $head) {
			$found = $ref;
		}
		if ($ref =~ /$pattern/) {
			$found = $ref;
		}
		if ($sha1 eq $head) {
			$found = $sha1;
		}
	}
	if ($found) {
		print "$found\n";
	}
''

setglobal ref = $[git ls-remote $url | @@PERL@@ -e $find_matching_ref $(remote:-HEAD) $headrev]

if test -z $ref
{
	echo "warn: No match for commit $headrev found at $url" > !2
	echo "warn: Are you sure you pushed '$(remote:-HEAD)' there?" > !2
	setglobal status = '1'
}

# Special case: turn "for_linus" to "tags/for_linus" when it is correct
if test $ref = "refs/tags/$pretty_remote"
{
	setglobal pretty_remote = "tags/$pretty_remote"
}

setglobal url = $[git ls-remote --get-url $url]

git show -s --format='The following changes since commit %H:

  %s (%ci)

are available in the git repository at:
' $merge_base &&
echo "  $url $pretty_remote" &&
git show -s --format='
for you to fetch changes up to %H:

  %s (%ci)

----------------------------------------------------------------' $headrev &&

if test $[git cat-file -t $head] = tag
{
	git cat-file tag $head |
	sed -n -e '1,/^$/d' -e '/^-----BEGIN PGP /q' -e p
	echo
	echo "----------------------------------------------------------------"
} &&

if test -n $branch_name
{
	echo "(from the branch description for $branch_name local branch)"
	echo
	git config "branch.$branch_name.description"
	echo "----------------------------------------------------------------"
} &&

git shortlog ^$baserev $headrev &&
git diff -M --stat --summary $patch $merge_base..$headrev || setglobal status = '1'

exit $status