#!/bin/bash

if [ "$#" -lt 1 ]; then
	printf "Usage: %s <commit range>\n", "$0" 1>&2
	exit 1
fi

commits=$(git rev-list --no-merges "$@")
if [ -z "$commits" ]; then
	printf "No commits\n"
	exit 0
fi

author_missing=
committer_missing=

print_commits()
{
	local t="$1"

	shift

	s=
	is='is'
	its='its'
	[ "$#" -gt 1 ] && {
		s='s'
		is='are'
		its='their'
	}
	printf "Commit%s\n\n" "$s"
	git log --no-walk --pretty='format:  %h ("%s")' "$@"
	printf "\n%s missing a Signed-off-by from %s %s%s.\n" "$is" "$its" "$t" "$s"
	printf "\n"
}

for c in $commits; do
	ae=$(git log -1 --format='<%ae>%n<%aE>%n %an %n %aN ' "$c" | sort -u)
	ce=$(git log -1 --format='<%ce>%n<%cE>%n %cn %n %cN ' "$c" | sort -u)
	msg=$(git log -1 --format='%b' "$c")
	sob=$(echo "$msg" | sed -En 's/^\s*Signed-off-by:?\s*/ /ip')

	am=false
	cm=false
	grep -i -F -q "$ae" <<<"$sob" ||
		am=true
	grep -i -F -q "$ce" <<<"$sob" ||
		cm=true
	"$am" && author_missing+=" $c"
	"$cm" && committer_missing+=" $c"
done

if [ "$author_missing" ]; then
	print_commits "author" $author_missing
fi
if [ "$committer_missing" ]; then
	print_commits "committer" $committer_missing
fi

exec gitk "$@"