#!/bin/sh

die() {
	printf '%s\n' "$*" >&2
	exit 1
}

command -v git >/dev/null 2>&1 ||
die "neither chroot-git nor git could be found!"

rev_parse() {
	if [ -n "$1" ]; then
		git rev-parse --verify "$1"
	else
		shift
		while test "$#" != 0
		do
			git rev-parse --verify "$1" 2>/dev/null && return
			shift
		done
		return 1
	fi
}

base=$(rev_parse "$1" FETCH_HEAD ORIG_HEAD) || die "base commit not found"
tip=$(rev_parse "$2" HEAD) || die "tip commit not found"
status=0

for cmt in $(git rev-list --abbrev-commit $base..$tip)
do
	git cat-file commit "$cmt" |
	awk -vC="$cmt" '
	# skip header
	/^$/ && !msg { msg = 1; next }
	/^author .*noreply/ && !msg {
		print "::error title=Commit Lint::" C ": authored by noreply email";
		ret=1;
	}
	!msg { next }
	# 3: long-line-is-banned-except-footnote-like-this-for-url
	(NF > 2) && (length > 80) {
		print "::error title=Commit Lint::" C ": long line: " $0
		ret = 1
	}
	!subject {
		if (length > 50) { print "::warning title=Commit Lint::" C ": subject is a bit long" }
		if (!($0 ~ ":" || $0 ~ "^Take over maintainership " || $0 ~ "^Orphan ")) { print "::error title=Commit Lint::" C ": subject does not follow CONTRIBUTING.md guildelines"; exit 1 }
		# Below check is too noisy?
		# if (!($0 ~ "^New package:" || $0 ~ ".*: update to")) {
		# 	print "::warning title=Commit Lint::" C ": not new package/update/removal?"
		# }
		subject = 1; next
	}
	/^$/ { body = 1; next }
	!body {
		print "::error title=Commit Lint::" C ": second line must be blank"
		ret = 1
	}
	END { exit ret }
	' || status=1
done
exit $status