#!/bin/bash
###############################################################################
#                                                                             #
# Pakfire - The IPFire package management system                              #
# Copyright (C) 2021 Pakfire development team                                 #
#                                                                             #
# This program is free software: you can redistribute it and/or modify        #
# it under the terms of the GNU General Public License as published by        #
# the Free Software Foundation, either version 3 of the License, or           #
# (at your option) any later version.                                         #
#                                                                             #
# This program is distributed in the hope that it will be useful,             #
# but WITHOUT ANY WARRANTY; without even the implied warranty of              #
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the               #
# GNU General Public License for more details.                                #
#                                                                             #
# You should have received a copy of the GNU General Public License           #
# along with this program.  If not, see <http://www.gnu.org/licenses/>.       #
#                                                                             #
###############################################################################

error() {
	echo "$@" >&2
}

main() {
	local buildroot="${1}"
	shift

	# Check if BUILDROOT exists
	if [ ! -d "${buildroot}" ]; then
		error "BUILDROOT does not exist"
		return 1
	fi

	local file
	local -A files

	# Find all executable files
	for file in $(find "${buildroot}" -type f -perm /111 | sort); do
		local shebang="$(head -c2 "${file}")"

		# Skip files that are not scripts
		if [ "${shebang:0:2}" != "#!" ]; then
			continue
		fi

		local interpreter="$(head -n1 "${file}")"
		interpreter="${interpreter:2}"

		case "${interpreter}" in
			# Interpreters in /usr/local are illegal
			/usr/local/*)
				files["${file}"]="${interpreter}"
				continue
				;;

			# We don't support "env"
			/usr/bin/env*)
				# Automatically fix this
				sed -i "${file}" \
					-e "s,#!/usr/bin/env \(/usr/bin/.*\),\1,"
				;;
		esac
	done

	if [ "${#files[@]}" -gt 0 ]; then
		error "Illegal interpreters found:"
		local file
		for file in "${!files[@]}"; do
			error "  ${file/${buildroot}/} (${files[${file}]})"
		done

		return 1
	fi

	return 0
}

main "$@" || exit $?
