#!/usr/bin/env -S LC_ALL=C LANGUAGE=C awk -E
# SPDX-License-Identifier: EUPL-1.2+
# SPDX-FileCopyrightText: 2025 Demi Marie Obenour <demiobenour@gmail.com>
function check_status(status) {
	if (status < 0) {
		printf "FATAL: getline: %s\n", status > "/dev/stderr";
		exit 1;
	}
	return status;
}

function check_close(value,    status) {
	status = check_status(close(value));
	if (status != 0) {
		printf "FATAL: command exited with status %d\n", status > "/dev/stderr";
		exit status;
	}
}

function shell_quote(command) {
	gsub(/'/, "'\\\\&'", command);
	return ("'" command "'");
}

function get(command,          line, path, array_index, inode_type, mode, modes, symlink_count, symlinks, file_count, files, rc_count, rc_files, is_license, is_rc) {
	file_count = 0;
	symlink_count = 0;
	rc_count = 0;
	modes["120000"] = "symlink";
	modes["040644"] = "directory";
	modes["040755"] = "directory";
	modes["100644"] = "regular";
	modes["100755"] = "regular";
	print "# SPDX-License-Identifier: CC0-1.0";
	print "# SPDX-FileCopyRightText: Not Copyrightable (machine-written)";
	print "# Generated by scripts/genfile.awk, DO NOT EDIT!";
	while (check_status(command | getline line)) {
		if (line !~ /^[0-7]{6}\t/) {
			# this is a git bug
			print "FATAL: git ls-files output didn't start with a valid mode" > "/dev/stderr";
			exit 1;
		}
		path = substr(line, 8);
		if (path !~ /^[ -~]+$/) {
			# also a git bug
			print "FATAL: git ls-files didn't quote properly" > "/dev/stderr";
			exit 1;
		}
		if (path ~ /^\/|((^|\/)\.{0,2}($|\/))/) {
			# also a git bug
			printf "FATAL: git ls-files output non-canonical path '%s'\n", path > "/dev/stderr";
			exit 1;
		}
		if (path !~ /^[[:alnum:]_.+@/-]+$/) {
			printf "FATAL: filename '%s' has forbidden characters\n", path > "/dev/stderr";
			exit 1;
		}
		mode = modes[substr(line, 1, 6)];
		is_license = path ~ /\.license$/;
		is_rc = path ~ /^etc\/s6-rc\//;
		if (mode == "regular") {
			if (is_license) {
				continue;
			}
			if (is_rc) {
				rc_count += 1;
				rc_files[rc_count] = path;
			} else {
				file_count += 1;
				files[file_count] = path;
			}
			continue;
		}
		if (mode == "symlink") {
			if (is_rc) {
				printf "FATAL: symlink in s6-rc-compile input: %s\n", path;
				exit 1;
			}
			symlink_count += 1;
			symlinks[symlink_count] = path;
		} else if (mode != "directory") {
			printf "FATAL: file %s has unknown mode %s\n", path, substr(line, 1, 6) > "/dev/stderr";
			exit 1;
		}
		if (is_license) {
			printf "FATAL: %s (type %s) ends in .license\n", path, mode > "/dev/stderr";
			exit 1;
		}
	}
	check_close(command);

	printf "override FILES ::=";
	for (array_index = 1; array_index <= file_count; array_index += 1) {
		printf " \\\n\t%s", files[array_index];
	}
	printf ("\n\n" \
"# These are separate because they need to be included, but putting\n" \
"# them as make dependencies would confuse make.\n" \
"override LINKS ::=");
	for (array_index = 1; array_index <= symlink_count; array_index += 1) {
		printf " \\\n\t%s", symlinks[array_index];
	}
	printf "\n\noverride S6_RC_FILES ::=";
	for (array_index = 1; array_index <= rc_count; array_index += 1) {
		printf " \\\n\t%s", rc_files[array_index];
	}
	printf "\n"
}

BEGIN {
	RS = "\n";
	FS = "\t";
	get("set -euo pipefail && { git -c core.quotePath=true -C " shell_quote(ARGV[1]) " ls-files '--format=%(objectmode)\t%(path)' -- .|sort -t '\t' -k 2;}");
	exit 0;
}