#!/bin/bash
# SPDX-License-Identifier: LGPL-2.1-or-later
#
# clang-format: a tool to run clang-format on files
# Copyright (C) 2016 Evan Klitzke <evan@eklitzke.org>
# Copyright (C) 2019 Reini Urban <rurban@cpan.org>
#
# 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/>.

function usage {
	echo "Usage: $0 FILE..."
	exit 1
}

if [ $# -eq 0 ]; then
	usage
fi

# Variable that will hold the name of the clang-format command
FMT=""

# Some distros just call it clang-format. Others (e.g. Ubuntu) are insistent
# that the version number be part of the command. We prefer the bare
# clang-format first (picks up the pre-commit-installed binary when running
# via pre-commit), then fall back to versioned and macports variants.
for clangfmt in clang-format clang-format{-mp,}{-devel,-{22,21,20,19,18,15,8,7,6,5,4,3}{,.9,.8,.7,.6,.5,.4,.3,.2,.1,.0},}; do
	if which "$clangfmt" &>/dev/null; then
		FMT="$clangfmt"
		break
	fi
done

# Check if we found a working clang-format
if [ -z "$FMT" ]; then
	echo "failed to find clang-format"
	exit 1
fi

# Check all of the arguments first to make sure they're all files
for file in "$@"; do
	if [ "$file" = "-style=file" ]; then
		continue
	fi
	if [ ! -e "${file}" ]; then
		echo "${file} not found"
		usage
	fi
done

# Find a dominating file, starting from a given directory and going up.
find-dominating-file() {
	if [ -r "$1"/"$2" ]; then
		return 0
	fi
	if [ "$1" = "/" ]; then
		return 1
	fi
	find-dominating-file "$(realpath "$1"/..)" "$2"
	return $?
}

# Run clang-format -i on all of the things
for file in "$@"; do
	if [ "$file" = "-style=file" ]; then
		continue
	fi
	dir="$(dirname "$file")"
	if [ "$dir" = "xxx" ]; then
		echo skip xxx
		continue
	fi
	if [ "$file" = "src/xxx.c" ]; then
		echo "skip generated $file"
		continue
	fi
	# pushd "${dir}" || exit
	if ! find-dominating-file "$dir" .clang-format; then
		echo "Failed to find dominating .clang-format starting at $PWD"
		continue
	fi
	if ! ${FMT} --dry-run --Werror "$file" 2>/dev/null; then
		echo "  Formatted $file"
		${FMT} -i "$file"
	fi
	# clang-format bugs, not needed for now:
	#if grep -q 'IGNORE (-W' "$file"; then
	#    # shellcheck disable=SC2046,2035
	#    sed -e's, (-Wformat - nonliteral) , (-Wformat-nonliteral)   ,;' \
	#        -e's, (-Wformat - nonliteral), (-Wformat-nonliteral),;' \
	#        -e's, (-Wmissing - prototypes), (-Wmissing-prototypes),;' \
	#        -e's, (-Wdeprecated - declarations), (-Wdeprecated-declarations),;' \
	#        -e's, (-Wpragma - pack), (-Wpragma-pack),;' \
	#        -e's, (-Wswitch - enum), (-Wswitch-enum),;' \
	#        -e's, (-Wformat - y2k), (-Wformat-y2k),;' \
	#        -e's, (-Wmaybe - uninitialized), (-Wmaybe-uninitialized),;' \
	#        -e's, (-Wstringop - truncation), (-Wstringop-truncation),;' \
	#        -e's, (-Wstringop - overflow), (-Wstringop-overflow),;' \
	#        -e's, (-Wanalyzer - allocation - size) , (-Wanalyzer-allocation-size)   ,;' \
	#        -e's, (-Wanalyzer - possible - null - dereference), (-Wanalyzer-possible-null-dereference),;' \
	#        -e's, (-Wanalyzer - null - dereference), (-Wanalyzer-null-dereference),;' \
	#        -e's, (-Wanalyzer - malloc - leak), (-Wanalyzer-malloc-leak),;' \
	#        <"${file}" >"${file}.new"
	#    if ! cmp -s "${file}" "${file}.new"; then
	#        echo "post clang-format fixups (clang-format bugs)"
	#        mv "${file}.new" "${file}"
	#    else
	#        rm -f "${file}.new"
	#    fi
	#fi
done
