#!/bin/bash
#
# SPDX-License-Identifier: GPL-2.0-only
#
# Copyright (C) 2020-2022 Philippe Proulx <pproulx@efficios.com>

expected_formatter_major_version=13

# Runs the formatter, making sure it's the expected version.
format_cpp() {
	local formatter=$1
	local version

	version=$($formatter --version)

        # shellcheck disable=SC2181
	if (($? != 0)); then
		echo "Cannot execute \`$formatter --version\`." >&2
		return 1
	fi

	if [[ "$version" != *"clang-format version $expected_formatter_major_version"* ]]; then
		echo "Expecting clang-format $expected_formatter_major_version." >&2
		echo >&2
		echo Got: >&2
		echo >&2
		echo "$version" >&2
		return 1
	fi

	local root_dir

	root_dir="$(dirname "${BASH_SOURCE[0]}")/.."

	# Using xargs to fail as soon as the formatter fails (`-exec`
	# won't stop if its subprocess fails).
	#
	# shellcheck disable=SC2086
	find "$root_dir" \( -name '*.cpp' -o -name '*.hpp' \) \
		! -wholename '*/cpp-common/optional.hpp' \
		! -wholename '*/cpp-common/string_view.hpp' \
		-print0 | xargs -n1 -0 $formatter
}

if [[ -n "$FORMATTER" ]]; then
	# Try using environment-provided formatter
	formatter=$FORMATTER
elif command -v clang-format-$expected_formatter_major_version &> /dev/null; then
	# Try using the expected version of clang-format
	formatter="clang-format-$expected_formatter_major_version -i"
else
	# Try using `clang-format` as is
	formatter='clang-format -i'
fi

# Try to format files
format_cpp "$formatter"