#!/bin/bash
# gentoo-infra: infra/githooks.git:update-03-filename
# Copyright 2015-2021 Ulrich Müller and others
# Distributed under the terms of the GNU General Public License v2 or later

# Author: Ulrich Müller <ulm@gentoo.org>

refname=$1
oldrev=$2
newrev=$3

# skip non-master commits
[[ ${refname} == refs/heads/master ]] || exit 0

# special cases
zeros=0000000000000000000000000000000000000000
# branch removal
[[ ${newrev} == "${zeros}" ]] && exit 0
# no need to check for new branch because we skip non-master commits above

# Filenames must contain only the characters [A-Za-z0-9._+-] and must
# not begin with a dot, a hyphen, or a plus sign.
# https://devmanual.gentoo.org/general-concepts/tree/#what-belongs-in-the-tree%3F
# https://devmanual.gentoo.org/ebuild-writing/file-format/#file-naming-rules
export LC_ALL=C
regex='^([A-Za-z0-9_][A-Za-z0-9._+-]*/)*[A-Za-z0-9_][A-Za-z0-9._+-]*$'
exceptions=(
    .editorconfig
    .mailmap
    .github/pull_request_template.md
    .gitignore
    metadata/.gitignore
)

ret=0
while IFS= read -r -d $'\0' path; do
    for e in "${exceptions[@]}"; do
        [[ ${path} = "${e}" ]] && continue 2
    done
    echo "Path \"${path}\" violates file naming rules" >&2
    ret=1
done < <(git diff -z --name-only --diff-filter=ACR "${oldrev}" "${newrev}" \
             | grep -z -Ev -e "${regex}")
# Preceding line needs >=grep-2.24 for -z working correctly (bug #574662)

exit ${ret}