#!/bin/bash
# gentoo-infra: infra/githooks.git:local/update-05-manifest
# Copyright 2017 Gentoo Foundation
# Distributed under the terms of the GNU General Public License v2 or later

# Author: Michał Górny <mgorny@gentoo.org>

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

export LC_MESSAGES=C

# enforce only on master branch
[[ ${refname} == refs/heads/master ]] || exit 0

# special cases
zeros=0000000000000000000000000000000000000000
# branch removal
[[ ${newrev} == "${zeros}" ]] && exit 0
# new branch; try to find a merge base with master
if [[ ${oldrev} == "${zeros}" && ${refname} != refs/heads/master ]]; then
	mergebase=$(git merge-base refs/heads/master "${newrev}")
	[[ -n ${mergebase} ]] && oldrev=${mergebase}
	[[ -z ${mergebase} ]] && echo "WARNING: No common commits with master!"
fi

ret=0
while read commithash; do
    # check for any Manifest changes
    while read fname; do
        if [[ ${fname} == */Manifest ]]; then
            # check the resulting Manifest line-by-line
            while read tag mfile size hashes; do
                if [[ ${tag} != DIST ]]; then
                    echo "Thin Manifests can contain only DIST lines!"
                    echo " commit: ${commithash}"
                    echo "   file: ${fname}"
                    echo "  entry: ${tag} ${mfile} ${size} ${hashes}"
                    ret=1
                    break
                fi

                case ${hashes} in
                    *SHA256*WHIRLPOOL*)
                        echo "Disallowed hash set in Manifest!"
                        echo " commit: ${commithash}"
                        echo "   file: ${fname}"
                        echo "  entry: ${tag} ${mfile} ${size} ${hashes}"
                        ret=1
                        break
                        ;;
                    *BLAKE2B*SHA512*)
                        ;;
                    *)
                        echo "Disallowed hash set in Manifest!"
                        echo " commit: ${commithash}"
                        echo "   file: ${fname}"
                        echo "  entry: ${tag} ${mfile} ${size} ${hashes}"
                        ret=1
                        break
                        ;;
                esac
            done < <(git cat-file -p "${commithash}:${fname}")
        fi
    done < <(git diff --diff-filter=d --name-only "${commithash}^".."${commithash}")
done < <(git rev-list "${oldrev}..${newrev}")

exit ${ret}