stargazing/auto-update

#!/usr/bin/env sh

note() { printf >&2 '\033[1m%s\033[0m\n' "$*" ;}

investigate() {
    url="${1?huh}"
    [ "${url#"https://github.com/"}" = "$url" ] \
    && re='/commit/' || re='/spoofed_commit_check/'
    curl $curlflags "$url" | grep -F "$re" | grep -Eo '[0-9a-f]{40}'
}

me="$(readlink -f "$0")" && cd "${me%/*}" || exit
curlflags="-L --no-progress-meter"
any=0
set -- \
cosmo           COSMO_COMMIT    https://github.com/jart/cosmopolitan \
cosmo-kuroko    KUROKO_COMMIT   https://github.com/kuroko-lang/kuroko \
cosmo-muon      MUON_COMMIT     https://git.sr.ht/~lattis/muon \
cosmo-perl      PERL_COMMIT     https://github.com/G4Vi/perl5/tree/cosmo \
cosmo-python    PYTHON_COMMIT   https://github.com/ahgamut/cpython/tree/cosmo_py311 \
cosmo-yices     KISSAT_COMMIT   https://github.com/BrunoDutertre/kissat \
cosmo-yices     YICES_COMMIT    https://github.com/SRI-CSL/yices2 \
;

while [ $# != 0 ]; do
    dir="$1" tag="$2" url="$3"
    shift && shift && shift || { note 'not a multiple of 3!'; exit 255 ;}
    if ! [ -d "$dir" -a -f "$dir/Dockerfile" -a -s "$dir/Dockerfile" ]; then
        note "missing Dockerfile, skipping $dir ($tag)"
        continue
    fi
    ours="$(grep -F "$tag"= "$dir/Dockerfile" | grep -Eo '[0-9a-f]{40}' | head -n1)"
    theirs="$(investigate "$url" | head -n1)"
    if [ ${#ours} == 0 -o ${#theirs} == 0 ]; then
        note "failed to retrieve update for $dir ($tag)"
    elif [ "$ours" != "$theirs" ]; then
        any=1 && note "updating $dir ($tag)"
        other="${tag%_COMMIT}_SHA256"
        tgz="${url%/}" && tgz="${tgz%%/tree/*}" && tgz="$tgz/archive/$theirs.tar.gz"
        { : \
         && sum="$(curl $curlflags "$tgz" | sha256sum - | awk '{print $1}')" \
         && notwa-util/shed "$dir/Dockerfile" "s/$ours/$theirs/g" \
         && notwa-util/shed "$dir/Dockerfile" "s/$other=.*/$other=$sum/g" \
         ;} \
     || note "failed to apply update for $dir ($tag)"
    fi
done
[ $any = 1 ] || note "no new updates"