#!/usr/bin/env zsh

setopt ERR_EXIT

vcsurl=$1
vcspath=$2
modname=$3
version=$4

dst=$modname/@v
mkdir -p $dst
cd $dst
[[ ! -s $version.zip ]] || exit 0

root=$0:h:a
zipcreate=$root/zip-create
ziphash=$root/zip-hash
zmodload -F zsh/datetime b:strftime
git -C $vcspath cat-file -p $version | while read line ; do
    [[ ! $line =~ ^object ]] || hsh=${${=line}[-1]}
    [[ ! $line =~ ^tagger ]] || {
        strftime -s sec -r "%s %z" "${${=line}[-2,-1]}"
        break
    }
done
[[ -n $hsh ]]
[[ -n $sec ]]
strftime -s when %Y-%m-%dT%H:%M:%SZ $sec

$zipcreate -vcs $vcspath -mod $modname -version $version > $version.zip
$ziphash $version.zip > $version.ziphash
unzip -p $version.zip ${modname}@${version}/go.mod > $version.mod
printf '{"Version":"%s","Time":"%s","Origin":{"VCS":"git","URL":"%s","Ref":"refs/tags/%s","Hash":"%s"}}' \
    $version $when $vcsurl $version $hsh > $version.info
touch -d $when $version.info $version.mod $version.zip $version.ziphash