#! /usr/bin/env nix-shell
#! nix-shell -i bash -p nix-prefetch-github gnused jq

function help() {
  echo "Regenerates packaging data for the fawltydeps package."
  echo "Usage: $0 <rev>"
  exit 1
}

if [[ $# -gt 1 || $1 == -* ]]; then
  help
fi

set -x

cd "$(dirname "$0")"
version="$1"

set -euo pipefail

if [ -z "$version" ]; then
  help
fi

src_hash=$(nix-prefetch-github tweag FawltyDeps --rev  "${version}" | jq -r .sha256)
src_hash=$(nix hash to-sri --type sha256 "$src_hash")

sed -i -E -e "s#rev = \".*\"#rev = \"$version\"#" default.nix
sed -i -E -e "s#sha256 = \".*\"#sha256 = \"$src_hash\"#" default.nix
sed -i -E -e "s#version = \".*\"#version = \"$(date +%Y-%m-%d)\"#" default.nix