set -e

export NIX_REMOTE=daemon

GIT_ROOT=$(git rev-parse --show-toplevel)
VERSION=$1

if [ "$GIT_ROOT" == "" ]; then
    GIT_ROOT=$(git rev-parse --show-toplevel)
fi

case $VERSION in
"19.03" | "unstable")
    nix-prefetch-git --rev "refs/heads/nixos-$1" https://github.com/NixOS/nixpkgs-channels.git | jq '{url: ("https://github.com/NixOS/nixpkgs-channels/archive/" + .rev + ".tar.gz"), rev: .rev, date: .date, sha256: .sha256}' >  "$GIT_ROOT/common/nixpkgs-$1.json"
    ;;
*)
    echo "usage: $0 <branchname>"
    echo "view $0 to see a list of valid branch names"
    exit 1
    ;;
esac