#!/bin/bash

# Fail on any error.
set -e

# Directory that holds the cached packages.
cache_dir=$1
# List of the packages to use.
packages="${@:2}"

mkdir -p $cache_dir
for package in $packages; do
  cache_filepath=$cache_dir/$package.tar.gz

  echo "* Clean installing $package... "
  sudo apt-get --yes install $package  

  echo "* Caching $package to $cache_filepath..."
  # Pipe all package files (no folders) to Tar.
  dpkg -L $package |
    while IFS= read -r f; do 
      if test -f $f; then echo $f; fi;
    done | 
    xargs tar -czf $cache_filepath -C /
done

echo "Action complete. ${#packages[@]} package(s) installed and cached."