#!/bin/bash

# download-boxes.sh
# Check all molecule.yml files for required Vagrant boxes and download the ones that are not
# already present on the system.

set -euo pipefail

GIT_ROOT=$(git rev-parse --show-toplevel)
PROVIDER=virtualbox

# Read all boxes for all platforms from the "molecule.yml" files
all_boxes=$(cat "${GIT_ROOT}"/molecule/*/molecule.yml |
    yq -r '.platforms[].box' |         # Read the "box" property of each node under "platforms"
    grep --invert-match --regexp=--- | # Filter out file separators
    sort |
    uniq)

# Read the boxes that are currently present on the system (for the current provider)
present_boxes=$(vagrant box list |
    grep "${PROVIDER}" | # Filter by boxes available for the current provider
    awk '{print $1;}' |  # The box name is the first word in each line
    sort |
    uniq)

# The boxes that we need to download are the ones present in $all_boxes, but not $present_boxes.
download_boxes=$(comm -2 -3 <(echo "${all_boxes}") <(echo "${present_boxes}"))

# Actually download the necessary boxes
if [ -n "${download_boxes}" ]; then
    echo "${download_boxes}" | while IFS= read -r box; do
        vagrant box add --provider "${PROVIDER}" "${box}"
    done
fi