#! /bin/bash

set -e -o pipefail

prog_name=$(basename ${0})

if [[ -z "$1" || -z "$2" ]]
then
    echo "Usage: ${prog_name} <REPO> <SUBDIR> [<DEST>]"
    exit 1
fi

REPO=$1
SUBDIR=$2
[[ -n $3 ]] && DEST=${3} || DEST=$(basename ${REPO} .git)

echo "[${prog_name}] Repository:   ${REPO}"
echo "[${prog_name}] Subdirectory: ${SUBDIR}"
echo "[${prog_name}] Destination:  ${DEST}"

# Clone without populating working tree
git clone --filter=blob:none --no-checkout --depth 1 ${REPO} ${DEST}

# Enter repo
cd ${DEST}

# *SET* (not `add`) subdirectory to sparse-checkout file
git sparse-checkout set ${SUBDIR}

# Checkout dir
git checkout