para

#!/usr/bin/env bash

echo "Para Launcher Activated!"

path () { echo "${1}" | sed "s+${TMPDIR:-\$TMPDIR}+\$TMPDIR+" | sed "s+${HOME}+\$HOME+"; }

echo "- Checking para.cfg.yaml in current directory for 'version: X.Y.Z'"
cfg="$(cat para.cfg.yaml 2>/dev/null | grep 'version:' | head -1 | cut -d' ' -f-2 | sed 's/ersion: //')"
version="${cfg:-latest}"

case "${version}" in
 latest) suffix="${version}/download" ;;
 *) suffix="download/${version}" ;;
esac
downloads="https://github.com/paraterraform/para/releases/${suffix}"

echo "- Desired version: ${version} (latest is used when no version specified)"

tmp=$(echo "${TMPDIR:-/tmp}")
cache="${tmp}/para-${UID}/para/${version}"
sha256sums="${cache}/SHA256SUMS"
platform="$(uname -s | tr '[:upper:]' '[:lower:]')"

if [[ ! -f "${sha256sums}" ]] || ( [[ "${version}" == "latest" ]] && ! find "${sha256sums}" -mmin +1440 -exec false '{}' + ) ; then
  echo "- Downloading checksums for version '${version}' to '$(path ${cache})'"
  mkdir -p "${cache}"
  checksumsUrl="${downloads}/SHA256SUMS"
  checksumsOutput=$(curl --fail --location --output "${sha256sums}" "${checksumsUrl}" 2>&1)
  checksumsResult=${?}
  if [[ ${checksumsResult} != 0 ]] && [[ ! -f "${sha256sums}" ]]; then
    echo "* Failed to fetch checksums for version '${version}' from ${checksumsUrl} with exit code '${checksumsResult}'"
    echo "  If the error below doesn't look like a transient one - please submit an issue at https://github.com/paraterraform/para/issues/new"
    echo
    echo "${checksumsOutput}"
    echo
    exit 1
  fi
fi

digest=$(grep "${platform}" "${sha256sums}")
if [[ $? -ne 0 ]]; then
  echo "* Para version '${version}' does not seem to have a build for your platform '${platform}'"
  echo "  Please submit an issue with the message above at https://github.com/paraterraform/para/issues/new"
  exit 1
fi

checksum=$(echo "${digest}" | awk '{ print $1 }')
filename=$(echo "${digest}" | awk '{ print $2 }')

para="${cache}/${filename}"

if [[ ! -f "${para}" ]]; then
  echo "- Downloading '${platform}' binary for version '${version}' to '$(path ${cache})'"
  binaryUrl="${downloads}/${filename}"
  binaryOutput=$(curl --fail --location --output "${para}" "${binaryUrl}" 2>&1)
  binaryResult=${?}
  if [[ ${binaryResult} != 0 ]]; then
    echo "* Failed to fetch binary for version '${version}' from ${binaryUrl} with exit code '${binaryResult}'"
    echo "  If the error below doesn't look like a transient one - please submit an issue at https://github.com/paraterraform/para/issues/new"
    echo
    echo "${binaryOutput}"
    echo
    exit 1
  fi
  chmod +x "${para}"
fi

if ! echo "${checksum}  ${para}" | shasum -a 256 -c - &>/dev/null; then
    echo "* Checksum for '$(path ${para})' didn't match expected value of '${digest}'"
    echo "  Please execute 'rm -rf $(path ${cache})' and run '${0}' again."
    echo "  If the above doesn't look right or the issue persists - please submit an issue at https://github.com/paraterraform/para/issues/new"
    exit 1
fi

echo "- Executing '$(path ${para})'"
echo
echo "------------------------------------------------------------------------"
echo
exec "${para}" "$@"