#!/usr/bin/env bash
set -euo pipefail
DOXYGEN_VERSION="1.12.0"
DOXYGEN_TAG="Release_${DOXYGEN_VERSION//./_}"

DOXYGEN_PATH="doxygen"

download_doxygen() {
  TEMP_DIR="$(mktemp -d)"
  trap 'rm -rf "$TEMP_DIR"' EXIT
  pushd "$TEMP_DIR" >/dev/null
  echo "downloading doxygen..."
  curl -o doxygen.tar.gz -L "https://github.com/doxygen/doxygen/releases/download/${DOXYGEN_TAG}/doxygen-${DOXYGEN_VERSION}.linux.bin.tar.gz"
  tar -xzf doxygen.tar.gz
  rm doxygen.tar.gz
  DOXYGEN_PATH="$TEMP_DIR/doxygen-${DOXYGEN_VERSION}/bin/doxygen"
  popd >/dev/null
  echo "doxygen downloaded successfully"
}

# if doxygen command not found or version not as above, download it
if command -v doxygen &>/dev/null; then
  DOXYGEN_VERSION_INSTALLED=$(doxygen --version)
  if [[ $DOXYGEN_VERSION_INSTALLED != $DOXYGEN_VERSION ]]; then
    echo "doxygen version $DOXYGEN_VERSION_INSTALLED found, but not the expected version $DOXYGEN_VERSION"
    download_doxygen
  else
    echo "doxygen version $DOXYGEN_VERSION_INSTALLED found, using it"
  fi
else
  download_doxygen
fi

exec $DOXYGEN_PATH