#!/usr/bin/env bash

set -e

install_mac() {
  command -v brew > /dev/null || \
    { echo "[ERROR]: 'brew' command not not found. Exiting" 1>&2; exit 1; }
  brew install flatbuffers
}

install_linux() {
  for CMD in curl cmake g++ make; do
    command -v $CMD > /dev/null || \
      { echo "[ERROR]: '$CMD' command not not found. Exiting" 1>&2; exit 1; }
  done

  ## Create Temp Build Directory
  BUILD_DIR=$(mktemp -d)
  pushd $BUILD_DIR

  ## Fetch Latest Tarball
  LATEST_VERSION=$(curl -s https://api.github.com/repos/google/flatbuffers/releases/latest | grep -oP '(?<=tag_name": ")[^"]+')
  curl -sLO   https://github.com/google/flatbuffers/archive/$LATEST_VERSION.tar.gz
  tar xf $LATEST_VERSION.tar.gz

  ## Build Binaries
  cd flatbuffers-${LATEST_VERSION#v}
  cmake -G "Unix Makefiles" -DCMAKE_BUILD_TYPE=Release
  make
  ./flattests
  cp flatc /usr/local/bin/flatc

  ## Cleanup Temp Build Directory
  popd
  rm -rf $BUILD_DIR
}

SYSTEM=$(uname -s)

case ${SYSTEM,,} in
  linux)
    sudo bash -c "$(declare -f install_linux); install_linux"
    ;;
  darwin)
    install_mac
    ;;
esac