configure

# NOTE:
# Taken wholesale from https://github.com/yutannihilation/string2path/blob/main/configure,
# which is based on configure script of package 'gifski' (https://github.com/r-rust/gifski/),
# distributed under the MIT license, authored by Jeroen Ooms.

# Even when `cargo` is on `PATH`, `rustc` might not (c.f. https://github.com/yutannihilation/string2path/issues/4).
export PATH="$HOME/.cargo/bin:$PATH"

# If cargo command already exists, do nothing.
cargo --version
if [ $? -eq 0 ]; then
  exit 0
fi

# If the OS is macOS, try installing cargo to a temporary dir on the fly.
# I feel this is doing too much, but this is needed to let the CRAN build success,
# (c.f. https://github.com/yutannihilation/string2path/issues/8), so I rely on
# this for now. Eventually, I will provide staticlib for macOS, just like I do
# for Windows.
if [ "`uname`" = "Darwin" ]; then
  echo "Note: installing cargo to a temporary dir..."

  # autobrew is a "Fork of homebrew for building CRAN packages" (https://github.com/autobrew/)
  # This also tweaks src/Makevars to use TMPDIR instead of CARGO_HOME.
  curl "https://autobrew.github.io/scripts/rust" -sSf | sh

  # If the installation succeeds, exit here.
  if [ $? -eq 0 ]; then
    exit 0
  fi
fi

# If cargo is not found, display a friendly message and exit with error.

echo "------------------ RUST COMPILER NOT FOUND --------------------"
echo ""
echo "Please refer to <https://www.rust-lang.org/tools/install>"
echo ""
echo "---------------------------------------------------------------"
echo ""

exit 1