configure

# The envvar used in libR-sys crate
LIBRSYS_R_VERSION=$("${R_HOME}/bin/Rscript" "./tools/print_r_version.R")

# Variables used for tweaking Makevars
BEFORE_CARGO_BUILD="export LIBRSYS_R_VERSION=\"${LIBRSYS_R_VERSION}\" \\&\\&"
AFTER_CARGO_BUILD=''

# Even when `cargo` is on `PATH`, `rustc` might not. We need to source
# ~/.cargo/env to ensure PATH is configured correctly in some cases
# (c.f. yutannihilation/string2path#4). However, this file is not always
# available (e.g. when Rust is installed via apt on Ubuntu), so it might be
# more straightforward to add `PATH` directly.
if [ -e "${HOME}/.cargo/env" ]; then
  . "${HOME}/.cargo/env"
  BEFORE_CARGO_BUILD="${BEFORE_CARGO_BUILD} . \"${HOME}/.cargo/env\" \\&\\&"
fi

# Check for rustc and report its version
if command -v rustc >/dev/null 2>&1; then
    echo "Using system rustc version: $(rustc --version)"
elif [ -x "$HOME/.cargo/bin/rustc" ]; then
    echo "Using user-installed rustc version: $($HOME/.cargo/bin/rustc --version)"
else
    echo "Error: rustc not found. Please install Rust using your system's package manager or from https://rustup.rs/"
    exit 1
fi

# Check the Rust installation, and abort if not available
"${R_HOME}/bin/Rscript" "./tools/configure.R"
ret=$?
if [ $ret -ne 0 ]; then
  exit $ret
fi

# If it's on CRAN, a package is not allowed to write in any other place than the
# temporary directory on installation. So, we need to tweak Makevars to make the
# compilation happen only within the package directory (i.e. `$(PWD)`).
if [ "${NOT_CRAN}" != "true" ]; then
  BEFORE_CARGO_BUILD="${BEFORE_CARGO_BUILD}"' export CARGO_HOME="$(PWD)/.cargo" \&\&'
  AFTER_CARGO_BUILD="${AFTER_CARGO_BUILD}"'rm -Rf $(PWD)/.cargo $(LIBDIR)/build'
else
  echo "*** Detected NOT_CRAN=true, do not override CARGO_HOME"
fi

sed \
  -e "s|@BEFORE_CARGO_BUILD@|${BEFORE_CARGO_BUILD}|" \
  -e "s|@AFTER_CARGO_BUILD@|${AFTER_CARGO_BUILD}|" \
  src/Makevars.in > src/Makevars

# Uncomment this to debug
#
# cat src/Makevars