# Anticonf (tm) script by Jeroen Ooms (2021)
# This script will query 'pkg-config' for the required cflags and ldflags.
# If pkg-config is unavailable or does not find the library, try setting
# INCLUDE_DIR and LIB_DIR manually via e.g:
# R CMD INSTALL --configure-vars='INCLUDE_DIR=/.../include LIB_DIR=/.../lib'

# Library settings
PKG_CONFIG_NAME="zlib"
PKG_DEB_NAME="zlib1g-dev"
PKG_RPM_NAME="zlib-devel"
PKG_CSW_NAME="libz_dev"
PKG_BREW_NAME="zlib"
PKG_TEST_HEADER="<zlib.h>"
PKG_LIBS="-lz"
PKG_CFLAGS=""

# Support static linking for binary packages on MacOS
if [ `uname` = "Darwin" ]; then
PKG_CONFIG_NAME="--static $PKG_CONFIG_NAME"
fi

# Use pkg-config if available
if [ "`command -v pkg-config`" ]; then
  PKGCONFIG_CFLAGS="`pkg-config --cflags --silence-errors ${PKG_CONFIG_NAME}`"
  PKGCONFIG_LIBS="`pkg-config --libs ${PKG_CONFIG_NAME}`"
fi

# Note that cflags may be empty in case of success
if [ "$INCLUDE_DIR" ] || [ "$LIB_DIR" ]; then
  echo "Found INCLUDE_DIR and/or LIB_DIR!"
  PKG_CFLAGS="-I$INCLUDE_DIR $PKG_CFLAGS"
  PKG_LIBS="-L$LIB_DIR $PKG_LIBS"
elif [ "$PKGCONFIG_CFLAGS" ] || [ "$PKGCONFIG_LIBS" ]; then
  echo "Found pkg-config cflags and libs!"
  PKG_CFLAGS=${PKGCONFIG_CFLAGS}
  PKG_LIBS=${PKGCONFIG_LIBS}
fi

# For debugging
echo "Using PKG_CFLAGS=$PKG_CFLAGS"
echo "Using PKG_LIBS=$PKG_LIBS"

# Find compiler
CC=`${R_HOME}/bin/R CMD config CC`
CFLAGS=`${R_HOME}/bin/R CMD config CFLAGS`
CPPFLAGS=`${R_HOME}/bin/R CMD config CPPFLAGS`

# Test configuration
echo "#include $PKG_TEST_HEADER" | ${CC} ${CPPFLAGS} ${PKG_CFLAGS} ${CFLAGS} -E -xc - >/dev/null 2>configure.log

# Customize the error
if [ $? -ne 0 ]; then
  echo "--------------------------- [ANTICONF] --------------------------------"
  echo "Configuration failed to find the $PKG_CONFIG_NAME library. Try installing:"
  echo " * deb: $PKG_DEB_NAME (Debian, Ubuntu, etc)"
  echo " * rpm: $PKG_RPM_NAME (Fedora, EPEL)"
  echo " * csw: $PKG_CSW_NAME (Solaris)"
  echo " * brew: $PKG_BREW_NAME (OSX)"
  echo "If $PKG_CONFIG_NAME is already installed, check that 'pkg-config' is in your"
  echo "PATH and PKG_CONFIG_PATH contains a $PKG_CONFIG_NAME.pc file. If pkg-config"
  echo "is unavailable you can set INCLUDE_DIR and LIB_DIR manually via:"
  echo "R CMD INSTALL --configure-vars='INCLUDE_DIR=... LIB_DIR=...'"
  echo "-------------------------- [ERROR MESSAGE] ---------------------------"
  cat configure.log
  echo "--------------------------------------------------------------------"
  exit 1
fi

# Write to Makevars
sed -e "s|@cflags@|$PKG_CFLAGS|" -e "s|@libs@|$PKG_LIBS|" src/Makevars.in > src/Makevars

# Success
exit 0