# Anticonf (tm) script by Jeroen Ooms (2025)
# 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="libavfilter"
PKG_DEB_NAME="libavfilter-dev"
PKG_RPM_NAME="ffmpeg-devel (https://rpmfusion.org)"
PKG_BREW_NAME="ffmpeg"
PKG_TEST_HEADER="<libavfilter/version.h>"
PKG_LIBS="-lavfilter"

# FFMPEG 3 and 4 include libavfilter 6.0
pkg-config ${PKG_CONFIG_NAME} --atleast-version=6 2>/dev/null
if [ $? -eq 0 ]; then
  PKGCONFIG_CFLAGS=`pkg-config --cflags --silence-errors ${PKG_CONFIG_NAME}`
  PKGCONFIG_LIBS=`pkg-config --libs ${PKG_CONFIG_NAME}`
fi

# Check for custom locations
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=${PKGCONFIG_LIBS}
elif [ `uname` = "Darwin" ]; then
  test ! "$CI" && brew --version 2>/dev/null
  if [ $? -eq 0 ]; then
    BREWDIR=`brew --prefix`
    PKG_CFLAGS="-I$BREWDIR/opt/$PKG_BREW_NAME/include"
    PKG_LIBS="-L$BREWDIR/opt/$PKG_BREW_NAME/lib $PKG_LIBS"
  else
    curl -sfL "https://autobrew.github.io/scripts/$PKG_BREW_NAME" > autobrew
    . ./autobrew
  fi
fi

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

# Find compiler
CXX=`${R_HOME}/bin/R CMD config CXX`
CXXFLAGS=`${R_HOME}/bin/R CMD config CXXFLAGS`
CPPFLAGS=`${R_HOME}/bin/R CMD config CPPFLAGS`

# Test for ffmpeg
echo "#include $PKG_TEST_HEADER" | ${CXX} -E ${CPPFLAGS} ${PKG_CFLAGS} ${CXXFLAGS} -xc++ - >/dev/null 2>configure.log
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)"
  echo " * rpm: $PKG_RPM_NAME (Fedora, CentOS, RHEL)"
  echo " * brew: $PKG_BREW_NAME (MacOS)"
  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
