#! /bin/sh
#
# ${R_HOME}/tools/fetch-recommended
#
# like rsync-recommended, but uses curl since rsync is often blocked nowadays
# (it is based on rsync-recommended with changes)
# The following envs vars can be used to change the mirror host and the curl invocation/path
: ${CRAN_MIRROR='cran.r-project.org'}
: ${CURL=curl}

## The intention here is to infer TOOLS_DIR from an explicit path.
## but the user might have called it from tools, so test that case
## separately.
TOOLS_DIR=`echo ${0} | sed 's%/[^/][^/]*$%%'`
if test ${TOOLS_DIR} = ${0} ; then
  TOOLS_DIR="."
fi
(cd "${TOOLS_DIR}"/..
  version=`cut -f1 -d' ' VERSION`
  if test "`cut -f2 -d' ' VERSION`" = "Patched"; then
    version=`echo ${version} | sed 's/\.[0-9]*$//'`
    version="${version}-patched"
  fi
  PKGS=`grep '^R_PKGS_RECOMMENDED *=' share/make/vars.mk | \
    sed 's/.*=//'`
  cd src/library/Recommended
  ## This is not perfect, but as good as it gets - just fetch the index and parse the
  ## current versions from the URLs there
  $CURL -sSfL -o index.html https://${CRAN_MIRROR}/src/contrib/${version}/Recommended/ || \
      { echo "*** failed to fetch https://${CRAN_MIRROR}/src/contrib/${version}/Recommended/ index ***" && exit 1; }

  for i in ${PKGS} ; do
      ## find out the version from the index file
      fn=$(sed -nE 's,.*"('$i'[^"]+[.]tar[.]gz)".*,\1,p' index.html| sed -n 1p)
      test -n "$fn" || { echo "*** failed to find $i in the index ***" && exit 1; }
      echo $fn
      if test -e "$fn"; then ## like rsync only fetch if newer (that's what the -z $fn does)
	  $CURL -sSfLOR -z "$fn" https://${CRAN_MIRROR}/src/contrib/${version}/Recommended/$fn || \
	      { echo "*** failed to fetch https://${CRAN_MIRROR}/src/contrib/${version}/Recommended/$fn ***" && exit 1; }
      else ## otherwise remove old and full fetch
	  rm -f ${i}_*.tar.gz
	  $CURL -sSfLOR https://${CRAN_MIRROR}/src/contrib/${version}/Recommended/$fn || \
	      { echo "*** failed to fetch https://${CRAN_MIRROR}/src/contrib/${version}/Recommended/$fn ***" && exit 1; }
      fi
  done
  rm -f index.html

  ## Link each package to a simplified name so that Make has an easier
  ## time.  Notice that as far as Make is concerned, the symlinks have
  ## the same timestamp as the file they point to.  Don't remove the 
  ## existing links until now in case fetch fails.

  echo "Creating links"
  rm -f *.tgz
  for i in ${PKGS} ; do
    ln -s $i*.tar.gz ${i}.tgz
  done
)