#!/bin/bash
#
#  Utility functions.
#


#  Returns the configured Node version
function get_node_version() {
   # read the app's package.json file
   package_json="${OPENSHIFT_REPO_DIR}/package.json"
   if [ ! -f "$package_json" ] ; then
     package_json="$(get_node_tmp_dir)/package.json"
   fi

   # attempt to detect the desired node.js version
   engine=$(grep "\"node\"" "$package_json" | tail -n 1 | sed -e 's/^.*" *[~=<>]*[=<>]* *v*\([0-9][^" ]*\) *[^"]*".*$/\1/p;d')

   # assume that a deprecated marker value is a reasonable default
   marker="${OPENSHIFT_REPO_DIR}.openshift/markers/NODEJS_VERSION"
   marker_ver=$(egrep -v "^\s*#.*" "$marker" 2>/dev/null | egrep -v "^\s*$" | tail -1)
   
   # use the OpenShift cart default of 0.6.20 as a final option:
   if [ -z $engine ]; then
       echo ${marker_ver-"0.6.20"}
   else
       echo ${engine}
   fi

}  #  End of function  get_node_version.


#  Returns the directory where Node is to be installed/is installed.
function get_node_install_dir() {
   echo "$OPENSHIFT_DATA_DIR"

}  #  End of function  get_node_install_dir.


#  Returns the path to the npm binary.
function get_npm_bin_path() {
   ver=${1:-"$(get_node_version)"}
   echo "$(get_node_install_dir)node-v$ver-linux-x64/bin"

}  #  End of function  get_npm_bin_path.


#  Returns the path to the node binary.
function get_node_bin_path() {
   echo "$(get_npm_bin_path $@)"

}  #  End of function  get_node_bin_path.


#  Returns the temporary directory we use for processing.
function get_node_tmp_dir() {
   ztmpdir="$OPENSHIFT_DATA_DIR/.nodejs.tmp"

   #  Ensure temp directory is created.
   [ -d "$ztmpdir" ]  ||  mkdir -p "$ztmpdir"

   echo "$ztmpdir"

}  #  End of function  get_node_tmp_dir.


#
#  Download and install the specified Node.js version.
#
function _install_nodejs() {
   ver=${1:-"$(get_node_version)"}

   # Sample download links:
   #    http://nodejs.org/dist/v0.8.9/node-v0.8.9-linux-x64.tar.gz
   #    http://nodejs.org/dist/v0.9.1/node-v0.9.1-linux-x64.tar.gz
   zfile="node-v${ver}-linux-x64.tar.gz"
   zlink="http://nodejs.org/dist/v${ver}/${zfile}"

   instdir="$(get_node_install_dir)"

   #  Download and extract the gzipped tarball.
   dldir="$OPENSHIFT_DATA_DIR/downloads"
   mkdir -p "$dldir"

   echo "  - Downloading and extracting $zlink ... "

   if ! curl -L -o "$dldir/$zfile" "$zlink"; then
      echo "  - ERROR  -- download failed for $zlink"
      echo "  - download uri = $dldir/$zfile"
      return 1
   fi

   (cd "$instdir"; tar -zxf "$dldir/$zfile")
   echo "  - Done installing Node.js version $ver"

}  #  End of function  _install_nodejs.



#  Ensure the shell env setup bits are added to user's .bash_profile.
function _ensure_bash_profile_setup() {
   dot_bash_profile=$OPENSHIFT_DATA_DIR/.bash_profile
   pattern='\s*source(.*)\.openshift/lib/setup_custom_nodejs_env\s*(.*)\s*'
   if ! egrep "$pattern" $dot_bash_profile > /dev/null 2>&1 ; then

      cat >> $dot_bash_profile  <<SRCEOF

#  Setup shell env for the custom Node[.js] version.
source "\$OPENSHIFT_REPO_DIR/.openshift/lib/setup_custom_nodejs_env"
SRCEOF

      echo "  - Added source setup_custom_nodejs_env to .bash_profile"
   fi

}  #  End of function  _ensure_bash_profile_setup.


#  Check and install custom Node[.js] version.
function ensure_node_is_installed() {
   ver=${1:-"$(get_node_version)"}

   echo "  - Checking to see if Node.js version $ver is installed ... "

   #
   #  To re-download and reinstall Node.js, uncomment these lines.
   #     rm -f downloads/node-v${ver}-linux-x64.tar.gz
   #     rm -rf $OPENSHIFT_DATA_DIR/node-v${ver}-linux-x64/
   #
   #  Note:  This function could be run multiple times on every git push,
   #         so use w/ caution (do once).
   #

   if [ -d  "$(get_node_bin_path)" ]; then
      echo "  - Node.js version $ver is already installed"
   else
      _install_nodejs "$ver"
   fi

   #  Ensure .bash_profile sets up path for custom Node[.js] version.
   _ensure_bash_profile_setup

}  #  End of function  ensure_node_is_installed.


#  Sets up PATH to include the custom node version binaries.
function setup_path_for_custom_node_version() {
   #  Get version.
   ver=${1:-"$(get_node_version)"}

   #  Get node binary path.
   node_bin_path=$(get_node_bin_path "$ver")

   #  Add the node binary path to the PATH.
   export PATH="$node_bin_path:${PATH}"

   if [ -n "$_SHOW_SETUP_PATH_MESSAGES" ]; then
      echo "  - PATH set to include custom node version ($ver) from"
      echo "       $node_bin_path "
      echo "    PATH = $PATH"
   fi

}  #  End of function  setup_path_for_custom_node_version.



#
# EOF
#