#!/bin/sh

# Change to the directory that contains this script.
cd `dirname $0`


# Explicitly set a minimal PATH so we won't run anything unexpected.
PATH="/bin:/usr/bin"
export PATH


# Define absolute paths to all commands that we will use in this script.
CAT="/usr/bin/cat"
RM="/usr/bin/rm"
GREP="/usr/bin/grep"
LN="/usr/bin/ln"


# Find the latest candidate.  If there isn't one, then fail.
SCRIPT_DIR=`/usr/bin/pwd`
BUILDS_DIR="/promoted-builds"
BUILD_NUMBER_FILE="buildnumber.txt"
CANDIDATE_DIR_NAME="candidate"
LATEST_DIR_NAME="latest"
CANDIDATE_DIR="${BUILDS_DIR}/${CANDIDATE_DIR_NAME}"
if test ! -L "${CANDIDATE_DIR}"
then
  echo "ERROR:  No candidate directory ${CANDIDATE_DIR} could be found"
  echo "Does a candidate build exist?"
  exit 1
fi


# Get the version number for this build.
VERSION_NUMBER_FILE=version.txt
VERSION_NUMBER_STRING=`${CAT} "${CANDIDATE_DIR}/${VERSION_NUMBER_FILE}"`


# Remove the existing "latest" symlink and create a new one pointing to the
# current candidate build.
cd "${BUILDS_DIR}"
${RM} -f "${LATEST_DIR_NAME}"
${LN} -s "${BUILDS_DIR}/${VERSION_NUMBER_STRING}" "${BUILDS_DIR}/${LATEST_DIR_NAME}"
${RM} -f "${CANDIDATE_DIR_NAME}"