#!/bin/sh

# Switch between OS-packaged Subversion and custom-built Subversion.
# 
# Usage: 'switch-svn <c|p>'    ("c" for custom, "p" for packaged)

DIRECTION="${1}"

# Use $USER instead of $UID because the latter doesn't always get set
# in a sudo-created shell, apparently.
if [ "${USER}" != "root" ]; then
  echo "ERROR: you must be root to run this" >&2
  exit 1
fi

if [ "${DIRECTION}" = "" ]; then
  echo "ERROR: missing required argument ('p')ackage or ('c')ustom" >&2
  exit 1
fi

if [ "${DIRECTION}" = "p" ]; then
  cd /usr/local/lib
  if [ -e libsvn_wc-1.so ]; then
    if [ -d svn-switch-locker ]; then
      mv svn-switch-locker TMP-SAFE-svn-switch-locker
    fi
    mkdir svn-switch-locker
    mv libsvn* svn-switch-locker/
    if [ -d TMP-SAFE-svn-switch-locker ]; then
      rm -rf TMP-SAFE-svn-switch-locker
    fi
  else
    echo "ERROR: no custom SVN libraries are present to move out of the way" \
         >&2
    exit 1
  fi

  cd /usr/local/bin
  if [ -e svn ]; then
    if [ -d svn-switch-locker ]; then
      mv svn-switch-locker TMP-SAFE-svn-switch-locker
    fi
    mkdir svn-switch-locker
    for name in svn svnadmin svnbench svndumpfilter \
                svnfsfs svnlook svnmucc svnrdump    \
                svnserve svnsync svnversion         \
    ; do
      mv ${name} svn-switch-locker/
    done
    if [ -d TMP-SAFE-svn-switch-locker ]; then
      rm -rf TMP-SAFE-svn-switch-locker
    fi
  else
    echo "ERROR: no custom SVN binaries are present to move out of the way" \
         >&2
    exit 1
  fi
elif [ "${DIRECTION}" = "c" ]; then
  cd /usr/local/lib
  if [ -d svn-switch-locker ]; then
    mv svn-switch-locker/* .
    rmdir svn-switch-locker
  else
    echo "ERROR: no custom SVN libraries are preserved to move back" \
         >&2
    exit 1
  fi

  cd /usr/local/bin
  if [ -d svn-switch-locker ]; then
    mv svn-switch-locker/* .
    rmdir svn-switch-locker
  else
    echo "ERROR: no custom SVN binaries are preserved to move back" \
         >&2
    exit 1
  fi
else
  echo "ERROR: argument '${DIRECTION}' is neither ('p')ackage nor ('c')ustom" \
       >&2
  exit 1
fi