#!/bin/sh

# Drupal Update Script
# Written by: Benjamin Shell
# Created: September 5, 2008
# Updated: March 18, 2009
# License: GNU GPL
#
# This script can be used to update the files affected by Drupal maintenance releases.
# When Drupal is checked out with CVS this script isn't necessary, but this method
# of updating works great when subversion is used for a site.
#
# INSTRUCTIONS:
# 1) Put this file somewhere within your PATH, or create an alias to it.
# 2) Navigate to the Drupal root of the site you want to update (where index.php lives).
# 3) Call this script.
#
# IMPORTANT NOTE:
# This only works for Drupal versions 4.7 and greater.  Anything older will be updated to
# Drupal 4.7 which will break lots of things.

# constants:
DRUPALSRC="/Users/ben/localhost/src"

# print the current path of the Drupal site to update
CWD=`pwd`

# verify that the current working directory contains Drupal (check for the index.php file)
if [ ! -f $CWD/index.php ]
then
  echo "ERROR: The current directory doesn't contain a Drupal site!"
  exit 0
fi

echo "Drupal site to update: $CWD"

# Find old Drupal version by searching the CHANGELOG file
OLDREV=`awk -F"," '/Drupal [0-9.]/ { print $1; exit }' CHANGELOG.txt`

# The $OLDREV variable should be in the form Drupal 5.15 but needs to be converted to
# the syntax used by CVS (DRUPAL-5-15)
OLDREV=`echo $OLDREV | tr '[:lower:]' '[:upper:]'`
OLDREV=`echo $OLDREV | tr '[:blank:]' '-'`
OLDREV=`echo $OLDREV | tr '.' '-'`
echo "This site is currently running $OLDREV."

# Get major version of current Drupal installation
MAJORVER=`echo $OLDREV | awk -F"-" '{ print $2; exit }'`

# Find newest available Drupal version
cd /tmp
cvs -z6 -d:pserver:anonymous:anonymous@cvs.drupal.org:/cvs/drupal rlog drupal/index.php > index.php.log
PATTERN="DRUPAL-$MAJORVER-[0-9-]+"
NEWREV=`awk -F":" -v pat="$PATTERN" '$0 ~ pat { print $1; exit }' index.php.log`
NEWREV=`echo $NEWREV | tr -d '[:space:]'`
echo "The latest Drupal release is $NEWREV."

# Is this site already running the latest Drupal release?
if [ $OLDREV = $NEWREV ]
then
  echo "You are already running the latest release of Drupal $MAJORVER!"
  exit 0
fi

# Prompt for confirmation before running the update
echo "Do you want to update this Drupal installation now? [y/n]"
read ANSWER
if [ "$ANSWER" != "y" ]
then
  exit 0
fi

# Checkout a fresh copy of the new Drupal versions in order to compare the differences
echo "Getting a temporary fresh copy of Drupal"
cd /tmp
rm -rf drupal-newrev
cvs -z6 -d:pserver:anonymous:anonymous@cvs.drupal.org:/cvs/drupal co -d drupal-newrev -r $NEWREV drupal

# Create a patch of the differences between new and old versions of Drupal
cd drupal-newrev
cvs diff -upN -r $OLDREV > $CWD/diff.patch
cd ..
rm -rf drupal-newrev

# Apply the patch
cd $CWD
patch -p0 < diff.patch

# Remove the patch
rm diff.patch