#!/bin/bash

#----------------------------------------------------------------------
# Called when system configuration changes and also at reboot.
#
# Detects when location has changed.
#
# Selects appropriate Retrospect configuration
# file, then restarts Retrospect daemon.
#
# Parameter 1 should be either 'reboot' or 'location changed'.
#
#----------------------------------------------------------------------
# This file (update_retrospect_config) is a Unix shell script.  It must
# be saved with Unix line endings, and must have execute permissions.
# It can be located anywhere, but for several reasons the suggested
# location is /usr/local/bin (create this directory if it doesn't
# exist).  It relies on two additional files to call it, both of which
# should be placed in the /Library/LaunchDaemons/ directory:
#     update_retrospect_config.plist
#     update_retrospect_config_reboot.plist
#
# The two .plist files in the LaunchDaemons directory instruct launchd
# (part of OS X Tiger) to invoke them whenever the system configuration
# changes (first file) or the system boots up (second file).  Each of
# these files then calls this script with a parameter indicating why it
# was called.
#
# This script examines the current location, compares it to the location
# when this file was last called, and if different, figures out which
# Retrospect configuration file should be made active.  It copies the
# current configuration file back where it came from, and copies the
# desired one as the current one, and restarts the Retrospect daemon.
#----------------------------------------------------------------------
#
# Version 2.0 and later use OS X's extended attribute functionality
# to save the current configuration file's source, using the handy
# 'xattr' utility from <http://dev.bignerdranch.com/public/bnr/eXttra.zip>
# (see Ars Technica article <http://arstechnica.com/reviews/os/macosx-10.4.ars/7>)
#
# For this to work, you need 'xattr' installed somewhere (I suggest
# /usr/local/bin, which is where this script looks for it).  You also
# need to run it once on each saved Retrospect configuration file, to
# store its full path in a new 'randy_FileWhence' extended attribute.
#
# For example, if you have two saved configuration files,
#    retroclient.state.qc
#    retroclient.state.home
#
# Then run the following commands:
#     /usr/local/bin/xattr --set "randy_FileWhence"
#                           "/Library/Preferences/retroclient.state.qc"
#                           /Library/Preferences/retroclient.state.qc
#
#     /usr/local/bin/xattr --set "randy_FileWhence"
#                           "/Library/Preferences/retroclient.state.home"
#                           /Library/Preferences/retroclient.state.home
#
#----------------------------------------------------------------------
# Customization:
#
# Look for the line 'case $LOCATION in' below.  Following this line are
# the specific names or partial names of locations (in my version of the
# file these are 'Pensive*' and 'QC*').  These match the computer
# network Location name that you've created in Network Preferences.
#
# Following each network name is a line that assigns the variable
# 'RetroConfigSrc' to a file name, such as:
#     '/Library/Preferences/retroclient.state.qc'
# This file name is the name of the specific Retrospect coniguration
# file to be used for this location.  To create this file, install
# Retrospect as usual, then copy the file
#     '/Library/Preferences/retroclient.state' as this file, then
# run the 'xattr' utility to set the 'randy_FileWhence' attribute to
# the file name (as described above).
#
# So, if you want to have two Retrospect configurations, one for work
# and one for home:
#   1: Set your Location to one of them, say work.
#   2: Uninstall Retrospect, then re-install Retrospect.
#   3: Copy the default Retrospect conifguration file (as above) to
#      a name specific to this location.
#   4: Run the 'xattr' utility to set the 'randy_FileWhence' attribute to
#      the file name (as described above).
#   5: Repeat for each location.
#
#
#-----------------------------------------------
# Version 2.1
# February 5, 2007
# Randall Gellens
#-----------------------------------------------






#-----------------------------------------------
# Timestamped messages
#-----------------------------------------------
function msg ()
{
    ts=`date +"%Y-%m-%d %H:%M:%S"`
    echo "$ts $1"
}


#-----------------------------------------------
# main script
#-----------------------------------------------

# Identify ourselves and list first parameter, which
# indicates if we were launched on reboot or because
# system configuration changed (for documentation in log).
X=`/usr/bin/basename $0`
msg "$X $1"

# Get current location
if [ -x /usr/local/bin/usleep ]; then
    /usr/local/bin/usleep 250000 # make sure location is stable
else
    /bin/sleep 1
fi
LOCATION=`echo show Setup:/ | scutil | awk -F ": " '/UserDefinedName/{print $2}'`

# get PID of Retrospect daemon
RETROSPECT=`ps auxww | grep -i pitond | fgrep -v "grep -i $1" | fgrep -v "fgrep" | fgrep -v "pfind" | awk '{print $2}'`

# Static file locations
RetroConfigDst="/Library/Preferences/retroclient.state"
LocationSaveFile="/tmp/last_location"

# If we have a saved location, extract it
if [ -f "$LocationSaveFile" ] ; then
    PREV_LOCATION=`cat "$LocationSaveFile"`
    msg "Last location: $PREV_LOCATION"
else
    msg "No previous saved location"
fi

# If called because location may have changed, see if it did
if [ "$1" != "reboot" ] ; then
    if [ "$LOCATION" != "$PREV_LOCATION" ] ; then
        msg "Location changed from $PREV_LOCATION"
    else
        msg "Location unchanged from $PREV_LOCATION"
        exit 0
    fi
else
    msg "Called on boot, not location change"
fi

if [ -n "$RETROSPECT" ] ; then
    msg "Retrospect daemon is running: pid $RETROSPECT"
else
    msg "Retrospect daemon not running"
fi

msg "Current location is \"$LOCATION\""

case $LOCATION in

    Pensive*)
        RetroConfigSrc="/Library/Preferences/retroclient.state.pensive"
        msg "Location is at home; will use $RetroConfigSrc"
        ;;
    
    QC*)
        RetroConfigSrc="/Library/Preferences/retroclient.state.qc"
        msg "Location is at work; will use $RetroConfigSrc"
        ;;
    
    *)
        msg "Location isn't home nor work"
        exit 0
        ;;

esac

# stop Retrospect if it is running
/sbin/SystemStarter stop RetroClient

# Be sure Retrospect is stopped
RETROSPECT=`ps auxww | grep -i pitond | fgrep -v "grep -i $1" | fgrep -v "fgrep" | fgrep -v "pfind" | awk '{print $2}'`
if [ -n "$RETROSPECT" ] ; then
    msg "Retrospect daemon is still running: pid $RETROSPECT"
    kill -TERM $RETROSPECT
fi

# Copy current Retrospect configuration file from whence it came
WHENCE=`/usr/local/bin/xattr --get-parseable "randy_FileWhence" $RetroConfigDst | fgrep "randy_FileWhence" | awk -F "=" '{print $2}'`
if [ -n "$WHENCE" ] ; then
    msg "Current config file came from: $WHENCE"
    cp $RetroConfigDst $WHENCE
    msg "Copied current config file back to $WHENCE"
else
    msg "Current config file randy_FileWhence not set; not copied back"
fi

# Copy desired Retrospect configuration file
if [ -f "$RetroConfigSrc" ] ; then
    cp $RetroConfigSrc $RetroConfigDst
    msg "Copied Retrospect Config ($RetroConfigSrc)"
else
    msg "No such file: $RetroConfigSrc"
    exit 1
fi

# Restart Retrosoect
/sbin/SystemStarter start RetroClient
RETROSPECT=`ps auxww | grep -i pitond | fgrep -v "grep -i $1" | fgrep -v "fgrep" | fgrep -v "pfind" | awk '{print $2}'`
if [ -n "$RETROSPECT" ] ; then
    msg "Retrospect daemon restarted: pid $RETROSPECT"
else
    msg "Retrospect daemon not started"
    exit 1
fi

# Save location for next time
echo "$LOCATION" > "$LocationSaveFile" 
exit 0