#!/bin/bash -u
#Firefox startup wrapper
#
#This script makes it easy maintain many firefox profiles at once
#
#The idea being only one instance of firefox can run on any given set of
#machines at any given point in time. Thus one profile can exist for many
#machines at once. This script is a wrapper to handle this.
#
#When ran, it inspects all the firefox profiles its knows about to decide which
#one is the most up-to-date. If the local profile is the most up-to-date it
#just hands off to the real firefox, if not it connects to the most up-to-date
#hosts and kills the remote firefox sesion. It then pulls the remote profile
#to the local one useing rsync. After this it hands everything off to the real
#firefox.
#
#Ultimatly, when ran the final outcome of the script is to allways run firefox
#via: #/usr/bin/firefox which is itself a self contained wrapper. The only time
#firefox is not run is when there is a remote host with a newer profile AND
#firefox is allready running locally.
#
#Requirements and Asumptions
#-rysnc, to transfare files (over ssh)
#-ntp'ed hosts, so time stamps are accurate
#-ssh access from all hosts to all hosts, get info, kill firefox and transfare
#-gmessage, for warnings
#
#To install: put this script on all machines in the path, adjust hosts=
#run this script with setup as first paraeter, this till connect to all hosts
#and gives them an old time stamp and give the current hosts a new stamp. ie
#the current host is the uptodate one

#list of sort hosts where firefox profiles resides. (must match ~/.ssh/config)
hosts="diamond d8s7c1j onyx"

#find out what hosts are up
newhosts=""
for host in $hosts; do
        ssh $host true
        test $? -eq 0 && newhosts="$newhosts $host"
done
hosts=$newhosts

#this hostname
hostname=`cat /proc/sys/kernel/hostname | awk -F. '{print $1}'`

#where thr profile lives
profile="$HOME/.mozilla/."

#display an message using X11
message() {
        gmessage -center --name "Firefox Wraper" -title "Firefox Wraper" \
                -wrap "$1" 
}

#updates local profile from $1 host
updatefrom() {
        host=$1

        #Kill remote firefox
        ssh $host pkill -TERM -u $USER firefox-bin &> /dev/null
        ssh $host pkill -TERM -u $USER sunbird-bin &> /dev/null

        ssh $host pkill -KILL -u $USER firefox-bin &> /dev/null
        ssh $host pkill -KILL -u $USER sunbird-bin &> /dev/null

        ssh $host pgrep -u $USER firefox-bin &> /dev/null
        test $? -ne 1 && message "Failed to kill Firefox" && exit 1
        ssh $host pgrep -u $USER sunbird-bin &> /dev/null
        test $? -ne 1 && message "Failed to kill Sunbird" && exit 1

        #Copy remote profile to local one
        rsync --archive --checksum --compress --delete --progress \
                $host:$profile $profile

        #Timestamp profile, this local profile is now definitive (ie uptodate)
        echo "`date +%Y%m%d%H%M%S` $hostname" > $profile/.datestamp
}

if [ $# -gt 1 ]; then
        if [ "$1" == "setup" ]; then
                shift
                for host in $hosts; do
                        ssh $host "echo \"00000000000000 $host\" > $profile/.datestamp" 
                done
                echo "`date +%Y%m%d%H%M%S` $hostname" > $profile/.datestamp
        fi
fi

#find most uptodata host
uptodatehost=$(
        for host in $hosts; do 
                ssh $host cat $profile/.datestamp 2> /dev/null
        done | sort -n | tail -1 | awk '{print $2}'
)

#if the most uptodate is us
if [ "$uptodatehost" == "$hostname" ]; then
        #we are up to date
        uptodate=true
else
        #we are not up to date
        uptodate=false
fi

#lets see if firefox is runnign locally
pgrep -u $USER firefox-bin &> /dev/null
if [ $? -eq 1 ]; then
        running=false
else
        running=true
fi

if [ "$uptodate" == "true"  -a "$running" == "true"  ]; then
        message "uptodate=$uptodate, running=$running\nnew window"
fi
if [ "$uptodate" == "true"  -a "$running" == "false" ]; then
        message "uptodate=$uptodate, running=$running\nstarting firefox"
fi
if [ "$uptodate" == "false" -a "$running" == "true"  ]; then
        message "uptodate=$uptodate, running=$running\nconfused, exiting"
        exit
fi
if [ "$uptodate" == "false" -a "$running" == "false" ]; then
        message "uptodate=$uptodate, running=$running\nupdating profile from $uptodatehost"
        updatefrom $uptodatehost
fi

/usr/bin/firefox $@ &