#!/bin/bash

# sheepdog version .03

# This is ludicrously beta software.  It will probably cause your hair to
# turn green or light on fire.  Seriously, it's barely been tested and has
# the capacity to blow up your entire world.  Use it carefully if at all.

# Copyright (c) 2006, Faisal N. Jawdat
# All rights reserved.
# 
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions are
# met:
# 
# Redistributions of source code must retain the above copyright notice,
# this list of conditions and the following disclaimer. Redistributions in
# binary form must reproduce the above copyright notice, this list of
# conditions and the following disclaimer in the documentation and/or
# other materials provided with the distribution. Neither the name of
# Faisal N. Jawdat nor the names of its contributors may be used to
# endorse or promote products derived from this software without specific
# prior written permission. THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT
# HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
# INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
# AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
# THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
# INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
# NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
# USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
# ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
# THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

SHEEP_ARGUMENT=$1

SHEEP_HOST=`grep '^host: ' ~/.sheepdogrc|cut -d\  -f2`
SHEEP_FILES=`grep '^files: ' ~/.sheepdogrc | cut -d: -f2`
SHEEP_SH_MASTERS='.profile .bashrc .bash_login .bash_logout .bash_profile .zshenv .zprofile .zshrc .zlogin .zlogout'
SHEEP_CSH_MASTERS='.cshrc .tcshrc .login .logout'

function help {
	echo 'Valid commands are:'
	echo ''
	echo '        help:  display this text.'
	echo '  initialize:  create the sheepdog directory structure.'
	echo '      import:  import your old . files into the (fresh) structure.'
	echo '   lninstall:  set up the symbolic links.'
	echo '   scmupdate:  get the latest files from the repository (cvs or svn).'
	echo '   scmcommit:  commit the current environment to the repository (cvs or svn).'
	echo ''
}

function initialize {
	if [ -d ~/.sheepdog ]; then
		echo "~/.sheepdog exists.  Cannot proceed."
		exit
	else
		mkdir ~/.sheepdog
		cd ~/.sheepdog

		mkdir scripts
		mkdir scripts/pre scripts/main scripts/post

		for file in $SHEEP_SH_MASTERS ; do create_sh $file; done
		for file in $SHEEP_CSH_MASTERS ; do create_csh $file; done

		mkdir configs
		create_rc

		echo 'Directories and templates initalized.'
		echo 'You should now create a ~/.sheepdogrc.'
		echo 'The easiest way is to copy ~/.sheepdog/configs/sample.sheeprc.'
	fi
}


function create_sh {
	echo 'SHEEPDOG_HOST=`grep "^host:" ~/.sheepdogrc|cut -d\  -f2`' > ~/.sheepdog/scripts/$1
	cat >> ~/.sheepdog/scripts/$1 << EOF
if [ -f ~/.sheepdog/scripts/pre/$1.\$SHEEPDOG_HOST ]; then . ~/.sheepdog/scripts/pre/$1.\$SHEEPDOG_HOST; fi
if [ -f ~/.sheepdog/scripts/main/$1 ]; then . ~/.sheepdog/scripts/main/$1; fi
if [ -f ~/.sheepdog/scripts/post/$1.\$SHEEPDOG_HOST ]; then . ~/.sheepdog/scripts/post/$1.\$SHEEPDOG_HOST; fi
EOF
}

function create_csh {
	echo 'setenv SHEEPDOG_HOST `grep "^host:" ~/.sheepdogrc|cut -d\  -f2`' > ~/.sheepdog/scripts/$1
	cat >> ~/.sheepdog/scripts/$1 << EOF
if -f ~/.sheepdog/scripts/pre/$1.\$SHEEPDOG_HOST source ~/.sheepdog/scripts/pre/$1.\$SHEEPDOG_HOST
if -f ~/.sheepdog/scripts/main/$1 source ~/.sheepdog/scripts/main/$1
if -f ~/.sheepdog/scripts/post/$1.\$SHEEPDOG_HOST source ~/.sheepdog/scripts/post/$1.\$SHEEPDOG_HOST
EOF
}

function create_rc {
	cat > ~/.sheepdog/configs/sample.sheepdogrc << EOF
host: hostname
files: .bashrc .profile
EOF

}

function import {
	if [ -f ~/.sheepdogrc ] && [ -d ~/.sheepdog ]; then
		echo "Importing $SHEEP_FILES"

		mkdir ~/.sheepdog/backup
		mkdir ~/.sheepdog/backup/$SHEEP_HOST

		for file in $SHEEP_FILES ; do
			cp $file ~/.sheepdog/backup/$SHEEP_HOST/$file
		done

		for file in $SHEEP_FILES ; do
			mv $file ~/.sheepdog/scripts/post/$file.$SHEEP_HOST
		done

		echo 'The files were moved to ~/.sheepdog/scripts/post/.'
		echo 'and will run as-is after any generic scripts.'
		echo "The files were also backed up to ~/.sheepdog/backup/$SHEEP_HOST."
		echo 'You should now run:'
		echo '  sheepdog lninstall'
	else
		echo 'Something is wrong with your config.'
		echo 'Have you initialized the .sheepdog directory?'
		echo 'Have you created a .sheepdogrc?'
		exit
	fi
}

function lninstall {
	if [ -f ~/.sheepdogrc ] && [ -d ~/.sheepdog ]; then
	    echo Host ID: $SHEEP_HOST;

		for file in $SHEEP_FILES ; do
			echo "Linking $file."
			ln -s .sheepdog/scripts/$file;
		done
	else
		echo 'Something is wrong with your config.'
		echo 'Have you initialized the .sheepdog directory?'
		echo 'Have you created a .sheepdogrc?'
		exit
	fi
}

function scmupdate {
	cd ~/.sheepdog

	if [ -d ~/.sheepdog/CVS ]; then
		cvs up
	elif [ -d ~/.sheepdog/.svn ]; then
		svn up
	else
		echo "~/.sheepdog doesn't seem to be under source control."
		exit
	fi
}

function scmcommit {
	cd ~/.sheepdog

	if [ -d ~/.sheepdog/CVS ]; then
		cvs ci
	elif [ -d ~/.sheepdog/.svn ]; then
		svn ci
	else
		echo "~/.sheepdog doesn't seem to be under source control."
		exit
	fi
}

cd ~

if [ "$SHEEP_ARGUMENT" = 'help' ]; then
	help
elif [ "$SHEEP_ARGUMENT" = 'initialize' ]; then
	initialize
elif [ "$SHEEP_ARGUMENT" = 'import' ]; then
	import
elif [ "$SHEEP_ARGUMENT" = 'lninstall' ]; then
	lninstall
elif [ "$SHEEP_ARGUMENT" = 'scmupdate' ]; then
	scmupdate
elif [ "$SHEEP_ARGUMENT" = 'scmcommit' ]; then
	scmcommit
else
	echo "No action specified.  Valid actions are:"
	echo "help, initialize, import, lninstall, scmupdate, scmcommit"
fi