#!/usr/bin/env bash
# 
# Be careful what you are doing with this script. You may overwrite files.
# cd into the repository before executing the script!
set -e;

usage() {
	echo "Script to synchronize system-helpers with your system";
	echo "";
	echo "(1) to sync the git folder's '/etc' --> system's '/etc'";
	echo "";
	echo "(2) to sync the git folder's '/etc' with all command line users with a certain shell";
	echo "";
	echo "(3) to sync the git folder's '/etc' ('/etc/skel') with a specific user's home folder"
	echo "";  
	echo "(4) to list command line users for sync";
	echo "";
	echo "(5) to sync the git folder's '/usr' with system's '/usr'";
	echo "";
	echo "(0) or [CTRL+C] to exit";
}

menu() {
	usage;
	read -n 1 -e -p ">" menuInput
	echo "";

	if [ "$menuInput" = "1" ]; then
		sudo rsync -r -t -v --chown=root:root --progress $(pwd)/etc/ /etc/
		echo "";
	elif [ "$menuInput" = "2" ]; then
		# require root
		[[ $UID -eq 0 ]] || (>&2 echo "ERROR: need to be root!" && exit 1)	

		# determine shell
		echo "Which shell (shortname, e.g. zsh)?";
		read -e -p ">" shellInput
		echo "";

		# shell users
		users=$(cat /etc/passwd|grep $shellInput| awk -F':' '{ print $1 }');

		# stage
		tmpDir=/tmp/system-helpers-sync/;
		mkdir -p $tmpDir;
		srcDir=$(pwd)/etc/skel/.
		cp -R $srcDir $tmpDir;

		# copy   
		for user in $users; do
		  exists=$(id -u $user);
		  primaryGroup=$(id -gn $user);
		  chown -R $user:$primaryGroup $tmpDir;
		  trgDir=$(eval echo ~$user/);
		  echo "Copy from $tmpDir to $trgDir";
		  cp -Rp $tmpDir/. $trgDir/;
		done

		# remove stage
		rm -rf $tmpDir;
	elif [ "$menuInput" = "3" ]; then
		# determine shell
		echo "Which user?";
		read -e -p ">" user
		echo "";

		# stage
		tmpDir=/tmp/system-helpers-sync/;
		mkdir -p $tmpDir;
		srcDir=$(pwd)/etc/skel/.
		cp -R $srcDir $tmpDir;

		# copy   
		exists=$(id -u $user);

		if [ $UID -ne $exists ] && [ $UID -ne 0 ]; then
		  echo "ERROR: need to be $user or root!";
		  exit 1;
		fi

		primaryGroup=$(id -gn $user);
		chown -R $user:$primaryGroup $tmpDir;
		trgDir=$(eval echo ~$user/);
		echo "Copy from $tmpDir to $trgDir";
		cp -Rp $tmpDir/. $trgDir/;

		# remove stage
		rm -rf $tmpDir;

	elif [ "$menuInput" = "4" ]; then
	    echo "Which shell (shortname, e.g. zsh)?";
	    read -e -p ">" shellInput
	    echo "";

	    # shell users
	    users=$(cat /etc/passwd|grep $shellInput| awk -F':' '{ print $1 }');
	    echo "Users with shell $shellInput"

	    for u in $users; do
	      echo $u;
	    done
	elif [ "$menuInput" = "5" ]; then
		sudo rsync -r -t -v --chown=root:root --progress $(pwd)/usr/ /usr/
		echo "";
	elif [ "$menuInput" = "0" ]; then
		exit 0;
  fi

  menu;
}

menu;