#!/bin/bash

# ESEMPI:
#toglie una parte del nome (a-l.) e la sostituisce con nulla
#for i in `ls *ogm`; do mv $i ${i/"a-l."/}; done
#
#cambia tutti i '_' in ' '
#for i in `ls *.avi`; do mv "$i" "${i//_/ }"; done
#
# THE SCRIPT:

echo "`basename $0` (c)2007-2014 PaulTT"

if [ $# -lt 4 ]; then
	set ""
fi

case $1 in
	-a|-s|-A|-S|-f|-F);;
	*)
		echo "Usage: "
		echo "  `basename $0` <-a|-s> '[*]<filename>[*]' 'from' 'to'"
	        echo "    substitutes 'from' with 'to' in \"'filename'\""
		echo "    and yes, you have to specify the \"'\" around from and to patterns"
		echo "    a pattern for matching filenames can be used, for example '*.avi'"
		echo "    (this one with apices too!!)"
		echo "    -a means all occurences in filename, -s only the first one"
		echo "    -A and -S have the above meaning, but search hidden files too"
		echo "    -f is the same as -a but without asking any confirmation (-F = -A)"
		echo ""
		exit 1

	;;
esac

IFS=$'\n\t'

PTT_MODE="$1"
PTT_FILES="$2"
PTT_FROM="$3"
PTT_TO="$4"

PTT_FORCE=""
shopt -u dotglob

case $PTT_MODE in
	-A)
		PTT_MODE="-a"
		shopt -s dotglob
	;;
	-S)
		PTT_MODE="-s"
		shopt -s dotglob
	;;
	-f)
		PTT_FORCE="y"
		PTT_MODE="-a"
	;;
	-F)
		PTT_FORCE="y"
		PTT_MODE="-a"
		shopt -s dotglob
	;;
esac

echo "I will do: "
for i in  $PTT_FILES; do
	if [ "$PTT_MODE" == "-a" ]; then
		if [ "$i" != "${i//$PTT_FROM/$PTT_TO}" ]; then
			echo "  mv \"$i\"	\"${i//$PTT_FROM/$PTT_TO}\""
		else
			echo "  \"$i\" not modified"
		fi
	else
		if [ "$i" != "${i/$PTT_FROM/$PTT_TO}" ]; then
			echo "  mv \"$i\"	\"${i/$PTT_FROM/$PTT_TO}\""
		else
			echo "  \"$i\" not modified"
		fi
	fi
done

if [ "$PTT_FORCE" == "y" ]; then
	echo -n "forced, I'll proceed... "
	reply=$PTT_FORCE
else
	echo -n "Are You Sure? [y/N] "
	read reply
fi
case $reply in
	y* | Y*)
		for i in  $PTT_FILES; do
			if [ "$PTT_MODE" == "-a" ]; then
				if [ "$i" != "${i//$PTT_FROM/$PTT_TO}" ]; then
					mv "./$i" "${i//$PTT_FROM/$PTT_TO}"
				fi
			else
				if [ "$i" != "${i/$PTT_FROM/$PTT_TO}" ]; then
					mv "./$i" "${i/$PTT_FROM/$PTT_TO}"
				fi
			fi
		done
		echo "done."
	;;
	n* | N*)
		echo "doing nothing, bye bye"
		exit	
	;;
	*)
		echo "doing nothing, bye bye"
		exit	
	;;
esac