#!/bin/bash

posix_chars="a-zA-Z._0-9-"
bad_chars="][|#?><*\$'\"(){}&"

only_query=0
only_print=0
only_posix=0
only_whitespace=0
replace_char='_'
append_chars="_2"
remove_dup_underscores=0
allow_recursion=0
start_with_dash=0

function test_name
{
	if [ $only_posix -eq 0 ]
	then
		test_chars="[${bad_chars}]"
		ret=0
		while(($#!=0))
		do
			ret=$(($(echo "$1" | wc -l)-1))
			echo "$1" | perl -n -l -e "exit 1 if m/[\s]/;"
			ret=$(($ret+$?))
			case "$1" in
				"" | -* | *${test_chars}*) ret=$(($ret+1))
				;;
				*"\\"*) ret=$(($ret+1)) #'\' is special !!
				;;
			esac
			shift
		done
	else
		test_chars="[!$posix_chars]"
		ret=0
		while(($#!=0))
		do
			case "$1" in
				"" | -* | *${test_chars}*) ret=$(($ret+1))
				;;
			esac
			shift
		done
	fi
	return $ret
}

function good_name
{
	rpl="${2:-_}"
	tmp=$(echo -n "$1" | tr '[ \t\r\n]' "$rpl")
	if [ $only_whitespace -eq 0 ]
	then
		echo $(echo "$tmp" | sed -e "s/[$bad_chars]/$rpl/g" | sed -e "s/[\\]/$rpl/g") 
	fi
}

function no_dup_underscore
{
	echo "$(echo "$1" | sed -e 's/__*/_/g')"
}

#assume in pwd directory
#get_new_name bad_name replace_char append
function get_new_name
{
	if test_name "$1"
	then
		if [ $remove_dup_underscores -eq 1 ]
		then
			echo "$(no_dup_underscore "$1")"
		else
			echo "$1"
		fi
		return
	fi
	apd="$3"
	new_name="$(good_name "$1" $2)"
	if [ $remove_dup_underscores -eq 1 ]
	then
		new_name=$(no_dup_underscore "${new_name}")
	fi
	if [ -e "${new_name}" ]
	then
		if [ ${new_name##*.} = ${new_name} ]
		then
			echo "${new_name%.*}${apd}"
		else
			echo "${new_name%.*}${apd}.${new_name##*.}"
		fi
	else
		echo "${new_name}"
	fi
}

function print_version
{
	echo "Copyright (C) WANG Cong, 2008."
	echo "Version 1.5"
}

function print_help
{
	prog=$(basename $0)
	cat <<EOF
$prog [options] file_name

Options are:
c - char, use the specified char to replace, instead of default '_'.
q - query, just query, don't rename
p - print, only print the new name, don't rename.
a - when the new name is already occupied, use what string to append
    at the end of the new name (before suffix, if it has)
s - only replace the whitespaces in the filename
r - recursion, rename all files with bad names in the directory recursively
o - pOsix, only posix file name.
u - allow to replace multiple underscores with one
x - FORCE  rename a file with a name starting with dash.
v - version, print the version
h - help, print help info
EOF
}

function main
{
	if [ $only_query -eq 1 ]
	then
		if [ $only_print -eq 1 ]
		then
			echo "Bad usage!" >&2
			echo >&2
			print_help >&2
			return 1
		fi
		test_name "$@"
		return $?
	else
		if [ $only_print -eq 0 ]
		then
			[ -e "$1" ] || (echo "No such file or directory." >&2 && return 2)
		fi
		last_name=$(get_new_name "$1" "${replace_char}" "${append_chars}")
		if [ $only_print -eq 1 ]
		then
			if [ $allow_recursion -eq 1 ]
			then
				echo "-p conflicts with -r." >&2
				print_help >&2
				return 3
			else
				echo "$last_name"
			fi
		else
			[ "$1" != "$last_name" ] && mv "$1" "$last_name"
			if [ $allow_recursion -eq 1 ]
			then
				if [ ! -d "$last_name" ]
				then
					echo "$1"" was not a directory!" >&2
					return 4
				fi
				(cd "$last_name"
				ls | while read file
				do
					echo "$file"
					if [ -d "$file" ]
					then
						main "$file"
					else
						allow_recursion=0
						main "$file"
					fi
				done)
				
			fi
		fi
	fi
	return 0
}


while getopts "rvhsuoqx:a:c:p" var
do
	case $var in
		v)
			print_version
			exit 0
			;;
		h)
			print_help
			exit 0
			;;
		c)
			replace_char=$OPTARG
			if [ ${#OPTARG} -ne 1 ]
			then
				echo "-c must be followed by a char." >&2
				print_help
				exit 1
			fi
			;;
		a)
			append_chars=$OPTARG
			;;
		q)
			only_query=1
			;;
		p)
			only_print=1
			;;
		o)
			only_posix=1
			;;
		r)
			allow_recursion=1
			;;
		u)
			remove_dup_underscores=1
			;;
		s)
			only_whitespace=1
			;;
		x)
			start_with_dash=1
			tmp=$OPTARG
			;;
		*)
			echo "Bad options!" >&2
			print_help
			exit 1
	esac
done

shift $(($OPTIND - 1))
if [ $start_with_dash -eq 0 ]
then
	main "$@"
else
	tmp=$(perl -e '$foo="'"$tmp"'";$bar=$foo;$foo=~s/^-*//;rename("$bar", "$foo");print $foo;')
	main "$tmp"
fi
exit $?