#!/bin/bash

E_ERR_ARG=65

if	(( "$#" <  1 ))
 then	 echo "----------------------------------------"
	 echo "Utilizzo: `basename $0` [-r] collezione "
	 echo "          -r genera una playlist casuale"
	 echo "----------------------------------------"
	 exit $E_ERR_ARG
elif	(( "$#" == 2 ))
 then	 path="$2"
 else	 path="$1"
fi

echo
if	[ ! -d "$path" ] && [ ! -w "$path" ]
 then	 echo "Controlla il percorso"
	 exit $E_ERR_ARG
fi

path=${path%/}
echo "Cerco i file.mp3 in \"$path/\" ricorsivamente"
find -P "$path" -name *.mp3 > "$path"/playlist
echo "Scrivo i file.mp3 in \"$path/playlist\""
echo "end" >> "$path"/playlist

if	[ "$1" == "-r" ]
 then	 echo "Randomizzo la playlist"
	 exec < "$path"/playlist
	 read song
	 number=1
	 while	[ "$song" != "end" ]
	  do	 array[$number]=$song
		 read song
	 	 let "number++"
	  done
	 count=1
	 if [ -e "$path"/rand_list ]; then rm "$path"/rand_list; fi
	 touch "$path"/rand_list
	 while	[ "$count" -le "$number" ]
	  do	 let "numero = $RANDOM % $number+1"
		 if 	[ casual[$numero] != 1 ]
		  then	 echo ${array[$numero]} >> "$path"/rand_list
			 casual[$numero]=1
			 let "count+=1"
		 fi
	 done
	 echo; echo
	 echo "---------------------------------------------------------------------------------------"
	 echo "Playlist casuale presente in \"$path/rand_list (/playlist per la lista ordinata)\""
	 echo "---------------------------------------------------------------------------------------"
	 echo
 else	 echo; echo
	 echo "-------------------------------------"
	 echo "Playlist presente in \"$path/playlist\""
	 echo "-------------------------------------"
	 echo
 fi

exit 0