#!/bin/bash -u
# copy_playlist.bsh
# This script reads the contents of a m3u playlist, copies each file to specified folder
# and optionally changes the album tag and track no tag of the new files
#
# Call without parameters to see usage. 
#
# FUNCTION DEFINITIONS
#
function pause(){
   read -p "$*"
}
#
# ROUTINE STARTS HERE
#
# check and validate inputs
#
if [ $# -lt 2 ]
then
   echo -e "\nThis script reads the contents of a m3u playlist, copies each file to specified folder
and optionally changes the album tag and the track no tag of the new files.
	    
Usage:
$0 sourcelist.m3u /homes/user/destinationpath [\"New Album Name\"]
"
   exit;
fi
# check that sourcelist exists & is > 0 bytes
#
SOURCELIST=$1
#
# does sourcelist exist and is it a regular file?
if [ ! -f "$SOURCELIST" ]
then
  echo -e "\n$SOURCELIST does not exist or is not a regular file\n"
  exit 1;
fi
#
# is sourcelist > 0 bytes?
if [ ! -s "$SOURCELIST" ]
then
  echo -e "\n$SOURCELIST is zero bytes! Please check the file. \nTry cat $SOURCELIST.\n"
  exit 2;
fi
# set DESTPATH
DESTPATH=$2
# check that destinationpath exists
if [ ! -e "$DESTPATH" ]
then
  echo -e "\n$DESTPATH does not exist!\n"
  exit 3;
fi
# check that destinationpath is a directory
if [ ! -d "$DESTPATH" ]
then
  echo -e "\n$DESTPATH is not a directory!\n"
  exit 4;
fi
# check that destinationpath is writable
if [ ! -w "$DESTPATH" ]
then
  echo -e "\n$DESTPATH is not writable!\n"
  exit 5;
fi
# reset error variable
strErrorDesc=""
# initilise/reset counter
TrackNo=0
# open sourcelist
# read a line of text
# loop until EOF:-
while read line
do
  #echo $line
  #	if it starts with "file:///"
  if [[ $line =~ ^file:// ]] 
  then
    (( TrackNo += 1))
    # increment the counter
    # extract string starting after "file:///" and ending at the end of the line
    strLen=`expr length $line`
    filenameLen=$(( strLen - 7 ))
    SourceFile=`expr substr $line 8 $filenameLen`
    #		replace all %20s with " " etc
    SourceFile=${SourceFile//%20/ }
    #		replace all %25 with "%" etc
    SourceFile=${SourceFile//%25/%}
    #		check that file exists 
    if [ -e "$SourceFile" ]
    then
       #echo -e "\nCopying $SourceFile to $DESTPATH"
	echo -e "Copying file $TrackNo"
         # copy file to destination path
	 cp "$SourceFile" "$DESTPATH"
         if [ $? != 0 ]; then
	    {
		strErrorDesc="$strErrorDesc\nUnable to copy the following file:\n $SourceFile"			        
	} fi
	 # test to see whether there is an album name 
	 if [ ! -z "$3" ]
	 then
	    NewFile="$DESTPATH${SourceFile##*/}"
   	    #TagAlbum "$NewFile" "$3" $TrackNo
	    FileExt=${NewFile#*.}
 	    #echo "File extension is $FileExt"
	    case "$FileExt" in
		"mp3" | "MP3" | "Mp3" | "mP3" )
			#check that suitable tagger exists
			if type -p id3tag &>/dev/null
			then
                            #call it
			    echo -e "Writing mp3/id3 tag to $NewFile"
			    id3tag -A "$3" -t $TrackNo "$NewFile" >/dev/null
			    if [ $? != 0 ]; then
			    {
				strErrorDesc="$strErrorDesc\nProblem with id3tag tagging the following file:\n $NewFile"			        
			    } fi
			else
			    strErrorDesc="$strErrorDesc\nUnable to tag the following file because id3tag is not installed:\n $NewFile"
			fi 
			;;
		"m4a" | "M4A" | "M4a" | "m4A" )
			#check that suitable tagger exists
			#call it
			if type -p AtomicParsley &>/dev/null
			then
                            #call it
			    echo -e "Writing m4a tag to $NewFile"
			    AtomicParsley "$NewFile" --album "$3" --tracknum $TrackNo --overWrite >/dev/null
			    if [ $? != 0 ]; then
			    {
				strErrorDesc="$strErrorDesc\nProblem with AtomicParsley tagging the following file:\n $NewFile"			        
			    } fi
			else
			    strErrorDesc="$strErrorDesc\nUnable to tag the following file because AtomicParsley is not installed:\n $NewFile"
			fi 
			;;
		* )
			# Default Option
			echo "\nError: $FileExt is an unrecognised format\n"
			;;
	    esac
	 fi
    else
       echo -e "\nError: $SourceFile does not exist! ********\n"
    fi
  fi
done <"$SOURCELIST"
if [ ${#strErrorDesc} -gt 0 ]
then
	echo -e $strErrorDesc
	exit 10
fi
exit 0