#! /bin/bash

#ASSUMPTIONS
#-fs on card is FAT32

#recursive file navigator to loop through everything
function sync()
{
	for i in "$1"/*; do
		#new file name without special chars to adhere to FAT32 limitations
		fat_path=${i//"?"/""}
		fat_path=${fat_path//"*"/""}
		fat_path=${fat_path//"<"/""}
		fat_path=${fat_path//">"/""}
		fat_path=${fat_path//"|"/""}
		fat_path=${fat_path//":"/""}

        fat_name="${fat_path##*/}"

		#if directory then call self and loop
		if [ -d "$i" ]; then

            if [ ! -d "$fat_name" ]; then
                #mkdir "${fat_path##*/}"
                mkdir "$fat_name"
            fi

			#cd "${fat_path##*/}"
            cd "$fat_name"
			sync "$i"
			cd ../
		#if file then check
		else

            if [ -f "$fat_name" ] || \
               [ -f "${fat_name//.flac/.mp4}" ] || \
               [ -f "${fat_name//.flac/.aac}" ] || \
               [ -f "${fat_name//.flac/.m4a}" ]; then
                echo skipping "$fat_name"
            else
        		echo $fat_path
			    #if these then copy (remove cover art)
			    if [ "${i: -4}" == ".mp3" -o \
				     "${i: -4}" == ".mp4" -o \
                     "${i: -4}" == ".m4a" -o \
				     "${i: -4}" == ".aac" -o \
                     "${i: -5}" == ".opus" ]; then

				    #~ cp "$i" "$fat_name"
				    ffmpeg -i "$i" -vn -codec:a copy "$fat_name"
			    #if flac then convert to m4a (if flag is not raised)
			    elif [ "${i: -5}" == ".flac" ]; then
				    if [ "$conv" == 1 ]; then
					    trimmed_name=${fat_path##*/}
                        ffmpeg -i "$i" -aq $quality -vn -strict -2 "${trimmed_name%%.flac}".m4a
				    else
					    #~ cp "$i" "$fat_name"
					    ffmpeg -i "$i" -vn -codec:a copy "$fat_name"
				    fi
			    fi
            fi
		fi
	done
}

help()
{
cat << EOF
help: $0 options

Sync memory device with music folder on ssd
Files will be saved/synced to current directory
If flac files are found they will be converted to m4a to conserve space

Uses ffmpeg

OPTIONS:
   -h      	You know what this is obviously
   -c		Do not convert flac to mp4
   -q       Quality (defaults to 2; 200-250 kbps)
   -f		Source Folder (defaults to ~/Music)

Note: if bit is given it will be used instead of quality

EOF
}

conv=1
quality=2 #highest quality
folder="$HOME/Music"

while getopts “hcf:q:” OPTION
do
	case $OPTION in
		h)
			help
			exit 1
			;;
		c)
			conv=0
			;;
        q)
            quality=$OPTARG
            ;;
		f)
			folder=$OPTARG
			;;
		*)
			break
			;;
	esac
done

sync "$folder"