#!/bin/bash
#
#/
#/ Usage:
#/ music-sync <options> -s|--source <source> -d|--dest <destination>
#/ music-sync <options> <source> <destination>
#/ 
#/ Syncronises music from one folder to another.
#/ 
#/ Options:
#/  -s, --source=<source>      The source folder of the music
#/  -d, --dest=<destination>   The destination folder of the music
#/  -t, --temp=<folder>        The temporary cache for converted files (default: /tmp/converted)
#/  -c, --convert=<bitrate>    Convert files to a given bitrate in kbps before syncing (default: 192)
#/  -a, --resize-art=<width>   Resize album-art before syncing (default width: 200)
#/  -j, --jobs=<nproc>         Number of processes to use in multi-threading (default: nproc - 2)
#/  -v, --verbose=<0-6>        Set log level (default: 2)
#/  -h, --help                 Display this help text
#/  -p, --playlists            Enable playlist sync
#/  -m, --mapping=DIR1,DIR2    Add mappings for playlists from DIR1 to DIR2
#/  -w, --windows-format       Use crlf and backslashes for playlists
#/ 
#/ Log levels:
#/  0 | Verbose
#/  1 | Debug
#/  2 | Info
#/  3 | Warning
#/  4 | Error
#/  5 | Fatal
#/  6 | Silence
#/ 
#/ Exit Codes:
#/  1 Dependencies not met
#/  2 Invalid Argument
#/  3 Source Unreachable
#/  4 Destination Unreachable
#/  5 Command failed
#/

begin=$(date +"%s")
# saner programming env: these switches turn some bugs into errors
set -o errexit -o pipefail -o noclobber -o nounset
source="-"
dest="-"
convert=false
verbose=2
bitrate=192
help=false
temp="/tmp/converted"
convertart=false
coverartsize=200
jobcount=$(expr $(nproc) - 2)
multithread=false
script_name=$(basename "${0}")
script_dir=$( cd "$( dirname "${BASH_SOURCE[0]}" )" && pwd )
mappingdest=''
mappingsrc=''
windowspaths=false
playlists=false

CheckDeps() {
	if [[ $1 == 2 ]]; then
		# Check getopt
		! getopt --test > /dev/null 
		if [[ ${PIPESTATUS[0]} -ne 4 ]]; then
			VerboseOutput 5 "\`getopt --test\` failed"
			VerboseOutput 5 "Sorry, It seems that your shell is not supported"
			VerboseOutput 5 "If you're using MacOS or another unix-like system, please install GNU getopt"
			ExecTime
			exit 1
		fi
		VerboseOutput 0 "\`getopt --test\` succeeded"
	fi

	if [[ $1 == 1 ]]; then
		# Check ffmpeg
		if [[ $convert == true ]]; then
			if [[ ! $(ffmpeg -h 2>/dev/null) ]]; then
				VerboseOutput 5 "\`ffmpeg -h\` failed"
				VerboseOutput 5 "Sorry, It seems that ffmpeg is not installed on your system"
				VerboseOutput 5 "Please install ffmpeg from your repositories and make sure it is available in your \$PATH"
				VerboseOutput 5 "Otherwise disable conversion"
				ExecTime
				exit 1
			fi
			VerboseOutput 0 "\`ffmpeg -h\` succeeded"
		fi

		# Check EyeD3
		if [[ $convertart == true ]]; then
			if [[ ! $(eyeD3 --version 2>/dev/null) ]]; then
				VerboseOutput 5 "\`eyeD3 --version\` failed"
				VerboseOutput 5 "Sorry, It seems that eyeD3 is not installed on your system"
				VerboseOutput 5 "Please install eyeD3 from your repositories and make sure it is available in your \$PATH"
				VerboseOutput 5 "Otherwise disable albumart conversion"
				ExecTime
				exit 1
			fi
			VerboseOutput 0 "\`eyeD3 --version\` succeeded"
		fi

		# Check ImageMagick
		if [[ $convertart == true ]]; then
			if [[ ! $(convert --version 2>/dev/null) ]]; then
				VerboseOutput 5 "\`convert --version\` failed"
				VerboseOutput 5 "Sorry, It seems that ImageMagick is not installed on your system"
				VerboseOutput 5 "Please install ImageMagick from your repositories and make sure it is available in your \$PATH"
				VerboseOutput 5 "Otherwise disable albumart conversion"
				ExecTime
				exit 1
			fi
			VerboseOutput 0 "\`convert --version\` succeeded"
		fi

		# Check Gnu parallel
		if [[ $multithread == true ]]; then
			if [[ ! $(parallel -h 2>/dev/null) ]]; then
				VerboseOutput 5 "\`parallel -h\` failed"
				VerboseOutput 5 "Sorry, It seems that parallel is not installed on your system"
				VerboseOutput 5 "Please install gnu-parallel from your repositories and make sure it is available in your \$PATH"
				VerboseOutput 5 "Otherwise disable multithreading"
				ExecTime
				exit 1
			fi
			VerboseOutput 0 "\`parallel -h\` succeeded"
		fi

		# Check playlist requirement
		if [[ $playlists == true ]]; then
			if [[ $windowspaths == true ]]; then
				if [[ ! $(unix2dos --version 2>/dev/null) ]]; then
					VerboseOutput 5 "\`unix2dos --version\` failed"
					VerboseOutput 5 "Sorry, It seems that unix2dos is not installed on your system"
					VerboseOutput 5 "Please install unix2dos from your repositories and make sure it is available in your \$PATH"
					VerboseOutput 5 "Otherwise disable windows-format playlists"
					ExecTime
					exit 1
				fi
			fi
			VerboseOutput 0 "\`unix2dos --version\` succeeded"
		fi
	fi
	VerboseOutput 1 "Dependency test OK"
}

GetOptions() {

	# https://stackoverflow.com/a/29754866
	OPTIONS=s:d:t:c::a::v::hj::pwm:
	LONGOPTS=source:,dest:,temp:,convert::,resize-art::,verbose::,help,jobs::,playlists,windows-format,mapping:

	# -use ! and PIPESTATUS to get exit code with errexit set
	# -temporarily store output to be able to check for errors
	# -activate quoting/enhanced mode (e.g. by writing out “--options”)
	# -pass arguments only via   -- "$@"   to separate them correctly
	! PARSED=$(getopt --options=$OPTIONS --longoptions=$LONGOPTS --name "$0" -- "$@")
	if [[ ${PIPESTATUS[0]} -ne 0 ]]; then
		# e.g. return value is 1
		#  then getopt has complained about wrong arguments to stdout
		Usage
		exit 2
	fi

	# read getopt's output this way to handle the quoting right:
	eval set -- "$PARSED"

	# now enjoy the options in order and nicely split until we see --
	while true; do
		case "$1" in
			-v|--verbose)
				if [[ $2 != "" ]]; then
					verbose=${2}
				fi
				shift 2
				;;
			-h|--help)
				help=true
				shift
				;;
			-s|--source)
				VerboseOutput 0 "--source given."
				VerboseOutput 1 "Source is ${2}"
				source="$2"
				shift 2
				;;
			-d|--dest)
				VerboseOutput 0 "--dest given."
				VerboseOutput 1 "Destination is ${2}"
				dest="$2"
				shift 2
				;;
			-t|--temp)
				VerboseOutput 0 "--temp given"
				VerboseOutput 1 "Tempfolder is ${2}"
				temp="$2"
				shift 2
				;;
			-c|--convert)
				VerboseOutput 0 "--convert given"
				convert=true
				if [[ $2 != "" ]]; then
					bitrate=${2}
				fi
				VerboseOutput 1 "Converted bitrate is ${bitrate}"
				shift 2
				;;
			-a|--resize-art)
				VerboseOutput 0 "--resize-art given"
				convertart=true
				if [[ $2 != "" ]]; then
					coverartsize=${2}
				fi
				shift 2
				VerboseOutput 1 "Album art will ${coverartsize}px wide"
				;;
			-j|--jobs)
				VerboseOutput 0 "--jobs given"
				multithread=true
				if [[ $2 != "" ]]; then
					jobcount=${2}
				fi
				shift 2
				VerboseOutput 1 "Multithreading will use ${jobcount} threads"
				;;
			-p|--playlists)
				VerboseOutput 0 "--playlists given"
				playlists=true
				shift
				VerboseOutput 1 "Playlist sync enabled"
				;;
			-w|--windows-format)
				VerboseOutput 0 "--windows given"
				windowspaths=true
				shift
				VerboseOutput 1 "Windows format playlists enabled"
				;;
			-m|--mapping)
				VerboseOutput 0 "--mapping given"
				listmappingparam=(${2//,/ })
				mappingsrc=${listmappingparam[0]:-""}
				mappingdest=${listmappingparam[1]:-""}
				shift 2
				VerboseOutput 1 "Playlist mappings enabled source=${mappingsrc} dest=${mappingdest}"
				;;
			--)
				shift
				break
				;;
			*)
				VerboseOutput 5 "Programming error"
				return 3
				;;
		esac
	done

	if [[ ! -z "${1+x}" ]]; then
		if [[ ${source} != "-" ]]; then
			VerboseOutput 4 "Source provided twice. Continueing with ${1}"
		fi
		source="$1"
		VerboseOutput 1 "Source is ${1}"
	fi

	if [[ ! -z "${2+x}" ]]; then
		if [[ ${dest} != "-" ]]; then
			VerboseOutput 4 "Destination provided twice. Continueing with ${2}"
		fi
		dest="$2"
		VerboseOutput 1 "Destination is ${2}"
	fi

	if [[ $dest == "-" ]] || [[ $source == "-" ]]; then
		help=true
	fi
	VerboseOutput 1 "Checks OK. Going on"
}

Usage() {
	grep '^#/' "${script_dir}/${script_name}" | sed 's/^#\/\w*//'
}

VerboseOutput() {
	level=""
	if [[ $verbose -le $1 ]]; then
		case "$1" in
			0) 
				level="\033[1;36mVerbose\033[0m"
				;;
			1)
				level="\033[1;34m Debug \033[0m"
				;;
			2)
				level="\033[1;37m Info  \033[0m"
				;;
			3)
				level="\033[1;33mWarning\033[0m"
				;;
			4)
				level="\033[1;31m Error \033[0m"
				;;

			5)
				level="\033[1;30m Fatal \033[0m"
				;;
		esac
		echo -e "[$level] $2" >&2
	fi
}

CreateFileList() {
	# ${1} /mnt/hdd/Example-Artist/Example-Album
	# ${2} /mnt/mtp/Example-Artist/Example-Album
	# ${3} Example-Artist/Example-Album
	IFS=""
	sourcepath="${1/\[/\\\[}/*"
	sourcepath="${sourcepath/\]/\\\]}"
	for file in $sourcepath; do
		origfile="${file#"$1/"}"
		relfile=$(echo ${origfile} | sed -e 's/\(\.\)*$//g' | tr -s ' ')
		mp3file=$(echo "${relfile}" | sed -e 's/.flac/.mp3/')
		VerboseOutput 0 "Checking ${3}${origfile}"
		if [[ -d "${1}/$origfile" ]]; then
			VerboseOutput 0 "${origfile} is folder"
			newdir="${3}$origfile"
			newdir=${newdir#"/"}
			VerboseOutput 1 "Entering $newdir"
			CreateFileList "${1}/$origfile/" "${2}/$relfile/" "$newdir/"
		elif [[ "${1}/$origfile" != *".m3u" ]] && [[ "${1}/$origfile" -nt "${2}/$mp3file" ]]; then
			echo ${3}$origfile >> /tmp/music-sync-filelist	
			VerboseOutput 0 "${origfile} is newer in source"
			VerboseOutput 2 "Added: ${3}${origfile}"
		elif [[ $playlists == true ]] && [[ "${1}/$origfile" == *".m3u" ]] && [[ "${1}/$origfile" -nt "${2}/$mp3file" ]]; then
			echo ${3}$origfile >> /tmp/music-sync-filelist	
			VerboseOutput 0 "${origfile} is newer in source"
			VerboseOutput 2 "Added playlist: ${3}${origfile}"
		fi
	done
}

Execute() {
	curline=0
	percentage=0
	IFS="
";
	if [[ $multithread == true ]]; then
		VerboseOutput 3 "Running in parallel. Mind your load"
		export -f ProcessFile
		export -f ConvertFile
		export -f ConvertPlaylist
		export -f CopyFile
		export -f VerboseOutput
		export -f ExecTime
		export dest
		export source
		export bitrate
		export convert
		export temp
		export verbose
		export coverartsize
		export begin
		export windowspaths
		export mappingsrc
		export mappingdest
		parallel --jobs ${jobcount} --will-cite --line-buffer --arg-file "/tmp/music-sync-filelist" ProcessFile 
	else
		for line in $(cat "/tmp/music-sync-filelist")
		do
			ProcessFile $line
		done
	fi
	VerboseOutput 2 "Done!"
}
ProcessFile() {
	line=${1}
	curline="$(grep -n "$line" /tmp/music-sync-filelist | head -n 1 | cut -d: -f1)"
	total=$(cat /tmp/music-sync-filelist | wc -l)
	percentage=$(echo "scale=4;${curline}/${total}" | bc)
	percentage=$(echo "scale=2;${percentage}*100" | bc)
	VerboseOutput 2 "Current File: $line"
	VerboseOutput 2 "Progress: $curline / $total (${percentage%00}%)"
	if [[ $convert == true ]]; then
		if [[ $line == *".m3u" ]]; then
			ConvertPlaylist "$line"
		else
			ConvertFile "$line"
		fi
	fi
	CopyFile "$line"
}

ConvertPlaylist() {
	line=${1}
	if [[ ! -f "${source}/$line" ]]; then
		VerboseOutput 5 "Source-file ${source}/$line Unreachable"
		ExecTime
		exit 3
	fi

	if [[ ! -d $(dirname "$temp/$line") ]]; then
		VerboseOutput 0 "Creating folder $temp/${line%/*}"
		mkdir -p "$temp/${line%/*}";
	fi;

	if [[ -f "$temp/$line" ]]; then
		rm "$temp/$line"
	fi
	VerboseOutput 0 "Creating playlist $temp/$line"
	IFS="
"
	for item in $(cat "$source/$line")
	do
		mp3item=$(echo $item | sed -e 's/\.*\//\//g'| tr -s ' ')
		if [[ $convert == true ]]; then
			mp3item=$(echo "$item" | sed -e 's/.flac/.mp3/')
		else 
			mp3item=$(echo "$item")
		fi
		playline=$(echo "${mp3item}" | sed -e "s,$mappingsrc,$mappingdest,g")
		if [[ $windowspaths == true ]]; then
			playline=$(echo "${playline}" | sed -e 's,\/,\\,g')
		fi
		echo $playline >> $temp/$line	
	done
	if [[ $windowspaths == true ]]; then
		VerboseOutput 0 "Converting lf to crlf"
		unix2dos $temp/$line 1>/dev/null 2>/dev/null
	fi
	VerboseOutput 1 "Converted: $line"

}

ConvertFile() {
	line=${1}
	if [[ ! -f "${source}/$line" ]]; then
		VerboseOutput 5 "Source-file ${source}/$line Unreachable"
		ExecTime
		exit 3
	fi

	if [[ ! -d $(dirname "$temp/$line") ]]; then
		VerboseOutput 0 "Creating folder $temp/${line%/*}"
		mkdir -p "$temp/${line%/*}";
	fi;
	mp3line=$(echo "$line" | sed -e 's/.flac/.mp3/')
	if [[ "${source}/$line" -nt "$temp/$mp3line" ]]; then
		if [[ $line != *".mp3" ]]; then
			VerboseOutput 3 "${line} will be converted to mp3-file ${mp3line}"
		fi
		VerboseOutput 0 "Converting MP3-file $line"
		ffmpeg -y -i "$source/$line" -acodec libmp3lame -map_metadata 0 -id3v2_version 3 -b:a ${bitrate}k "$temp/${mp3line}" 1>/dev/null 2>/dev/null
		if [[ $convertart == true ]]; then
			VerboseOutput 0 "Creating folder $temp/${mp3line}-images/"
			mkdir -p "$temp/${mp3line}-images/"
			VerboseOutput 0 "Extracted albumart"
			eyeD3 --write-images "$temp/${mp3line}-images/" "$temp/${mp3line}" 1>/dev/null 2>/dev/null
			frontcovers=(${temp}/${mp3line}-images/FRONT_COVER.*)
			if [ -e "$frontcovers" ]; then
				VerboseOutput 0 "Converting albumart"
				convert "$temp/${mp3line}-images/FRONT_COVER.*" -resize ${coverartsize}x${coverartsize} "$temp/${mp3line}-images/FRONT_COVER.jpg" 1>/dev/null 2>/dev/null
				eyeD3 --remove-all-images "$temp/${mp3line}" 1>/dev/null 2>/dev/null
				VerboseOutput 0 "Embedding albumart"
				eyeD3 --add-image "$temp/${mp3line}-images/FRONT_COVER.jpg:FRONT_COVER" "$temp/${mp3line}" 1>/dev/null 2>/dev/null
				VerboseOutput 1 "Converted cover art: ${mp3line}"
			else
				VerboseOutput 4 "No front cover art found for ${mp3line}"
			fi
		fi
		VerboseOutput 1 "Converted: $line"
	else
		VerboseOutput 3 "$line already converted"
	fi;
}

CopyFile() {
	line=${1}
	if [[ ! -d "$dest" ]]; then
		VerboseOutput 5 "Destination unreachable"
		ExecTime
		exit 4
	fi

	if [[ $convert == true ]]; then
		mp3line=$(echo "$line" | sed -e 's/.flac/.mp3/')
	else 
		mp3line=$(echo "$line")
	fi

	if [[ ! -f "${temp}/$mp3line" ]]; then
		VerboseOutput 5 "Source-file ${temp}/$mp3line Unreachable"
		ExecTime
		exit 3
	fi

	destline=$(echo $mp3line | sed -e 's/\.*\//\//g'| tr -s ' ')
	VerboseOutput 1 "Copying: $line"
	
	if [[ ! -d $(dirname "$dest/$line") ]]; then
		VerboseOutput 0 "Creating folder $dest/${line%/*}"
		mkdir -p "$dest/${destline%/*}";
	fi;

	cp -fv "$temp/$mp3line" "$dest/${destline}" 1>/dev/null 2>/dev/null

	VerboseOutput 1 "Copied: $line"
}


CleanUp() {
	VerboseOutput 1 "Cleaning Up"
	if [[ -f /tmp/music-sync-filelist ]]; then
		VerboseOutput 1 "Removing filelist"
		rm "/tmp/music-sync-filelist"
	fi
	VerboseOutput 1 "Done"
}

ExecTime() {
	termin=$(date +"%s")
	difftimelps=$(($termin-$begin))
	VerboseOutput 1 "$(($difftimelps / 60)) minutes and $(($difftimelps % 60)) seconds elapsed for Script Execution."
}

ErrorHandler() {
	VerboseOutput 5 "Error while executing $1"
	CleanUp
	exit 5
}

ExitHandler() {
	VerboseOutput 5 "Aborted"
	CleanUp
	exit 0
}

trap 'ExitHandler' SIGINT
trap 'ErrorHandler $BASH_COMMAND' ERR

CheckDeps 2
GetOptions $@
CheckDeps 1
if [[ $help == true ]]; then
	Usage
	exit
fi
if [[ -f /tmp/music-sync-filelist ]]; then
	rm /tmp/music-sync-filelist
fi
VerboseOutput 2 "Scanning for new or updated files"
CreateFileList $source $dest ""
if [[ ! -f /tmp/music-sync-filelist ]]; then
	VerboseOutput 2 "Nothing to do!"
	CleanUp
	exit 0
fi

if [[ $convert == true ]]; then
	temp=${temp}/bitrate-${bitrate}
	if [[ $convertart == true ]]; then
		temp="${temp}/coverart-${coverartsize}"
	else
		temp="${temp}/coverart-original"
	fi
	VerboseOutput 2 "Conversion enabled. Using $temp as temp-folder"
else
	if [[ $temp != "/tmp/converted" ]]; then
		VerboseOutput 2 "Conversion not enabled. Ignoring temp folder"
	fi
	temp=$source
fi	
Execute
CleanUp
ExecTime