#!/bin/bash

source /etc/transogg.conf

[ ! -d "$TEMPDIR" ] && mkdir -p "$TEMPDIR"

# log errors
exec 2> $TEMPDIR/debug-$$.log

set -E

MyPID=$$

tty=$(who -m|awk '{print $2}')

cleanup() {
	pkill -t $tty find||true
	unset files
	export killed=1
}

export -f cleanup

usage() {
	cat <<-EOF
	$0 [-D] [-n <instances>] [-F] [-s <source directory>] [-t <target directory>]

	    -n <instances>: run <instances> simultaneous processes (overrides config
	                    file)
	    -l <max load>: Don't start transcoding if the load average reaches <max
	                   load>
	    -T <time>: time before raising instance number again after reaching max
	               load
	    -F: ignore any existing timestamp file (useful if you change target
	        quality)
	    -D: increase debug level (produces potentially huge log files in
	        $TEMPDIR)
	    -c <conf-file>: Alternate configuration file
	EOF
}

trap cleanup 1 2 15 EXIT

declare -i DEBUG=0

while getopts 'l:FhiDs:t:T:c:' opt
do
	case $opt in
		s) ORIGDIR=$OPTARG ;;
		t) DESTDIR=$OPTARG ;;
		l) TARGETLOAD=$OPTARG
		;;
		F) rm -f "$TIMESTAMP"
		;;
		h) usage ; exit 0 ;;
		T) LOADTIME=$OPTARG ;;
		D) DEBUG+=1; set -x ;;
		c) source "$OPTARG" ;;
		*) exit 127
		;;
	esac
done

(( DEBUG >= 2 )) && set -v

COLUMNS=$(tput cols)
LINES=$(tput lines)
trap 'COLUMNS=$(tput cols) LINES=$(tput lines)' WINCH
declare -a children
declare -i filenum=0
declare -i lastid=-1
FIFO=/tmp/transogg-$UID-$MyPID-status
IDFIFO=/tmp/transogg-$UID-$MyPID-finished
shopt -s extglob
declare -i lastINSTchange=0
((instances = TARGETLOAD / 2))

[ -d "$TEMPDIR" ] \
		|| mkdir -p "$TEMPDIR" \
		|| exit 1

[ -d "$DESTDIR" ] \
		|| mkdir -p "$DESTDIR" \
		|| exit 1

[ -f "$TIMESTAMP" ] \
		|| touch -t 197001010100 "$TIMESTAMP"

case $FORMAT in
	ogg)
		function encode {
			nice -n $NICENESS ionice -c3 \
				oggenc \
				-Q \
				-a "${artist:-?}" \
				-l "${album:-?}" \
				-N "${tracknum}${tracktotal/#//}" \
				-t "${title:-$(basename "$1")}" \
				-q $QUALITY \
				-d "$year" \
				-G "$genre" \
				-c DISCNUMBER="$disc" \
				-o "$2" \
				$tmpfile \
				2> /dev/null
		}
	;;
	mp3)
		function encode {
			nice -n $NICENESS ionice -c3 \
				lame \
				--quiet \
				--ta "${artist:-?}" \
				--tl "${album:-?}" \
				--tn "${tracknum}${tracktotal/#//}" \
				--tt "${title:-$(basename "$1")}" \
				-v \
				--abr $BITRATE \
				--ty "$year" \
				--tg "$genre" \
				$tmpfile \
				"$2" \
				2> /dev/null
		}
	;;
	*)
		exit 127
	;;
esac

gettag() {
	echo -e "$1" \
		 | egrep -i '^'${2}= \
		 | cut -d = -f 2
}

mpc_info() {
	infos=$(ionice -c3 \
			 strings "$1" \
			 | egrep -A1 'artist|album|title|track|year|genre')
	title=$(echo -e "$infos"|sed -n /title/I {n;p})
	artist=$(echo -e "$infos"|sed -n /artist/I {n;p})
	track=$(echo -e "$infos"|sed -n /track/I {n;p})
	album=$(echo -e "$infos"|sed -n /album/I {n;p})
	year=$(echo -e "$infos"|sed -n /year/I {n;p})
	genre=$(echo -e "$infos"|sed -n /genre/I {n;p})
	unset infos
}

flac_info() {
	infos=$(ionice -c3 \
			 metaflac \
			 --show-tag=TITLE \
			 --show-tag=ARTIST \
			 --show-tag=ALBUM \
			 --show-tag=TRACKNUMBER \
			 --show-tag=TRACKTOTAL \
			 --show-tag=DATE \
			 --show-tag=DISCNUMBER \
			 --show-tag=GENRE \
			 "$1")

	artist=$(gettag "$infos" artist)

	album=$(gettag "$infos" album)

	title=$(gettag "$infos" title)

	tracknum=$(gettag "$infos" tracknumber)

	tracktotal=$(gettag "$infos" tracktotal)

	year=$(gettag "$infos" date)

	disc=$(gettag "$infos" discnumber)

	genre=$(gettag "$infos" genre)

	unset infos
}

function vorbis_info {
	infos=$(ionice -c3 ogginfo "$1" | sed 's/^\t//')

    artist=$(gettag "$infos" artist)

    album=$(gettag "$infos" album)
    
    title=$(gettag "$infos" title)
    
    tracknum=$(gettag "$infos" tracknumber)

	tracktotal=$(gettag "$infos" tracktotal)

	year=$(gettag "$infos" date)

	disc=$(gettag "$infos" discnumber)

	genre=$(gettag "$infos" genre)

	unset infos
}

function mp3_info {
	infos=$(ionice -c3 mp3info -p 'artist=%a
album=%l
title=%t
tracknum=%n
year=%y
genre=%g' "$1" | iconv -f $ID3CHARSET -t utf-8//TRANSLIT)
    artist=$(gettag "$infos" artist|iconv -t utf-8)
    album=$(gettag "$infos" album|iconv -t utf-8)
    title=$(gettag "$infos" title|iconv -t utf-8)
    tracknum=$(gettag "$infos" tracknum|iconv -t utf-8)
	year=$(gettag "$infos" year)
	genre=$(gettag "$infos" genre)

	unset infos
}

function get_info {
    case "$(file "$1")" in
				   *Musepack*)
					   mpc_info "$1"
					   ;;
				   *MPEG*)
					   mp3_info "$1"
					   ;;
				   *MP3*)
					   mp3_info "$1"
					   ;;
				   *Vorbis*)
					   vorbis_info "$1"
					   ;;
				   *FLAC*)
					   flac_info "$1"
					   ;;
				   *)
					   :
					   ;;
    esac
}

function theRealSox {
	echo "$1: $2 → $3" >&2
    get_info "$2" 2>/dev/null
    tmpfile="$TEMPDIR"/transogg-$UID-$(date +%Y%m%d%H%M%S%N).wav
    nice -n $NICENESS ionice -c3 \
			sox \
			--norm \
			--single-threaded "$2" \
			-r ${RATE:=44100} \
			-c ${CHANNELS:=2} \
			--temp $TEMPDIR \
			$tmpfile \
			> /dev/null || true
    encode "$2" "$3" || true
	rm -f $tmpfile
    unset artist album tracknum tracktotal title year genre tmpfile
	until echo $1 >> $IDFIFO
	do
		sleep 1
	done
}

function CleanIdFile {
	while read curid
	do
		if (( lastid + 1 == $curid ))
		then
			if [ -n "${files[$curid]}" ]
			then
				touch -r "$ORIGDIR/${files[$curid]}" "$TIMESTAMP"
			fi
			sed -n -i "/^$curid$/d;p" $IDFIFO
			lastid=$curid
		fi
		unset children[$curid]
		echo -n '' > $FIFO
		for processInd in ${!children[@]}
		do
			echo ${children[$processInd]} >> $FIFO
		done
		echo $filenum $instances $TARGETLOAD $message
	done < <(sort -n $IDFIFO)
}

function MySox {
	load=$(sed 's/^\([0-9]\+\)[. ].*/\1/' /proc/loadavg)
	if (( load > TARGETLOAD && instances > 1 && $(date +%s) - lastINSTchange >= LOADTIME))
	then
		((instances -= 1))
		if ((instances < 1))
		then
			instances=1
		fi
		lastINSTchange=$(date +%s)
		echo $filenum $instances $TARGETLOAD $message
	elif (( load < TARGETLOAD && $(date +%s) - lastINSTchange >= LOADTIME))
	then
		((instances += 1))
		lastINSTchange=$(date +%s)
		echo $filenum $instances $TARGETLOAD $message
	fi
	CleanIdFile
	until [ ${#children[@]} -lt $instances ]
	do
		load=$(sed 's/^\([0-9]\+\)[. ].*/\1/' /proc/loadavg)
		if (( load > TARGETLOAD && instances > 1 && $(date +%s) - lastINSTchange >= LOADTIME))
		then
			((instances -= 1))
			if ((instances < 1))
			then
				instances=1
			fi
			lastINSTchange=$(date +%s)
			echo $filenum $instances $TARGETLOAD $message
		elif (( load < TARGETLOAD && $(date +%s) - lastINSTchange >= LOADTIME))
		then
			((instances += 1))
			lastINSTchange=$(date +%s)
			echo $filenum $instances $TARGETLOAD $message
		fi
		CleanIdFile
		read -t 0.5 -n 1 load_change||true
		case $load_change in
			+) ((TARGETLOAD += 1))
			   echo $filenum $instances $TARGETLOAD $message
			   ;;
			-) ((TARGETLOAD -= 1))
			   echo $filenum $instances $TARGETLOAD $message
			   ;;
			q) cleanup
			   message=Exiting...
			   echo $filenum $instances $TARGETLOAD $message
			   ;;
		esac
		if ((instances < 1))
		then
			instances=1
			echo $filenum $instances $TARGETLOAD $message
		fi
		unset message
	done
	theRealSox $filenum "$1" "$2" 2>>$TEMPDIR/debug-$MyPID-theRealSox &
	children[$filenum]="${1#$ORIGDIR/}"
}

function FileDisappeared {
	dialog --yes-label "Continue" \
		--no-label "Rescan" \
		--yesno "File $1 disappeared!" \
		$LINES $COLUMNS
}

function FindFiles {
	cd "$ORIGDIR" || {
		echo "Could not cd into $ORIGDIR"
		exit 1
	}
	cd -
	readarray -t files < <(find "$ORIGDIR"/ \
		-newer "$TIMESTAMP" \
		-type f \
		-printf "%TY%Tm%Td%TH%TM.%TS %P\n" \
		| grep -v .timestamp \
		| tee >(dialog --output-fd 1 --progressbox "Looking for new files..." \
			$LINES $COLUMNS) \
		| sort \
		| sed 's/^[^ ]* //' )
}

function ShowProgress {
	while read filenum concurrency targetload message
	do
		stamp=$(ls -go --time-style="+%d/%m/%Y %H:%M:%S" $TIMESTAMP | \
			awk '{print $4 " " $5}')
		if [ "$filenum" -gt 0 -a $nfiles -gt 0 ]
		then
			percent=$((${filenum:-${#files[@]}}*100/$nfiles))
		else
			percent=0
		fi
		echo XXX
		echo $percent
		echo "Position: ${filenum:-?} / $nfiles ($stamp) $message"
		echo "$concurrency processes max. Target load: $targetload."
		echo -e "(+/- to change, q to quit)\n"
		sed 's/$/\n/' $FIFO
		echo XXX
	done \
	| dialog \
		--title "Transcoding files from $ORIGDIR to $DESTDIR..." \
		--no-shadow \
		--gauge "Transcoding files from $ORIGDIR to $DESTDIR..." \
		$LINES $COLUMNS
}

function ProcessFiles {
	lastINSTchange=$(date +%s)
	for filenum in ${!files[@]}
	do
		filename=${files[$filenum]}
		if [ -z "$filename" ]
		then
			break
		fi
		if [ ! -e "$ORIGDIR/$filename" ]
		then
			restart=1
			return 0
		fi
		destfile="$DESTDIR/${filename%.*}.$FORMAT"
		[ -d "${destfile%/?*}" ] || mkdir -p "${destfile%/?*}"
		MySox "$ORIGDIR/$filename" "$destfile"
		echo -n '' > $FIFO
		for processInd in ${!children[@]}
		do
			echo ${children[$processInd]} >> $FIFO
		done
		echo $filenum $instances $TARGETLOAD $message
		sleep 0.01
	done
	until [ ${#children[@]} -eq 0 ]
	do
		echo ${#files[@]} $instances $TARGETLOAD Finishing...
		sleep 1
		CleanIdFile
	done
	echo ${#files[@]} $instances $TARGETLOAD Done\!
}

function Work {
	echo "Looking for new files..."
	FindFiles 2>$TEMPDIR/debug-$MyPID-FindFiles

	nfiles=${#files[@]}

	ProcessFiles 2>$TEMPDIR/debug-$MyPID-ProcessFiles \
	> >(ShowProgress 2>$TEMPDIR/debug-$MyPID-ShowProgress)
	sleep 1
	clear
	if [ -n "$killed" ]
	then
		rm $FIFO $IDFIFO
		exit 1
	fi
	while [ -n "$restart" ]
	do
		unset restart
		if FileDisappeared
		then
			for indice in {0..$lastid}
			do
				unset files[$indice]
			done
			ProcessFiles 2>>$TEMPDIR/debug-$MyPID-ProcessFiles \
			> >(ShowProgress 2>>$TEMPDIR/debug-$MyPID-ShowProgress)
		else
			Work
		fi
	done
}

Work
rm $FIFO $IDFIFO

set +x

clear

cd "$DESTDIR" || {
	echo "Could not cd into $DESTDIR"
	exit 1
}
(
	echo "Obsolete files..."
	find . -type f \
		| grep -v .timestamp \
		| grep -v 00-INDEX.txt \
		| while read filename
		do
			if [ ! -e "$ORIGDIR/${filename%.$FORMAT}".* ]
			then
				echo "Deleting $filename..."
				rm -f "$filename"
			fi
		done
	cd "$DESTDIR"
	cd "$OLDPWD"
	echo -e "\nEmpty directories..."
	find "$DESTDIR" -type d -empty -print -delete
) | dialog --output-fd 1 --progressbox "Removing obsolete files..." $LINES $COLUMNS