#!/bin/bash

version=0.1.0

tmpdir=$TMPDIR

if test -z "$tmpdir"; then

	tmpdir="/tmp"

fi

tmpdir=$tmpdir/alsa-delay-script

delay=

pcard=

pdev=

ccard=

cdev=

yes=

quiet=

clean=

remove=

pdevice="default:%s"

pdevice_set=

cdevice="plughw:%s,%s,%s"

pctl=

cctl=

one=

arg=

mix=

pa=

useprocfs=yes

fuser_prg=fuser

insmod_prg=insmod

rmmod_prg=rmmod

lsmod_prg=lsmod

modprobe_prg=modprobe

chkconfig_prg=chkconfig

systemctl_prg=systemctl

pidof_prg=pidof

alsaloop_prg=alsaloop

amixer_prg=amixer

test -x /sbin/fuser && fuser_prg=/sbin/fuser

test -x /sbin/insmod && insmod_prg=/sbin/insmod

test -x /sbin/rmmod && rmmod_prg=/sbin/rmmod

test -x /sbin/lsmod && lsmod_prg=/sbin/lsmod

test -x /sbin/modprobe && modprobe_prg=/sbin/modprobe

test -x /sbin/chkconfig && chkconfig_prg=/sbin/chkconfig

test -x /bin/systemctl && systemctl_prg=/bin/systemctl

test -x /sbin/pidof && pidof_prg=/sbin/pidof

test -x /usr/bin/alsaloop && alsaloop_prg=/usr/bin/alsaloop

test -x /usr/local/bin/alsaloop && alsaloop_prg=/usr/local/bin/alsaloop

test -x /usr/bin/amixer && amixer_prg=/usr/bin/amixer

modprobeconf=/etc/modprobe.d/alsa.conf

test -r /etc/modprobe.conf && modprobeconf=/etc/modprobe.conf && useprocfs=""

alsaloopconf=/etc/alsaloop.conf

test -r modprobe.work && modprobeconf=modprobe.work

test -r modprobe.work && alsaloopconf=alsaloop.conf

usage() {

	echo "Usage: $0 [OPTION]... <requested_delay_in_ms> [<output_card>[,<device>]]"

	cat <

This is a delay utility version $version. The snd-aloop ALSA driver is

used to send all PCM streams back to the user space and the alsaloop

utility is used to send this stream to a real hardware.

<output_card> is ALSA card index (number) or string card identifier

<device> is ALSA device number

Use 'aplay -l' to list available cards and devices.

Operation modes:

  -h, --help		print this help, then exit

  -q, --quiet		quiet mode

  -y, --yes		do not ask any questions - answer is always yes

  -c, --clean           clean temporary directory and exit

  -r, --remove          remove the alsa-delay config modifications and exit

  --tmpdir=<DIR>        set temporary directory

Alsaloop options:

  --pdevice=<DEV>       force playback device

  --cdevice=<DEV>       force capture device

  --pctl=<DEV>          force playback ctl device

  --cctl=<DEV>          force capture ctl device

  --one=<ARG>           pass this argument to last thread

  --arg=<ARG>           pass this argument to all threads

  --mix=<ARG>           redirect ALSA mixer controls to OSS mixer

			(default is Master)

  --pa			Redirect PA to alsaloop

Note: For devices, the string %s is replaced with the card index

      and second string %s is replaced with the device index

      and third string %s is replaced the substream index (0-7).

      Example: hw:%s,%s,%s    (card, device, substream)

EOF

}

while :

do

	case "$1" in

	-h|--help)

		usage

		exit 0

		;;

	-q|--quiet)

		quiet=true ;;

	-y|--yes)

		yes=true ;;

	-c|--clean)

		clean="full" ;;

	-r|--remove)

		remove="full" ;;

	--tmpdir*)

		case "$#,$1" in

		*,*=*)

			tmpdir=`expr "z$1" : 'z-[^=]*=\(.*\)'` ;;

		1,*)

			usage ;;

		*)

			tmpdir="$2"

			shift ;;

		esac

		tmpdir="$tmpdir/alsa-compile-script"

		;;

	--pdevice*)

		case "$#,$1" in

		*,*=*)

			pdevice=`expr "z$1" : 'z-[^=]*=\(.*\)'`

			pdevice_set=yes ;;

		1,*)

			usage ;;

		*)

			pdevice="$2"

			pdevice_set=yes

			shift ;;

		esac

		;;

	--cdevice*)

		case "$#,$1" in

		*,*=*)

			cdevice=`expr "z$1" : 'z-[^=]*=\(.*\)'` ;;

		1,*)

			usage ;;

		*)

			cdevice="$2"

			shift ;;

		esac

		;;

	--pctl*)

		case "$#,$1" in

		*,*=*)

			pctl=`expr "z$1" : 'z-[^=]*=\(.*\)'` ;;

		1,*)

			usage ;;

		*)

			pctl="$2"

			shift ;;

		esac

		;;

	--cctl*)

		case "$#,$1" in

		*,*=*)

			cctl=`expr "z$1" : 'z-[^=]*=\(.*\)'` ;;

		1,*)

			usage ;;

		*)

			cctl="$2"

			shift ;;

		esac

		;;

	--one*)

		case "$#,$1" in

		*,*=*)

			one1=`expr "z$1" : 'z-[^=]*=\(.*\)'` ;;

		1,*)

			usage ;;

		*)

			one1="$2"

			shift ;;

		esac

		one="$one $one1"

		;;

	--arg*)

		case "$#,$1" in

		*,*=*)

			arg1=`expr "z$1" : 'z-[^=]*=\(.*\)'` ;;

		1,*)

			usage ;;

		*)

			arg1="$2"

			shift ;;

		esac

		arg="$arg $arg1"

		;;

	--mix*)

		case "$#,$1" in

		*,*=*)

			mix=`expr "z$1" : 'z-[^=]*=\(.*\)'` ;;

		1,*)

			usage ;;

		*)

			mix="$2"

			shift ;;

		esac

		arg="$arg $arg1"

		;;

	--pa)

		pa=true

		;;

	*)

		if test -n "$1"; then

			ok=

			if test -z "$delay"; then

				delay="$1"

				if test "$delay" -lt 1000; then

					delay=$[$delay * 1000]

				fi

				ok=true

			fi

			if test -z "$ok" -a -z "$pcard"; then

				pcard="$1"

				ok=true

			fi

			if test -z "$ok"; then

				echo "Unknown parameter '$1'"

				break

			fi

		else

			break

		fi

		;;

	esac

	shift

done

test -z "$pdevice_set" -a -n "$pa" && pdevice="plug:dmix:%s"

test -z "$delay" && delay="50000"

test -z "$pcard" && pcard="1"

pdev=$(echo $pcard | cut -s -d , -f 2)

pcard=$(echo $pcard | cut -d , -f 1)

test -z "$pdev" && pdev="0"

test -z "$ccard" && ccard="Loopback,1"

cdev=$(echo $ccard | cut -s -d , -f 2)

ccard=$(echo $ccard | cut -d , -f 1)

test -z "$cdev" && cdev="0"

# Echo "true" or "false", depending on $yes and user response to prompt

# $1 is prompt message

question_bool() {

	if test "$yes" = "yes"; then

		echo "true"

	else

		echo >&2 -n "$1 (Y/ ) "

		read i

		local i=${i:0:1}

		if test "$i" = "Y" -o "$i" = "y"; then

			echo "true"

		else

			echo "false"

		fi

	fi

}

# Safe exit

safe_exit() {

	if test -r /etc/pulse/client.conf ; then

		if grep "# alsa-delay-line-to-be-removed-1234" /etc/pulse/client.conf 2> /dev/null > /dev/null ; then

			grep -v alsa-delay-line-to-be-removed-1234 /etc/pulse/client.conf > /etc/pulse/client.conf.new

			if test -s /etc/pulse/client.conf.new; then

				mv /etc/pulse/client.conf.new /etc/pulse/client.conf

			fi

		fi

	fi

	exit $1

}

# Log and execute $@ and check success

do_cmd() {

	if test -z "$quiet"; then

		echo "> $@"

	fi

	$@ || safe_exit 1

}

# Cache or restore $protocol and $url and $package in $tmpdir

check_environment() {

	if ! test -d $tmpdir ; then

		mkdir -p $tmpdir

		if ! test -d $tmpdir; then

			echo >&2 "Unable to create directory $tmpdir."

			exit 1

		fi

	fi

	echo "Using temporary tree: $tmpdir"

	test -x /bin/depmod && depmodbin=/bin/depmod

	test -x /sbin/depmod && depmodbin=/sbin/depmod

	if test -z "$depmodbin"; then

		echo >&2 "Unable to find depmod utility."

		exit 1

	fi

	test -x /bin/modinfo && modinfobin=/bin/modinfo

	test -x /sbin/modinfo && modinfobin=/sbin/modinfo

	if test -z "$modinfobin"; then

		echo >&2 "Unable to find modinfo utility."

		exit 1

	fi

}

# Kill processes currently accessing the audio devices

kill_audio_apps() {

	local pids0=$($fuser_prg /dev/snd/* 2> /dev/null)

	local pids1=$($fuser_prg /dev/mixer* 2> /dev/null)

	local pids2=$($fuser_prg /dev/sequencer* 2> /dev/null)

	local pids=

	for pid in $pids0 $pids1 $pids2; do

		local pids="$pids $pid"

	done

	if ! test -z "$pids"; then

		echo

		echo "WARNING! An audio application uses ALSA driver:"

		echo

		for pid in $pids; do

			ps --no-headers -p $pids || safe_exit 1

		done

		echo

		if test $(question_bool "Would you like to kill these apps?") = "true"; then

			if test -w /etc/pulse/client.conf ; then

				echo "autospawn = no # alsa-delay-line-to-be-removed-1234" >> /etc/pulse/client.conf

			fi

			for pid in $pids; do

				do_cmd kill $pid

			done

			sleep 2

			local killed=

			for pid in $pids; do

				local a=$(ps --no-headers -p $pids)

				if test -n "$a"; then

					do_cmd kill -9 $pid

					local killed="true"

				fi

			done

			if test "$killed" = "true"; then

				sleep 2

				for pid in $pids; do

					local a=$(ps --no-headers -p $pids)

					if test -n "$a"; then

						echo >&2 "Unable to kill application:"

						echo >&2 "  $a"

						safe_exit 1

					fi

				done

			fi

		else

			echo >&2 "Cannot continue with running audio applications."

			safe_exit 1

		fi

	fi

}

# Echo the list of configured sound modules

configured_modules() {

	if test -z "$useprocfs"; then

		cat $modprobeconf | grep -E "^alias snd-card-" | cut -d ' ' -f 3

	else

		cat /proc/asound/modules | colrm 1 3

	fi

}

# Echo the list of loaded sound modules

current_modules() {

	$lsmod_prg | cut -d ' ' -f 1 | grep -E "^(snd[_-])"

}

# The loopback kernel driver detection

aloop_present() {

	if test -r /proc/asound/card0/id; then

		local id=$(cat /proc/asound/card0/id)

	else

		local id=""

	fi

	if test "$id" = "Loopback"; then

		echo "yes"

	fi

}

# Remove kernel modules, using two phases

# $@ is module names

my_rmmod() {

	local phase2=

	while test -n "$1"; do

		if ! $rmmod_prg $1 2> /dev/null > /dev/null; then

			local phase2="$phase2 $1"

		else

			echo "> rmmod $1"

		fi

		shift

	done

	for mod in $phase2; do

		echo "> rmmod $mod"

		if ! $rmmod_prg $mod ; then

			echo >&2 "Unable to remove kernel module $mod."

			safe_exit 1

		fi

	done

}

# Reload kernel modules

kernel_modules() {

	kill_audio_apps

	if test "$1" = "unload"; then

		local present=$(aloop_present)

		if test "$present" = "yes"; then

			if ! $rmmod_prg snd-aloop; then

				echo >&2 "Unable to remove kernel module snd-aloop."

				safe_exit 1

			fi

		fi

	fi

	local curmods=$(current_modules)

	local usermods=$(configured_modules)

	my_rmmod $curmods

	$modprobe_prg soundcore || safe_exit 1

	if test "$1" = "load"; then

		if ! $modprobe_prg snd-aloop; then

			echo >&2 "Unable to install kernel module snd-aloop."

			safe_exit 1

		fi

	fi

	for mod in $usermods; do

		if ! $modprobe_prg $mod; then

			echo >&2 "Unable to install kernel module $mod."

			safe_exit 1

		fi

	done

	echo "Kernel modules ready:"

	cat /proc/asound/cards

	sleep 0.5

}

# If $package is alsa-driver then remove current modules

kernel_modules_remove() {

	local curmods=$(current_modules)

	if test -z "$curmods"; then

		echo "No ALSA kernel modules to remove."

		safe_exit 0

	fi

	kill_audio_apps

	my_rmmod $curmods

	echo "ALSA kernel modules removed."

}

function clean() {

	echo -n "Removing tree $tmpdir:"

	if test -d "$tmpdir"; then

		if ! rm -rf "$tmpdir"; then

			echo " failed"

			safe_exit 1

		fi

	fi

	echo " success"

}

function reindex_modprobe_conf() {

	if test -z "$useprocfs"; then

		cat > $tmpdir/run.awk <

function rewrite_line(line,   res, c, i, j) {

	split(line, l, " ")

	if (l[1] == "alias") {

		printf(l[1])

		c = int(substr(l[2], 9)) + 1

		printf(" snd-card-%i %s\n", c, l[3])

	} else if (l[1] == "options") {

		printf(l[1])

		for (i = 2; i <= length(l); i++) {

			c = substr(l[i], 0, 9)

			if (c == "snd-card-") {

				c = int(substr(l[i], 9)) + 1

				printf(" snd-card-%i", c)

				continue

			}

			c = substr(l[i], 0, 6)

			if (c == "index=") {

				printf(" index=")

				c = substr(l[i], 6)

				split(c, y, ",")

				for (j = 1; j <= length(y); j++) {

					c = int(y[j]) + 1

					if (j > 1)

						printf(",")

					printf("%i", c)

				}

				continue

			}

			printf(" %s", l[i])

		}

		printf("\n")

	} else if (l[1] == "remove") {

		printf(l[1])

		flag = 0

		for (i = 2; i <= length(l); i++) {

			if (l[i] == "/usr/sbin/alsactl" || l[i] == "store") {

				flag++;

				printf(" %s", l[i]);

				continue;

			}

			if (flag == 2) {

				c = int(l[i]) + 1;

				printf(" %i", c);

				flag = 0;

				continue;

			}

			flag = 0;

			printf(" %s", l[i]);

		}

		printf("\n")

	} else {

		print line

	}

}

BEGIN			{ aloop=0; }

/alias snd-card-0 snd-aloop/ { aloop=1; next; }

/options snd-card-0 index=0/ { if (aloop) next; }

/options snd-aloop/	{ next; }

/alias snd-card-/	{ rewrite_line(\$0); next; }

/options snd-/		{ rewrite_line(\$0); next; }

/remove snd-/		{ rewrite_line(\$0); next; }

			{ print \$0; }

EOF

		cat $modprobeconf | awk -f $tmpdir/run.awk > $modprobeconf.new

		rm $tmpdir/run.awk || safe_exit 1

	else

		local index=1

		echo -n "" > $modprobeconf.new

		declare -a modules printed

		for mod in $(cat /proc/asound/modules | grep -Ev "^2[6789]" | colrm 1 3); do

			if test "$mod" != "snd_aloop" -a "$mod" != "snd-aloop"; then

				if test -z ${modules[$mod]}; then

					modules[$mod]=$index

				else

					modules[$mod]="${modules[mod]},$index"

				fi

				echo "alias snd-card-$index $mod" >> $modprobeconf.new

				echo "options snd-card-$index index=$index" >> $modprobeconf.new

			fi

			index=$(expr $index + 1)

		done

		for mod in $(cat /proc/asound/modules | grep -Ev "^2[6789]" | colrm 1 3); do

			if test "$mod" != "snd_aloop" -a "$mod" != "snd-aloop"; then

				if test -z ${printed[$mod]}; then

					echo "options $mod index=${modules[$mod]}" >> $modprobeconf.new

					printed[$mod]=yes

				fi

			fi

		done

	fi

cat >> $modprobeconf.new <

alias snd-card-0 snd-aloop

options snd-card-0 index=0

options snd-aloop index=0

EOF

	if ! test -f $modprobeconf.alsa-delay.save ; then

		if ! test -f $modprobeconf ; then

			touch $modprobeconf.alsa-delay.save

		else

			cp $modprobeconf $modprobeconf.alsa-delay.save

		fi

	fi

	mv $modprobeconf.new $modprobeconf || safe_exit 1

}

function modify_modprobe_conf() {

	local check=$(cat $modprobeconf 2> /dev/null | grep -E "^alias snd-card-0 snd-aloop")

	local present=$(aloop_present)

	if test -n "$check"; then

		echo "Module snd-aloop is already installed."

		if ! test "$present" = "yes"; then

			kernel_modules load

		fi

	else

		reindex_modprobe_conf

		if ! test "$present" = "yes"; then

			kernel_modules load

		else

			kernel_modules

		fi

	fi

}

function myprintf() {

	local cnt=$(echo "$1" | grep -o "%" | wc -l)

	if test $cnt -eq 1; then

		printf "$1" "$2"

	else if test $cnt -eq 2; then

		printf "$1" "$2" "$3"

	else

		printf "$1" "$2" "$3" "$4"

	fi

	fi

}

function check_ctl_name() {

	$amixer_prg -D "$1" contents | grep "name='$2'"

}

function check_oss_mixer() {

	grep ": mixer" /proc/asound/oss/devices

}

function get_card_id() {

	$amixer_prg -D "$1" info | head -1 | cut -d '/' -f 1 | cut -d ' ' -f 3- | awk '{ print substr($0, 2, length($0)-2) }'

}

function generate_alsaloop_line() {

	local file="$1"

	local idx="$2"

	local carg=$(myprintf "$cdevice" $ccard $cdev $idx)

	local parg=$(myprintf "$pdevice" $pcard $pdev $idx)

	local res="-C $carg -P $parg -T $idx -t $delay"

	if test -n "$cctl"; then

		local carg=$(myprintf "$cctl" $pcard $cdev $idx)

		local res="$res -Y $carg"

	fi

	if test -n "$pctl"; then

		local parg=$(myprintf "$pctl" $pcard $pdev $idx)

		local res="$res -X $parg"

	fi

	if test -n "$arg"; then

		local res="$res $arg"

	fi

	if test $idx -eq 7; then

		if test -n "$one"; then

			local res="$res $one"

		fi

		if test -z "$pctl"; then

			local res="$res -X hw:$pcard"

		fi

		local mymix="$mix"

		if test -z "$mymix"; then

			local mymix="Master"

			for mymix in Master "Master Mono" Headphone Headphone2 PCM Speaker \

				     "Desktop Speaker" Beep Front Rear Center LFE Side \

				     Surround ; do

				local check=$(check_ctl_name hw:$pcard "$mymix Playback Switch")

				if test -n "$check"; then

					local res="$res -m \"name='$mymix Playback Switch'\""

				fi

				local check=$(check_ctl_name hw:$pcard "$mymix Playback Volume")

				if test -n "$check"; then

					local res="$res -m \"name='$mymix Playback Volume'\""

				fi

			done

		else

			local check=$(check_ctl_name hw:$pcard "$mymix Playback Switch")

			if test -n "$check"; then

				local res="$res -m \"name='$mymix Playback Switch'\""

			fi

			local check=$(check_ctl_name hw:$pcard "$mymix Playback Volume")

			if test -n "$check"; then

				local res="$res -m \"name='$mymix Playback Volume'\""

			fi

		fi

		local check=$(check_oss_mixer)

		if test -n "$check"; then

			local res="$res -O \"$mymix@VOLUME\""

		fi

	fi

	echo $res >> $file

}

function generate_alsaloop_conf() {

	local idx=0

	rm -f $alsaloopconf.new

	while test $idx -lt 8; do

		generate_alsaloop_line $alsaloopconf.new $idx

		idx=$(expr $idx + 1)

	done

	mv $alsaloopconf.new $alsaloopconf || safe_exit 1

}

function kill_alsaloop() {

	local pid=$($pidof_prg alsaloop)

	if test -n "$pid"; then

		echo "Killing alsaloop..."

	fi

	while test -n "$pid"; do

		kill $pid

		sleep 0.01

		pid=$($pidof_prg alsaloop)

	done

}

function restart_alsaloop() {

	echo "Restarting alsaloop: delay $delay us."

	if test -d /etc/systemd/system; then

		systemctl start alsaloop.service

	else

		/etc/init.d/alsaloop start

	fi

	sleep 0.4

	local pid=$($pidof_prg alsaloop)

	if test -z "$pid"; then

		echo "ERROR: Not started, check /var/log/messages for details"

	else

		if test -d /etc/systemd/system; then

			systemctl status alsaloop.service

		else

			ps -p $pid

		fi

	fi

}

function create_systemd_service() {

	if test -r /etc/systemd/system/alsaloop.service; then

		echo "/etc/systemd/system/alsaloop.service exists"

	else

		cat >> /etc/systemd/system/alsaloop.service <