#!/bin/sh
#
# setting up the alsa configuration.

. /etc/rc.config

if [ "$ALSA_DEVICE" = "all" ]; then
	cards="$(LC_ALL=C aplay -l | grep '^card' | sed 's/card \([0-9]\+\).*device \([0-9]\+\).*/\1 \2/')"
elif [ -n "${ALSA_DEVICE##-*}" -a "$ALSA_DEVICE" != "auto" ]; then
	cards="$(echo "$ALSA_DEVICE" | sed "s/,/\n/g")"
else
	rm -f /etc/asound.conf
	exit
fi
channels=$(echo -e "$cards" | wc -l)

char()
{
	echo "abcdefghijklmnopqrstuvwxyz" | cut -b $(($1+1))
}

if [ $channels = 1 ]; then
	echo -e "$cards" | { 
		read card device name
		echo "pcm.!default {"
		echo "  type hw"
		echo "  card $card"
		echo "  device $device"
		echo "}"
	} > /etc/asound.conf
	exit
fi

cat > /etc/asound.conf << EOF
pcm.!default {
  type plug
  slave {
    pcm "all"
  }
}
pcm.all {
  type route
  slave {
    pcm multi
    channels $(($channels*2))
  }
$(
	i=0
	while [ $i -lt $channels ]; do
		echo "  ttable.0.$(($i*2+0)) 1.0"
		echo "  ttable.1.$(($i*2+1)) 1.0"
		i=$(($i+1))
	done
)
}
pcm.multi {
  type multi
$(
	i=0
	while [ $i -lt $channels ]; do
		echo "  slaves.$(char $i) {"
		echo "    pcm \"$(char $i)\""
		echo "    channels 2"
		echo "  }"
		i=$(($i+1))
	done
	i=0
	while [ $i -lt $channels ]; do
		echo "  bindings.$(($i*2+0)).slave $(char $i)"
		echo "  bindings.$(($i*2+0)).channel 0"
		echo "  bindings.$(($i*2+1)).slave $(char $i)"
		echo "  bindings.$(($i*2+1)).channel 1"
		i=$(($i+1))
	done
)
}
$(
	i=0
	echo -e "$cards" | while [ $i -lt $channels ]; do
		read card device name
		echo "pcm.$(char $i) {"
		echo "  type hw"
		echo "  card $card"
		echo "  device $device"
		echo "  channels 2"
		echo "}"
		i=$(($i+1))
	done
)
EOF