#!/bin/bash
## This script will print an asoundrc stream which add virtual boards from one physical board.
## Output must be directed into a file to be stored

### FUNCTIONS ###
user_manual() {
 echo  "Required Parameters
    1. Phy board id like "hw:CARD=Alp882e,DEV=0"
    2. Phy board channels quantity
    3. Virtual boards base name like : \"Emulated analog Alp222\"
    4. Virtual boards channels quantities (2: stéréo, ...)" >&2
}


build_phy_node() {
 node_type=$1
 card_id=$2
 channels_qty=$3
 echo -e "pcm_slave.$node_type { \n	pcm \"$card_id\"\n	channels $channels_qty\n }\n"
}

build_virtual_node() {
node_alias=$1
node_type=$2
node_id=$3
ipc_key=$4
phy_name=$5
phy_channels_base=$6
phy_channels_qty=$7
description=$8
direction=$9

echo -e "pcm.$node_alias$node_id {
	type $node_type
	ipc_key $ipc_key
	ipc_key_add_uid true
	slave $phy_name"

    for channel_id in $(seq 0 "$(($phy_channels_qty-1))")
    do
    echo -e "\tbindings.$channel_id $(($channel_id+$phy_channels_base))"
    done


	echo -e "\thint.description" \"$description \#$node_id $direction\"
	echo -e "}\n"
}

### MAIN ###

[ "$#" -ne "4" ] && user_manual && exit 1

ipc_key=$(date +%N)
card_id=$1
channels_qty=$2
virtual_basename=$3
stream_width=$4
virt_qty=$(($channels_qty / $stream_width))

echo "#Building Alsa sound RC file for $virt_qty virtual boards of $stream_width channels from physical board $card_id with $channels_qty."

##Build the entries first
build_phy_node "ins" "$card_id" "$channels_qty"

for entry_idx in $(seq 0 $(($virt_qty-1)))
do
    build_virtual_node "mic" "dsnoop" "$entry_idx" "$ipc_key" "ins" "$(($stream_width * $entry_idx))" "$stream_width" "virtual Alp-$stream_width" "in"
done

##Now the outpus
build_phy_node "outs" "$card_id" "$channels_qty"

ipc_key=$(date +%N)

for entry_idx in $(seq 0 $(($virt_qty-1)))
do
    build_virtual_node "out" "dshare" "$entry_idx" "$ipc_key" "outs" "$(($stream_width * $entry_idx))" "$stream_width" "virtual Alp-$stream_width" "out"
done