combine-sinks

#!/bin/bash

# Script: combine-sinks
# Description: Manages PulseAudio/PipeWire sinks by creating a combined sink
# for multiple audio outputs.
#
# Usage: /usr/libexec/combine-sinks

# Set the necessary environment variables for PipeWire (or PulseAudio)
export PULSE_RUNTIME_PATH="/run/user/1000/pulse/"
export XDG_RUNTIME_DIR="/run/user/1000/"

# Set error handling
set -euo pipefail


OVOS_USER="$(getent passwd 1000 | cut -d: -f1)"
MK1_CARD_NAME="snd_rpi_proto"  # Mark 1 soundcard
HDMI_CARD_NAME="vc4-hdmi"       # HDMI soundcard
HEADPHONES_CARD_NAME="bcm2835"  # Onboard soundcard, not available on rpi5


# Function to handle errors
error_handler() {
    local line_no=$1
    local error_code=$2
    log_message "Error (code: ${error_code}) occurred on line ${line_no}"
    exit ${error_code}
}

trap 'error_handler ${LINENO} $?' ERR

# Log function to write to a log file
# Args:
#   $1: Message to log
log_message() {
    echo "$1"
    echo "$(date) - $1" >> /tmp/autosink.log
}


log_message "Setting up audio output as combined sinks"

if [ "$EUID" -eq 0 ]; then
    log_message "Running as root"
else
    log_message "Running as user"
fi

# Wait for the 'auto_null' sink if present (system booting phase)
if pactl list short sinks | grep -q "auto_null"; then
    log_message "auto_null sink exists, still booting? Sleeping for 3 seconds..."
    sleep 3
fi

# Check if the file exists before reading it
if [ -f /etc/OpenVoiceOS/i2c_platform ]; then
    i2c_platform=$(cat /etc/OpenVoiceOS/i2c_platform)
    log_message "ovos-i2csound detection: $i2c_platform"
else
    log_message "/etc/OpenVoiceOS/i2c_platform not found."
    i2c_platform=""
fi

# log mk1 related warnings just for info and debug
if echo "$i2c_platform" | grep -q "MARK1"; then
    # If it's a Mark 1 device, configure the Mark 1 soundcard
    # NOTE: sometimes errors here if early in boot process, it's fine as the .service retries on failure
    if aplay -l | grep "$MK1_CARD_NAME"; then
        CARD_NUMBER=$(aplay -l | grep "$MK1_CARD_NAME" | awk '{print $2}' | cut -d':' -f1)
        log_message "Detected CARD_NUMBER for Mark 1 soundcard: $CARD_NUMBER"
    else
        log_message "Error: ovos-i2csound detected Mark1 but 'aplay -l' could not detect '$MK1_CARD_NAME'"
    fi
fi

# Log the current sinks before any action
log_message "Sinks before action: $(pactl list short sinks)"

# Get all sinks, excluding 'auto_combined' and 'auto_null'
# NOTE: sometimes errors here if early in boot process, its fine as the .service retries on failure
SINKS=$(pactl list short sinks | awk '{print $2}' | grep -v 'auto_combined' | grep -v 'auto_null' | tr '\n' ',' | sed 's/,$//')
NUM_SINKS=$(echo "$SINKS" | tr ',' '\n' | wc -l)

# Retry logic if no sinks are found
RETRIES=5
while [ "$NUM_SINKS" -eq 0 ] && [ "$RETRIES" -gt 0 ]; do
    log_message "Retrying to find sinks... ($RETRIES retries left)"
    sleep 1
    RETRIES=$((RETRIES - 1))
    SINKS=$(pactl list short sinks | awk '{print $2}' | grep -v 'auto_combined' | grep -v 'auto_null' | tr '\n' ',' | sed 's/,$//')
    NUM_SINKS=$(echo "$SINKS" | tr ',' '\n' | wc -l)
done

# Check if auto_combined is present
if pactl list short sinks | grep -q "auto_combined"; then
    log_message "auto_combined sink exists"
else
    log_message "auto_combined sink missing"
fi

log_message "Total sinks: $NUM_SINKS"

# Create a combined sink if there is more than one sink
if [ "$NUM_SINKS" -gt 1 ]; then
    # Unload any existing combined sink module
    pactl unload-module module-combine-sink 2>/dev/null

    # Create a new combined sink with all available sinks
    if ! MODULE_ID=$(pactl load-module module-combine-sink slaves="$SINKS" sink_name=auto_combined); then
        log_message "Failed to create combined sink"
        exit 1
    fi

    # Verify the sink exists before setting as default
    if pactl list short sinks | grep -q "auto_combined"; then
        pactl set-default-sink auto_combined
        log_message "Combined sink created with outputs: $SINKS (module ID: $MODULE_ID)"
    else
        log_message "Combined sink creation failed"
        exit 1
    fi
else
    log_message "No sinks found to combine"
fi

# Log the current sinks after action
log_message "Sinks after action: $(pactl list short sinks)"