[Unit]
Description=ESP32 Serial Audio to PulseAudio
After=pulseaudio.service
Requires=pulseaudio.service
# Tie service start to the device node so it won’t launch until udev creates it
Requires=dev-ttyESP32_A.device
After=dev-ttyESP32_A.device

[Service]
# Ensure PulseAudio runtime dir is set so pactl can connect
Environment=XDG_RUNTIME_DIR=/run/user/%U
Environment=LANG=en_US.UTF-8
WorkingDirectory=/home/littlesophia/serial_audio_catcher

# Wait until PulseAudio socket and serial device exist
ExecStartPre=/bin/sh -c 'until [ -S "$XDG_RUNTIME_DIR/pulse/native" ] && [ -e /dev/ttyESP32_A ]; do sleep 2; done'

# Create the null sink before starting the pipeline
ExecStartPre=/usr/bin/pactl unload-module module-null-sink
ExecStartPre=/usr/bin/pactl load-module module-null-sink sink_name=esp32 rate=16000 channels=2 format=s16le

# Run the pipeline through a shell so the pipe is interpreted correctly
ExecStart=/bin/sh -c '/home/littlesophia/serial_audio_catcher/serial_to_stdout /dev/ttyESP32_A | /usr/bin/pacat --raw --rate=16000 --channels=2 --format=s16le --device=esp32'

# Restart automatically if it crashes or exits
Restart=always
RestartSec=5

# Log output to journal
StandardOutput=journal
StandardError=journal

[Install]
WantedBy=default.target