#!/bin/bash
# CHT Sender: muxed video + audio over TCP/mpegts
# Source: Wayland (kmsgrab) + desktop audio + webcam mic
# Usage: ./stream_av.sh [RECEIVER_IP] [PORT]
#
# Requires: sudo for kmsgrab, PulseAudio for audio capture
# Audio is non-blocking (monitor source = passive tap)

set -uo pipefail

RECEIVER_IP="${1:-mcrndeb}"
PORT="${2:-4444}"

# Let root access the user's PulseAudio session
REAL_UID="${SUDO_UID:-$(id -u)}"
export PULSE_SERVER="unix:/run/user/${REAL_UID}/pulse/native"

# Find the default sink's monitor source (desktop audio - what you hear)
MONITOR=$(PULSE_SERVER="$PULSE_SERVER" pactl info 2>/dev/null | grep "Default Sink" | awk '{print $3}').monitor
# Webcam mic - find by partial match (serial number varies)
WEBCAM_MIC=$(PULSE_SERVER="$PULSE_SERVER" pactl list short sources 2>/dev/null | grep -i "C922" | awk '{print $2}' || true)

echo "Monitor source: $MONITOR"
echo "Webcam mic: ${WEBCAM_MIC:-not found}"
echo "Streaming to: ${RECEIVER_IP}:${PORT}"

if [ -n "$WEBCAM_MIC" ]; then
    echo "Webcam mic found, mixing desktop + mic"
    # Two pulse inputs: desktop monitor + webcam mic, mixed into one audio stream
    exec ffmpeg \
        -init_hw_device drm=drm:/dev/dri/card0 \
        -init_hw_device vaapi=va@drm \
        -device /dev/dri/card0 -f kmsgrab -framerate 30 -i - \
        -f pulse -i "$MONITOR" \
        -f pulse -i "$WEBCAM_MIC" \
        -filter_complex "[1:a][2:a]amix=inputs=2:duration=longest[aout]" \
        -map 0:v -map "[aout]" \
        -vf 'hwmap=derive_device=vaapi,scale_vaapi=w=1920:h=1080:format=nv12,fps=30' \
        -c:v h264_vaapi -qp 20 -g 30 -keyint_min 30 -bf 0 \
        -c:a aac -b:a 128k \
        -flush_packets 1 -fflags nobuffer -muxdelay 0 -muxpreload 0 \
        -f mpegts "tcp://${RECEIVER_IP}:${PORT}" \
        -hide_banner
else
    echo "No webcam mic, desktop audio only"
    exec ffmpeg \
        -init_hw_device drm=drm:/dev/dri/card0 \
        -init_hw_device vaapi=va@drm \
        -device /dev/dri/card0 -f kmsgrab -framerate 30 -i - \
        -f pulse -i "$MONITOR" \
        -vf 'hwmap=derive_device=vaapi,scale_vaapi=w=1920:h=1080:format=nv12,fps=30' \
        -c:v h264_vaapi -qp 20 -g 30 -keyint_min 30 -bf 0 \
        -c:a aac -b:a 128k \
        -flush_packets 1 -fflags nobuffer -muxdelay 0 -muxpreload 0 \
        -f mpegts "tcp://${RECEIVER_IP}:${PORT}" \
        -hide_banner
fi