#!/usr/bin/env bash
set -euo pipefail
# Disable history expansion so PUBLISH_URL values with "!" are safe when sourcing env files.
set +H

ENV_FILE="${VIDEO_ENV_FILE:-/var/lib/roverd/video.env}"

if [[ ! -f "$ENV_FILE" ]]; then
	echo "Environment file ${ENV_FILE} missing; cannot publish" >&2
	exit 1
fi

# shellcheck disable=SC1090
# Strip any CRLFs to avoid sourcing a PUBLISH_URL with a stray carriage return in the name.
source <(tr -d '\r' < "$ENV_FILE")
PUBLISH_URL="${PUBLISH_URL:-}"
if [[ -z "${PUBLISH_URL}" ]]; then
	# Fallback parser in case sourcing missed due to weird whitespace/BOM
	PUBLISH_URL="$(grep -E '^PUBLISH_URL=' "$ENV_FILE" | head -n1 | cut -d= -f2- | tr -d '\r')"
fi
if [[ -z "${PUBLISH_URL}" ]]; then
	echo "PUBLISH_URL not set in ${ENV_FILE}; contents:" >&2
	sed -n '1,200p' "$ENV_FILE" >&2
	exit 1
fi

VIDEO_WIDTH="${VIDEO_WIDTH:-1920}"
VIDEO_HEIGHT="${VIDEO_HEIGHT:-1080}"
VIDEO_FPS="${VIDEO_FPS:-30}"
VIDEO_BITRATE="${VIDEO_BITRATE:-3000000}"
AUDIO_ENABLE="${AUDIO_ENABLE:-0}"
AUDIO_FIFO="${AUDIO_FIFO:-/var/lib/roverd/audio.pcm}"
AUDIO_CODEC="libopus"
# Raw PCM from the capture FIFO; transcode to low-bitrate Opus for TS/mediamtx/WHEP compatibility.
AUDIO_DEVICE="${AUDIO_DEVICE:-hw:0,0}"
AUDIO_RATE="${AUDIO_RATE:-48000}"
AUDIO_CHANNELS="${AUDIO_CHANNELS:-2}"
# Output params (tuned for low CPU/bandwidth).
AUDIO_OUT_RATE="${AUDIO_OUT_RATE:-16000}"
AUDIO_OUT_CHANNELS="${AUDIO_OUT_CHANNELS:-1}"
AUDIO_BITRATE="${AUDIO_BITRATE:-32000}"
AUDIO_FORMAT="${AUDIO_FORMAT:-s32le}"
# Flip the camera 180deg (supported by rpicam-vid/libcamera-vid)
FLIP_ARGS=(--rotation 180)

if [[ -n "${LIBCAMERA_BIN:-}" ]]; then
	LIBCAMERA_BIN_PATH="$LIBCAMERA_BIN"
elif command -v rpicam-vid >/dev/null 2>&1; then
	LIBCAMERA_BIN_PATH="$(command -v rpicam-vid)"
elif command -v libcamera-vid >/dev/null 2>&1; then
	LIBCAMERA_BIN_PATH="$(command -v libcamera-vid)"
else
	echo "Neither rpicam-vid nor libcamera-vid found; install libcamera-apps." >&2
	exit 1
fi

if [[ -n "${FFMPEG_BIN:-}" ]]; then
	FFMPEG_BIN_PATH="$FFMPEG_BIN"
elif command -v ffmpeg >/dev/null 2>&1; then
	FFMPEG_BIN_PATH="$(command -v ffmpeg)"
else
	echo "ffmpeg not found; install it via apt install ffmpeg." >&2
	exit 1
fi

run_pipeline() {
	if [[ "${AUDIO_ENABLE}" -eq 1 ]]; then
		if [[ ! -p "${AUDIO_FIFO}" ]]; then
			echo "Audio FIFO ${AUDIO_FIFO} missing; falling back to video-only" >&2
			AUDIO_ENABLE=0
		fi
	fi

	if [[ "${AUDIO_ENABLE}" -eq 1 ]]; then
		# Try audio + video; if FIFO is missing/empty, fallback to video-only.
		if ! "${LIBCAMERA_BIN_PATH}" \
			--inline \
			--timeout 0 \
			--width "${VIDEO_WIDTH}" \
			--height "${VIDEO_HEIGHT}" \
			"${FLIP_ARGS[@]}" \
			--framerate "${VIDEO_FPS}" \
			--bitrate "${VIDEO_BITRATE}" \
			--codec h264 \
			--profile baseline \
			--denoise cdn_off \
			--nopreview \
			--awb custom \
			--awbgains 1.5,1.8 \
			--output - \
			| "${FFMPEG_BIN_PATH}" \
				-hide_banner \
				-loglevel warning \
				-fflags nobuffer+genpts \
				-flags low_delay \
				-max_interleave_delta 0 \
				-use_wallclock_as_timestamps 1 \
				-thread_queue_size 512 \
				-f h264 \
				-i pipe:0 \
				-thread_queue_size 512 \
				-f "${AUDIO_FORMAT}" \
				-ar "${AUDIO_RATE}" \
				-ac "${AUDIO_CHANNELS}" \
				-i "${AUDIO_FIFO}" \
				-map 0:v:0 -map 1:a:0 \
				-c:v copy \
				-c:a "${AUDIO_CODEC}" \
				-b:a "${AUDIO_BITRATE}" \
				-ar:a "${AUDIO_OUT_RATE}" \
				-ac:a "${AUDIO_OUT_CHANNELS}" \
				-application lowdelay \
				-frame_duration 20 \
				-compression_level 0 \
				-muxpreload 0 \
				-muxdelay 0 \
				-vsync passthrough \
				-flush_packets 1 \
				-f mpegts \
				"${PUBLISH_URL}"
		then
			echo "Audio pipeline failed; falling back to video-only this run" >&2
			AUDIO_ENABLE=0
		fi
	fi

	if [[ "${AUDIO_ENABLE}" -ne 1 ]]; then
		"${LIBCAMERA_BIN_PATH}" \
			--inline \
			--timeout 0 \
			--width "${VIDEO_WIDTH}" \
			--height "${VIDEO_HEIGHT}" \
			"${FLIP_ARGS[@]}" \
			--framerate "${VIDEO_FPS}" \
			--bitrate "${VIDEO_BITRATE}" \
			--codec h264 \
			--profile baseline \
			--denoise cdn_off \
			--nopreview \
			--awb custom \
			--awbgains 1.5,1.8 \
			--output - \
			| "${FFMPEG_BIN_PATH}" \
				-hide_banner \
				-loglevel warning \
				-fflags nobuffer \
				-use_wallclock_as_timestamps 1 \
				-thread_queue_size 512 \
				-f h264 \
				-i pipe:0 \
				-c:v copy \
				-an \
				-flush_packets 1 \
				-f mpegts \
				"${PUBLISH_URL}"
	fi
}

while true; do
	if run_pipeline; then
		exit 0
	fi
	echo "Video publisher exited, restarting in 2s..." >&2
	sleep 2
done