#!/usr/bin/env bash
set -euo pipefail

ROOT_DIR="$(cd -- "$(dirname -- "${BASH_SOURCE[0]}")/.." && pwd)"
BUILD_DIR="${BUILD_DIR:-$ROOT_DIR/build}"
STREAMER_BIN="${STREAMER_BIN:-$BUILD_DIR/cvmmap_streamer}"
SRS_ROOT="${SRS_ROOT:-$HOME/Code/srs}"
SRS_BIN="${SRS_BIN:-$SRS_ROOT/trunk/objs/srs}"
SRS_CONF="${SRS_CONF:-$SRS_ROOT/trunk/conf/srs.conf}"
FFPROBE_BIN="${FFPROBE_BIN:-ffprobe}"
FFMPEG_BIN="${FFMPEG_BIN:-ffmpeg}"
CURL_BIN="${CURL_BIN:-curl}"

INPUT_URI="${INPUT_URI:-}"
STREAM_NAME="${STREAM_NAME:-}"
CODEC="${CODEC:-h264}"
ENCODER_BACKEND="${ENCODER_BACKEND:-ffmpeg}"
ENCODER_DEVICE="${ENCODER_DEVICE:-nvidia}"
RTMP_TRANSPORT="${RTMP_TRANSPORT:-libavformat}"
INGEST_MAX_FRAMES="${INGEST_MAX_FRAMES:-120}"
PROBE_TIMEOUT_S="${PROBE_TIMEOUT_S:-20}"
DECODE_FRAMES="${DECODE_FRAMES:-15}"
SRS_MAX_CONNECTIONS="${SRS_MAX_CONNECTIONS:-64}"

RUN_DIR="${RUN_DIR:-$BUILD_DIR/live_srs_forward_smoke_$(date +%Y%m%d_%H%M%S)}"
mkdir -p "$RUN_DIR"

SRS_LOG="$RUN_DIR/srs.log"
STREAMER_LOG="$RUN_DIR/streamer.log"
HTTP_PROBE_LOG="$RUN_DIR/ffprobe_httpflv.log"
DECODE_LOG="$RUN_DIR/ffmpeg_decode_httpflv.log"
API_LOG="$RUN_DIR/srs_api_streams.json"
SRS_TEMP_CONF="$RUN_DIR/srs.conf"

RTMP_URL="rtmp://127.0.0.1/live/${STREAM_NAME}"
HTTP_FLV_URL="http://127.0.0.1:8080/live/${STREAM_NAME}.flv"

SRS_PID=""
STREAMER_PID=""
STARTED_SRS=0

require_bin() {
	local path="$1"
	local label="$2"
	if ! command -v "$path" >/dev/null 2>&1 && [[ ! -x "$path" ]]; then
		echo "$label not found: $path" >&2
		exit 1
	fi
}

usage() {
	cat <<'EOF'
Usage:
  live_srs_forward_smoke.sh <input-uri> [stream-name]

Environment overrides:
  INPUT_URI           cvmmap source URI, if positional argument is omitted
  STREAM_NAME         RTMP/HTTP-FLV stream name, default derived from INPUT_URI
  CODEC               h264|h265
  ENCODER_BACKEND     auto|ffmpeg
  ENCODER_DEVICE      auto|nvidia|software
  RTMP_TRANSPORT      libavformat|ffmpeg_process
  INGEST_MAX_FRAMES   bounded frame count for the smoke
  DECODE_FRAMES       frames to decode from HTTP-FLV after probe
  SRS_ROOT            local SRS checkout, default ~/Code/srs
EOF
}

derive_stream_name() {
	local uri="$1"
	local body="${uri#cvmmap://}"
	local instance="${body%%@*}"
	instance="${instance%%\?*}"
	instance="${instance%%/*}"
	if [[ -z "$instance" || "$instance" == "$uri" ]]; then
		instance="stream"
	fi
	instance="${instance//[^a-zA-Z0-9_-]/_}"
	printf '%s_live' "$instance"
}

wait_for_http() {
	local url="$1"
	local attempts="$2"
	for _ in $(seq 1 "$attempts"); do
		if "${CURL_BIN}" -fsS "$url" >/dev/null 2>&1; then
			return 0
		fi
		sleep 0.25
	done
	return 1
}

wait_for_http_flv() {
	local attempts="$1"
	for _ in $(seq 1 "$attempts"); do
		if "${FFPROBE_BIN}" \
			-v error \
			-select_streams v:0 \
			-show_entries stream=index,codec_name,width,height,avg_frame_rate \
			-of default=noprint_wrappers=1 \
			"$HTTP_FLV_URL" >"$HTTP_PROBE_LOG" 2>&1; then
			return 0
		fi
		if [[ -n "$STREAMER_PID" ]] && ! kill -0 "$STREAMER_PID" >/dev/null 2>&1; then
			return 1
		fi
		sleep 0.25
	done
	return 1
}

print_failure_context() {
	echo "--- artifacts ---" >&2
	echo "RUN_DIR=$RUN_DIR" >&2
	echo "--- streamer log tail ---" >&2
	tail -n 120 "$STREAMER_LOG" >&2 || true
	echo "--- srs log tail ---" >&2
	tail -n 120 "$SRS_LOG" >&2 || true
}

cleanup() {
	if [[ -n "$STREAMER_PID" ]] && kill -0 "$STREAMER_PID" >/dev/null 2>&1; then
		kill "$STREAMER_PID" >/dev/null 2>&1 || true
		wait "$STREAMER_PID" >/dev/null 2>&1 || true
	fi
	if [[ "$STARTED_SRS" -eq 1 ]] && [[ -n "$SRS_PID" ]] && kill -0 "$SRS_PID" >/dev/null 2>&1; then
		kill "$SRS_PID" >/dev/null 2>&1 || true
		wait "$SRS_PID" >/dev/null 2>&1 || true
	fi
}
trap cleanup EXIT

require_bin "$STREAMER_BIN" "streamer binary"
require_bin "$SRS_BIN" "SRS binary"
require_bin "$FFPROBE_BIN" "ffprobe"
require_bin "$FFMPEG_BIN" "ffmpeg"
require_bin "$CURL_BIN" "curl"

if [[ "${1:-}" == "--help" || "${1:-}" == "-h" ]]; then
	usage
	exit 0
fi

if [[ -n "${1:-}" ]]; then
	INPUT_URI="$1"
fi
if [[ -n "${2:-}" ]]; then
	STREAM_NAME="$2"
fi

if [[ -z "$INPUT_URI" ]]; then
	echo "input URI is required" >&2
	usage >&2
	exit 1
fi
if [[ -z "$STREAM_NAME" ]]; then
	STREAM_NAME="$(derive_stream_name "$INPUT_URI")"
fi

RTMP_URL="rtmp://127.0.0.1/live/${STREAM_NAME}"
HTTP_FLV_URL="http://127.0.0.1:8080/live/${STREAM_NAME}.flv"

if [[ ! -f "$SRS_CONF" ]]; then
	echo "SRS config not found: $SRS_CONF" >&2
	exit 1
fi

if wait_for_http "http://127.0.0.1:1985/api/v1/versions" 4; then
	echo "Reusing running SRS on 127.0.0.1:1935"
else
	sed \
		-e 's/^daemon[[:space:]]\+on;/daemon              off;/' \
		-e "s/^max_connections[[:space:]]\\+[0-9]\\+;/max_connections     ${SRS_MAX_CONNECTIONS};/" \
		"$SRS_CONF" >"$SRS_TEMP_CONF"
	(
		cd "$SRS_ROOT/trunk"
		"$SRS_BIN" -c "$SRS_TEMP_CONF" >"$SRS_LOG" 2>&1 &
		echo $! >"$RUN_DIR/srs.pid"
	)
	SRS_PID="$(cat "$RUN_DIR/srs.pid")"
	STARTED_SRS=1
	if ! wait_for_http "http://127.0.0.1:1985/api/v1/versions" 40; then
		echo "SRS failed to become ready on 127.0.0.1:1985" >&2
		print_failure_context
		exit 1
	fi
fi

"$STREAMER_BIN" \
	--run-mode pipeline \
	--input-uri "$INPUT_URI" \
	--codec "$CODEC" \
	--encoder-backend "$ENCODER_BACKEND" \
	--encoder-device "$ENCODER_DEVICE" \
	--rtmp \
	--rtmp-url "$RTMP_URL" \
	--rtmp-transport "$RTMP_TRANSPORT" \
	--ingest-max-frames "$INGEST_MAX_FRAMES" \
	>"$STREAMER_LOG" 2>&1 &
STREAMER_PID=$!

if ! wait_for_http_flv $((PROBE_TIMEOUT_S * 4)); then
	echo "HTTP-FLV stream never became probeable: $HTTP_FLV_URL" >&2
	print_failure_context
	exit 1
fi

if ! "$FFMPEG_BIN" -v error -i "$HTTP_FLV_URL" -an -frames:v "$DECODE_FRAMES" -f null - >"$DECODE_LOG" 2>&1; then
	echo "warning: HTTP-FLV decode sample failed, see $DECODE_LOG" >&2
fi
"$CURL_BIN" -fsSL "http://127.0.0.1:1985/api/v1/streams/" >"$API_LOG" 2>/dev/null || true

wait "$STREAMER_PID"
STREAMER_RC=$?
STREAMER_PID=""

echo "RUN_DIR=$RUN_DIR"
echo "STREAMER_RC=$STREAMER_RC"
echo "INPUT_URI=$INPUT_URI"
echo "RTMP_URL=$RTMP_URL"
echo "HTTP_FLV_URL=$HTTP_FLV_URL"
echo "--- http-flv ffprobe ---"
cat "$HTTP_PROBE_LOG"
echo "--- http-flv decode log ---"
cat "$DECODE_LOG"
echo "--- srs api streams ---"
cat "$API_LOG" 2>/dev/null || true
echo "--- streamer log tail ---"
tail -n 80 "$STREAMER_LOG"