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

SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
# shellcheck disable=SC1091
source "${SCRIPT_DIR}/common.sh"

STEP="5g-link-logger"

resolve_target_ip() {
  if [[ -n "${BLITZ_TIME_SERVER_IP:-}" ]]; then
    printf '%s\n' "${BLITZ_TIME_SERVER_IP}"
    return 0
  fi

  for candidate in ${BLITZ_5G_ROUTE_TARGETS//,/ }; do
    if [[ -n "${candidate}" ]]; then
      printf '%s\n' "${candidate}"
      return 0
    fi
  done
  return 1
}

emit_sample_json() {
  local interface_name="${1:-}"
  local target_ip="${2:-}"

  python3 - "${interface_name}" "${target_ip}" <<'PY'
import json
import subprocess
import sys
import time

interface_name = sys.argv[1]
target_ip = sys.argv[2]

payload = {
    "ts_unix_ms": time.time_ns() // 1_000_000,
    "interface": interface_name,
    "target_ip": target_ip,
    "link_present": False,
    "route_output": "",
    "route_ok": False,
    "probe_ok": False,
    "ping_rtt_ms": None,
    "rx_bytes": 0,
    "tx_bytes": 0,
    "rx_packets": 0,
    "tx_packets": 0,
    "rx_errors": 0,
    "tx_errors": 0,
    "rx_drops": 0,
    "tx_drops": 0,
}

if interface_name:
    try:
        output = subprocess.check_output(
            ["ip", "-j", "-s", "link", "show", "dev", interface_name],
            text=True,
            stderr=subprocess.DEVNULL,
        )
        stats = json.loads(output)
        if stats:
            item = stats[0]
            payload["link_present"] = True
            rx = item.get("stats64", {}).get("rx", {})
            tx = item.get("stats64", {}).get("tx", {})
            if not rx and not tx:
                rx = item.get("stats", {}).get("rx", {})
                tx = item.get("stats", {}).get("tx", {})
            payload["rx_bytes"] = int(rx.get("bytes") or 0)
            payload["tx_bytes"] = int(tx.get("bytes") or 0)
            payload["rx_packets"] = int(rx.get("packets") or 0)
            payload["tx_packets"] = int(tx.get("packets") or 0)
            payload["rx_errors"] = int(rx.get("errors") or 0)
            payload["tx_errors"] = int(tx.get("errors") or 0)
            payload["rx_drops"] = int(rx.get("dropped") or 0)
            payload["tx_drops"] = int(tx.get("dropped") or 0)
    except Exception:
        pass

if target_ip:
    try:
        route = subprocess.check_output(
            ["ip", "route", "get", target_ip],
            text=True,
            stderr=subprocess.STDOUT,
        ).strip()
        payload["route_output"] = route.splitlines()[0] if route else ""
        payload["route_ok"] = bool(payload["route_output"]) and (
            not interface_name or f" dev {interface_name}" in payload["route_output"]
        )
    except Exception as exc:
        payload["route_output"] = str(exc)

    ping_cmd = ["ping", "-c", "1", "-W", "2", target_ip]
    if interface_name:
        ping_cmd[1:1] = ["-I", interface_name]
    ping = subprocess.run(ping_cmd, capture_output=True, text=True)
    payload["probe_ok"] = ping.returncode == 0
    output = (ping.stdout or "") + "\n" + (ping.stderr or "")
    for token in output.replace("\n", " ").split():
        if token.startswith("time="):
            value = token.split("=", 1)[1].rstrip("ms")
            try:
                payload["ping_rtt_ms"] = float(value)
            except ValueError:
                pass
            break

print(json.dumps(payload, separators=(",", ":"), ensure_ascii=False))
PY
}

if [[ "${OMNI_BOOT_MODE:-0}" == "1" ]]; then
  blitz_load_boot_env
  blitz_require_run_context
fi

if [[ -z "${BLITZ_RUN_DIR:-}" && -f "${BLITZ_RUN_CONTEXT_FILE:-}" ]]; then
  blitz_load_run_context_env || true
fi
blitz_ensure_instance_id

export BLITZ_5G_LINK_LOG_PATH="${BLITZ_5G_LINK_LOG_PATH:-${BLITZ_RUN_DIR}/b-5g-link-quality.${BLITZ_INSTANCE_ID}.jsonl}"
target_ip="$(resolve_target_ip || true)"

blitz_log "${STEP}" "start" "start" "path=${BLITZ_5G_LINK_LOG_PATH} interval_sec=${BLITZ_5G_LINK_LOG_INTERVAL_SEC}" 0

while true; do
  interface_name="$(blitz_resolve_5g_interface || true)"
  line="$(emit_sample_json "${interface_name}" "${target_ip}")"
  blitz_jsonl_append_line "${BLITZ_5G_LINK_LOG_PATH}" "${line}"
  sleep "${BLITZ_5G_LINK_LOG_INTERVAL_SEC}"
done