#!/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-dial"

append_route_targets() {
  local raw_list="$1"
  local target

  if [[ -z "${raw_list}" ]]; then
    return 0
  fi

  for target in ${raw_list//,/ }; do
    if [[ -z "${target}" ]]; then
      continue
    fi
    dial_cmd+=(--route-target "${target}")
  done
}

read_detected_interface() {
  local info_json="$1"

  if [[ ! -f "${info_json}" ]]; then
    return 1
  fi

  python3 -c 'import json, sys; print((json.load(open(sys.argv[1], encoding="utf-8")).get("interface") or "").strip())' "${info_json}"
}

disable_interfaces() {
  local raw_list="$1"
  local iface
  local nmcli_available=0

  if [[ -z "${raw_list}" ]]; then
    return 0
  fi
  if command -v nmcli >/dev/null 2>&1; then
    nmcli_available=1
  fi

  for iface in ${raw_list//,/ }; do
    if [[ -z "${iface}" ]]; then
      continue
    fi
    blitz_log "${STEP}" "disable-interface" "start" "iface=${iface}" 0
    if [[ "${nmcli_available}" -eq 1 ]]; then
      nmcli device disconnect "${iface}" >/dev/null 2>&1 || true
    fi
    if ip link show dev "${iface}" >/dev/null 2>&1; then
      if ip link set dev "${iface}" down; then
        blitz_log "${STEP}" "disable-interface" "success" "iface=${iface}" 0
      else
        rc=$?
        blitz_log "${STEP}" "disable-interface" "failure" "iface=${iface}" "${rc}"
        return "${rc}"
      fi
    else
      blitz_log "${STEP}" "disable-interface" "success" "iface=${iface} not present, skipping" 0
    fi
  done
}

wait_for_serial() {
  local serial_port="$1"
  local timeout_sec="$2"
  local waited=0

  while (( waited < timeout_sec )); do
    if [[ -e "${serial_port}" ]]; then
      blitz_log "${STEP}" "wait-serial" "success" "serial_port=${serial_port} waited_sec=${waited}" 0
      return 0
    fi
    if (( waited == 0 || waited % 5 == 0 )); then
      blitz_log "${STEP}" "wait-serial" "waiting" "serial_port=${serial_port} waited_sec=${waited}" 0
    fi
    sleep 1
    waited=$(( waited + 1 ))
  done

  blitz_log "${STEP}" "wait-serial" "failure" "serial_port=${serial_port} timeout_sec=${timeout_sec}" 1
  return 1
}

wait_for_route() {
  local target_ip="$1"
  local timeout_sec="$2"
  local expected_interface="${3:-}"
  local waited=0
  local route_output

  while (( waited < timeout_sec )); do
    route_output="$(blitz_route_ready "${target_ip}" "${expected_interface}" || true)"
    if [[ -n "${route_output}" ]]; then
      blitz_log "${STEP}" "route-check" "success" "target_ip=${target_ip} interface=${expected_interface:-auto} route=${route_output}" 0
      return 0
    fi
    if (( waited == 0 || waited % 5 == 0 )); then
      blitz_log "${STEP}" "route-check" "waiting" "target_ip=${target_ip} interface=${expected_interface:-auto} waited_sec=${waited}" 0
    fi
    sleep 1
    waited=$(( waited + 1 ))
  done

  blitz_log "${STEP}" "route-check" "failure" "target_ip=${target_ip} interface=${expected_interface:-auto} timeout_sec=${timeout_sec}" 1
  return 1
}

blitz_load_boot_env
blitz_require_root "${STEP}"
blitz_require_command ip "${STEP}"
blitz_require_command python3 "${STEP}"
blitz_require_file "${BLITZ_5G_DIAL_DIR}/rndis_dial.py" "${STEP}"

if [[ -z "${BLITZ_TIME_SERVER_IP}" ]]; then
  blitz_log "${STEP}" "precheck" "failure" "BLITZ_TIME_SERVER_IP is empty and no fallback could be derived" 1
  exit 1
fi

disable_interfaces "${BLITZ_5G_DISABLE_INTERFACES:-}"

if [[ -n "${BLITZ_5G_INTERFACE:-}" ]]; then
  route_output="$(blitz_route_ready "${BLITZ_TIME_SERVER_IP}" "${BLITZ_5G_INTERFACE}" || true)"
  if [[ -n "${route_output}" ]]; then
    blitz_log "${STEP}" "dial" "already_up" "target_ip=${BLITZ_TIME_SERVER_IP} interface=${BLITZ_5G_INTERFACE} route=${route_output}" 0
    exit 0
  fi
else
  blitz_log "${STEP}" "route-check" "info" "BLITZ_5G_INTERFACE is empty, skipping pre-dial route shortcut and using auto-detect mode" 0
fi

wait_for_serial "${BLITZ_5G_SERIAL_PORT}" "${BLITZ_5G_SERIAL_WAIT_SEC}"

dial_cmd=(
  python3
  rndis_dial.py
  --serial-port "${BLITZ_5G_SERIAL_PORT}"
  --modem-subnet "${BLITZ_5G_MODEM_SUBNET}"
)
if [[ -n "${BLITZ_5G_INTERFACE:-}" ]]; then
  dial_cmd+=(--interface "${BLITZ_5G_INTERFACE}")
fi
case "${BLITZ_5G_SKIP_DHCP:-0}" in
  1|true|TRUE|yes|YES)
    dial_cmd+=(--skip-dhcp)
    ;;
esac
case "${BLITZ_5G_REMOVE_DEFAULT_ROUTE:-1}" in
  1|true|TRUE|yes|YES)
    dial_cmd+=(--remove-default-route --gateway "${BLITZ_5G_GATEWAY}" --route-target "${BLITZ_TIME_SERVER_IP}")
    append_route_targets "${BLITZ_5G_ROUTE_TARGETS:-}"
    ;;
esac

pushd "${BLITZ_5G_DIAL_DIR}" >/dev/null
blitz_run "${STEP}" "dial" "${dial_cmd[@]}"
popd >/dev/null

resolved_interface="${BLITZ_5G_INTERFACE:-}"
if [[ -z "${resolved_interface}" ]]; then
  resolved_interface="$(read_detected_interface "${BLITZ_5G_INFO_JSON}" || true)"
  if [[ -n "${resolved_interface}" ]]; then
    blitz_log "${STEP}" "resolve-interface" "success" "resolved interface from ${BLITZ_5G_INFO_JSON}: ${resolved_interface}" 0
  else
    blitz_log "${STEP}" "resolve-interface" "failure" "failed to read detected interface from ${BLITZ_5G_INFO_JSON}" 1
  fi
fi

if [[ -n "${resolved_interface}" ]]; then
  wait_for_route "${BLITZ_TIME_SERVER_IP}" "${BLITZ_5G_ROUTE_WAIT_SEC}" "${resolved_interface}"
  blitz_log "${STEP}" "complete" "success" "5G dial completed and route is ready on ${resolved_interface}" 0
else
  blitz_log "${STEP}" "complete" "success" "5G dial completed but route wait was skipped because no interface could be resolved; refer to rndis_dial.py logs" 0
fi