#!/usr/bin/env bash
# Bring up the CANable at IDS-CAN speed and log timestamped raw frames.
#
# Usage:
#   ./log-can.sh            # bring up can0 @ 250k, live candump
#   ./log-can.sh rec NAME   # also tee a timestamped log to NAME-<date>.log
#   ./log-can.sh watch      # cansniffer color-diff view (operate a load, watch bytes)
#   ./log-can.sh down       # take the interface down
#
# Requires: can-utils (paru -S can-utils on Arch). This CANable shipped with
# slcan firmware (a /dev/ttyACM* serial device) — bridge it to can0 first with
#   sudo slcand -o -s5 /dev/ttyACMx can0
# A candleLight/gs_usb reflash would instead give a native socketcan can0 and let
# the up() path below set the bitrate directly.

set -euo pipefail
IFACE="${IFACE:-can0}"
BITRATE=250000          # IDS-CAN is 250k
CMD="${1:-up}"

up() {
  if ! ip link show "$IFACE" &>/dev/null; then
    echo "No $IFACE — is the CANable plugged in? (dmesg | grep -i gs_usb)" >&2
    exit 1
  fi
  sudo ip link set "$IFACE" down 2>/dev/null || true
  sudo ip link set "$IFACE" up type can bitrate "$BITRATE"
  echo "$IFACE up @ ${BITRATE} bps"
}

case "$CMD" in
  up)    up; exec candump -ta -x "$IFACE" ;;
  rec)   up
         name="${2:-onecontrol}"; out="$(dirname "$0")/${name}-$(date +%F_%H%M%S).log"
         echo "logging -> $out  (Ctrl-C to stop)"
         exec candump -ta -x "$IFACE" | tee "$out" ;;
  watch) up; exec cansniffer -c "$IFACE" ;;
  down)  sudo ip link set "$IFACE" down; echo "$IFACE down" ;;
  *)     echo "usage: $0 {up|rec NAME|watch|down}" >&2; exit 2 ;;
esac