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

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

camera_device="${OMNI_CAMERA_DEVICE}"
camera_profile="${OMNI_CAMERA_PROFILE}"
camera_brightness="${OMNI_CAMERA_BRIGHTNESS}"
camera_custom_ctrl="${OMNI_CAMERA_CUSTOM_CTRL}"
camera_verify="${OMNI_CAMERA_VERIFY}"

is_truthy() {
  case "${1:-0}" in
    1|true|TRUE|yes|YES|on|ON)
      return 0
      ;;
    *)
      return 1
      ;;
  esac
}

require_v4l2_ctl() {
  if command -v v4l2-ctl >/dev/null 2>&1; then
    return 0
  fi

  echo "Missing required command: v4l2-ctl. Install v4l-utils on the robot side before starting b_side_omnid." >&2
  exit 1
}

run_v4l2_ctl() {
  v4l2-ctl -d "${camera_device}" "$@"
}

set_ctrl() {
  local ctrl="$1"

  echo "[camera-controls] set ${camera_device} ${ctrl}"
  run_v4l2_ctl "--set-ctrl=${ctrl}"
}

verify_ctrl() {
  local ctrl="$1"

  echo "[camera-controls] verify ${camera_device} ${ctrl}"
  run_v4l2_ctl "--get-ctrl=${ctrl}"
}

needs_v4l2_ctl=0

case "${camera_profile}" in
  night)
    needs_v4l2_ctl=1
    ;;
  day)
    if [[ -n "${camera_brightness}" ]]; then
      needs_v4l2_ctl=1
    fi
    ;;
  custom)
    if [[ -z "${camera_custom_ctrl}" ]]; then
      echo "OMNI_CAMERA_CUSTOM_CTRL must be non-empty when OMNI_CAMERA_PROFILE=custom." >&2
      exit 1
    fi
    needs_v4l2_ctl=1
    ;;
  *)
    echo "Unsupported OMNI_CAMERA_PROFILE: ${camera_profile}. Expected one of: night, day, custom." >&2
    exit 1
    ;;
esac

if is_truthy "${camera_verify}"; then
  needs_v4l2_ctl=1
fi

if [[ "${needs_v4l2_ctl}" == "0" ]]; then
  echo "[camera-controls] profile=${camera_profile}; no camera controls requested"
  exit 0
fi

require_v4l2_ctl

case "${camera_profile}" in
  night)
    set_ctrl "auto_exposure=1"
    set_ctrl "exposure_time_absolute=800"
    set_ctrl "gain=64"
    if [[ -n "${camera_brightness}" ]]; then
      set_ctrl "brightness=${camera_brightness}"
    fi
    ;;
  day)
    if [[ -n "${camera_brightness}" ]]; then
      set_ctrl "brightness=${camera_brightness}"
    fi
    ;;
  custom)
    set_ctrl "${camera_custom_ctrl}"
    ;;
esac

if is_truthy "${camera_verify}"; then
  verify_ctrl "auto_exposure"
  verify_ctrl "exposure_time_absolute"
  verify_ctrl "gain"
  verify_ctrl "brightness"
fi