#!/bin/bash
# SPDX-License-Identifier: Apache-2.0
# Copyright (C) 2023-present Fewtarius

. /etc/profile

# ARGS:
#
# 1 - property to adjust (gamma (brightness)/contrast/saturation/hue)
# 2 - up/down or a defined value

PROPERTY=${1}
NEWVAL=${2}

# Command usage:
# drm_tool set /dev/dri/card0 133 saturation value

# Define the basics
MIN=1
MAX=100
STEP=1

if [ ! -e /dev/dri/card0 ]
then
  echo "ERROR: No display found."
  exit 1
fi

log() {
  $DEBUG && echo "Info: ${*}" >>/var/log/display.log
}

getValue() {
  MYVAL=$(get_setting display.${1})
  if [ -n "${MYVAL}" ]
  then
    if [ "${MYVAL}" > "${MAX}" ]
    then
      MYVAL=${MAX}
    elif [ "${MYVAL}" < "${MIN}" ]
    then
      MYVAL=${MIN}
    fi
    echo ${MYVAL}
  else
    echo $(drm_tool list 2>/dev/null | sed -n '/Connector: '${CONNECTOR}'/,$p' | awk '/'${1}'/ {print $5}')
  fi
}

setValue() {
  log "Set (${1}: ${2})"
  drm_tool set /dev/dri/card0 ${CONNECTOR} ${1} ${2} 2>/dev/null
  if [ $? = 0 ]
  then
    set_setting display.${1} ${2}
  fi
}

stepUp() {
  LASTVAL=$(getValue ${PROPERTY})
  NEWVAL=$(expr ${LASTVAL} + 1)
  log "Step up (${PROPERTY}: ${NEWVAL})"
  setValue ${PROPERTY} ${NEWVAL}
}

stepDown() {
  LASTVAL=$(getValue ${PROPERTY})
  NEWVAL=$(expr ${LASTVAL} - 1)
  log "Step down (${PROPERTY}: ${NEWVAL})"
  setValue ${PROPERTY} ${NEWVAL}
}

restoreSettings() {
  for PROPERTY in brightness contrast saturation hue
  do
    RESTVAL=$(getValue ${PROPERTY})
    setValue ${PROPERTY} ${RESTVAL}
  done
}

CONNECTOR=$(drm_tool list | grep -B1 "mode.*:" | awk '/Connector/ {print $2}')

case ${NEWVAL} in
  "up")
    stepUp
  ;;
  "down")
    stepDown
  ;;
  "restore")
    restoreSettings
  ;;
  *)
    if [[ "${NEWVAL}" =~ ^[0-9] ]] && \
       [ "${NEWVAL}" -le "${MAX}" ] && \
       [ "${NEWVAL}" -ge "${MIN}" ]
    then
      setValue ${PROPERTY} ${NEWVAL}
    else
      echo "Error: Invalid value."
      exit 1
    fi
  ;;
esac