#!/bin/bash

# Root?
if [ "$(id -u)" != "0" ]; then
  exec sudo "$0" "$@"
fi

fan_speeds()
{
  echo "Available fan speeds on this iMac:"
  echo "1) Fan speed: $one_min - $one_max"
  echo "2) Fan speed: $two_min - $two_max"
  echo "3) Fan speed: $three_min - $three_max"
}

fan_manual()
{
  echo 1 > /sys/devices/platform/applesmc.768/fan1_manual
  echo 1 > /sys/devices/platform/applesmc.768/fan2_manual
  echo 1 > /sys/devices/platform/applesmc.768/fan3_manual
}

fan1_speed()
{
  echo $1 > /sys/devices/platform/applesmc.768/fan1_output
}

fan2_speed()
{
  echo $1 > /sys/devices/platform/applesmc.768/fan2_output
}

fan3_speed()
{
  echo $1 > /sys/devices/platform/applesmc.768/fan3_output
}

# Variables
one_min=$(cat /sys/devices/platform/applesmc.768/fan1_min)
one_max=$(cat /sys/devices/platform/applesmc.768/fan1_max)
two_min=$(cat /sys/devices/platform/applesmc.768/fan2_min)
two_max=$(cat /sys/devices/platform/applesmc.768/fan2_max)
three_min=$(cat /sys/devices/platform/applesmc.768/fan3_min)
three_max=$(cat /sys/devices/platform/applesmc.768/fan3_max)

# Main
if [ $# = 0 ]
then
  echo "Define Speed"
  fan_speeds
elif [ $# = 1 ]
then
   fan_manual
   fan1_speed $1
   fan2_speed $1
   fan3_speed $1
elif [ $# = 2 ]
then
  echo "Define 3 Speeds"
elif [ $# = 3 ]
then
  fan_manual
  fan1_speed $1
  fan2_speed $2
  fan3_speed $3
fi