#!/usr/bin/env bash

set -e

DEVICE="$1" # eg: /sys/class/drm/card1/device
HWMON=$(echo "$DEVICE"/hwmon/hwmon*)

exit() {
    echo "Setting controll to auto" >&2
    echo 2 > "$HWMON/pwm1_enable"
}

trap exit EXIT INT

bail() {
    echo "Error: $@" >&2
    echo "Exiting..." >&2
    exit 1
}

if ! [ -d $HWMON ]; then
    bail "Invalid HWMON"
fi

TEMP_INPUT="$HWMON/temp2_input"

if ! [ -f $TEMP_INPUT ]; then
    bail "Invalid TEMP_INPUT"
fi

MIN="$2"
MAX="$3"

echo "Running..." >&2
while true; do
    TEMPERATURE_RAW=$(cat "$TEMP_INPUT")
    TEMPERATURE="$(( $TEMPERATURE_RAW / 1000 ))"
    # Remap from a number between 60_000..90_000 to 0..255
    PWM=$(( ($TEMPERATURE - $MIN) * 255 / ($MAX - $MIN) ))

    if [ "$PWM" -gt 255 ]; then
        PWM=255
    elif [ "$PWM" -lt 0 ]; then
        PWM=0
    fi

    echo 1 > "$HWMON/pwm1_enable"
    echo "$PWM" > "$HWMON/pwm1"
    sleep .1s
done