#!/bin/bash

DEVICE="intel_backlight"
BRIGHTNESS=$(brightnessctl get)
MAX_BRIGHTNESS=$(brightnessctl max)
PERCENTAGE=$((BRIGHTNESS * 100 / MAX_BRIGHTNESS))

# Define icons
ICON_BRIGHT=""
ICON_DIM=""

# Set icon based on brightness level
if [ $PERCENTAGE -ge 50 ]; then
    ICON=$ICON_BRIGHT
else
    ICON=$ICON_DIM
fi

# Function to calculate the step size dynamically
calculate_step() {
    local percentage=$1
    local min_step=$((MAX_BRIGHTNESS / 100))  # 1% step
    local max_step=$((MAX_BRIGHTNESS * 15 / 100))  # 15% step

    # Scale the step size linearly between min_step and max_step
    local step=$((min_step + (max_step - min_step) * percentage / 100))

    # Ensure the step is within bounds
    if [ $step -lt $min_step ]; then
        step=$min_step
    elif [ $step -gt $max_step ]; then
        step=$max_step
    fi

    echo $step
}

# Function to calculate the new brightness value
calculate_new_brightness() {
    local current=$1
    local max=$2
    local change=$3

    # Calculate the new brightness value
    local new_value=$((current + change))

    # Ensure the new value is within the valid range (1% to 100%)
    if [ $new_value -lt 1 ]; then
        new_value=1
    elif [ $new_value -gt $max ]; then
        new_value=$max
    fi

    echo $new_value
}

# Handle click actions
case $1 in
    "up")
        STEP=$(calculate_step $PERCENTAGE)
        NEW_BRIGHTNESS=$(calculate_new_brightness $BRIGHTNESS $MAX_BRIGHTNESS $STEP)
        brightnessctl set $NEW_BRIGHTNESS > /dev/null
        ;;
    "down")
        STEP=$(calculate_step $PERCENTAGE)
        NEW_BRIGHTNESS=$(calculate_new_brightness $BRIGHTNESS $MAX_BRIGHTNESS $(( -STEP )))
        brightnessctl set $NEW_BRIGHTNESS > /dev/null
        ;;
esac

# Output for Polybar
echo "$ICON $PERCENTAGE%"