#!/bin/bash

# parses upower -e and grabs device/battery level

usage() {
    cat <<EOF
usage $0: [-i][-d][-b][-c][-h]

Options:
  -b, --battery-icon    uses battery level NF icon instead of percentage
  -c, --color           enables polybar color codes
  -d, --dev-icon        uses device NF icon instead of name 
  -i, --icon-test       prints all icons used to test rendering
  -h, --help            shows this message
EOF
}

LOW_BATTERY_THRESHOLD=15
LOW_BATTERY_COLOR='%{F#F00}' # polybar red
CHARGING_COLOR='%{F#0F0}' # polybar green
MOUSE_ICON=$(echo -e '\Uf098b') # bt mouse
HEADSET_ICON=$(echo -e '\Uf0970')

battery_icon() {
    # grabs corresponding battery level icon; state in 2, level in 1
    if [ "$2" == "charging" ] ; then
        # mouse is charging, battery icon represents
        if [ $1 -gt 95 ] ; then
            echo -e '\Uf0085'
        elif [ $1 -gt 85 ] ; then
            echo -e '\Uf008b'
        elif [ $1 -gt 75 ] ; then
            echo -e '\Uf008a'
        elif [ $1 -gt 65 ] ; then
            echo -e '\Uf089e'
        elif [ $1 -gt 55 ] ; then
            echo -e '\Uf0089'
        elif [ $1 -gt 45 ] ; then
            echo -e '\Uf089d'
        elif [ $1 -gt 35 ] ; then
            echo -e '\Uf0088'
        elif [ $1 -gt 25 ] ; then
            echo -e '\Uf0087'
        elif [ $1 -gt 15 ] ; then
            echo -e '\Uf0086'
        elif [ $1 -gt 5 ] ; then
            echo -e '\Uf089c'
        else
            echo -e '\Uf089f'
        fi
    else
        # regular battery icon
        if [ $1 -gt 95 ] ; then
            echo -e '\Uf0079'
        elif [ $1 -gt 85 ] ; then
            echo -e '\Uf0081'
        elif [ $1 -gt 75 ] ; then
            echo -e '\Uf0081'
        elif [ $1 -gt 65 ] ; then
            echo -e '\Uf0080'
        elif [ $1 -gt 55 ] ; then
            echo -e '\Uf007f'
        elif [ $1 -gt 45 ] ; then
            echo -e '\Uf007e'
        elif [ $1 -gt 35 ] ; then
            echo -e '\Uf007d'
        elif [ $1 -gt 25 ] ; then
            echo -e '\Uf007c'
        elif [ $1 -gt 15 ] ; then
            echo -e '\Uf007b'
        elif [ $1 -gt 5 ] ; then
            echo -e '\Uf007a'
        else
            echo -e '\Uf008e'
        fi
    fi
}

icon_test() {
    echo "Icon test for $1. (0-100)"
    for ((i=-4; i<=100; i+=10)); do
        battery_icon $i "$1"
    done
}

identifier() {
    # returns device name or icon based on options; dev in $1
    
    if [ -n "$DEV_ICON" ] ; then
        [[ "$1" =~ [Mm]ouse ]] && echo "$MOUSE_ICON"
        [[ "$1" =~ [Hh]eadset ]] && echo "$HEADSET_ICON"
    else
        echo "$1" | grep 'model:' | awk '{print $2}'
    fi
}


color() {
    # sets battery color; level in $1, state in $2
    if [ "$2" == "charging" ] ; then
        echo "$CHARGING_COLOR"
    elif [ $1 -le $LOW_BATTERY_THRESHOLD ] ; then
        echo "$LOW_BATTERY_COLOR"
    fi
}

# parsing long args
for arg in "$@"; do
    shift
    case "$arg" in
        '--help')           set -- "$@" '-h'    ;;
        '--color')          set -- "$@" '-c'    ;;
        '--icon-test')      set -- "$@" '-i'    ;;
        '--dev-icon')       set -- "$@" '-d'    ;;
        '--battery-icon')   set -- "$@" '-b'    ;;
        *)                  set -- "$@" "$arg"  ;;
    esac
done

# parsing args
while getopts "hcidb" opt ; do
    case "$opt" in
        'h')
            usage
            exit 0
            ;;
        'c')
            COLOR=true
            ;;
        'i')
            echo "Headset: $HEADSET_ICON"
            echo "Mouse: $MOUSE_ICON"
            icon_test "default"
            icon_test "charging"
            exit 0
            ;;
        'd')
            DEV_ICON=true
            ;;
        'b')
            BATTERY_ICON=true
            ;;
        '?')
            usage
            exit 1
            ;;
    esac
done

for dev in `upower -e | grep -v 'DisplayDevice'`; do
    # allows proper spacing
    devs+=1
    # getting device info
    info=$(upower -i "$dev")
    state=$(echo "$info" | awk '{if($1 == "state:"){print $2}}')

    dev_id=$(identifier "$info")
    dev_battery=`echo "$info" | awk '{if($1 == "percentage:"){print $2}}'`


    if [ -n "$COLOR" ] ; then
        clr=$(color `echo $dev_battery | tr -d '%'` "$state")
    fi

    if [ -n "$BATTERY_ICON" ] ; then
        dev_battery=$(battery_icon `echo $dev_battery | tr -d '%'` "$state")
    fi

    if [ "$state" == "unknown" ] ; then
        # override to always show if device asleep
        if [ -n "$DEV_ICON" ] ; then
            printf '%s %s' "$dev_id" `echo -e '\Uf04b2 '` && continue
        else
            printf '%s %s' "$dev_id" '?' && continue
        fi
    fi

    # seperator
    [ $devs -gt 1 ] & printf ' '

    printf '%s %s%s' "$dev_id" "$clr" "$dev_battery"
done