#!/bin/bash

function update_crypto() {
    local c

    c="$(crypto 2> /dev/null)" && crypto="$c"
}

function update_cpu() {
    cpu=" $(awk '{print $1}' /proc/loadavg)"
}

function update_memory() {
    memory=" $(free -h | awk '/^Mem:/{print $3}')"
}

function update_bat() {
    local dir cap

    dir='/sys/class/power_supply/BAT0'
    cap="$(cat "$dir/capacity")"
    { grep -qv Discharging "$dir/status" && bat=" $cap%"; } ||
    { [ "$cap" -gt 80 ]                  && bat=" $cap%"; } ||
    { [ "$cap" -gt 60 ]                  && bat=" $cap%"; } ||
    { [ "$cap" -gt 40 ]                  && bat=" $cap%"; } ||
    { [ "$cap" -gt 20 ]                  && bat=" $cap%"; } ||
    {                                       bat=" $cap%"; }
}

function update_sink_vol() {
    local sink vol

    sink="$(wpctl get-volume '@DEFAULT_AUDIO_SINK@')"
    if grep -q MUTED <<< "$sink"; then
        sink_vol='🔇'
        return
    fi
    vol="$(awk '{print int($2 * 100)}' <<< "$sink")"
    { [ "$vol" -gt 67 ] && sink_vol=" $vol"; } ||
    { [ "$vol" -gt 33 ] && sink_vol=" $vol"; } ||
    {                      sink_vol=" $vol"; }
}

function update_source_vol() {
    local source vol

    source="$(wpctl get-volume '@DEFAULT_AUDIO_SOURCE@')"
    if grep -q MUTED <<< "$source"; then
        source_vol=''
        return
    fi
    source_vol=" $(awk '{print int($2 * 100)}' <<< "$source")"
}

function update_wlp() {
    local sig ssid dev=wlan0

    sig="$(awk "/$dev/{print int(\$3)}" /proc/net/wireless)"
    if [ -z "$sig" ]; then
        wlp='⚠'
        return
    fi
    ssid="$(networkctl status "$dev" | grep -Po 'Wi-Fi access point:\s*\K\w+')"
    { [ "$sig" -gt 56 ] && wlp="▂▄▆█ $ssid"; } ||
    { [ "$sig" -gt 38 ] && wlp="▂▄▆_ $ssid"; } ||
    { [ "$sig" -gt 21 ] && wlp="▂▄__ $ssid"; } ||
    { [ "$sig" -gt  3 ] && wlp="▂___ $ssid"; } ||
    {                      wlp="____ $ssid"; }
}

function update_time() {
    time="$(date "+%a %m-%d %R")"
}

function display() {
    "${DISPLAYCMD[@]}" "$crypto | $cpu | $memory | $sink_vol $source_vol | $wlp | $bat | $time"
}

if [ "$XDG_SESSION_TYPE" = wayland ]; then
    DISPLAYCMD=(echo)
else
    DISPLAYCMD=(xsetroot -name)
fi

# SIGNALING
# trap  '<function>;display;wait'       'RTMIN+n'
trap    'update_sink_vol;display;wait'  'RTMIN'
trap    'update_wlp;display;wait'       'RTMIN+1'
# to update it from external commands
## kill -m "$(cat ~/.cache/pidofbar)"
# where m = 34 + n

echo "$$" > "$HOME/.cache/pidofbar"

sec=0
while true; do
    wait && {
        [ "$((sec % 300))" = 10 ] && update_crypto
        [ "$((sec %  10))" =  0 ] && {
            update_cpu
            update_memory
            update_sink_vol
            update_source_vol
            update_wlp
            update_bat
            update_time
            display
        }
        sec="$((sec + 10))"
    }
    awk "@load \"time\"; BEGIN {d=10; s=$(date '+%S.%N'); sleep(d - s % d)}" &
done