#!/bin/bash

# MODULES
function update_crypto() {
    local c; c="$(crypto)" && crypto="$c"
}

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

function update_memory() {
    memory=" $(free -h | awk '$1 == "Mem:" {print $3}')"
}

function update_bat() {
    local dir; dir="$(find /sys/class/power_supply/ -mindepth 1 -name 'BAT*' -print -quit)"
    local cap; cap="$(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; sink="$(wpctl get-volume '@DEFAULT_AUDIO_SINK@')"
    local vol;

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

function update_source_vol() {
    local source; source="$(wpctl get-volume '@DEFAULT_AUDIO_SOURCE@')"
    local vol;

    if grep -q 'MUTED' <<< "$source"; then
        source_vol=""
    else
        vol="$(awk '{print int($2 * 100)}' <<< "$sink")"
        source_vol=" $(awk '{print int($2 * 100)}' <<< "$source")"
    fi
}

function update_wlp() {
    local sig; sig="$(awk '$1 ~ "wlp" {print int($3)}' /proc/net/wireless)"
    local ssid; ssid="$(nmcli device wifi show-password | sed -n 's/SSID: //p')"

    [ -z "$ssid" ] && wlp='⚠' && return
    [ -z "$sig"  ] && sig=0

    # https://gitlab.freedesktop.org/NetworkManager/NetworkManager/-/blob/d9b06a95/src/libnmc-base/nm-client-utils.c#L628
    { [ "$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'       'RTMIN+n'
trap    'update_sink_vol;display'       'RTMIN'
# to update it from external commands
## kill -m "$(cat ~/.cache/pidofbar)"
# where m = 34 + n

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

sec=0
while true; do
    [ "$((sec % 300))" = 0 ] && update_crypto
    [ "$((sec %  10))" = 0 ] && {
        update_cpu
        update_memory
        update_sink_vol
        update_source_vol
        update_wlp
        update_bat
        update_time
        display
    }

    sleep "$(awk "BEGIN {s=$(date '+%S.%N'); print 10 - s % 10}")" & wait
    sec="$((sec + 10))"
done