#!/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 '{printf "%.0f", $2 * 100}' <<< "$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 '{printf "%.0f", $2 * 100}' <<< "$source")"
}

function update_net() {
    local dev j ssid sig

    dev="$(ip route show default | sed -n 's/.*dev\s\+\(\w\+\).*/\1/p;q')"
    j="$(networkctl status "$dev" --json=short)"
    case "$(jq -r .Type <<< "$j")" in
        ether)
            net="🌐 $dev"
            ;;
        wlan)
            ssid="$(jq -r .SSID <<< "$j")"
            sig="$(awk "/$dev/{printf \"%.0f\", \$3}" /proc/net/wireless)"
            { [ "$sig" -gt 56 ] && net="▂▄▆█ $ssid"; } ||
            { [ "$sig" -gt 38 ] && net="▂▄▆_ $ssid"; } ||
            { [ "$sig" -gt 21 ] && net="▂▄__ $ssid"; } ||
            { [ "$sig" -gt  3 ] && net="▂___ $ssid"; } ||
            {                      net="____ $ssid"; }
            ;;
        *)
            net='⚠'
            ;;
    esac
}

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

function reload() {
    sec=0
}

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

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

# SIGNALING
# trap  '<function>;display;wait'        'RTMIN+n'
trap    'reload'                         'RTMIN'
trap    'update_sink_vol;display;wait'   'RTMIN+1'
trap    'update_source_vol;display;wait' 'RTMIN+2'
trap    'update_net;display;wait'        'RTMIN+3'
# to update it from external commands
## kill -m "$(cat ~/.cache/pidofbar)"
# where m = 34 + n

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

sec=0
while true; do
    [ "$((sec % 300))" -eq 5 ] && update_crypto
    [ "$((sec %   5))" -eq 0 ] && {
        update_cpu
        update_memory
        update_sink_vol
        update_source_vol
        update_net
        update_bat
        update_time
        display
    }
    ((sec += 5))
    awk "@load \"time\"; BEGIN {d=5; s=$(date '+%S.%N'); sleep(d - s % d)}" &
    wait
done