#!/bin/bash

function update_crypto() {
    local c

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

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

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

function update_bat() {
    local cap; cap="$(cat /sys/class/power_supply/BAT0/capacity)"

    if grep -qv Discharging /sys/class/power_supply/BAT0/status; then
        echo " $cap%" > "$SBAR/bat"
    else
        echo " $cap%" > "$SBAR/bat"
    fi
}

function update_sink_vol() {
    local vol mute

    read -r _ vol mute < <(wpctl get-volume '@DEFAULT_AUDIO_SINK@') || return
    if [ -n "$mute" ]; then
        echo '🔇' > "$SBAR/sink"
    else
        echo " $((10#${vol/./}))" > "$SBAR/sink"
    fi
}

function update_source_vol() {
    local vol mute

    read -r _ vol mute < <(wpctl get-volume '@DEFAULT_AUDIO_SOURCE@') || return
    if [ -n "$mute" ]; then
        echo '' > "$SBAR/source"
    else
        echo " $((10#${vol/./}))" > "$SBAR/source"
    fi
}

function update_net() {
    local dev j ssid sig

    dev="$(ip route | grep -oP 'default.*dev\s+\K[^\s]+')"
    j="$(networkctl status "$dev" --json=short)"
    case "$(jq -r .Type <<< "$j")" in
        ether)
            echo "🌐 $dev" > "$SBAR/net"
            ;;
        wlan)
            ssid="$(jq -r .SSID <<< "$j")"
            sig="$(awk "/$dev/{printf \"%.0f\", \$3}" /proc/net/wireless)"
            if   [ "$sig" -gt 56 ]; then echo "▂▄▆█ $ssid" > "$SBAR/net"
            elif [ "$sig" -gt 38 ]; then echo "▂▄▆_ $ssid" > "$SBAR/net"
            elif [ "$sig" -gt 21 ]; then echo "▂▄__ $ssid" > "$SBAR/net"
            elif [ "$sig" -gt  3 ]; then echo "▂___ $ssid" > "$SBAR/net"
            else                         echo "____ $ssid" > "$SBAR/net"
            fi
            ;;
        *)
            echo '⚠' > "$SBAR/net"
            ;;
    esac
}

function update_vpn() {
    local v; v="$(ip -br link show type wireguard | awk '{print $1}')"

    if [ -n "$v" ]; then
        echo " 🔒 $v" > "$SBAR/vpn"
    else
        : > "$SBAR/vpn"
    fi
}

function update_time() {
    echo "$(TZ=Asia/Makassar date '+%R %Z') - $(date -u '+%a %m-%d %R')" \
        > "$SBAR/time"
}

function display() {
    for f in "$SBAR"/*; do
        local "$(basename "$f")"="$(cat "$f")"
    done
    # shellcheck disable=SC2154
    xsetroot -name "$crypto | $cpu | $memory | $sink $source | $net$vpn | $bat | $time"
}

# SIGNALING
# trap  '<function>;display;wait -n'        'RTMIN+n'
trap    'update_sink_vol;display;wait -n'   'RTMIN+0'
trap    'update_source_vol;display;wait -n' 'RTMIN+1'
trap    'update_net;display;wait -n'        'RTMIN+2'
trap    'update_vpn;display;wait -n'        'RTMIN+3'
# to update it from external commands
## kill -m "$(cat "$XDG_CACHE_HOME/pidofbar")"
# where m = 34 + n

SBAR="$XDG_CACHE_HOME/sbar"
mkdir -p "$SBAR"
echo "$$" > "$SBAR/pid"

(while :; do
    update_crypto
    sleep $((300 - 10#$(date '+%S') % 300)) & wait -n
done &)

while true; do
    update_cpu
    update_memory
    update_sink_vol
    update_source_vol
    update_net
    update_vpn
    update_bat
    update_time
    display
    sleep $((5 - 10#$(date '+%S') % 5)) & wait -n
done