#!/usr/bin/env bash
# dwm status feeder — sets the root window name, which dwm paints in the bar.
# Run `dwmstatus once` to print the line a single time (no xsetroot required).
set -u

# Echo the primary temperature (temp1_input, whole °C) of the first hwmon chip
# whose name matches the given ERE. Echoes nothing if no such chip/sensor exists.
read_temp() {
    local want=$1 d n milli
    for d in /sys/class/hwmon/hwmon*/; do
        [[ -r ${d}name ]] || continue
        read -r n < "${d}name"
        [[ $n =~ $want ]] || continue
        [[ -r ${d}temp1_input ]] || return 0
        read -r milli < "${d}temp1_input"
        printf '%d' "$((milli / 1000))"
        return 0
    done
}

# Format kibibytes as a compact GiB/MiB string (e.g. 11.2GiB).
fmt_kib() {
    local mib=$(( $1 / 1024 ))
    if ((mib >= 1024)); then
        printf '%d.%dGiB' "$((mib / 1024))" "$((((mib % 1024) * 10) / 1024))"
    else
        printf '%dMiB' "$mib"
    fi
}

# Assemble the whole status line into $_status.
build_status() {
    local cpu gpu mb load total avail raw mute vol now temps=""

    cpu=$(read_temp 'k10temp|coretemp')
    gpu=$(read_temp 'amdgpu|nouveau|radeon')
    mb=$(read_temp 'nct[0-9]|it87|f71')
    [[ -n $cpu ]] && temps+="CPU ${cpu}C  "
    [[ -n $gpu ]] && temps+="GPU ${gpu}C  "
    [[ -n $mb ]] && temps+="MB ${mb}C  "

    read -r load _ < /proc/loadavg

    total=0 avail=0
    while IFS=' :' read -r key value _; do
        case $key in
            MemTotal) total=$value ;;
            MemAvailable) avail=$value ;;
        esac
    done < /proc/meminfo

    vol="?"
    raw=$(pactl get-sink-volume @DEFAULT_SINK@ 2>/dev/null) || raw=""
    [[ $raw =~ ([0-9]+)% ]] && vol="${BASH_REMATCH[1]}%"
    mute=$(pactl get-sink-mute @DEFAULT_SINK@ 2>/dev/null) || mute=""
    [[ $mute == *yes ]] && vol="mute"

    printf -v now '%(%Y-%m-%d %H:%M)T' -1

    _status="  ${temps}RAM $(fmt_kib "$((total - avail))")/$(fmt_kib "$total")  load ${load}  vol ${vol}  ${now}  "
}

if [[ ${1:-} == once ]]; then
    build_status
    printf '%s\n' "$_status"
    exit 0
fi

# Need xsetroot to actually paint the bar; without it the bar just stays empty.
if ! command -v xsetroot >/dev/null 2>&1; then
    printf 'dwmstatus: xorg-xsetroot not installed; run: sudo pacman -S xorg-xsetroot\n' >&2
    exit 0
fi

while :; do
    build_status
    xsetroot -name "$_status"
    sleep 5
done