#!/bin/bash

# Waybar power-profiles-daemon module.
#   default : print the current profile as JSON (empty -> Waybar hides the module)
#   toggle  : cycle to the next available profile, then signal Waybar to refresh
#
# Wired as interval:"once" + signal in config.jsonc, so the script runs exactly
# once at Waybar startup and thereafter only when we signal it on click. On a
# desktop the single startup run hits an unavailable PPD, prints empty, and the
# module stays hidden forever with no recurring cost.
#
# Availability keys off the systemd unit being *enabled* rather than
# `powerprofilesctl get` succeeding: PPD is D-Bus-activatable and desktop CPUs
# expose EPP too, so `get` would answer on a desktop as well. The repo only
# enables the service on laptops (IS_DESKTOP=0), so `is-enabled` is the honest
# "is this a laptop that uses PPD" signal.

SERVICE=power-profiles-daemon.service

available() {
    command -v powerprofilesctl >/dev/null 2>&1 || return 1
    systemctl is-enabled "$SERVICE" >/dev/null 2>&1
}

# Available profile names in the order PPD lists them (power-saver … performance).
# Profile header lines are just "name:" (optionally "* name:" for the active one);
# every other line (Driver:, Degraded:, …) has text after the colon.
profiles() {
    powerprofilesctl list 2>/dev/null | sed -nE 's/^[[:space:]]*\*?[[:space:]]*([a-z-]+):[[:space:]]*$/\1/p'
}

# FontAwesome glyphs (Nerd Font): f0e7 bolt, f6ad yin-yang, f06c leaf, f011 power.
icon() {
    case "$1" in
        performance) printf '' ;;
        balanced)    printf '' ;;
        power-saver) printf '' ;;
        *)           printf '' ;;   # power symbol, fallback
    esac
}

cycle() {
    mapfile -t list < <(profiles)
    [ "${#list[@]}" -eq 0 ] && exit 0
    cur=$(powerprofilesctl get 2>/dev/null)
    next=0
    for i in "${!list[@]}"; do
        if [ "${list[$i]}" = "$cur" ]; then
            next=$(( (i + 1) % ${#list[@]} ))
            break
        fi
    done
    powerprofilesctl set "${list[$next]}"
    pkill -SIGRTMIN+9 waybar
}

output() {
    if ! available; then
        printf '{"text":""}\n'
        exit 0
    fi
    cur=$(powerprofilesctl get 2>/dev/null)
    [ -z "$cur" ] && { printf '{"text":""}\n'; exit 0; }
    printf '{"text":"%s","tooltip":"Power profile: %s\\nClick to cycle","class":"%s"}\n' \
        "$(icon "$cur")" "$cur" "$cur"
}

case "$1" in
    toggle|cycle) cycle ;;
    *)            output ;;
esac