#!/bin/bash
# start-swayidle.sh — canonical swayidle startup for the Sway session.
#
# Single source of truth for the swayidle command. Invoked from:
#   1. ~/.config/sway/config:         exec $HOME/.config/sway/start-swayidle.sh
#   2. ~/.config/sway/caffeine.sh:    after killall swayidle, to re-arm
#
# Why a wrapper instead of inlining the command in sway/config? Because
# caffeine.sh needs to RESTART swayidle after killing it, and the restart
# must use the same timeouts and lock command as the original. Hardcoding
# it twice drifts (see git log — swayidle line in caffeine.sh got out of
# sync with the one in sway/config, so toggling caffeine off would
# silently change your lock command and timeout values).
#
# Env: this script is run by:
#   - sway at session start, with the full Wayland/Sway env (correct)
#   - caffeine.sh from waybar's on-click, with NO Wayland env (broken — see below)
# When run from caffeine.sh, swayidle needs WAYLAND_DISPLAY to talk to the
# compositor. We probe /proc for the env of an already-running Wayland client
# (mako, swaybar, foot, etc.) and inherit WAYLAND_DISPLAY / DISPLAY /
# DBUS_SESSION_BUS_ADDRESS / XDG_RUNTIME_DIR from it. This is the same
# trick `dbus-update-activation-environment` uses internally, just per-process.
#
# Returns: never. Runs as the foreground process; sway's exec replaces the
# shell with this script, and swayidle takes over. When started from
# caffeine.sh, the script is backgrounded (&) and this function returns.
set -e

# --- 1. Restore Wayland env if missing -----------------------------------
# The bug we're fixing: clicking the caffeine button runs this script
# from waybar's on-click context, which doesn't inherit sway's env.
# swayidle and lock-fancy.sh both call swaymsg/grim which need
# WAYLAND_DISPLAY — without it, swayidle silently exits and the user
# has NO idle lock at all (the worst possible failure mode: looks normal
# in the bar, but auto-lock is silently dead).
if [[ -z "$WAYLAND_DISPLAY" && -z "$SWAYSOCK" ]]; then
    # Find any running Wayland client and steal its env. mako (notification
    # daemon) is always present and always has the right env.
    for pid in /proc/[0-9]*; do
        [[ -r "$pid/environ" ]] || continue
        candidate=$(tr '\0' '\n' < "$pid/environ" 2>/dev/null | grep -E '^(WAYLAND_DISPLAY|DBUS_SESSION_BUS_ADDRESS|XDG_RUNTIME_DIR|DISPLAY)=' || true)
        if [[ -n "$candidate" ]]; then
            export $candidate
            break
        fi
    done
fi

# --- 2. Start swayidle ----------------------------------------------------
# If invoked from sway's `exec` line (config), swayidle replaces this shell
# and runs forever. If invoked from caffeine.sh (backgrounded with &), it
# runs as a child of the parent shell and caffeine.sh returns immediately.
exec swayidle -w \
    timeout 300 "$HOME/.config/sway/lock-fancy.sh" \
    timeout 600 'swaymsg "output * power off"' \
    resume 'swaymsg "output * power on"' \
    before-sleep "$HOME/.config/sway/lock-fancy.sh"