#!/bin/bash
# restore-wayland-env.sh — probe /proc for a running Wayland client and
# inherit its WAYLAND_DISPLAY / DISPLAY / DBUS_SESSION_BUS_ADDRESS /
# XDG_RUNTIME_DIR. Used by caffeine.sh and start-swayidle.sh so on-click
# scripts run from waybar's context (which doesn't inherit the Sway env)
# can still talk to the compositor.
#
# Why probe /proc? waybar's on-click handler forks the script in waybar's
# own process context. That context has WAYLAND_DISPLAY set (waybar is a
# Wayland client), but other Sway context (XDG_CURRENT_DESKTOP, sway IPC
# socket, etc.) isn't passed to children. We need WAYLAND_DISPLAY for
# swaymsg/grim/wl-copy/notify-send, so the env-restoration here covers the
# "Wayland client tools" subset. Swaymsg-specific env (I3SOCK / SWAYSOCK)
# isn't included because swaymsg falls back to discovery via the
# /run/user/UID/sway-ipc.*.sock path.
#
# Idempotent: if WAYLAND_DISPLAY and DISPLAY are already set, does nothing.
# Source-able: `source "$HOME/.config/sway/restore-wayland-env.sh"`.

if [[ -n "$WAYLAND_DISPLAY" || -n "$DISPLAY" ]]; then
    return 0 2>/dev/null || exit 0
fi

# Find a running Wayland client. mako, swaybar, foot, wofi — anything
# bound to wayland-N. We grab the first one with WAYLAND_DISPLAY set.
for pid in /proc/[0-9]*; do
    [[ -r "$pid/environ" ]] || continue
    candidate=$(tr '\0' '\n' < "$pid/environ" 2>/dev/null | grep -E '^(WAYLAND_DISPLAY|DISPLAY|DBUS_SESSION_BUS_ADDRESS|XDG_RUNTIME_DIR)=' || true)
    if [[ -n "$candidate" ]]; then
        # shellcheck disable=SC2086
        export $candidate
        return 0 2>/dev/null || exit 0
    fi
done