#!/usr/bin/env bash
# Switch the running Frametop desktop's window decoration without restarting it: Frametop's
# own (this folder, with the float button) or back to Breeze. The session script does the
# same at every desktop start (session/frametop-session.sh), so this is for trying changes.
#   decoration/apply.sh        install this folder's copy and use it
#   decoration/apply.sh --off  back to Breeze (until the next desktop start)
set -euo pipefail
here=$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)
deco=kwin4_decoration_qml_frametop
cfg=$HOME/.config/frametop
kwinrc=$cfg/kwinrc

# The desktop's D-Bus: from its Plasma shell, which uses Frametop's config folder (KWin's own
# environment isn't readable: it runs with extra capabilities).
bus=
for pid in $(pgrep -x plasmashell); do
  env=$( (tr '\0' '\n' < "/proc/$pid/environ") 2>/dev/null) || continue
  grep -qx "XDG_CONFIG_HOME=$cfg" <<<"$env" || continue
  bus=$(sed -n 's/^DBUS_SESSION_BUS_ADDRESS=//p' <<<"$env")
done
[ -n "$bus" ] || { echo "the Frametop desktop isn't running" >&2; exit 1; }

if [ "${1:-}" = --off ]; then
  kwriteconfig6 --file "$kwinrc" --group org.kde.kdecoration2 --key library --delete
  kwriteconfig6 --file "$kwinrc" --group org.kde.kdecoration2 --key theme --delete
else
  # Under a new name each time: KWin keeps a decoration's QML (even a broken one) by name
  # until it restarts. The next desktop start goes back to the plain name.
  decos=${XDG_DATA_HOME:-$HOME/.local/share}/kwin/decorations
  rm -rf "$decos/${deco}"_try*
  deco=${deco}_try$(date +%s)
  mkdir -p "$decos"
  cp -r "$here" "$decos/$deco"
  rm -f "$decos/$deco/apply.sh"
  sed -i "s/\"Id\": \"[^\"]*\"/\"Id\": \"$deco\"/" "$decos/$deco/metadata.json"
  kwriteconfig6 --file "$kwinrc" --group org.kde.kdecoration2 --key library org.kde.kwin.aurorae
  kwriteconfig6 --file "$kwinrc" --group org.kde.kdecoration2 --key theme "$deco"
fi
DBUS_SESSION_BUS_ADDRESS=$bus gdbus call --session -d org.kde.KWin -o /KWin -m org.kde.KWin.reconfigure >/dev/null
echo "decoration: $(kreadconfig6 --file "$kwinrc" --group org.kde.kdecoration2 --key theme --default Breeze)"