#!/bin/bash
# Optional. KWin's "Fading Popups" effect fades popup windows in over 150 ms
# and out over 600 ms, and the Fcitx5 candidate window counts as a popup. This
# script copies the effect from the system into your home directory and
# patches the copy so that only the Fcitx5 window ("fcitx fcitx") skips the
# fade in and uses a short fade out. All other popups are untouched.
#
# The effect is KWin's code (GPL-2.0-or-later), so it is generated from the
# copy installed on your system instead of being shipped in this repository.
set -euo pipefail

fade_out_ms=${FADE_OUT_MS:-90}
src=
for dir in /usr/share/kwin-wayland/effects/fadingpopups /usr/share/kwin/effects/fadingpopups; do
    [ -d "$dir" ] && src=$dir && break
done
[ -n "$src" ] || { echo "KWin fadingpopups effect not found" >&2; exit 1; }

dst=${XDG_DATA_HOME:-$HOME/.local/share}/kwin-wayland/effects/fadingpopups
rm -rf "$dst"
mkdir -p "$(dirname "$dst")"
cp -r "$src" "$dst"

python3 - "$dst/contents/code/main.js" "$fade_out_ms" <<'PY'
import sys
path, fade_out = sys.argv[1], sys.argv[2]
s = open(path).read()

def rep(old, new):
    global s
    if old not in s:
        sys.exit("effect source changed upstream, cannot patch: " + old[:50])
    s = s.replace(old, new, 1)

rep("var fadingPopupsEffect = {", f'''// Added by m3ui: the Fcitx5 candidate window animates itself.
var inputMethodWindowClass = "fcitx fcitx";
var inputMethodFadeOutMs = {fade_out};

function isInputMethodWindow(window) {{
    return window.windowClass == inputMethodWindowClass;
}}

var fadingPopupsEffect = {{''')
rep('''        if (!isPopupWindow(window)) {
            return;
        }
        if (!window.visible) {
            return;
        }''', '''        if (!isPopupWindow(window) || isInputMethodWindow(window)) {
            return;
        }
        if (!window.visible) {
            return;
        }''')
rep("            duration: fadingPopupsEffect.fadeOutDuration,",
    '''            duration: isInputMethodWindow(window)
                ? animationTime(inputMethodFadeOutMs)
                : fadingPopupsEffect.fadeOutDuration,''')
open(path, "w").write(s)
PY

if command -v gdbus >/dev/null; then
    gdbus call --session --dest org.kde.KWin --object-path /Effects \
        --method org.kde.kwin.Effects.unloadEffect fadingpopups >/dev/null || true
    gdbus call --session --dest org.kde.KWin --object-path /Effects \
        --method org.kde.kwin.Effects.loadEffect fadingpopups >/dev/null || true
fi
echo "Installed to $dst"
echo "To undo: rm -rf '$dst' and reload the effect."