#!/bin/sh

set -euo pipefail

get_layout_display_name() {
    idx="$1"
    dbus-send --session --print-reply --dest=org.kde.keyboard /Layouts org.kde.KeyboardLayouts.getLayoutsList 2>/dev/null \
        | grep 'string "' \
        | sed 's/.*string "\([^"]*\)".*/\1/' \
        | awk -v idx="$idx" 'NR%3==0 { if (c++ == idx) { print; exit } }'
}

get_layout_index() {
    dbus-send --session --print-reply --dest=org.kde.keyboard /Layouts org.kde.KeyboardLayouts.getLayout 2>/dev/null \
        | awk '/uint32/ { print $2; exit }'
}

LAST_LAYOUT=""

apply_layout() {
    idx="$1"
    CURRENT_LAYOUT=$(get_layout_display_name "$idx")

    if test "$LAST_LAYOUT" = "$CURRENT_LAYOUT"; then
        return 0
    elif test "$CURRENT_LAYOUT" = "English (Colemak)"; then
        echo "Setting layout to colemak"
        setxkbmap us colemak
    elif test "$CURRENT_LAYOUT" = "Portuguese (Brazil)"; then
        echo "Setting layout to br"
        setxkbmap br
    fi

    LAST_LAYOUT="$CURRENT_LAYOUT"
}

update_layout() {
    INDEX=$(get_layout_index)
    apply_layout "$INDEX"
}

while ! get_layout_index; do
    sleep 1s
done
update_layout

dbus-monitor --session \
    "type='signal',interface='org.kde.KeyboardLayouts',member='layoutChanged',path='/Layouts'" \
    | while read -r line; do
        update_layout
    done