#!/bin/sh

CHANNEL="xfce4-keyboard-shortcuts"
PROPERTY="/commands/custom/<Shift>space"
DEFAULT_COMMAND="xfce4-popup-whiskermenu"
NOTIFY_TITLE="xfce4-popup-whiskermenu"

STATE_BASE="${XDG_STATE_HOME:-$HOME/.local/state}"
STATE_DIR="$STATE_BASE/xfce-shortcuts"
STATE_FILE="$STATE_DIR/shift-space-command"

usage() {
    printf 'usage: %s [toggle|on|off|status]\n' "$0"
}

notify() {
    if command -v notify-send >/dev/null 2>&1; then
        notify-send "$NOTIFY_TITLE" "$1" -t 2500
    else
        printf '%s: %s\n' "$NOTIFY_TITLE" "$1"
    fi
}

die() {
    printf 'error: %s\n' "$1" >&2
    exit 1
}

shortcut_exists() {
    xfconf-query -c "$CHANNEL" -p "$PROPERTY" >/dev/null 2>&1
}

shortcut_value() {
    xfconf-query -c "$CHANNEL" -p "$PROPERTY" 2>/dev/null
}

save_current_shortcut() {
    current_value=$(shortcut_value)
    [ -n "$current_value" ] || return 0

    mkdir -p "$STATE_DIR" || die "failed to create state directory: $STATE_DIR"
    printf '%s\n' "$current_value" > "$STATE_FILE" || die "failed to write state file: $STATE_FILE"
}

restore_command() {
    if [ -r "$STATE_FILE" ]; then
        read_saved=""
        IFS= read -r read_saved < "$STATE_FILE" || true
        [ -n "$read_saved" ] && {
            printf '%s\n' "$read_saved"
            return 0
        }
    fi

    printf '%s\n' "$DEFAULT_COMMAND"
}

disable_shortcut() {
    if ! shortcut_exists; then
        notify "shift+space is already disabled."
        return 0
    fi

    save_current_shortcut

    xfconf-query -c "$CHANNEL" -p "$PROPERTY" -r \
        || die "failed to remove $PROPERTY"

    notify "shift+space disabled"
}

enable_shortcut() {
    if shortcut_exists; then
        current_value=$(shortcut_value)
        notify "shift+space is already enabled: $current_value"
        return 0
    fi

    restore_value=$(restore_command)

    xfconf-query -c "$CHANNEL" -p "$PROPERTY" -n -t string -s "$restore_value" \
        || die "failed to restore $PROPERTY"

    rm -f "$STATE_FILE"
    notify "shift+space enabled"
}

status_shortcut() {
    if shortcut_exists; then
        current_value=$(shortcut_value)
        printf 'enabled: %s -> %s\n' "$PROPERTY" "$current_value"
    else
        printf 'disabled: %s\n' "$PROPERTY"
    fi
}

command -v xfconf-query >/dev/null 2>&1 \
    || die "xfconf-query not found"

action=${1:-toggle}

case "$action" in
    toggle)
        if shortcut_exists; then
            disable_shortcut
        else
            enable_shortcut
        fi
        ;;
    on)
        enable_shortcut
        ;;
    off)
        disable_shortcut
        ;;
    status)
        status_shortcut
        ;;
    -h|--help|help)
        usage
        ;;
    *)
        usage >&2
        exit 2
        ;;
esac