import Carbon
import AppKit

final class HotkeyManager {
    static let shared = HotkeyManager()

    var onTrigger: (() -> Void)?

    private var hotKeyRef: EventHotKeyRef?
    private var eventHandlerRef: EventHandlerRef?
    private var hotKeyID = EventHotKeyID(signature: 0x4B505452, id: 1)

    private init() {}

    func register() {
        var eventType = EventTypeSpec(
            eventClass: OSType(kEventClassKeyboard),
            eventKind: UInt32(kEventHotKeyPressed)
        )
        InstallEventHandler(GetApplicationEventTarget(), { _, _, _ in
            HotkeyManager.shared.onTrigger?()
            return noErr
        }, 1, &eventType, nil, &eventHandlerRef)

        RegisterEventHotKey(
            UInt32(kVK_ANSI_S),
            UInt32(cmdKey | shiftKey),
            hotKeyID,
            GetApplicationEventTarget(),
            0,
            &hotKeyRef
        )
    }
}