import Carbon

final class HotKeyManager: @unchecked Sendable {
    var onLocal: (@Sendable () -> Void)?
    var onCloud: (@Sendable () -> Void)?

    private var localRef: EventHotKeyRef?
    private var cloudRef: EventHotKeyRef?
    private var handlerRef: EventHandlerRef?
    private let signature: OSType = 0x574B4559 // WKEY

    func register() throws {
        unregister()
        var eventType = EventTypeSpec(eventClass: OSType(kEventClassKeyboard), eventKind: UInt32(kEventHotKeyPressed))
        let status = InstallEventHandler(
            GetApplicationEventTarget(),
            { _, event, context in
                guard let context, let event else { return noErr }
                let manager = Unmanaged<HotKeyManager>.fromOpaque(context).takeUnretainedValue()
                var id = EventHotKeyID()
                GetEventParameter(
                    event,
                    EventParamName(kEventParamDirectObject),
                    EventParamType(typeEventHotKeyID),
                    nil,
                    MemoryLayout<EventHotKeyID>.size,
                    nil,
                    &id
                )
                if id.id == 1 { manager.onLocal?() }
                if id.id == 2 { manager.onCloud?() }
                return noErr
            },
            1,
            &eventType,
            Unmanaged.passUnretained(self).toOpaque(),
            &handlerRef
        )
        guard status == noErr else { throw WhisperKeyError.processFailed("Carbon handler: \(status)") }

        let localID = EventHotKeyID(signature: signature, id: 1)
        let cloudID = EventHotKeyID(signature: signature, id: 2)
        guard RegisterEventHotKey(UInt32(kVK_F5), 0, localID, GetApplicationEventTarget(), 0, &localRef) == noErr else {
            throw WhisperKeyError.processFailed("F5 уже занята. Отключите сочетание системной диктовки.")
        }
        guard RegisterEventHotKey(UInt32(kVK_F5), UInt32(optionKey), cloudID, GetApplicationEventTarget(), 0, &cloudRef) == noErr else {
            throw WhisperKeyError.processFailed("Option+F5 уже занята.")
        }
    }

    func unregister() {
        if let localRef { UnregisterEventHotKey(localRef) }
        if let cloudRef { UnregisterEventHotKey(cloudRef) }
        if let handlerRef { RemoveEventHandler(handlerRef) }
        localRef = nil
        cloudRef = nil
        handlerRef = nil
    }

    deinit { unregister() }
}