import Foundation
import CoreFoundation

public final class CoreNotificationCenter {

    public static let darwin = CoreNotificationCenter(CFNotificationCenterGetDarwinNotifyCenter())
    public static let local = CoreNotificationCenter(CFNotificationCenterGetLocalCenter())
#if os(macOS)
    public static let distributed = CoreNotificationCenter(CFNotificationCenterGetDistributedCenter())
#endif

    private let center: CFNotificationCenter
    private var observations: [Notification.Name: (Notification) -> Void] = [:]

    private init(_ center: CFNotificationCenter) {
        self.center = center
    }


    private func handleNotification(_ notification: Notification) {
        observations[notification.name]?(notification)
    }

    public func addObserver(forName name: Notification.Name, suspensionBehavior: CFNotificationSuspensionBehavior = .deliverImmediately, using block: @escaping (Notification) -> Void) {
        observations[name] = block

        let callback: CFNotificationCallback = { (_, observer, optCFName, pObject, optCFDict) in
            // needs to be an unsafeBitCast here - it's LITERALY the pointer in memory
            let center = unsafeBitCast(observer, to: CoreNotificationCenter.self)

            guard let cfName: CFNotificationName = optCFName else {
                assertionFailure("Nameless notification")
                return
            }
            let name = Notification.Name(cfName.rawValue as String)


            let object: Any?
            if let pObject = pObject {
                object = unsafeBitCast(pObject, to: Any.self)
            } else {
                object = nil
            }

            let userInfo: [AnyHashable: Any]?
            if let dictionary = optCFDict as? [String: AnyObject] {
                userInfo = dictionary
            } else {
                userInfo = nil
            }


            let notification = Notification(name: name,
                                            object: object,
                                            userInfo: userInfo)



            center.handleNotification(notification)
        }

        CFNotificationCenterAddObserver(
            center,
            Unmanaged.passUnretained(self).toOpaque(),
            callback,
            name.rawValue as CFString,
            nil,
            suspensionBehavior
        )

    }

    public func removeObserver(withName name: Notification.Name) {
        observations.removeValue(forKey: name)

        CFNotificationCenterRemoveObserver(
            center,
            Unmanaged.passUnretained(self).toOpaque(),
            CFNotificationName(name.rawValue as CFString),
            nil
        )
    }

    public func removeAllObservers() {
        CFNotificationCenterRemoveEveryObserver(
            center,
            Unmanaged.passUnretained(self).toOpaque()
        )
    }

    public func post(name: Notification.Name) {
        CFNotificationCenterPostNotification(
            center,
            CFNotificationName(name.rawValue as CFString),
            nil,
            nil,
            true
        )
    }
}



// https://www.iphonedevwiki.net/index.php/SpringBoard.app/Notifications
// https://employment12werft.blogspot.com/2011/02/ios-detect-monitor-when-system-messages.html
// https://developpaper.com/examples-of-the-underlying-notification-framework-library-of-ios-system/
// https://github.com/SCTCoding/LaunchEvents/blob/main/LaunchEvents.csv
extension Notification.Name {
    public static let springboardActiveCallStateChanged = Notification.Name("com.apple.springboard.activeCallStateChanged")
    public static let springboardAttemptActivation = Notification.Name("com.apple.springboard.attemptactivation")
    public static let springboardBootedCleanly = Notification.Name("com.apple.springboard.bootedcleanly")
    public static let springboardCallInterruptedApp = Notification.Name("com.apple.springboard.callinterruptedapp")
    public static let springboardCurvedBatteryCapacity = Notification.Name("com.apple.springboard.curvedBatteryCapacity")
    public static let springboardDeviceLockStatusChanged = Notification.Name("com.apple.springboard.DeviceLockStatusChanged")
    public static let springboardDeviceWillShotDown = Notification.Name("com.apple.springboard.deviceWillShutDown")
    public static let springboardDoubleHeightMode = Notification.Name("com.apple.springboard.doubleheightmode")
    public static let springboardFullyCharged = Notification.Name("com.apple.springboard.fullycharged")
    public static let springboardHasBlankedScreen = Notification.Name("com.apple.springboard.hasBlankedScreen")
    public static let springboardLockComplete = Notification.Name("com.apple.springboard.lockcomplete")
    public static let springboardLockInterrupted = Notification.Name("com.apple.springboard.lockinterrupted")
    public static let springboardLockState = Notification.Name("com.apple.springboard.lockstate")
    public static let springboardLowPowerAlertPresented = Notification.Name("com.apple.springboard.lowPowerAlertPresented")
    public static let springboardOrientation = Notification.Name("com.apple.springboard.orientation")
    public static let springboardPluggedIn = Notification.Name("com.apple.springboard.pluggedin")
    public static let springboardProximityChanged = Notification.Name("com.apple.springboard.proximity.changed")
    public static let springboardRawOrientation = Notification.Name("com.apple.springboard.rawOrientation")
    public static let springboardRentalsExpiredNotification = Notification.Name("com.apple.springboard.RentalsExpiredNotification")
    public static let springboardResetEnded = Notification.Name("com.apple.springboard.reset-ended")
    public static let springboardResetReady = Notification.Name("com.apple.springboard.reset-ready")
    public static let springboardResetWillEnd = Notification.Name("com.apple.springboard.reset-willend")
    public static let springboardRingerState = Notification.Name("com.apple.springboard.ringerstate")
    public static let springboardShowingAlertItem = Notification.Name("com.apple.springboard.showingAlertItem")
    public static let springboardSyncingUnblocked = Notification.Name("com.apple.springboard.syncingUnblocked")
    public static let springboardUnambiguousOrientation = Notification.Name("com.apple.springboard.unambiguousOrientation")


    public static let airportUserNotification = Notification.Name("com.apple.airport.userNotification")
    public static let airportSettingsVisible = Notification.Name("com.apple.airportsettingsvisible")
    public static let alarmAlarmChanged = Notification.Name("com.apple.alarm.alarmchanged")
    public static let alarmAlarmFired = Notification.Name("com.apple.alarm.alarmfired")
    public static let mobileSubstantialTransition = Notification.Name("com.apple.mobile.SubstantialTransition")
    public static let powerlogExit = Notification.Name("com.apple.powerlog.exit")
    public static let remoteNotificationDelivered = Notification.Name("com.apple.remotenotification.notificationdelivered")


    // AppleDatePreferencesChangedNotification
    // AppleLanguagePreferencesChangedNotification
    // AppleNumberPreferencesChangedNotification
    // ApplePreferredContentSizeCategoryChangedNotification
    // AppleTextBehaviorPreferencesChangedNotification
    // AppleTimePreferencesChangedNotification
    // com.apple.frontboard.systemappservices.serverNotifyToken
    // com.apple.frontboard.workspace.serverNotifyToken
    // com.apple.hangtracer.prefchangednotification
    // kCTDaemonReadyNotification
    // kKeepAppsUpToDateEnabledChangedNotification
    // PINPolicyChangedNotification
    // UIBacklightLevelChangedNotification

}