Get started with Game Center

GKLocalPlayer.local.authenticateHandler = { _, error in
    print("\(GKLocalPlayer.local.alias) is ready to play!")
}

var player = await GKLocalPlayer.Authenticate();
Debug.Log($"{player.alias} is ready to play!");

// Submit score

GKLeaderboard.submitScore(points, 
         context: 0, 
         player: GKLocalPlayer.local,
         leaderboardIDs: ["thecoast.lb.capecod"])

// Activity properties 

extension AppDelegate: GKLocalPlayerListener {

    func player(_ player: GKPlayer, wantsToPlay activity: GKGameActivity) async -> Bool {
        let activityId = activity.activityDefinition.identifier
        
        if activityId == "thecoast.activity" {
            let level = activity.properties["level"]
            
            if level == "capecod" {
                startCapeCod(activity)
            }
        }
        
        return true
    }

}

// Managing score submission with activity 

class GameplayManager {
    let activity: GKGameActivity
    let leaderboard: GKLeaderboard
    
    init(activity: GKGameActivity, leaderboard: GKLeaderboard) {
        self.activity = activity
        self.leaderboard = leaderboard
        
        activity.start()
    }
    
    func setScore(_ newScore: Int) {
        activity.setScore(on: leaderboard, to: newScore)
    }

    deinit {
        activity.end()
    }
}

extension AppDelegate: GKLocalPlayerListener {
    func player(_ player: GKPlayer, wantsToPlay activity: GKGameActivity) async -> Bool {
        let activityId = activity.activityDefinition.identifier
        
        if activityId == "thecoast.multiplayer" {
            startMultiplayer(partyCode: activity.partyCode)
        }
        
        return true
    }
}

let match = try await activity.findMatch()