.package(url: "https://github.com/michaelhenry/XConfigs", .upToNextMinor(from: "1.0.0")),

let kvProvider = SampleKeyValueProvider()

// Register the AppConfigs and set which keyValueProvider and option to use. Note that `.allowInAppModification(InAppModificationOption)` option accepts a `KeyValueStore`.
XConfigs.configure(with: AppConfigs.self, keyValueProvider: kvProvider, option: .allowInAppModification(.init(store: UserDefaults.standard)))

#if DEBUG
    XConfigs.configure(with: MockConfigs.self, keyValueProvider: kvProvider, option: .allowInAppModification(.init(store: UserDefaults.standard)))
#else
    XConfigs.configure(with: MockConfigs.self, keyValueProvider: kvProvider, option: .readonly)
#endif

struct AppConfigs: XConfigSpec {

    @XConfig(key: "isOnboardingEnabled", defaultValue: false)
    var isOnboardingEnabled: Bool

    @XConfig(key: "apiURL", defaultValue: URL(string: "https://google.com")!)
    var apiURL: URL

    @XConfig(key: "region", defaultValue: .north)
    var region: Region

    @XConfig(key: "maxRetry", defaultValue: 10)
    var maxRetry: Int

    @XConfig(key: "threshold", defaultValue: 1)
    var threshold: Int

    @XConfig(key: "rate", defaultValue: 2.5)
    var rate: Double
}

enum Region: String, CaseIterable, RawStringValueRepresentable {
    case north
    case south
    case east
    case west
}

import FirebaseRemoteConfig

struct FirebaseKeyValueProvider: KeyValueProvider {

    private let remoteConfig: RemoteConfig = {
        let rconfig = RemoteConfig.remoteConfig()
        let settings = RemoteConfigSettings()
        settings.minimumFetchInterval = 0
        rconfig.configSettings = settings
        return rconfig
    }()
    
    // Please refer to https://firebase.google.com/docs/remote-config/get-started?platform=ios
    func fetch() {
        remoteConfig.fetch { (status, error) -> Void in
            if status == .success {
                print("Config fetched!")
                self.remoteConfig.activate { changed, error in
                    // ...
                }
            } else {
                print("Config not fetched")
                print("Error: \(error?.localizedDescription ?? "No error available.")")
            }
        }
    }

    // XConfigs KeyValueProvider protocol
    func get<Value>(for key: String) -> Value? where Value : RawStringValueRepresentable {
        guard let rawValue = remoteConfig.configValue(forKey: key).stringValue, let value = Value(rawString: rawValue) else { return nil }
        return value
    }
}