swiftapp/swift/Sources/Core/Services/AppStateStore.swift

import Foundation

enum SharedDefaults {
    static let appGroupIdentifier = "group.global.idp.app"

    static var userDefaults: UserDefaults {
        UserDefaults(suiteName: appGroupIdentifier) ?? .standard
    }
}

struct PersistedAppState: Codable, Equatable {
    let session: AuthSession
    let profile: MemberProfile
    let requests: [ApprovalRequest]
    let notifications: [AppNotification]
}

protocol AppStateStoring {
    func load() -> PersistedAppState?
    func save(_ state: PersistedAppState)
    func clear()
}

final class UserDefaultsAppStateStore: AppStateStoring {
    private let defaults: UserDefaults
    private let storageKey: String
    private let encoder = JSONEncoder()
    private let decoder = JSONDecoder()

    init(defaults: UserDefaults = SharedDefaults.userDefaults, storageKey: String = "persisted-app-state") {
        self.defaults = defaults
        self.storageKey = storageKey
    }

    func load() -> PersistedAppState? {
        guard let data = defaults.data(forKey: storageKey) else {
            return nil
        }

        return try? decoder.decode(PersistedAppState.self, from: data)
    }

    func save(_ state: PersistedAppState) {
        guard let data = try? encoder.encode(state) else {
            return
        }

        defaults.set(data, forKey: storageKey)
    }

    func clear() {
        defaults.removeObject(forKey: storageKey)
    }
}