import Foundation

// Encrypted account cache backed by UserDefaults (AES-256-GCM via CacheEncryption).
// Used by HomeViewModel to display cached data instantly on launch while a fresh
// network fetch runs in the background.
struct AccountCache {
    static let shared = AccountCache()
    private let udKey = "thijooree_accounts_v1"
    private init() {}

    func save(_ accounts: [BankAccount]) {
        guard let json = try? JSONEncoder().encode(accounts),
              let encrypted = try? CacheEncryption.shared.encryptData(json) else { return }
        UserDefaults.standard.set(encrypted, forKey: udKey)
    }

    func load() -> [BankAccount] {
        guard let encrypted = UserDefaults.standard.string(forKey: udKey),
              let json = try? CacheEncryption.shared.decryptData(encrypted),
              let accounts = try? JSONDecoder().decode([BankAccount].self, from: json) else { return [] }
        return accounts
    }

    func clear() {
        UserDefaults.standard.removeObject(forKey: udKey)
    }
}