import Foundation
import Security

enum KeychainStore {
    private static let service = "xyz.lschaefer.Six-Card-Golf"
    /// Shared by the app and Messages extension via Keychain Sharing.
    private static let accessGroup = "6TY4NWX4TF.xyz.lschaefer.Six-Card-Golf"

    static func string(forKey account: String) -> String? {
        let query: [String: Any] = [
            kSecClass as String: kSecClassGenericPassword,
            kSecAttrService as String: service,
            kSecAttrAccount as String: account,
            kSecAttrAccessGroup as String: accessGroup,
            kSecReturnData as String: true,
            kSecMatchLimit as String: kSecMatchLimitOne
        ]
        var item: CFTypeRef?
        let status = SecItemCopyMatching(query as CFDictionary, &item)
        guard status == errSecSuccess,
              let data = item as? Data,
              let value = String(data: data, encoding: .utf8)
        else { return nil }
        return value
    }

    static func set(_ value: String?, forKey account: String) {
        delete(account)
        guard let value, let data = value.data(using: .utf8) else { return }
        let query: [String: Any] = [
            kSecClass as String: kSecClassGenericPassword,
            kSecAttrService as String: service,
            kSecAttrAccount as String: account,
            kSecAttrAccessGroup as String: accessGroup,
            kSecValueData as String: data,
            kSecAttrAccessible as String: kSecAttrAccessibleAfterFirstUnlockThisDeviceOnly
        ]
        SecItemAdd(query as CFDictionary, nil)
    }

    static func delete(_ account: String) {
        let query: [String: Any] = [
            kSecClass as String: kSecClassGenericPassword,
            kSecAttrService as String: service,
            kSecAttrAccount as String: account,
            kSecAttrAccessGroup as String: accessGroup
        ]
        SecItemDelete(query as CFDictionary)
    }
}