import Foundation
import Security

enum KeychainStore {
    private static let service = "uk.co.kasztelan.app.ios"
    private static let account = "api-token"

    static func save(token: String) throws {
        let data = Data(token.utf8)
        let query: [String: Any] = [
            kSecClass as String: kSecClassGenericPassword,
            kSecAttrService as String: service,
            kSecAttrAccount as String: account
        ]
        SecItemDelete(query as CFDictionary)
        var item = query
        item[kSecValueData as String] = data
        item[kSecAttrAccessible as String] = kSecAttrAccessibleAfterFirstUnlockThisDeviceOnly
        let status = SecItemAdd(item as CFDictionary, nil)
        guard status == errSecSuccess else { throw NSError(domain: NSOSStatusErrorDomain, code: Int(status)) }
    }

    static func load() -> String {
        let query: [String: Any] = [
            kSecClass as String: kSecClassGenericPassword,
            kSecAttrService as String: service,
            kSecAttrAccount as String: account,
            kSecReturnData as String: true,
            kSecMatchLimit as String: kSecMatchLimitOne
        ]
        var result: CFTypeRef?
        guard SecItemCopyMatching(query as CFDictionary, &result) == errSecSuccess,
              let data = result as? Data else { return "" }
        return String(data: data, encoding: .utf8) ?? ""
    }

    static func clear() {
        SecItemDelete([
            kSecClass as String: kSecClassGenericPassword,
            kSecAttrService as String: service,
            kSecAttrAccount as String: account
        ] as CFDictionary)
    }
}