import Foundation
import Security

enum KeychainStore {
    private static let service = "net.absdev.RsyncManager"

    static func string(for account: String) -> 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 item: CFTypeRef?
        guard SecItemCopyMatching(query as CFDictionary, &item) == errSecSuccess,
              let data = item as? Data,
              let value = String(data: data, encoding: .utf8) else { return "" }
        return value
    }

    @discardableResult
    static func set(_ value: String, for account: String) -> OSStatus {
        let base: [String: Any] = [
            kSecClass as String: kSecClassGenericPassword,
            kSecAttrService as String: service,
            kSecAttrAccount as String: account
        ]
        if value.isEmpty { return delete(account) }

        let data = Data(value.utf8)
        let update: [String: Any] = [
            kSecValueData as String: data,
            kSecAttrAccessible as String: kSecAttrAccessibleWhenUnlocked
        ]
        let updateStatus = SecItemUpdate(base as CFDictionary, update as CFDictionary)
        if updateStatus != errSecItemNotFound { return updateStatus }

        var add = base
        add[kSecValueData as String] = data
        add[kSecAttrAccessible as String] = kSecAttrAccessibleWhenUnlocked
        return SecItemAdd(add as CFDictionary, nil)
    }

    @discardableResult
    static func delete(_ account: String) -> OSStatus {
        let query: [String: Any] = [
            kSecClass as String: kSecClassGenericPassword,
            kSecAttrService as String: service,
            kSecAttrAccount as String: account
        ]
        let status = SecItemDelete(query as CFDictionary)
        return status == errSecItemNotFound ? errSecSuccess : status
    }
}