//
//  MakeAuthorizationHeaderUseCase.swift
//  APIService
//
//  Created by Javier Cicchelli on 04/12/2022.
//  Copyright © 2022 Röck+Cöde. All rights reserved.
//

import Foundation

struct MakeAuthorizationHeaderUseCase {
    func callAsFunction(
        username: String,
        password: String
    ) throws -> [String: String] {
        guard !username.isEmpty else { throw MakeAuthorizationHeaderError.usernameIsEmpty }
        guard !password.isEmpty else { throw MakeAuthorizationHeaderError.passwordIsEmpty }
        
        let loginString = String(format: .Formats.usernameAndPassword, username, password)
        
        guard let loginData = loginString.data(using: .utf8) else {
            throw MakeAuthorizationHeaderError.loginDataNotCreated
        }
        
        let loginBase64 = loginData.base64EncodedString()
        
        return [.Header.Keys.authorization: String(format: .Formats.authorizationValue, loginBase64)]
    }
}

// MARK: - Errors

enum MakeAuthorizationHeaderError: Error {
    case usernameIsEmpty
    case passwordIsEmpty
    case loginDataNotCreated
}

// MARK: - String+Formats

private extension String {
    enum Formats {
        static let usernameAndPassword = "%@:%@"
        static let authorizationValue = "Basic %@"
    }
}