EncodingHelpers.swift

//
//  EncodingHelpers.swift
//  QuickHatch
//
//  Created by Daniel Koster on 8/14/19.
//  Copyright © 2019 DaVinci Labs. All rights reserved.
//

import Foundation

public struct EncodingHelpers {
    public static func queryComponents(fromKey key: String, value: Any) -> [(String, String)] {
        var components: [(String, String)] = []
        
        if let dictionary = value as? [String: Any] {
            for (nestedKey, value) in dictionary {
                components += queryComponents(fromKey: "\(key)[\(nestedKey)]", value: value)
            }
        } else if let array = value as? [Any] {
            for value in array {
                components += queryComponents(fromKey: "\(key)", value: value)
            }
        }
        else if let bool = value as? Bool {
            components.append((escape(key), escape((bool ? "1" : "0"))))
        } else {
            components.append((escape(key), escape("\(value)")))
        }
        
        return components
    }
    
    public static func escape(_ string: String) -> String {
        let generalDelimitersToEncode = ":#[]@" // does not include "?" or "/" due to RFC 3986 - Section 3.4
        let subDelimitersToEncode = "!$&'()*+,;="
        
        var allowedCharacterSet = CharacterSet.urlQueryAllowed
        allowedCharacterSet.remove(charactersIn: "\(generalDelimitersToEncode)\(subDelimitersToEncode)")
        return string.addingPercentEncoding(withAllowedCharacters: allowedCharacterSet) ?? string
    }
}