No Dependencies Swift Router

NoDepsRouter.swift

import Foundation

public protocol RequestConvertible {
    var asRequest: NSMutableURLRequest { get }
}

enum NoDepsRouter: RequestConvertible {

    case thing(id: String)
    case postThings(id: String)
    
    var host: String {
        return "google.com"
    }
    
    var path: String {
        switch self {
        case .thing(let id):
            return "/" + id
        case .postThings(let id):
            return "/things/" + id
        }
    }
    
    var method: Method {
        switch self {
        case .thing: return .get
        case .postThings: return .post
        }
    }
    
    var params: Any? {
        switch self {
        case .thing:
            return nil
        case .postThings(let id):
            return ["id": id,
                    "name":"blah"]
        }
    }
    
    var query: [URLQueryItem]? {
        return [URLQueryItem(name:"$filter", value: "1")]
    }
    
    var asRequest: NSMutableURLRequest {
        var urlComponents = URLComponents()
        urlComponents.scheme = "https"
        urlComponents.host = host
        urlComponents.path = path
        urlComponents.queryItems = query
        
        guard let URL = urlComponents.url else {
            fatalError("Couldn't build URL from components. Are you sure you're not missing a '/' at the start of the path value?")
        }
        
        let mutableURLRequest = NSMutableURLRequest(url: URL)
        mutableURLRequest.httpMethod = method.rawValue
        mutableURLRequest.setValue("Custom User-Agent", forHTTPHeaderField: "User-Agent")
        
        if let params = params {
            mutableURLRequest.encode(with: params)
        }
        
        return mutableURLRequest
    }
}

private extension NSMutableURLRequest {
    func encode(with jsonDictionary: Any) {
        do {
            let data = try JSONSerialization.data(withJSONObject: jsonDictionary, options: [])
            self.setValue("application/json", forHTTPHeaderField: "Content-Type")
            self.httpBody = data
            
        } catch let error as NSError {
            fatalError("Failed to encode JSON: \(error)")
        }
    }
}