import Alamofire
import SwiftyJSON

///HTTP-Layer
///Creates with DeviceToken the URL to request the user-credentials
class TokenConverterConnector {

    static let GOOGLETOKENURL = "https://www.googleapis.com/oauth2/v1/userinfo?access_token="

    static func requestGoogleCredentials(accessToken:String, completion: @escaping (_ jsonObject: SwiftyJSON?) -> Void) {

        let url = GOOGLETOKENURL + accessToken

        Alamofire.request(url).responseJSON {
            response in

            var jsonValue:SwiftyJSON?

            if let JSON = response.result.value {
                jsonValue = SwiftyJSON(JSON)
            }

            completion(jsonValue)
        }
    }
}

///Service-Layer
///Converts Device Token of the User into his E-Mail, which is necessary for the Backend.
class TokenConverterService {

    static func extractGoogleToken(accessToken:String, completion: @escaping (_ extraionSuccessful:Bool) -> Void) {

        TokenConverterConnector.requestGoogleCredentials(accessToken: accessToken, completion: {
            (jsonObject) in

            var extractionSuccessful:Bool = false

            if let json = jsonObject {

                let email = json["email"].string

                if let newMail = email {

                    SettingsService.saveMail(newMail)
                    extractionSuccessful = true
                }
            }

            completion(extractionSuccessful)
        })
    }
}