weatherAPI.swift

//
//  main.swift
//  weatherAPIcall
//
//  Created by Adir Burke on 25/8/20.
//  Copyright © 2020 WorkDesk. All rights reserved.
//

import Foundation

// MARK :- Models
struct WeatherResponse : Codable {
    let main : MainResponse
}

struct MainResponse : Codable {
    let temp : Double
    let feelsLike : Double
    let tempMin: Double
    let tempMax: Double
    let pressure: Double
    let humidity: Double
}

// MARK :- API Request
func fetchWeather(url : URL) -> WeatherResponse? {
 let semaphore = DispatchSemaphore(value: 0)
    var result : WeatherResponse? = nil
  let task = URLSession.shared.dataTask(with: url, completionHandler: { (data, response, error) in
    if let error = error {
      print("Error with fetching: \(error)")
        semaphore.signal()
      return
    }
    
    guard let httpResponse = response as? HTTPURLResponse,
          (200...299).contains(httpResponse.statusCode) else {
      print("Error with the response, unexpected status code: \(response)")
      semaphore.signal()
            return
    }

    if let data = data {
        do {
            let decoder = JSONDecoder()
            decoder.keyDecodingStrategy = .convertFromSnakeCase
            let weatherResponse = try decoder.decode(WeatherResponse.self, from: data)
        
              result = weatherResponse
        } catch {
            print(error)
        }

        
    }
    semaphore.signal()
  })
  task.resume()
    semaphore.wait()
    
    return result
}

// MARK :- Main

let APIKey = "XXXXXXX"
let city = "London"

guard var url2 = URLComponents(string: "https://api.openweathermap.org/data/2.5/weather") else { fatalError() }
url2.queryItems = [ .init(name: "q", value: city),
                    .init(name: "appid", value: APIKey),
                    .init(name: "units", value: "metric")]
guard let url = url2.url else { fatalError() }
guard let response = fetchWeather(url: url) else { fatalError() }

print("Current temp in \(city) is \(response.main.temp)")