Rytov flightApp

import com.google.gson.Gson;
import com.google.gson.JsonObject;
import com.google.gson.JsonParser;
import com.google.gson.reflect.TypeToken;

import java.io.IOException;
import java.nio.file.Files;
import java.nio.file.Paths;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

public class App {
    // parameters
    private static String filePath = "src/flights_and_forecast.json";
    private static double windMax = 30;
    private static double visibilityMin = 200;
    private static Map<String, Integer> timeZones = new HashMap<>();

    private static List<Map<String, Object>> flightsList;
    private static Map<String, Object> forecastMap;

    public static void main(String[] args) {
        init();
    }

    private static void init() {

        timeZones.put("moscow", 3);
        timeZones.put("omsk", 6);
        timeZones.put("novosibirsk", 7);

        try {
            String json = new String(Files.readAllBytes(Paths.get(filePath)));
            JsonObject jsonObject = JsonParser.parseString(json).getAsJsonObject();
            Gson gson = new Gson();

            // Get flights from JSON
            flightsList = gson.fromJson(jsonObject.getAsJsonArray("flights"),
                    new TypeToken<List<Map<String, Object>>>() {
                    }.getType());

            // Get forecast from JSON
            JsonObject forecastObject = jsonObject.getAsJsonObject("forecast");
            forecastMap = gson.fromJson(forecastObject, Map.class);

            for (Map<String, Object> flight : flightsList) {

                String no = (String) flight.get("no");
                String from = (String) flight.get("from");
                String to = (String) flight.get("to");

                Double departureDouble = (Double)flight.get("departure");
                int departure = departureDouble.intValue();
    
                Double durationDouble = (Double)flight.get("duration");
                int duration = durationDouble.intValue();


                boolean canDeparture = calculatePossibility(departure, from);
                if (!canDeparture) {
                    printFlightStatus(no, from, to, canDeparture);
                    continue;
                }

                int arrivalTime = calculateArrivalTime(from, to, departure, duration);

                boolean canArrive = calculatePossibility(arrivalTime, to);
                printFlightStatus(no, from, to, canArrive);
            }

        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    // method for calculating arrival time
    private static int calculateArrivalTime(String from, String to, int departure, int duration) {

        // calculate diff between timezones
        int timeDiff = (int) timeZones.get(to) - (int) timeZones.get(from);
        int time = departure + duration + timeDiff;
        //System.out.println("City time will be: "+time);
        int result = time;

        // parse time to 24 format
        if (time > 24) {
            result = time % 24;
        } else if (time < 0) {
            result = 24 - time;
        }

        // return calculated time
        return result;
    }

    // method for calculating possibility of flight
    private static boolean calculatePossibility(int time, String city) {

        List<Map<String, Double>> cityList = (List<Map<String, Double>>) forecastMap.get(city);
        Map<String, Double> timeForecast = cityList.get(time);

        if (timeForecast.get("wind") >  windMax) {
            //System.out.println("В "+time+" в городе "+city+" слишком сильный ветер - "+timeForecast.get("wind"));
            return false;

        } else if (timeForecast.get("visibility") < visibilityMin) {
            //System.out.println("В "+time+" в городе "+city+" слишком слабая видимость - "+timeForecast.get("visibility"));
            return false;

        } else {
            return true;
        }

    }

    // method for printing status of flight to console
    private static void printFlightStatus(String no, String from, String to, boolean willFlight) {

        String flightStatus;
        if (willFlight) {
            flightStatus = "по расписанию";
        } else {
            flightStatus = "отменен";
        }

        System.out.println(no + " | " + from + " -> " + to + " | " + flightStatus);
        //System.out.println();
    }

}