using System;

using System.Net.Http;

using System.Collections.Generic;

using System.Threading.Tasks;

using Microsoft.Extensions.Hosting;

using Microsoft.Extensions.DependencyInjection;

public class Program

{

    public static async Task<int> Main()

    {

        var host = GetHost();

        using(var scope = host.Services.CreateScope())

        {

            var services = scope.ServiceProvider;

            try

            {

                var weatherService = services.GetRequiredService<WeatherService>();

                var report = await weatherService.GetWeatherReportAsync(InputList.Cities[0]);

                Console.WriteLine(report);

            }

            catch(Exception excep)

            {

                Console.WriteLine($"Error Occured: {excep.Message}");

            }

        }

        return 0;

    }

    private static IHost GetHost()

    {

        var builder = new HostBuilder()

            .ConfigureServices((hostContext, services) => 

            {

                services.AddHttpClient();

                services.AddTransient<WeatherService>();

            }).UseConsoleLifetime();

        return builder.Build();

    }

}

​

public class WeatherService

{   

    // Http Client Factory

    private readonly IHttpClientFactory _httpFactory;

    // Constructor

    public WeatherService(IHttpClientFactory httpFactory){

        _httpFactory = httpFactory;

    }

    // Function to make api call and get result from api.

    public async Task<string> GetWeatherReportAsync(Location location){

        var client = _httpFactory.CreateClient();

        var request = CreateOpenWeatherMapRequest(location);

        var response = await client.SendAsync(request);

        if(response.IsSuccessStatusCode){

            return await response.Content.ReadAsStringAsync();

        } else {

            return $"Failure in fetching API response: {response.StatusCode}";

        }

    }

    // Create API request

    private HttpRequestMessage CreateOpenWeatherMapRequest(Location location){

        var paramString =  $"?q={location.City},{location.State}&appid={Config.CONFIDENTIAL_API_KEY}";

        return new HttpRequestMessage(HttpMethod.Get, Config.URL_TO_HIT + paramString);

    }

}

​

// Configuration entries, should be in AppSettings

public class Config

{

    public const string URL_TO_HIT = "http://api.openweathermap.org/data/2.5/forecast";

    public const string CONFIDENTIAL_API_KEY = "d2bb2b0318a1c3f0a7d04e7a3f2b3aba";

}

​

// Location class to fetch weather forcast for

public class Location

{

    public string City {get; set;}

    public string State{get; set;}

}

​

// Input list to be initialized with static result.

public class InputList

{

    public static readonly List<Location> Cities = new List<Location> 

    {

        new Location(){City="Marlboro", State="MA"},

        new Location(){City="San Diego", State="CA"},

        new Location(){City="Cheyenne", State="WY"},

        new Location(){City="Anchorage", State="AK"},

        new Location(){City="Austin", State="TX"},

        new Location(){City="Orlando", State="FL"},

        new Location(){City="Seattle", State="WA"},

        new Location(){City="Cleveland", State="OH"},

        new Location(){City="Portland", State="ME"},

        new Location(){City="Honolulu", State="HI"},

    };

}

​

​

​