Subscribe-Controller.cs

using System.Net;
using System.Net.Mail;
using System.ComponentModel.DataAnnotations;
using Microsoft.Extensions.Options;
using Microsoft.AspNetCore.Mvc;

namespace WebApplication2
{
    public class Program
    {
        public static void Main(string[] args)
        {
            var builder = WebApplication.CreateBuilder(args);
            builder.Services.AddTransient<IMailService, MailService>();

            var app = builder.Build();

            app.MapPost("/api/send-email", async (EmailRequest mailData, IMailService mailService) =>
            {
                if (mailService.SendEmail(mailData.Email, "Welcome to the Swamp!", "Stay Froggy!"))
                {
                    return Results.Ok("Email sent");
                }
                else
                {
                    return Results.Problem();
                }
            });
            app.MapGet("/", async context =>
            {
                context.Response.ContentType = "text/html";
                await context.Response.WriteAsync(@"
<!DOCTYPE html>
<html>
<head>
    <title>Тест отправки email через Mailgun (SMTP)</title>
    <meta charset=""UTF-8"">
</head>
<body>
    <h2>Отправка тестового письма через Mailgun (SMTP)</h2>
    <form id=""emailForm"">
        <input type=""email"" id=""email"" required placeholder=""user@example.com"">
        <button type=""submit"">Отправить</button>
    </form>
    <div id=""result"" class=""result""></div>
    <script>
        document.getElementById('emailForm').addEventListener('submit', async (e) => {
            e.preventDefault();
            const resultDiv = document.getElementById('result');
            resultDiv.style.display = 'none';

            const data = {
                email: document.getElementById('email').value
            };

            try {
                const response = await fetch('api/send-email', {
                    method: 'POST',
                    headers: { 'Content-Type': 'application/json' },
                    body: JSON.stringify(data)
                });
                const result = await response.json();
                resultDiv.className = 'result ' + (response.ok ? 'success' : 'error');
                resultDiv.textContent = response.ok ? '✅ ' + result.message : '❌ ' + result.error;
                resultDiv.style.display = 'block';
            } catch (err) {
                resultDiv.className = 'result error';
                resultDiv.textContent = '❌ Ошибка сети или сервера: ' + err.message;
                resultDiv.style.display = 'block';
            }
        });
    </script>
</body>
</html>
    ");
            });

            app.Run();
        }
    }

    public class EmailRequest
    {
        [Required]
        [EmailAddress]
        public string Email { get; set; }
    }

    public interface IMailService
    {
        bool SendEmail(string toEmail, string subject, string body);
    }

    public class MailService : IMailService
    {
        private string _smtpServer = "smtp.mailgun.org";
        private int _smtpPort = 587;
        private string _smtpUsername = "ваш-smtp-логин";
        private string _smtpPassword = "ваш-smtp-пароль";

        private string _senderName = "Greenswamp Community";
        private string _senderEmail = "info@greenswamp.com";

        private readonly ILogger<MailService> _logger;

        public MailService(ILogger<MailService> logger)
        {
            _logger = logger;
        }

        public bool SendEmail(string toEmail, string subject, string body)
        {
            try
            {
                using (var client = new SmtpClient(_smtpServer, _smtpPort))
                {

                    client.EnableSsl = true;
                    client.Credentials = new NetworkCredential(_smtpUsername, _smtpPassword);

                    var fromAddress = new MailAddress(_senderEmail, _senderName);
                    var toAddress = new MailAddress(toEmail);

                    using (var message = new MailMessage(fromAddress, toAddress))
                    {
                        message.Subject = subject;
                        message.Body = body;
                        message.IsBodyHtml = true;
                        client.Send(message);
                    }
                }

                _logger.LogInformation("Email successfully sent to {ToEmail}", toEmail);
                return true;
            }
            catch (Exception ex)
            {
                _logger.LogError(ex, "An unexpected error occurred while sending email to {ToEmail}", toEmail);
                return false;
            }
        }

    }
}