using System;
using System.ComponentModel.DataAnnotations;
using System.Linq;
using System.Threading.Tasks;
using MailKit.Net.Smtp;
using MailKit.Security;
using Microsoft.AspNetCore.Mvc;
using Microsoft.AspNetCore.Mvc.RazorPages;
using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.Logging;
using MimeKit;

namespace contact.Pages
{
    [BindProperties(SupportsGet = true)]
    public class ContactFormModel
    {
        public ContactFormModel()
        {
            DbId = "n/a v7";
        }
        [Required]
        public string Name { get; set; }
        [Required]
        public string Company { get; set; }
        [BindProperty(SupportsGet = true)]
        public string DbId { get; set; }
        [Required, EmailAddress]
        public string Email { get; set; }
        [Required]
        public string Message { get; set; }
    }

    public class ContactModel : PageModel
    {
        private const string ConfirmedUrl = "https://ayanova.com/confirmed.htm";

        //2022-05-06 Company names containing any of these are dropped silently but still get the
        //success redirect, so the spammer gets no signal and has to pay someone to enter them by hand
        private static readonly string[] SpamBlocks = { "google", "jumboleadmagnet", "boostleadgeneration" };

        public string Message { get; set; }

        [BindProperty(SupportsGet = true)]
        public ContactFormModel Contact { get; set; }

        //Set when the send fails, so Contact.cshtml can tell the visitor instead of claiming success
        public bool SendFailed { get; set; }

        private readonly IConfiguration _configuration;
        private readonly ILogger<ContactModel> _logger;

        public ContactModel(IConfiguration configuration, ILogger<ContactModel> logger)
        {
            _configuration = configuration;
            _logger = logger;
        }

        public void OnGet()
        {
            Message = "Your contact page.";
        }

        public async Task<IActionResult> OnPostAsync()
        {
            if (!ModelState.IsValid)
            {
                return Page();
            }

            //2025-11-01 reCAPTCHA removed (Google service change). Replacement deferred, see runbook Phase 6.

            var company = Contact.Company.ToLowerInvariant();
            if (SpamBlocks.Any(s => company.Contains(s)))
            {
                return Redirect(ConfirmedUrl);
            }

            try
            {
                await SendMailAsync();
            }
            catch (Exception ex)
            {
                //Log the whole submission so it can be recovered from the journal, not lost
                _logger.LogError(ex,
                    "Contact form send failed. Name: {Name} | Company: {Company} | Email: {Email} | DbId: {DbId} | Message: {Message}",
                    Contact.Name, Contact.Company, Contact.Email, Contact.DbId, Contact.Message);
                SendFailed = true;
                return Page();
            }

            return Redirect(ConfirmedUrl);
        }

        private async Task SendMailAsync()
        {
            var smtp = _configuration.GetSection("Smtp");

            //Email is in the body as well as Reply-To, so it survives even if Reply-To can't be set
            var body = $"Name:\r\n{Contact.Name}\r\n\r\nCompany:\r\n{Contact.Company}\r\n\r\nEmail:\r\n{Contact.Email}\r\n\r\nDatabase Id:\r\n{Contact.DbId}\r\n\r\nMessage:\r\n{Contact.Message}";

            var message = new MimeMessage();
            //From is always the authenticated account; the visitor goes in Reply-To (no sender spoofing)
            message.From.Add(new MailboxAddress("AyaNova contact form", smtp["User"]));
            message.To.Add(MailboxAddress.Parse("support@ayanova.com"));
            if (MailboxAddress.TryParse(Contact.Email, out var replyTo))
            {
                replyTo.Name = Contact.Name;
                message.ReplyTo.Add(replyTo);
            }
            message.Subject = $"Question about AyaNova from {OneLine(Contact.Company)}";
            message.Body = new TextPart("plain") { Text = body };

            using var client = new SmtpClient();
            await client.ConnectAsync(smtp["Host"], smtp.GetValue<int>("Port"), SecureSocketOptions.StartTls);
            await client.AuthenticateAsync(smtp["User"], smtp["Password"]);
            await client.SendAsync(message);
            await client.DisconnectAsync(true);
        }

        private static string OneLine(string s) => s.Replace("\r", " ").Replace("\n", " ");
    }
}