Wave/Wave/Components/Pages/EmailSignup.razor

@page "/Email/Subscribe"
@page "/Email/Confirm"

@using Microsoft.Extensions.Options
@using Wave.Data
@using System.ComponentModel.DataAnnotations
@using System.Net
@using Microsoft.EntityFrameworkCore
@using Wave.Services
@using Wave.Utilities

@inject ILogger<EmailSignup> Logger
@inject IStringLocalizer<EmailSignup> Localizer
@inject IDbContextFactory<ApplicationDbContext> ContextFactory
@inject IOptions<Features> Features
@inject IOptions<Customization> Customizations
@inject NavigationManager Navigation
@inject IAdvancedEmailSender EmailSender
@inject EmailTemplateService TemplateService

<PageTitle>@(TitlePrefix + Localizer["Title"])</PageTitle>

@if (!string.IsNullOrWhiteSpace(Message)) {
	<div class="alert alert-success">
		<span>@Message</span>
	</div>
}

<BoardComponent CenterContent="true">
	<BoardCardComponent Heading="@Localizer["Title"]">
		<EditForm method="post" FormName="email-signup" Model="Model" OnValidSubmit="OnValidSubmit">
			<DataAnnotationsValidator />

			<InputLabelComponent LabelText="@Localizer["Name_Label"]" For="() => Model.Name">
				<InputText @bind-Value="Model.Name" class="input input-bordered w-full" autocomplete="name"
				           placeholder="@Localizer["Name_Placeholder"]" />
			</InputLabelComponent>
			<InputLabelComponent LabelText="@Localizer["Email_Label"]" For="() => Model.Name">
				<InputText @bind-Value="Model.Email" class="input input-bordered w-full" autocomplete="email" type="email"
						   required aria-required="true" placeholder="@Localizer["Email_Placeholder"]" />
			</InputLabelComponent>

			<button type="submit" class="btn btn-primary w-full">@Localizer["Submit"]</button>
		</EditForm>
	</BoardCardComponent>
</BoardComponent>

@code {
	[CascadingParameter(Name = "TitlePrefix")]
	private string TitlePrefix { get; set; } = default!;
	[SupplyParameterFromForm(FormName = "email-signup")]
	private InputModel Model { get; set; } = new();

	[Parameter, SupplyParameterFromQuery(Name = "user")]
	public string? Id { get; set; }
	[Parameter, SupplyParameterFromQuery(Name = "token")]
    public string? Token { get; set; }

	private string Message { get; set; } = string.Empty;

	protected override async Task OnInitializedAsync() {
		if (Features.Value.EmailSubscriptions is not true)
			throw new ApplicationException("Email subscriptions not enabled.");

		if (Id is null || Token is null) return;
		try {
			var id = await TemplateService.ValidateTokensAsync(Id, Token, deleteToken: false);

			if (id is null) {
				Message = Localizer["Failure_Message"];
				return;
			}

			await using var context = await ContextFactory.CreateDbContextAsync();
			var subscriber = context.Set<EmailSubscriber>().IgnoreQueryFilters().FirstOrDefault(s => s.Id == id);
			if (subscriber is null) {
				Message = Localizer["Failure_Message"];
				return;
			}
			subscriber.Unsubscribed = false;
			await context.SaveChangesAsync();
			Message = Localizer["Success_Message"];

			await TemplateService.ValidateTokensAsync(Id, Token, deleteToken: true);

			var articles = await context.Set<EmailNewsletter>()
				.IgnoreAutoIncludes()
				.Include(a => a.Article).ThenInclude(a => a.Author)
				.OrderByDescending(a => a.DistributionDateTime)
				.Take(3)
				.ToListAsync();
			string body = $"<p>{Localizer["WelcomeEmailBody"]}</p>\n";

			foreach (var n in articles) {
				string articleLink = ArticleUtilities.GenerateArticleLink(n.Article, new Uri(Customizations.Value.AppUrl, UriKind.Absolute));
				body = body +
				       "<div style=\"padding: 10px; background: #333; color: #fff; margin-bottom: 10px\">" +
				       $"<h3>{n.Article.Title}</h3>" +
				       $"<small>{n.Article.Author.Name}</small>" +
				       $"<p>{n.Article.Body[..Math.Min(100, n.Article.Body.Length)]}...</p>" +
				       $"<a href=\"{articleLink}\">Link</a>" +
				       "</div>";
			}
			await EmailSender.SendSubscribedMailAsync(subscriber, 
				Localizer["WelcomeEmailSubject"], Localizer["WelcomeEmailTitle"], body, subscribedRole: "welcome");
		} catch (Exception ex) {
			Logger.LogError(ex, "Error trying to confirm subscriber.");
			Message = Localizer["Failure_Message"];
		}
	}

	private async Task OnValidSubmit() {
		if (Features.Value.EmailSubscriptions is not true)
			throw new ApplicationException("Email subscriptions not enabled.");

		try {
			Message = Localizer["Submit_Message"];
			await using var context = await ContextFactory.CreateDbContextAsync();

			var subscriber = context.Set<EmailSubscriber>().IgnoreQueryFilters().FirstOrDefault(s => s.Email == Model.Email);
			if (subscriber?.Unsubscribed is false) return;

			subscriber ??= new EmailSubscriber {
				Email = Model.Email.Trim(),
				Unsubscribed = true
			};
			subscriber.Name = Model.Name;
			context.Update(subscriber);
			await context.SaveChangesAsync();

			if (subscriber.Unsubscribed) {
				(string id, string token) = await TemplateService.CreateConfirmTokensAsync(subscriber.Id);

				string confirmLink = Navigation.ToAbsoluteUri(
					$"/Email/Confirm?user={WebUtility.UrlEncode(id)}&token={WebUtility.UrlEncode(token)}").AbsoluteUri;
				string body = string.Format(Localizer["ConfirmEmailBody"], Customizations.Value.AppName) +
				              $"""<p style="text-align: center"><a href="{confirmLink}">{Localizer["Submit"]}</a></p>""";
				await EmailSender.SendDefaultMailAsync(subscriber.Email, subscriber.Name, Localizer["ConfirmEmailSubject"],
					Localizer["ConfirmEmailTitle"], body);
			}
		} catch (Exception ex) {
			Logger.LogError(ex, "Failed to create subscriber/send confirmation mail.");
			Message = Localizer["Failure_Message"];
		}
	}

	private sealed class InputModel {
		[MaxLength(128)]
		public string? Name { get; set; }
		[EmailAddress, Required(AllowEmptyStrings = false), MaxLength(256)]
		public string Email { get; set; } = string.Empty;
	}
}