OSOE-693: Display and send warnings also when 80 and 90% of the e-mail quota is reached

Lombiq.Hosting.Tenants.EmailQuotaManagement.Tests.UI/Extensions/TestCaseUITestContextExtensions.cs

@@ -2,7 +2,9 @@
 using Lombiq.Tests.UI.Helpers;
 using Lombiq.Tests.UI.Services;
 using OpenQA.Selenium;
+using Shouldly;
 using System;
+using System.Collections.Generic;
 using System.Threading.Tasks;
 
 namespace Lombiq.Hosting.Tenants.EmailQuotaManagement.Tests.UI.Extensions;
@@ -11,7 +13,8 @@ public static class TestCaseUITestContextExtensions
 {
     private const string SuccessfulSubject = "Successful test message";
     private const string UnSuccessfulSubject = "Unsuccessful test message";
-    private const string DashboardWarning =
+    private const string WarningSubject = "[Warning] Your DotNest site has used";
+    private const string DashboardExceededMessage =
         "//p[contains(@class,'alert-danger')][contains(.,'It seems that your site sent out more e-mails')]";
 
     public static async Task TestEmailQuotaManagementBehaviorAsync(
@@ -21,26 +24,56 @@ public static async Task TestEmailQuotaManagementBehaviorAsync(
     {
         await context.SignInDirectlyAndGoToDashboardAsync();
 
-        context.Missing(By.XPath(DashboardWarning));
+        context.Missing(By.XPath(DashboardExceededMessage));
 
         await context.GoToAdminRelativeUrlAsync("/Settings/email");
 
         CheckEmailsSentWarningMessage(context, exists: moduleShouldInterfere, maximumEmailQuota, 0);
 
-        await SendTestEmailAsync(context, SuccessfulSubject);
-        context.SuccessMessageExists();
+        var warningEmails = new List<int>();
+        for (int i = 0; i < maximumEmailQuota; i++)
+        {
+            await SendTestEmailAsync(context, SuccessfulSubject);
+            context.SuccessMessageExists();
+            CheckEmailsSentWarningMessage(context, exists: moduleShouldInterfere, maximumEmailQuota, i + 1);
+            var warningLevel = Convert.ToInt32((double)(i + 1) / maximumEmailQuota * 100) / 10 * 10;
+            if (!moduleShouldInterfere) continue;
 
-        CheckEmailsSentWarningMessage(context, exists: moduleShouldInterfere, maximumEmailQuota, 1);
-
-        await context.GoToDashboardAsync();
-        context.CheckExistence(By.XPath(DashboardWarning), exists: moduleShouldInterfere);
+            if (warningLevel >= 100)
+            {
+                await context.GoToDashboardAsync();
+                context.CheckExistence(By.XPath(DashboardExceededMessage), exists: moduleShouldInterfere);
+            }
+            else if (warningLevel >= 80)
+            {
+                await context.GoToDashboardAsync();
+                context.CheckExistence(
+                    By.XPath($"//p[contains(@class,'alert-warning')]" +
+                        $"[contains(.,'It seems that your site sent out {warningLevel.ToTechnicalString()}% of e-mail')]"),
+                    exists: moduleShouldInterfere);
+                if (!warningEmails.Contains(warningLevel))
+                {
+                    warningEmails.Add(warningLevel);
+                }
+            }
+        }
 
         await SendTestEmailAsync(context, UnSuccessfulSubject);
         await context.GoToSmtpWebUIAsync();
         context.CheckExistence(ByHelper.SmtpInboxRow(SuccessfulSubject), exists: true);
         context.CheckExistence(
             ByHelper.SmtpInboxRow("[Action Required] Your DotNest site has run over its e-mail quota"),
             exists: moduleShouldInterfere);
+        var warningMessageExists = context.CheckExistence(
+            ByHelper.SmtpInboxRow(WarningSubject),
+            exists: moduleShouldInterfere);
+        if (warningMessageExists)
+        {
+            (context.GetAll(
+                ByHelper.SmtpInboxRow(WarningSubject)).Count == warningEmails.Count)
+                .ShouldBeTrue();
+        }
+
         context.CheckExistence(ByHelper.SmtpInboxRow(UnSuccessfulSubject), exists: !moduleShouldInterfere);
     }
 

Lombiq.Hosting.Tenants.EmailQuotaManagement/Filters/EmailQuotaErrorFilter.cs

@@ -41,13 +41,24 @@ public async Task OnResultExecutionAsync(ResultExecutingContext context, ResultE
             actionRouteArea == $"{nameof(OrchardCore)}.{nameof(OrchardCore.Admin)}" &&
             actionRouteValue is nameof(AdminController.Index) &&
             context.Result is ViewResult &&
-            _quotaService.ShouldLimitEmails() &&
-            (await _quotaService.IsQuotaOverTheLimitAsync()).IsOverQuota)
+            _quotaService.ShouldLimitEmails())
         {
             var layout = await _layoutAccessor.GetLayoutAsync();
             var contentZone = layout.Zones["Content"];
+            var currentEmailQuota = await _quotaService.IsQuotaOverTheLimitAsync();
 
-            await contentZone.AddAsync(await _shapeFactory.CreateAsync("EmailQuotaError"), "0");
+            var roundedCurrentPercentage = _quotaService.CurrentUsagePercentage(currentEmailQuota.EmailQuota) / 10 * 10;
+
+            if (roundedCurrentPercentage >= 80)
+            {
+                await contentZone.AddAsync(
+                    await _shapeFactory.CreateAsync("EmailQuotaError", new
+                    {
+                        currentEmailQuota.IsOverQuota,
+                        UsagePercentage = roundedCurrentPercentage,
+                    }),
+                    "0");
+            }
         }
 
         await next();

Lombiq.Hosting.Tenants.EmailQuotaManagement/Indexes/EmailQuotaIndex.cs

@@ -8,6 +8,7 @@ public class EmailQuotaIndex : MapIndex
 {
     public int CurrentEmailQuotaCount { get; set; }
     public DateTime LastReminder { get; set; }
+    public int LastReminderPercentage { get; set; }
 }
 
 public class EmailQuotaIndexProvider : IndexProvider<EmailQuota>
@@ -18,5 +19,6 @@ public override void Describe(DescribeContext<EmailQuota> context) =>
             {
                 CurrentEmailQuotaCount = emailQuota.CurrentEmailQuotaCount,
                 LastReminder = emailQuota.LastReminder,
+                LastReminderPercentage = emailQuota.LastReminderPercentage,
             });
 }

Lombiq.Hosting.Tenants.EmailQuotaManagement/Migrations/EmailQuotaMigrations.cs

@@ -11,8 +11,18 @@ public int Create()
     {
         SchemaBuilder.CreateMapIndexTable<EmailQuotaIndex>(
             table => table.Column<int>(nameof(EmailQuotaIndex.CurrentEmailQuotaCount))
-                .Column<DateTime>(nameof(EmailQuotaIndex.LastReminder)));
+                .Column<DateTime>(nameof(EmailQuotaIndex.LastReminder))
+                .Column<int>(nameof(EmailQuotaIndex.LastReminderPercentage)));
 
-        return 1;
+        return 2;
+    }
+
+    public int UpdateFrom1()
+    {
+        SchemaBuilder.AlterTable(nameof(EmailQuotaIndex), table => table
+            .AddColumn<int>(nameof(EmailQuotaIndex.LastReminderPercentage))
+        );
+
+        return 2;
     }
 }

Lombiq.Hosting.Tenants.EmailQuotaManagement/Models/EmailQuota.cs

@@ -6,4 +6,5 @@ public class EmailQuota
 {
     public int CurrentEmailQuotaCount { get; set; }
     public DateTime LastReminder { get; set; }
+    public int LastReminderPercentage { get; set; }
 }

Lombiq.Hosting.Tenants.EmailQuotaManagement/Services/EmailSenderQuotaService.cs

@@ -4,8 +4,8 @@
 using OrchardCore.Email;
 using OrchardCore.Environment.Shell;
 using OrchardCore.Environment.Shell.Scope;
-using OrchardCore.Modules;
-using System;
+using System.Collections.Generic;
+using System.Linq;
 using System.Threading.Tasks;
 
 namespace Lombiq.Hosting.Tenants.EmailQuotaManagement.Services;
@@ -16,7 +16,6 @@ public class EmailSenderQuotaService : ISmtpService
     private readonly ISmtpService _smtpService;
     private readonly IQuotaService _quotaService;
     private readonly IEmailQuotaEmailService _emailQuotaEmailService;
-    private readonly IClock _clock;
     private readonly ShellSettings _shellSettings;
     private readonly IEmailTemplateService _emailTemplateService;
 
@@ -25,15 +24,13 @@ public EmailSenderQuotaService(
         IStringLocalizer<EmailSenderQuotaService> stringLocalizer,
         IQuotaService quotaService,
         IEmailQuotaEmailService emailQuotaEmailService,
-        IClock clock,
         ShellSettings shellSettings,
         IEmailTemplateService emailTemplateService)
     {
         _smtpService = smtpService;
         T = stringLocalizer;
         _quotaService = quotaService;
         _emailQuotaEmailService = emailQuotaEmailService;
-        _clock = clock;
         _shellSettings = shellSettings;
         _emailTemplateService = emailTemplateService;
     }
@@ -46,10 +43,11 @@ public async Task<SmtpResult> SendAsync(MailMessage message)
         }
 
         var isQuotaOverResult = await _quotaService.IsQuotaOverTheLimitAsync();
+        await SendAlertEmailIfNecessaryAsync(isQuotaOverResult.EmailQuota);
+
+        // Should send the email if the quota is not over the limit.
         if (isQuotaOverResult.IsOverQuota)
         {
-            await SendAlertEmailIfNecessaryAsync(isQuotaOverResult.EmailQuota);
-
             return SmtpResult.Failed(T["The email quota for the site has been exceeded."]);
         }
 
@@ -64,32 +62,58 @@ public async Task<SmtpResult> SendAsync(MailMessage message)
 
     private async Task SendAlertEmailIfNecessaryAsync(EmailQuota emailQuota)
     {
-        if (IsSameMonth(_clock.UtcNow, emailQuota.LastReminder)) return;
+        var currentUsagePercentage = _quotaService.CurrentUsagePercentage(emailQuota);
+        if (!_quotaService.ShouldSendReminderEmail(emailQuota, currentUsagePercentage)) return;
 
-        emailQuota.LastReminder = _clock.UtcNow;
-        _quotaService.SaveQuota(emailQuota);
+        var siteOwnerEmails = (await _emailQuotaEmailService.CollectUserEmailsForExceedingQuotaAsync()).ToList();
+        if (currentUsagePercentage >= 100)
+        {
+            var emailMessage = new MailMessage
+            {
+                Subject = T["[Action Required] Your DotNest site has run over its e-mail quota"],
+                IsHtmlBody = true,
+            };
+            SendQuotaEmail(siteOwnerEmails, emailMessage, "EmailQuota", currentUsagePercentage);
+            _quotaService.SaveQuotaReminder(emailQuota);
+            return;
+        }
 
-        var siteOwnerEmails = await _emailQuotaEmailService.CollectUserEmailsForExceedingQuotaAsync();
+        SendQuotaEmailWithPercentage(siteOwnerEmails, currentUsagePercentage / 10 * 10);
+        _quotaService.SaveQuotaReminder(emailQuota);
+    }
+
+    private void SendQuotaEmailWithPercentage(
+        IEnumerable<string> siteOwnerEmails,
+        int percentage)
+    {
         var emailMessage = new MailMessage
         {
-            Subject = T["[Action Required] Your DotNest site has run over its e-mail quota"],
+            Subject = T["[Warning] Your DotNest site has used {0}% of its e-mail quota", percentage],
             IsHtmlBody = true,
         };
+        SendQuotaEmail(siteOwnerEmails, emailMessage, $"EmailQuotaWarning", percentage);
+    }
 
+    private void SendQuotaEmail(
+        IEnumerable<string> siteOwnerEmails,
+        MailMessage emailMessage,
+        string emailTemplateName,
+        int percentage)
+    {
         foreach (var siteOwnerEmail in siteOwnerEmails)
         {
             ShellScope.AddDeferredTask(async _ =>
             {
                 emailMessage.To = siteOwnerEmail;
-                emailMessage.Body = await _emailTemplateService.RenderEmailTemplateAsync("EmailQuota", new
+                emailMessage.Body = await _emailTemplateService.RenderEmailTemplateAsync(emailTemplateName, new
                 {
                     HostName = _shellSettings.Name,
+                    Percentage = percentage,
                 });
+                // ISmtpService must be used within this class otherwise it won't call the original ISmtpService
+                // implementation, but loop back to here.
                 await _smtpService.SendAsync(emailMessage);
             });
         }
     }
-
-    private static bool IsSameMonth(DateTime date1, DateTime date2) =>
-        date1.Month == date2.Month && date1.Year == date2.Year;
 }

Lombiq.Hosting.Tenants.EmailQuotaManagement/Services/IQuotaService.cs

@@ -34,7 +34,17 @@ public interface IQuotaService
     void ResetQuota(EmailQuota emailQuota);
 
     /// <summary>
-    /// Saves the given quota.
+    /// Saves the given quota on reminder sent.
     /// </summary>
-    void SaveQuota(EmailQuota emailQuota);
+    void SaveQuotaReminder(EmailQuota emailQuota);
+
+    /// <summary>
+    /// Returns <see langword="true"/> if the reminder email should be sent.
+    /// </summary>
+    bool ShouldSendReminderEmail(EmailQuota emailQuota, int? currentPercentage = null);
+
+    /// <summary>
+    /// Returns the current quota usage percentage.
+    /// </summary>
+    int CurrentUsagePercentage(EmailQuota emailQuota);
 }

Lombiq.Hosting.Tenants.EmailQuotaManagement/Services/QuotaService.cs

@@ -5,6 +5,7 @@
 using OrchardCore.Email;
 using OrchardCore.Environment.Shell.Configuration;
 using OrchardCore.Modules;
+using System;
 using System.Threading.Tasks;
 using YesSql;
 
@@ -67,15 +68,51 @@ public async Task<EmailQuota> GetCurrentQuotaAsync()
     public void IncreaseQuota(EmailQuota emailQuota)
     {
         emailQuota.CurrentEmailQuotaCount++;
-        SaveQuota(emailQuota);
+        _session.Save(emailQuota);
     }
 
-    public void SaveQuota(EmailQuota emailQuota) =>
+    public void SaveQuotaReminder(EmailQuota emailQuota)
+    {
+        emailQuota.LastReminder = _clock.UtcNow;
+        emailQuota.LastReminderPercentage = CurrentUsagePercentage(emailQuota);
         _session.Save(emailQuota);
+    }
+
+    public bool ShouldSendReminderEmail(EmailQuota emailQuota, int? currentPercentage = null)
+    {
+        currentPercentage ??= CurrentUsagePercentage(emailQuota);
+        if (currentPercentage < 80)
+        {
+            return false;
+        }
+
+        var isSameMonth = IsSameMonth(_clock.UtcNow, emailQuota.LastReminder);
+
+        if (!isSameMonth)
+        {
+            return true;
+        }
+
+        switch (emailQuota.LastReminderPercentage)
+        {
+            case >= 80 when currentPercentage < 90:
+            case >= 90 when currentPercentage < 100:
+            case >= 100:
+                return false;
+            default:
+                return true;
+        }
+    }
 
     public void ResetQuota(EmailQuota emailQuota)
     {
         emailQuota.CurrentEmailQuotaCount = 0;
         _session.Save(emailQuota);
     }
+
+    public int CurrentUsagePercentage(EmailQuota emailQuota) =>
+        Convert.ToInt32(Math.Round((double)emailQuota.CurrentEmailQuotaCount / _emailQuotaOptions.EmailQuotaPerMonth * 100, 0));
+
+    private static bool IsSameMonth(DateTime date1, DateTime date2) =>
+        date1.Month == date2.Month && date1.Year == date2.Year;
 }

Lombiq.Hosting.Tenants.EmailQuotaManagement/Views/EmailQuotaError.cshtml

@@ -1 +1,8 @@
-<p class="alert alert-danger">@T["It seems that your site sent out more e-mails than the available quota for this month. E-mail sending has been stopped until next month (any feature sending out e-mails will fail)."]</p>
+@if (Model.IsOverQuota)
+{
+    <p class="alert alert-danger">@T["It seems that your site sent out more e-mails than the available quota for this month. E-mail sending has been stopped until next month (any feature sending out e-mails will fail)."]</p>
+}
+else
+{
+    <p class="alert alert-warning">@T["It seems that your site sent out {0}% of e-mails from the available quota for this month. E-mail sending will be stopped until next month (any feature sending out e-mails will fail), when the quota is exceeded.", Model.UsagePercentage]</p>
+}

Lombiq.Hosting.Tenants.EmailQuotaManagement/Views/EmailTemplate__EmailQuota.cshtml

@@ -1,4 +1,4 @@
 @{
     ViewLayout = "Layout__EmailTemplate";
 }
-@T["<p>Hi</p><p> It seems that your {0} site sent out more e-mails than the available quota for this month. E-mail sending has been stopped until next month (any feature sending out e-mails will fail).</p><p> Thank you,<br/> Your Admin Crew</p> ", Model.HostName]
+@T["<p>Hi,</p><p> It seems that your {0} site sent out more e-mails than the available quota for this month. E-mail sending has been stopped until next month (any feature sending out e-mails will fail).</p><p> Thank you,<br/> Your Admin Crew</p> ", Model.HostName]

Lombiq.Hosting.Tenants.EmailQuotaManagement/Views/EmailTemplate__EmailQuotaWarning.cshtml

@@ -0,0 +1,4 @@
+@{
+    ViewLayout = "Layout__EmailTemplate";
+}
+@T["<p>Hi,</p><p> It seems that your {0} site sent out {1}% of the available e-mail quota for this month. E-mail sending will be stopped until next month (any feature sending out e-mails will fail), when the quota is exceeded.</p><p> Thank you,<br/> Your Admin Crew</p> ", Model.HostName, Model.Percentage]