From c349a55747747b3b2107ae8f4446612080986f9c Mon Sep 17 00:00:00 2001
From: Maksim Makushchenko <maksalmak@gmail.com>
Date: Sun, 5 May 2024 16:14:24 +0300
Subject: [PATCH] setup storing metrics in memory and serve by url

---
 .../ImageMetricsMiddleware.cs                 | 14 ------
 Excursion360.Desktop/Program.cs               | 17 +++++--
 .../Services/IStateImagesMetricsStore.cs      | 47 +++++++++++++++++++
 ReleaseNotes.md                               |  7 ++-
 4 files changed, 66 insertions(+), 19 deletions(-)
 delete mode 100644 Excursion360.Desktop/ImageMetricsMiddleware.cs
 create mode 100644 Excursion360.Desktop/Services/IStateImagesMetricsStore.cs

diff --git a/Excursion360.Desktop/ImageMetricsMiddleware.cs b/Excursion360.Desktop/ImageMetricsMiddleware.cs
deleted file mode 100644
index 9b01253..0000000
--- a/Excursion360.Desktop/ImageMetricsMiddleware.cs
+++ /dev/null
@@ -1,14 +0,0 @@
-namespace Excursion360.Desktop;
-
-public class ImageMetricsMiddleware(RequestDelegate next, ILogger<ImageMetricsMiddleware> logger)
-{
-    public async Task InvokeAsync(HttpContext context)
-    {
-        var pathString = context.Request.Path.ToString();
-        if (pathString.Contains("state_") && pathString.EndsWith(".jpg", StringComparison.OrdinalIgnoreCase))
-        {
-            logger.LogWarning("Hey! {Path}", pathString);
-        }
-        await next(context);
-    }
-}
diff --git a/Excursion360.Desktop/Program.cs b/Excursion360.Desktop/Program.cs
index 0f46742..d54e3e7 100644
--- a/Excursion360.Desktop/Program.cs
+++ b/Excursion360.Desktop/Program.cs
@@ -11,8 +11,8 @@
 Console.ForegroundColor = ConsoleColor.White;
 
 var builder = WebApplication.CreateBuilder(args);
-
 builder.Logging.SetMinimumLevel(LogLevel.Information);
+builder.Services.AddSingleton<IStateImagesMetricsStore, InMemoryIStateImagesMetricsStore>();
 
 if (RuntimeInformation.IsOSPlatform(OSPlatform.Windows))
 {
@@ -24,9 +24,15 @@
 }
 
 var app = builder.Build();
-app.UseMiddleware<ImageMetricsMiddleware>();
 var targetDirectory = GetExcursionDirectory(builder.Configuration.ExcursionDirectoryPath());
 
+app.MapGet("/eapi/preload.json", (IStateImagesMetricsStore stateImagesMetrics) => {
+    return new
+    {
+        images = stateImagesMetrics.MostPopularUrls(),
+    };
+});
+
 var fso = new FileServerOptions
 {
     FileProvider = new CompositeFileProvider(
@@ -36,8 +42,11 @@
 fso.DefaultFilesOptions.DefaultFileNames.Add("Resources/NotFound.html");
 fso.StaticFileOptions.OnPrepareResponse = (context) =>
 {
-    context.Context.Response.Headers.CacheControl = "no-cache, no-store";
-    context.Context.Response.Headers.Expires = "-1";
+    if (context.File.Name.EndsWith(".jpg", StringComparison.OrdinalIgnoreCase) && context.File.PhysicalPath is not null)
+    {
+        var stateImagesMetricsStore = context.Context.RequestServices.GetRequiredService<IStateImagesMetricsStore>();
+        stateImagesMetricsStore.IncrementImageHit(context.Context.Request.Path);
+    }
 };
 app.UseFileServer(fso);
 
diff --git a/Excursion360.Desktop/Services/IStateImagesMetricsStore.cs b/Excursion360.Desktop/Services/IStateImagesMetricsStore.cs
new file mode 100644
index 0000000..ea6a1c6
--- /dev/null
+++ b/Excursion360.Desktop/Services/IStateImagesMetricsStore.cs
@@ -0,0 +1,47 @@
+using System.Collections.Concurrent;
+using System.Text.Json;
+using System.Text.RegularExpressions;
+
+namespace Excursion360.Desktop.Services;
+
+public interface IStateImagesMetricsStore
+{
+    void IncrementImageHit(string path);
+    string[] MostPopularUrls();
+}
+
+public partial class InMemoryIStateImagesMetricsStore : IStateImagesMetricsStore
+{
+    /// <summary>
+    /// Количества получений картинок по адресу. ключ = адрес картинки. Значение - количество получений.
+    /// </summary>
+    private readonly ConcurrentDictionary<string, int>
+        hitCounts = new();
+    private Regex stateAndImageRegex = GetStateAndImageRegex();
+    public void IncrementImageHit(string path)
+    {
+        var match = stateAndImageRegex.Match(path);
+        if (!match.Success)
+        {
+            return;
+        }
+        hitCounts.AddOrUpdate(path, 1, (_, old) => old + 1);
+        Console.WriteLine(JsonSerializer.Serialize(hitCounts, new JsonSerializerOptions
+        {
+            WriteIndented = true,
+        }));
+    }
+    public string[] MostPopularUrls()
+    {
+        return hitCounts
+            .OrderByDescending(kvp => kvp.Value)
+            .ThenBy(kvp => kvp.Key)
+            .Select(kvp => kvp.Key)
+            .Take(10)
+            .ToArray();
+    }
+
+    [GeneratedRegex(@"state_.+[/\\].+\.jpg$")]
+    private static partial Regex GetStateAndImageRegex();
+
+}
diff --git a/ReleaseNotes.md b/ReleaseNotes.md
index 24e213d..5eca5c7 100644
--- a/ReleaseNotes.md
+++ b/ReleaseNotes.md
@@ -1 +1,6 @@
-# Возможность выбирать используемый браузер из установленных на ПК
+- `v4.0`
+	- Обновлен .NET/Nuke до 8, убраны все предупреждения
+	- Обновлена структура проекта до последней версии ASP.NET Core
+	- Базовая папка для выбора экскурсий может выбираться через `--excursionsPath путь_к_папке`
+	- Добавлена обработка `/eapi/preload.json`, по которому будут отдаваться адреса изображений, которые чаще всего просматриваются
+- `v3.0` Возможность выбирать используемый браузер из установленных на ПК