Implement ChangelogWindow function

src/Ryujinx/UI/Windows/ChangelogWindow.axaml.cs

@@ -0,0 +1,150 @@
+using Avalonia.Controls;
+using Avalonia.Input;
+using Avalonia.Interactivity;
+using Avalonia.Layout;
+using Avalonia.Styling;
+using FluentAvalonia.UI.Controls;
+using HtmlAgilityPack;
+using Ryujinx.Ava.Common.Locale;
+using Ryujinx.Ava.UI.Helpers;
+using Ryujinx.Ava.UI.ViewModels;
+using Ryujinx.UI.Common.Helper;
+using System;
+using System.Diagnostics;
+using System.Text;
+using System.Threading.Tasks;
+using Button = Avalonia.Controls.Button;
+using System.Net.Http;
+
+
+namespace Ryujinx.Ava.UI.Windows
+{
+    public partial class ChangelogWindow : Window
+    {
+        public ChangelogWindow()
+        {
+            InitializeComponent();
+            InitializeAsync();
+        }
+
+        private async void InitializeAsync()
+        {
+            try
+            {
+                LoadingTextBlock.IsVisible = true;  // Show the loading text
+                ChangelogTextBlock.IsVisible = false;  // Hide the changelog text initially
+
+                string changelogHtml = await FetchChangelogHtml();
+                string changelog = ParseChangelogForRecentVersions(changelogHtml, 10);
+                LoadChangelog(changelog);
+
+                LoadingTextBlock.IsVisible = false;  // Hide the loading text
+                ChangelogTextBlock.IsVisible = true;  // Show the changelog text
+            }
+            catch (Exception ex)
+            {
+                LoadingTextBlock.Text = "Failed to load changelog: " + ex.Message;
+            }
+        }
+
+        private void LoadChangelog(string changelog)
+        {
+            ChangelogTextBlock.Text = changelog;
+        }
+
+        private static async Task<string> FetchChangelogHtml()
+        {
+            using (var client = new HttpClient())
+            {
+                client.DefaultRequestHeaders.UserAgent.ParseAdd("Ryujinx-Updater/1.0.0");
+                return await client.GetStringAsync("https://github.com/Ryujinx/Ryujinx/wiki/Changelog");
+            }
+        }
+
+        private static string ParseChangelogForRecentVersions(string html, int count)
+        {
+            var doc = new HtmlDocument();
+            doc.LoadHtml(html);
+
+            var headers = doc.DocumentNode.SelectNodes("//div[contains(@class, 'markdown-heading')]//h2");
+            if (headers != null)
+            {
+                var content = new StringBuilder();
+                int versionsFound = 0;
+
+                foreach (var header in headers)
+                {
+                    if (versionsFound >= count) break; // Stop after finding the desired number of versions
+                    content.Append(header.OuterHtml);
+                    var currentNode = header.ParentNode.NextSibling;
+
+                    while (currentNode != null && versionsFound < count)
+                    {
+                        if (currentNode.Name == "div" && currentNode.SelectSingleNode("h2") != null)
+                        {
+                            versionsFound++; // Increment for each version header found
+                            if (versionsFound >= count) break;
+                        }
+                        content.Append(currentNode.OuterHtml);
+                        currentNode = currentNode.NextSibling;
+                    }
+                }
+
+                return ConvertHtmlToPlainText(content.ToString());
+            }
+            return "No changelog found.";
+        }
+
+        private static string ConvertHtmlToPlainText(string html)
+        {
+            var doc = new HtmlDocument();
+            doc.LoadHtml(html);
+
+            // Recursively format nodes
+            string formattedText = FormatNode(doc.DocumentNode);
+
+            return HtmlEntity.DeEntitize(formattedText);
+        }
+
+        private static string FormatNode(HtmlNode node, int depth = 0)
+        {
+            StringBuilder sb = new StringBuilder();
+            foreach (var child in node.ChildNodes)
+            {
+                switch (child.Name)
+                {
+                    case "ul":
+                        // Recursively format the list items
+                        sb.Append(FormatNode(child, depth));
+                        sb.AppendLine();
+                        break;
+
+                    case "li":
+                        // Format list item based on depth: "-" for top-level, "+" for nested items
+                        string prefix = (depth == 0 ? "- " : new string(' ', depth * 4) + "+ ");
+                        sb.AppendLine($"{prefix}{FormatNode(child, depth + 1).Trim()}");
+                        break;
+
+                    case "p":
+                    case "#text":  // Handling direct text nodes
+                        if (!string.IsNullOrWhiteSpace(child.InnerText))
+                        {
+                            // Trim the text
+                            string text = HtmlEntity.DeEntitize(child.InnerText).Trim();
+                            sb.Append($"{text}\n");
+                        }
+                        break;
+
+                    default:
+                        // Recursively process other types of nodes
+                        if (child.HasChildNodes)
+                        {
+                            sb.Append(FormatNode(child, depth));  // Keep current depth for other types
+                        }
+                        break;
+                }
+            }
+            return sb.ToString();
+        }
+    }
+}