Initial release of Orbit 1.1.2

WebsiteIcons.cs

@@ -0,0 +1,93 @@
+using System.IO;
+using System.Net;
+using System.Net.Http;
+using System.Text;
+using System.Text.RegularExpressions;
+using System.Windows.Media.Imaging;
+
+namespace ShortcutsPanel;
+
+public static class WebsiteIcons
+{
+    static readonly HttpClient Client = new() { Timeout = TimeSpan.FromSeconds(12) };
+    static readonly SemaphoreSlim Slots = new(4);
+    static readonly TimeSpan RegexTimeout = TimeSpan.FromMilliseconds(200);
+
+    // Read declared favicons and touch icons, including relative and CDN URLs.
+    public static IEnumerable<Uri> Discover(string html, Uri page)
+    {
+        var baseTag = Regex.Match(html, @"<base\b[^>]*>", RegexOptions.IgnoreCase, RegexTimeout);
+        var baseAttrs = Attributes(baseTag.Value);
+        if (baseAttrs.TryGetValue("href", out var baseHref) && SafeUri(page, baseHref) is Uri resolvedBase) page = resolvedBase;
+        var found = new List<(Uri Uri, int Rank)>();
+        foreach (Match tag in Regex.Matches(html, @"<link\b[^>]*>", RegexOptions.IgnoreCase, RegexTimeout))
+        {
+            var attrs = Attributes(tag.Value);
+            if (!attrs.TryGetValue("rel", out var rel) || !attrs.TryGetValue("href", out var href)) continue;
+            var tokens = rel.ToLowerInvariant().Split((char[]?)null, StringSplitOptions.RemoveEmptyEntries);
+            if (!tokens.Contains("icon") && !tokens.Contains("apple-touch-icon") && !tokens.Contains("apple-touch-icon-precomposed")) continue;
+            var uri = SafeUri(page, href);
+            if (uri == null || uri.AbsolutePath.EndsWith(".svg", StringComparison.OrdinalIgnoreCase) || attrs.GetValueOrDefault("type", "").Contains("svg", StringComparison.OrdinalIgnoreCase)) continue;
+            found.Add((uri, tokens.Contains("apple-touch-icon") ? 0 : 1));
+        }
+        return found.OrderBy(x => x.Rank).Select(x => x.Uri).Distinct().Take(6).ToArray();
+    }
+    static Dictionary<string, string> Attributes(string tag)
+    {
+        var result = new Dictionary<string, string>(StringComparer.OrdinalIgnoreCase);
+        foreach (Match match in Regex.Matches(tag, "([\\w:-]+)\\s*=\\s*(?:\"([^\"]*)\"|'([^']*)'|([^\\s>]+))", RegexOptions.None, RegexTimeout))
+            result[match.Groups[1].Value] = WebUtility.HtmlDecode(match.Groups[2].Success ? match.Groups[2].Value : match.Groups[3].Success ? match.Groups[3].Value : match.Groups[4].Value);
+        return result;
+    }
+    static Uri? SafeUri(Uri page, string href) => Uri.TryCreate(page, href, out var uri) && (uri.Scheme == "http" || uri.Scheme == "https") && string.IsNullOrEmpty(uri.UserInfo) ? uri : null;
+    static async Task<(byte[] Bytes, Uri FinalUri)> Download(Uri uri, int limit, CancellationToken token)
+    {
+        using var response = await Client.GetAsync(uri, HttpCompletionOption.ResponseHeadersRead, token);
+        response.EnsureSuccessStatusCode();
+        if (response.Content.Headers.ContentLength > limit) throw new IOException("Icon response too large.");
+        using var stream = await response.Content.ReadAsStreamAsync(token);
+        using var output = new MemoryStream(); var buffer = new byte[8192]; int count;
+        while ((count = await stream.ReadAsync(buffer, token)) > 0)
+        {
+            if (output.Length + count > limit) throw new IOException("Icon response too large.");
+            output.Write(buffer, 0, count);
+        }
+        return (output.ToArray(), response.RequestMessage?.RequestUri ?? uri);
+    }
+    public static async Task<BitmapSource?> Fetch(string address)
+    {
+        await Slots.WaitAsync();
+        try
+        {
+            using var timeout = new CancellationTokenSource(TimeSpan.FromSeconds(15));
+            var page = new Uri(address); var candidates = new List<Uri>();
+            try
+            {
+                using var pageTimeout = CancellationTokenSource.CreateLinkedTokenSource(timeout.Token);
+                pageTimeout.CancelAfter(TimeSpan.FromSeconds(5));
+                var document = await Download(page, 1024 * 1024, pageTimeout.Token);
+                page = document.FinalUri;
+                candidates.AddRange(Discover(Encoding.UTF8.GetString(document.Bytes), page));
+            }
+            catch { /* Try the conventional favicon when HTML discovery is unavailable. */ }
+            candidates.Add(new Uri(page.GetLeftPart(UriPartial.Authority) + "/favicon.ico"));
+            foreach (var candidate in candidates.Distinct())
+            {
+                if (timeout.IsCancellationRequested) break;
+                try
+                {
+                    using var iconTimeout = CancellationTokenSource.CreateLinkedTokenSource(timeout.Token);
+                    iconTimeout.CancelAfter(TimeSpan.FromSeconds(3));
+                    var data = await Download(candidate, 512 * 1024, iconTimeout.Token);
+                    using var bytes = new MemoryStream(data.Bytes);
+                    var bitmap = new BitmapImage(); bitmap.BeginInit(); bitmap.CacheOption = BitmapCacheOption.OnLoad;
+                    bitmap.DecodePixelWidth = 32; bitmap.StreamSource = bytes; bitmap.EndInit(); bitmap.Freeze(); return bitmap;
+                }
+                catch { /* A missing or unsupported icon must not prevent using a shortcut. */ }
+            }
+            return null;
+        }
+        catch { return null; }
+        finally { Slots.Release(); }
+    }
+}