feature: add a button to scan repositories under default clone dir (#427)

src/ViewModels/ScanRepositories.cs

@@ -0,0 +1,94 @@
+using System.Collections.Generic;
+using System.IO;
+using System.Threading.Tasks;
+using Avalonia.Threading;
+
+namespace SourceGit.ViewModels
+{
+    public class ScanRepositories : Popup
+    {
+        public string RootDir
+        {
+            get;
+            private set;
+        } = string.Empty;
+
+        public ScanRepositories(string rootDir)
+        {
+            GetManagedRepositories(Preference.Instance.RepositoryNodes, _managed);
+
+            RootDir = rootDir;
+            View = new Views.ScanRepositories() { DataContext = this };
+        }
+
+        public override Task<bool> Sure()
+        {
+            ProgressDescription = $"Scan repositories under '{RootDir}' ...";
+
+            return Task.Run(() =>
+            {
+                // If it is too fast, the panel will dispear very quickly, the we'll have a bad experience.
+                Task.Delay(500).Wait();
+
+                var founded = new List<string>();
+                GetUnmanagedRepositories(new DirectoryInfo(RootDir), founded, new EnumerationOptions()
+                {
+                    AttributesToSkip = FileAttributes.Hidden | FileAttributes.System,
+                    IgnoreInaccessible = true,
+                });
+
+                Dispatcher.UIThread.Invoke(() =>
+                {
+                    foreach (var f in founded)
+                        Preference.Instance.FindOrAddNodeByRepositoryPath(f, null, false);
+                    Welcome.Instance.Refresh();
+                });
+
+                return true;
+            });
+        }
+
+        private void GetManagedRepositories(List<RepositoryNode> group, HashSet<string> repos)
+        {
+            foreach (RepositoryNode node in group)
+            {
+                if (node.IsRepository)
+                    repos.Add(node.Id);
+                else
+                    GetManagedRepositories(node.SubNodes, repos);
+            }
+        }
+
+        private void GetUnmanagedRepositories(DirectoryInfo dir, List<string> outs, EnumerationOptions opts, int depth = 0)
+        {
+            var subdirs = dir.GetDirectories("*", opts);
+            foreach (var subdir in subdirs)
+            {
+                SetProgressDescription($"Scanning {subdir.FullName}...");
+
+                var normalizedSelf = subdir.FullName.Replace("\\", "/");
+                if (_managed.Contains(normalizedSelf))
+                    continue;
+
+                var gitDir = Path.Combine(subdir.FullName, ".git");
+                if (Directory.Exists(gitDir) || File.Exists(gitDir))
+                {
+                    var test = new Commands.QueryRepositoryRootPath(subdir.FullName).ReadToEnd();
+                    if (test.IsSuccess && !string.IsNullOrEmpty(test.StdOut))
+                    {
+                        var normalized = test.StdOut.Trim().Replace("\\", "/");
+                        if (!_managed.Contains(normalizedSelf))
+                            outs.Add(normalized);
+
+                        continue;
+                    }
+                }
+
+                if (depth < 8)
+                    GetUnmanagedRepositories(subdir, outs, opts, depth + 1);
+            }
+        }
+
+        private HashSet<string> _managed = new HashSet<string>();
+    }
+}