From 18f7d73132534daccf736a6ffb622e60948074d3 Mon Sep 17 00:00:00 2001
From: Shreyas Zare <shreyas@technitium.com>
Date: Sat, 27 Feb 2021 19:41:36 +0530
Subject: [PATCH] added DnsApplicationManager

---
 .../Dns/Applications/DnsApplicationManager.cs | 136 ++++++++++++++++++
 1 file changed, 136 insertions(+)
 create mode 100644 DnsServerCore/Dns/Applications/DnsApplicationManager.cs

diff --git a/DnsServerCore/Dns/Applications/DnsApplicationManager.cs b/DnsServerCore/Dns/Applications/DnsApplicationManager.cs
new file mode 100644
index 00000000..9fa985d2
--- /dev/null
+++ b/DnsServerCore/Dns/Applications/DnsApplicationManager.cs
@@ -0,0 +1,136 @@
+/*
+Technitium DNS Server
+Copyright (C) 2021  Shreyas Zare (shreyas@technitium.com)
+
+This program is free software: you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation, either version 3 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+*/
+
+using System;
+using System.Collections.Concurrent;
+using System.Collections.Generic;
+using System.IO;
+using System.IO.Compression;
+using System.Text;
+
+namespace DnsServerCore.Dns.Applications
+{
+    public sealed class DnsApplicationManager : IDisposable
+    {
+        #region variables
+
+        readonly string _packagesPath;
+
+        readonly ConcurrentDictionary<string, DnsApplicationPackage> _packages = new ConcurrentDictionary<string, DnsApplicationPackage>();
+
+        #endregion
+
+        #region constructor
+
+        public DnsApplicationManager(string configFolder)
+        {
+            _packagesPath = Path.Combine(configFolder, "apps");
+
+            if (!Directory.Exists(_packagesPath))
+                Directory.CreateDirectory(_packagesPath);
+        }
+
+        #endregion
+
+        #region IDisposable
+
+        bool _disposed;
+
+        private void Dispose(bool disposing)
+        {
+            if (_disposed)
+                return;
+
+            if (disposing)
+            {
+                if (_packages != null)
+                {
+                    foreach (DnsApplicationPackage package in _packages.Values)
+                        package.Dispose();
+
+                    _packages.Clear();
+                }
+            }
+
+            _disposed = true;
+        }
+
+        public void Dispose()
+        {
+            Dispose(true);
+        }
+
+        #endregion
+
+        #region private
+
+        private void LoadPackage(string packagePath)
+        {
+            DnsApplicationPackage package = new DnsApplicationPackage(packagePath);
+
+            if (!_packages.TryAdd(package.Name, package))
+                package.Dispose();
+        }
+
+        #endregion
+
+        #region public
+
+        public void LoadAllPackages()
+        {
+            foreach (string packagePath in Directory.GetDirectories(_packagesPath))
+            {
+                LoadPackage(packagePath);
+            }
+        }
+
+        public void InstallPackage(string packageName, Stream package)
+        {
+            if (_packages.ContainsKey(packageName))
+                throw new DnsServerException("Package already exists: " + packageName);
+
+            using (ZipArchive packageZip = new ZipArchive(package, ZipArchiveMode.Read, false, Encoding.UTF8))
+            {
+                string packagePath = Path.Combine(_packagesPath, packageName);
+
+                packageZip.ExtractToDirectory(packagePath, true);
+
+                LoadPackage(packagePath);
+            }
+        }
+
+        public void UninstallPackage(string packageName)
+        {
+            if (_packages.TryRemove(packageName, out DnsApplicationPackage package))
+                package.Dispose();
+
+            if (Directory.Exists(package.PackagePath))
+                Directory.Delete(package.PackagePath, true);
+        }
+
+        #endregion
+
+        #region properties
+
+        public IReadOnlyDictionary<string, DnsApplicationPackage> Packages
+        { get { return _packages; } }
+
+        #endregion
+    }
+}