Checkpoint

Alpm/Handle.cs

@@ -1,15 +1,19 @@
 using System;
 using System.Collections.Generic;
+using Foodsoft.Alpm.Interop;
 
 namespace Foodsoft.Alpm
 {
     public sealed class Handle : IDisposable
     {
+        private readonly object _eventLock = new object();
         private readonly SafeAlpmHandle _handle;
 
-        public Handle(string root, string dbpath)
+        private EventHandler<LogEventArgs> _logEvent;
+
+        public Handle(string root, string dbPath)
         {
-            _handle = alpm.alpm_initialize(root, dbpath, out var err);
+            _handle = alpm.alpm_initialize(root, dbPath, out var err);
             if (_handle.IsInvalid) throw new AlpmException(err);
         }
 
@@ -22,6 +26,8 @@ namespace Foodsoft.Alpm
             set => Detail.SetStringCollection(value, _handle, s => alpm.alpm_option_add_cachedir(_handle, s));
         }
 
+        public LogLevel LogLevel { get; set; }
+
         public void Dispose()
         {
             _handle.Dispose();
@@ -55,5 +61,42 @@ namespace Foodsoft.Alpm
         {
             return alpm.alpm_pkg_should_ignore(_handle, pkg.Handle) == 0;
         }
+
+        public event EventHandler<LogEventArgs> Log
+        {
+            add
+            {
+                void LogCallback(LogLevel level, IntPtr format, IntPtr args)
+                {
+                    if (level > LogLevel) return;
+                    _logEvent?.Invoke(this,
+                        new LogEventArgs {Level = level, Message = CFormatter.Format(format, args)});
+                }
+
+                lock (_eventLock)
+                {
+                    var wasEmpty = _logEvent == null;
+                    _logEvent += value;
+                    if (wasEmpty)
+                        alpm.alpm_option_set_logcb(_handle, LogCallback);
+                }
+            }
+            remove
+            {
+                lock (_eventLock)
+                {
+                    // ReSharper disable once DelegateSubtraction
+                    _logEvent -= value;
+                    if (_logEvent == null)
+                        alpm.alpm_option_set_logcb(_handle, null);
+                }
+            }
+        }
+
+        public struct LogEventArgs
+        {
+            public LogLevel Level;
+            public string Message;
+        }
     }
 }