scriptcs · filipw · Jul 27, 2015 · Mar 30, 2015 · Mar 30, 2015 · Mar 30, 2015
diff --git a/...Cs.Core/App_Packages/LibLog.3.1/LibLog.cs → ...ntracts/App_Packages/LibLog.4.2/LibLog.cs b/...Cs.Core/App_Packages/LibLog.3.1/LibLog.cs → ...ntracts/App_Packages/LibLog.4.2/LibLog.cs
diff --git a/src/ScriptCs.Contracts/DefaultLogProvider.cs b/src/ScriptCs.Contracts/DefaultLogProvider.cs
@@ -0,0 +1,97 @@
+namespace ScriptCs.Contracts
+{
+    using System;
+
+    public class DefaultLogProvider : ILogProvider
+    {
+        private readonly ILogProvider _provider = ResolveLogProvider() ?? new NullLogProvider();
+
+        [Obsolete("Should not be called directly. Instead, call a method on LogProviderExtensions.")]
+        public Logger GetLogger(string name)
+        {
+            return _provider.GetLogger(name);
+        }
+
+        /// <summary>
+        /// Opens a nested diagnostics context. Not supported in <seealso cref="http://msdn.microsoft.com/entlib"/>.
+        /// </summary>
+        /// <param name="message">The message to add to the diagnostics context.</param>
+        /// <returns>A disposable that when disposed removes the message from the context.</returns>
+        public IDisposable OpenNestedContext(string message)
+        {
+            return _provider.OpenNestedContext(message);
+        }
+
+        /// <summary>
+        /// Opens a mapped diagnostics context. Not supported in <seealso cref="http://msdn.microsoft.com/entlib"/>.
+        /// </summary>
+        /// <param name="key">A key.</param>
+        /// <param name="value">A value.</param>
+        /// <returns>A disposable that when disposed removes the map from the context.</returns>
+        public IDisposable OpenMappedContext(string key, string value)
+        {
+            return _provider.OpenMappedContext(key, value);
+        }
+
+        private static ILogProvider ResolveLogProvider()
+        {
+            var libLogProvider = LibLog.LogProvider.ResolveLogProvider();
+            return libLogProvider == null ? null : new LibLogAdapter(libLogProvider);
+        }
+
+        private class NullLogProvider : ILogProvider
+        {
+            private static readonly Logger logger = (_, __, ___, ____) => false;
+            private static readonly Disposable disposable = new Disposable();
+
+            [Obsolete("Should not be called directly. Instead, call a method on LogProviderExtensions.")]
+            public Logger GetLogger(string name)
+            {
+                return logger;
+            }
+
+            public IDisposable OpenNestedContext(string message)
+            {
+                return disposable;
+            }
+
+            public IDisposable OpenMappedContext(string key, string value)
+            {
+                return disposable;
+            }
+
+            private sealed class Disposable : IDisposable
+            {
+                public void Dispose()
+                {
+                }
+            }
+        }
+
+        private class LibLogAdapter : ILogProvider
+        {
+            private readonly LibLog.ILogProvider _libLogProvider;
+
+            public LibLogAdapter(LibLog.ILogProvider libLogProvider)
+            {
+                _libLogProvider = libLogProvider;
+            }
+
+            public Logger GetLogger(string name)
+            {
+                return (logLevel, messageFunc, exception, formatParameters) =>
+                    _libLogProvider.GetLogger(name)((LibLog.LogLevel)logLevel, messageFunc, exception, formatParameters);
+            }
+
+            public IDisposable OpenNestedContext(string message)
+            {
+                return _libLogProvider.OpenNestedContext(message);
+            }
+
+            public IDisposable OpenMappedContext(string key, string value)
+            {
+                return _libLogProvider.OpenMappedContext(key, value);
+            }
+        }
+    }
+}
diff --git a/src/ScriptCs.Contracts/ILog.cs b/src/ScriptCs.Contracts/ILog.cs
@@ -0,0 +1,36 @@
+namespace ScriptCs.Contracts
+{
+    using System;
+
+    public interface ILog
+    {
+        /// <summary>
+        /// Logs a message for a specified log level, if the <see cref="ILog"/> is enabled for that log level.
+        /// </summary>
+        /// <param name="logLevel">The log level.</param>
+        /// <param name="createMessage">
+        /// Optional function which creates the message.
+        /// Specify <c>null</c> to simply check if the logger is enabled for the <paramref name="logLevel"/>.
+        /// </param>
+        /// <param name="exception">An optional exception to include with the message.</param>
+        /// <param name="formatArgs">
+        /// Optional arguments for formatting the message created by <paramref name="createMessage"/>.
+        /// </param>
+        /// <returns>
+        /// <c>true</c> if the <see cref="ILog"/> is enabled for the <paramref name="logLevel"/>.
+        /// Otherwise <c>false</c>.
+        /// </returns>
+        /// <remarks>
+        /// Note to implementers for optimal performance:
+        /// When the <paramref name="createMessage"/> is <c>null</c>, simply return a <see cref="bool"/>
+        /// indicating whether the <see cref="ILog"/> is enabled for the specified <paramref name="logLevel"/>.
+        /// When the <paramref name="createMessage"/> is not <c>null</c>, it should only be invoked
+        /// if the <see cref="ILog"/> is enabled for the specified <paramref name="logLevel"/>.
+        /// </remarks>
+        bool Log(
+            LogLevel logLevel,
+            Func<string> createMessage = null,
+            Exception exception = null,
+            params object[] formatArgs);
+    }
+}
diff --git a/src/ScriptCs.Contracts/ILogProvider.cs b/src/ScriptCs.Contracts/ILogProvider.cs
@@ -0,0 +1,21 @@
+namespace ScriptCs.Contracts
+{
+    using System;
+
+    public interface ILogProvider
+    {
+        /// <summary>
+        /// Gets the specified named logger.
+        /// </summary>
+        /// <param name="name">Name of the logger.</param>
+        /// <returns>The logger reference.</returns>
+        /// <remarks>
+        /// Do not call this method directly. Instead, call a method on <see cref="LogProviderExtensions"/>.
+        /// </remarks>
+        Logger GetLogger(string name);
+
+        IDisposable OpenNestedContext(string message);
+
+        IDisposable OpenMappedContext(string key, string value);
+    }
+}