--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/Implab.ServiceHost/Unity/TypeResolver.cs	Wed Apr 25 04:44:40 2018 +0300
@@ -0,0 +1,124 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Text.RegularExpressions;
+using Implab.Diagnostics;
+
+namespace Implab.ServiceHost.Unity
+{
+    using static Trace<TypeResolver>;
+    public class TypeResolver
+    {
+        readonly Dictionary<string, Type> m_cache = new Dictionary<string, Type>();
+
+        Regex _nsRx = new Regex(@"^\w+(\.\w+)*$", RegexOptions.Compiled);
+        readonly LinkedList<string> m_namespases = new LinkedList<string>();
+
+        LinkedListNode<string> m_insertAt;
+
+        readonly TypeResolver m_parent;
+
+        public TypeResolver() : this(null) {
+
+        }
+
+        public TypeResolver(TypeResolver parent) {
+            m_insertAt = new LinkedListNode<string>(string.Empty);
+            m_namespases.AddFirst(m_insertAt);
+        }
+
+        public void AddNamespace(string ns) {
+            Safe.ArgumentMatch(ns, nameof(ns), _nsRx);
+            if (m_insertAt != null)
+                m_namespases.AddAfter(m_insertAt, ns);
+            else
+                m_namespases.AddFirst(ns);
+        }
+
+        public void AddMapping(string typeName, Type type) {
+            Safe.ArgumentNotEmpty(typeName, nameof(typeName));
+            Safe.ArgumentNotNull(type, nameof(type));
+
+            m_cache[typeName] = type;
+        }
+
+        public Type Resolve(TypeReference reference) {
+            var args = reference.IsGeneric && !reference.IsOpenGeneric ? reference.GenericParameters?.Select(Resolve).ToArray() : null;
+            var argc = reference.IsGeneric ? reference.GenericParameters.Length : 0;
+
+            Type resolved;
+            if(!m_cache.TryGetValue(reference.ToString(), out resolved)) {
+                resolved = ResolveInternal(reference, args, argc);
+                if (resolved == null)
+                    throw new Exception($"Failed to resolve {reference}");
+                m_cache[reference.ToString()] = resolved;
+            }
+
+            return resolved;
+        }
+
+        Type ResolveInternal(TypeReference reference, Type[] args, int argc) {
+            var resolved = ProbeInNamespaces(
+                String.Join(".", new [] { reference.Namespace, reference.TypeName }.Where(x => !string.IsNullOrEmpty(x)) ),
+                args,
+                argc,
+                reference.IsArray,
+                reference.ToString()
+            );
+
+            if (resolved == null && m_parent != null)
+                resolved = m_parent.Resolve(reference);
+            
+            return resolved;
+        }
+
+        public Type ProbeInNamespaces(string localName, Type[] args, int argc, bool isArray, string referenceName) {
+            foreach (var ns in m_namespases) {
+                var typeName = FormatName(new [] { ns, localName}, argc, args, isArray);
+
+                var resolved = Probe(typeName);
+                if (resolved != null) {
+                    Log("Probe succeed {0} in '{1}': {2} -> {3}", referenceName, ns, typeName, resolved.AssemblyQualifiedName);
+                    return resolved;
+                } else {
+                    Log("Probe failed {0} in '{1}': {2}", referenceName, ns, typeName);
+                }
+            }
+
+            return null;
+        }
+
+        Type Probe(string typeName) {
+            var assemblies = AppDomain.CurrentDomain.GetAssemblies();
+
+            foreach(var assembly in assemblies) {
+                var type = assembly.GetType(typeName);
+                if (type != null)
+                    return type;
+            }
+            return null;
+        }
+
+        string FormatName(string[] parts, int argc, Type[] args, bool isArray) {
+            var builder = new StringBuilder();
+            
+            builder.Append(String.Join(".", parts.Where(x => !string.IsNullOrEmpty(x))));
+            if (argc > 0) {
+                builder.Append('`');
+                builder.Append(argc);
+            }
+
+            if (args!= null && args.Length > 0) {
+                builder.Append('[');
+                builder.Append(string.Join(",", args.Select(x => $"[{x.AssemblyQualifiedName}]")));
+                builder.Append(']');
+            }
+
+            if(isArray)
+                builder.Append("[]");
+
+                return builder.ToString();
+        }
+    }
+}
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