//
// ResolveFromXmlStep.cs
//
// Author:
//   Jb Evain (jbevain@gmail.com)
//
// (C) 2006 Jb Evain
// (C) 2007 Novell, Inc.
//
// Permission is hereby granted, free of charge, to any person obtaining
// a copy of this software and associated documentation files (the
// "Software"), to deal in the Software without restriction, including
// without limitation the rights to use, copy, modify, merge, publish,
// distribute, sublicense, and/or sell copies of the Software, and to
// permit persons to whom the Software is furnished to do so, subject to
// the following conditions:
//
// The above copyright notice and this permission notice shall be
// included in all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
// EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
// NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
// LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
// OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
// WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
//

using System;
using SR = System.Reflection;
using System.Text;
using System.Text.RegularExpressions;
using System.Xml.XPath;

using Mono.Cecil;

namespace Mono.Linker.Steps {

	public class ResolveFromXmlStep : ResolveStep {

		static readonly string _signature = "signature";
		static readonly string _fullname = "fullname";
		static readonly string _required = "required";
		static readonly string _preserve = "preserve";
		static readonly string _ns = string.Empty;

		XPathDocument _document;

		public ResolveFromXmlStep (XPathDocument document)
		{
			_document = document;
		}

		public override void Process (LinkContext context)
		{
			XPathNavigator nav = _document.CreateNavigator ();
			nav.MoveToFirstChild ();
			ProcessAssemblies (context, nav.SelectChildren ("assembly", _ns));
		}

		void ProcessAssemblies (LinkContext context, XPathNodeIterator iterator)
		{
			while (iterator.MoveNext ()) {
				AssemblyDefinition assembly = GetAssembly (context, GetFullName (iterator.Current));
				ProcessTypes (assembly, iterator.Current.SelectChildren ("type", _ns));
				ProcessNamespaces (assembly, iterator.Current.SelectChildren ("namespace", _ns));
			}
		}

		void ProcessNamespaces (AssemblyDefinition assembly, XPathNodeIterator iterator)
		{
			while (iterator.MoveNext ()) {
				string fullname = GetFullName (iterator.Current);
				foreach (TypeDefinition type in assembly.MainModule.Types) {
					if (type.Namespace != fullname)
						continue;

					MarkAndPreserveAll (type);
				}
			}
		}

		static void MarkAndPreserveAll (TypeDefinition type)
		{
			Annotations.Mark (type);
			Annotations.SetPreserve (type, TypePreserve.All);

			if (!type.HasNestedTypes)
				return;

			foreach (TypeDefinition nested in type.NestedTypes)
				MarkAndPreserveAll (nested);
		}

		void ProcessTypes (AssemblyDefinition assembly, XPathNodeIterator iterator)
		{
			while (iterator.MoveNext ()) {
				XPathNavigator nav = iterator.Current;
				string fullname = GetFullName (nav);

				if (IsTypePattern (fullname)) {
					ProcessTypePattern (fullname, assembly, nav);
					continue;
				}

				TypeDefinition type = assembly.MainModule.Types [fullname];
				if (type == null)
					continue;

				ProcessType (type, nav);
			}
		}

		static bool IsTypePattern (string fullname)
		{
			return fullname.IndexOf ("*") != -1;
		}

		static Regex CreateRegexFromPattern (string pattern)
		{
			return new Regex (pattern.Replace(".", @"\.").Replace("*", "(.*)"));
		}

		void ProcessTypePattern (string fullname, AssemblyDefinition assembly, XPathNavigator nav)
		{
			Regex regex = CreateRegexFromPattern (fullname);

			foreach (TypeDefinition type in assembly.MainModule.Types) {
				if (!regex.Match (type.FullName).Success)
					continue;

				ProcessType (type, nav);
			}
		}

		void ProcessType (TypeDefinition type, XPathNavigator nav)
		{
			TypePreserve preserve = GetTypePreserve (nav);

			if (!IsRequired (nav)) {
				Annotations.SetPreserve (type, preserve);
				return;
			}

			Annotations.Mark (type);

			switch (preserve) {
			case TypePreserve.Nothing:
				if (!nav.HasChildren)
					Annotations.SetPreserve (type, TypePreserve.All);
				break;
			default:
				Annotations.SetPreserve (type, preserve);
				break;
			}

			if (nav.HasChildren) {
				MarkSelectedFields (nav, type);
				MarkSelectedMethods (nav, type);
			}
		}

		void MarkSelectedFields (XPathNavigator nav, TypeDefinition type)
		{
			XPathNodeIterator fields = nav.SelectChildren ("field", _ns);
			if (fields.Count == 0)
				return;

			ProcessFields (type, fields);
		}

		void MarkSelectedMethods (XPathNavigator nav, TypeDefinition type)
		{
			XPathNodeIterator methods = nav.SelectChildren ("method", _ns);
			if (methods.Count == 0)
				return;

			ProcessMethods (type, methods);
		}

		static TypePreserve GetTypePreserve (XPathNavigator nav)
		{
			string attribute = GetAttribute (nav, _preserve);
			if (attribute == null || attribute.Length == 0)
				return TypePreserve.Nothing;

			try {
				return (TypePreserve) Enum.Parse (typeof (TypePreserve), attribute, true);
			} catch {
				return TypePreserve.Nothing;
			}
		}

		void ProcessFields (TypeDefinition type, XPathNodeIterator iterator)
		{
			while (iterator.MoveNext ()) {
				if (GetAttribute (iterator.Current, "signature") != null)
					ProcessFieldSignature (type, iterator.Current);

				if (GetAttribute (iterator.Current, "name") != null)
					ProcessFieldName (type, iterator.Current);
			}
		}

		void ProcessFieldSignature (TypeDefinition type, XPathNavigator nav)
		{
			string signature = GetSignature (nav);
			FieldDefinition field = GetField (type, signature);
			MarkField (type, field, signature);
		}

		void MarkField (TypeDefinition type, FieldDefinition field, string signature)
		{
			if (field != null)
				Annotations.Mark (field);
			else
				AddUnresolveMarker (string.Format ("T: {0}; F: {1}", type, signature));
		}

		void ProcessFieldName (TypeDefinition type, XPathNavigator nav)
		{
			if (!type.HasFields)
				return;

			string name = GetAttribute (nav, "name");
			foreach (FieldDefinition field in type.Fields)
				if (field.Name == name)
					MarkField (type, field, name);
		}

		static FieldDefinition GetField (TypeDefinition type, string signature)
		{
			if (!type.HasFields)
				return null;

			foreach (FieldDefinition field in type.Fields)
				if (signature == GetFieldSignature (field))
					return field;

			return null;
		}

		static string GetFieldSignature (FieldDefinition field)
		{
			return field.FieldType.FullName + " " + field.Name;
		}

		void ProcessMethods (TypeDefinition type, XPathNodeIterator iterator)
		{
			while (iterator.MoveNext()) {
				if (GetAttribute (iterator.Current, "signature") != null)
					ProcessMethodSignature (type, iterator.Current);

				if (GetAttribute (iterator.Current, "name") != null)
					ProcessMethodName (type, iterator.Current);
			}
		}

		void ProcessMethodSignature (TypeDefinition type, XPathNavigator nav)
		{
			string signature = GetSignature (nav);
			MethodDefinition meth = GetMethod (type, signature);
			MarkMethod (type, meth, signature);
		}

		void MarkMethod (TypeDefinition type, MethodDefinition method, string signature)
		{
			if (method != null) {
				Annotations.Mark (method);
				Annotations.SetAction (method, MethodAction.Parse);
			} else
				AddUnresolveMarker (string.Format ("T: {0}; M: {1}", type, signature));
		}

		void ProcessMethodName (TypeDefinition type, XPathNavigator nav)
		{
			string name = GetAttribute (nav, "name");
			if (name == ".ctor" || name == ".cctor" && type.HasConstructors)
				foreach (MethodDefinition ctor in type.Constructors)
					if (name == ctor.Name)
						MarkMethod (type, ctor, name);

			if (type.HasMethods)
				foreach (MethodDefinition method in type.Methods)
					if (name == method.Name)
						MarkMethod (type, method, name);
		}

		static MethodDefinition GetMethod (TypeDefinition type, string signature)
		{
			if (type.HasMethods)
				foreach (MethodDefinition meth in type.Methods)
					if (signature == GetMethodSignature (meth))
						return meth;

			if (type.HasConstructors)
				foreach (MethodDefinition ctor in type.Constructors)
					if (signature == GetMethodSignature (ctor))
						return ctor;

			return null;
		}

		static string GetMethodSignature (MethodDefinition meth)
		{
			StringBuilder sb = new StringBuilder ();
			sb.Append (meth.ReturnType.ReturnType.FullName);
			sb.Append (" ");
			sb.Append (meth.Name);
			sb.Append ("(");
			if (meth.HasParameters) {
				for (int i = 0; i < meth.Parameters.Count; i++) {
					if (i > 0)
						sb.Append (",");

					sb.Append (meth.Parameters [i].ParameterType.FullName);
				}
			}
			sb.Append (")");
			return sb.ToString ();
		}

		static AssemblyDefinition GetAssembly (LinkContext context, string assemblyName)
		{
			AssemblyNameReference reference = AssemblyNameReference.Parse (assemblyName);
			AssemblyDefinition assembly;

			assembly = context.Resolve (reference);

			ProcessReferences (assembly, context);
			return assembly;
		}

		static void ProcessReferences (AssemblyDefinition assembly, LinkContext context)
		{
			foreach (AssemblyNameReference name in assembly.MainModule.AssemblyReferences)
				context.Resolve (name);
		}

		static bool IsRequired (XPathNavigator nav)
		{
			string attribute = GetAttribute (nav, _required);
			if (attribute == null || attribute.Length == 0)
				return true;

			return TryParseBool (attribute);
		}

		static bool TryParseBool (string s)
		{
			try {
				return bool.Parse (s);
			} catch {
				return false;
			}
		}

		static string GetSignature (XPathNavigator nav)
		{
			return GetAttribute (nav, _signature);
		}

		static string GetFullName (XPathNavigator nav)
		{
			return GetAttribute (nav, _fullname);
		}

		static string GetAttribute (XPathNavigator nav, string attribute)
		{
			return nav.GetAttribute (attribute, _ns);
		}
	}
}