//
// CodeWriter.cs
//
// Author:
//   Iain McCoy (iain@mccoy.id.au)
//
// (C) 2005 Iain McCoy
//
// 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 System.Diagnostics;
using System.Reflection;
using System.IO;
using System.Xml;
using System.Collections;
using System.CodeDom;
using System.CodeDom.Compiler;
using System.Windows.Serialization;
using System.Windows;

namespace Mono.Windows.Serialization {
	public class CodeWriter {
		TextWriter writer;
		ICodeGenerator generator;
		bool isPartial;
		
		ArrayList objects = new ArrayList();
		Hashtable nameClashes = new Hashtable();
		int tempIndex = 0;

		CodeCompileUnit code;
		CodeTypeDeclaration type;
		CodeConstructor constructor;

		public static string Parse(XmlTextReader reader, ICodeGenerator generator,  bool isPartial)
		{
			CodeWriter cw = new CodeWriter(reader, generator, isPartial);
			return ((StringWriter)cw.writer).ToString();
		}

		// pushes: the code writer
		private void init(ICodeGenerator generator, bool isPartial)
		{
			this.generator = generator;
			this.isPartial = isPartial;
			this.writer = new StringWriter();
			code = new CodeCompileUnit();
			push(code);
		}

		
		private CodeWriter(XmlTextReader reader, ICodeGenerator generator, bool isPartial)
		{
			init(generator, isPartial);
			XamlParser p = new XamlParser(reader);
			XamlNode n;
			while (true) {
				n = p.GetNextNode();
				if (n == null)
					break;
				Debug.WriteLine("CodeWriter: INCOMING " + n.GetType());
				if (n is XamlDocumentStartNode) {
					Debug.WriteLine("CodeWriter: document begins");
					// do nothing
				} else if (n is XamlElementStartNode && n.Depth == 0) {
					Debug.WriteLine("CodeWriter: element begins as top-level");
					CreateTopLevel(((XamlElementStartNode)n).ElementType, ((XamlElementStartNode)n).name);
				} else if (n is XamlElementStartNode && ((XamlElementStartNode)n).propertyObject) {
					Debug.WriteLine("CodeWriter: element begins as property value");
					CreatePropertyObject(((XamlElementStartNode)n).ElementType, ((XamlElementStartNode)n).name);
				} else if (n is XamlElementStartNode) {
					Debug.WriteLine("CodeWriter: element begins");
					CreateObject(((XamlElementStartNode)n).ElementType, ((XamlElementStartNode)n).name);
				} else if (n is XamlPropertyNode && ((XamlPropertyNode)n).PropInfo != null) {
					Debug.WriteLine("CodeWriter: normal property begins");
					CreateProperty(((XamlPropertyNode)n).PropInfo);
				} else if (n is XamlPropertyNode && ((XamlPropertyNode)n).DP != null) {
					Debug.WriteLine("CodeWriter: dependency property begins");
					DependencyProperty dp = ((XamlPropertyNode)n).DP;
					Type typeAttachedTo = dp.OwnerType;
					string propertyName = ((XamlPropertyNode)n).PropertyName;
					
					CreateDependencyProperty(typeAttachedTo, propertyName, dp.PropertyType);
				} else if (n is XamlClrEventNode && !(((XamlClrEventNode)n).EventMember is EventInfo)) {
					Debug.WriteLine("CodeWriter: delegate property");
					CreatePropertyDelegate(((XamlClrEventNode)n).Value, ((PropertyInfo)((XamlClrEventNode)n).EventMember).PropertyType);
					EndProperty();


				} else if (n is XamlClrEventNode) {
					Debug.WriteLine("CodeWriter: event");
					CreateEvent((EventInfo)((XamlClrEventNode)n).EventMember);
					CreateEventDelegate(((XamlClrEventNode)n).Value, ((EventInfo)((XamlClrEventNode)n).EventMember).EventHandlerType);
					EndEvent();

				} else if (n is XamlTextNode && ((XamlTextNode)n).mode == XamlParseMode.Object){
					Debug.WriteLine("CodeWriter: text for object");
					CreateObjectText(((XamlTextNode)n).TextContent);
				} else if (n is XamlTextNode && ((XamlTextNode)n).mode == XamlParseMode.Property){
					Debug.WriteLine("CodeWriter: text for property");
					CreatePropertyText(((XamlTextNode)n).TextContent, ((XamlTextNode)n).finalType);
					EndProperty();
				} else if (n is XamlTextNode && ((XamlTextNode)n).mode == XamlParseMode.DependencyProperty){
					Debug.WriteLine("CodeWriter: text for dependency property");
					CreateDependencyPropertyText(((XamlTextNode)n).TextContent, ((XamlTextNode)n).finalType);
					EndDependencyProperty();
				} else if (n is XamlPropertyComplexEndNode) {
					Debug.WriteLine("CodeWriter: end complex property");
					Debug.WriteLine("CodeWriter: final type is " + ((XamlPropertyComplexEndNode)n).finalType);
					EndPropertyObject(((XamlPropertyComplexEndNode)n).finalType);
					EndProperty();
				} else if (n is XamlLiteralContentNode) {
					Debug.WriteLine("CodeWriter: literal content");
					CreateCode(((XamlLiteralContentNode)n).Content);
				} else if (n is XamlElementEndNode) {
					Debug.WriteLine("CodeWriter: end element");
					if (!((XamlElementEndNode)n).propertyObject)
						EndObject();
				} else if (n is XamlDocumentEndNode) {
					Debug.WriteLine("CodeWriter: end document");
					Finish();
				} else {
					throw new Exception("Unknown node " + n.GetType());
				}
			}

		}
			
	
		// pushes: a CodeVariableReferenceExpression to the present
		// 	instance
		public void CreateTopLevel(Type parent, string className)
		{
			debug();
			if (className == null) {
				className = "derived" + parent.Name;
			}
			int endNamespaceName = className.LastIndexOf(".");
			string clrNamespace;
			if (endNamespaceName < 0) {
				clrNamespace = "DefaultNamespace";
			} else {
				clrNamespace = className.Substring(0,
						endNamespaceName);
				className = className.Substring(endNamespaceName+1);
			}
			CodeNamespace ns = new CodeNamespace(clrNamespace);
			((CodeCompileUnit)objects[0]).Namespaces.Add(ns);

			type = new CodeTypeDeclaration(className);
			if (isPartial) {
#if NET_2_0
				type.IsPartial = isPartial;
#else
				throw new Exception("Cannot create partial class");
#endif
			}
			type.BaseTypes.Add(new CodeTypeReference(parent));
			constructor = new CodeConstructor();
			type.Members.Add(constructor);
			ns.Types.Add(type);
			
			push(new CodeThisReferenceExpression());
		}

		// bottom of stack holds CodeVariableReferenceExpression
		// pushes a reference to the new current type
		public void CreateObject(Type type, string varName)
		{
			debug();
			bool isDefaultName;
			if (varName == null) {
				isDefaultName = true;
				varName = Char.ToLower(type.Name[0]) + type.Name.Substring(1);
				// make sure something sensible happens when class
				// names start with a lowercase letter
				if (varName == type.Name)
					varName = "_" + varName;
			} else {
				isDefaultName = false;
			}

			if (isDefaultName) {
				if (!nameClashes.ContainsKey(varName))
					nameClashes[varName] = 0;

				nameClashes[varName] = 1 + (int)nameClashes[varName];
				varName += (int)nameClashes[varName];
			}


			if (isDefaultName) {
				CodeVariableDeclarationStatement declaration = 
						new CodeVariableDeclarationStatement(type, 
								varName,
								new CodeObjectCreateExpression(type));
				constructor.Statements.Add(declaration);
			} else {
				CodeMemberField declaration = new CodeMemberField(type, varName);
				declaration.InitExpression = new CodeObjectCreateExpression(type);
				this.type.Members.Add(declaration);
			}
			CodeVariableReferenceExpression varRef = new CodeVariableReferenceExpression(varName);
			CodeMethodInvokeExpression addChild = new CodeMethodInvokeExpression(
					(CodeExpression)peek(),
					"AddChild",
					varRef);
			constructor.Statements.Add(addChild);
			push(varRef);
		}

		// top of stack is a reference to an object
		// pushes a reference to the property
		public void CreateProperty(PropertyInfo property)
		{
			debug();
			CodePropertyReferenceExpression prop = new CodePropertyReferenceExpression(
					(CodeExpression)peek(),
					property.Name);
			push(prop);
		}

		// top of stack is a reference to an object
		// pushes a reference to the event
		public void CreateEvent(EventInfo evt)
		{
			debug();
			CodeEventReferenceExpression expr = new CodeEventReferenceExpression(
					(CodeExpression)peek(),
					evt.Name);
			push(expr);
		}

		// top of stack is a reference to an object
		// pushes a reference to the expression that
		// will set the property and a reference to
		// the name of the temp variable to hold the
		// property
		public void CreateDependencyProperty(Type attachedTo, string propertyName, Type propertyType)
		{
			debug();
			string varName = "temp";
			varName += tempIndex;
			tempIndex += 1;
			CodeVariableDeclarationStatement decl = new CodeVariableDeclarationStatement(propertyType, varName);
			constructor.Statements.Add(decl);


			CodeMethodInvokeExpression call = new CodeMethodInvokeExpression(
					new CodeTypeReferenceExpression(attachedTo),
					"Set" + propertyName,
					(CodeExpression)peek(),
					new CodeVariableReferenceExpression(varName));

			push(call);
			push(new CodeVariableReferenceExpression(varName));
		}

		// pops 2 items: the name of the property, and the object to attach to
		public void EndDependencyProperty()
		{
			debug();
			pop(); // pop the variable name - we don't need it since it's already baked into the call
			CodeExpression call = (CodeExpression)pop();
			constructor.Statements.Add(call);
		}

		// top of stack must be an object reference
		public void CreateObjectText(string text)
		{
			debug();
			CodeVariableReferenceExpression var = (CodeVariableReferenceExpression)peek();
			CodeMethodInvokeExpression call = new CodeMethodInvokeExpression(
					var,
					"AddText",
					new CodePrimitiveExpression(text));
			constructor.Statements.Add(call);
		}

		// top of stack is reference to an event
		public void CreateEventDelegate(string functionName, Type eventDelegateType)
		{
			debug();
			CodeExpression expr = new CodeObjectCreateExpression(
					eventDelegateType,
					new CodeMethodReferenceExpression(
							new CodeThisReferenceExpression(),
							functionName));
			CodeAttachEventStatement attach = new CodeAttachEventStatement(
					(CodeEventReferenceExpression)peek(),
					expr);
			constructor.Statements.Add(attach);

		}
		// top of stack is reference to a property
		public void CreatePropertyDelegate(string functionName, Type propertyType)
		{
			debug();
			CodeExpression expr = new CodeObjectCreateExpression(
					propertyType,
					new CodeMethodReferenceExpression(
							new CodeThisReferenceExpression(),
							functionName));
			CodeAssignStatement assignment = new CodeAssignStatement(
					(CodeExpression)peek(),
					expr);
			constructor.Statements.Add(assignment);
		}

		private CodeExpression fetchConverter(Type propertyType)
		{
			return new CodeMethodInvokeExpression(
					new CodeMethodReferenceExpression(
							new CodeTypeReferenceExpression(typeof(System.ComponentModel.TypeDescriptor)),
							"GetConverter"),
					new CodeTypeOfExpression(propertyType));
		}

		// top of stack is reference to a property
		public void CreatePropertyText(string text, Type propertyType)
		{
			debug();
			CreateDependencyPropertyText(text, propertyType);
		}
		// top of stack is reference to an attached property
		public void CreateDependencyPropertyText(string text, Type propertyType)
		{
			debug();
			CodeExpression expr = new CodePrimitiveExpression(text);
			if (propertyType != typeof(string)) {
				expr = new CodeCastExpression(
						new CodeTypeReference(propertyType),
						new CodeMethodInvokeExpression(
								fetchConverter(propertyType),
								"ConvertFromString",
								expr));
			}
			CodeAssignStatement assignment = new CodeAssignStatement(
					(CodeExpression)peek(),
					expr);
			
			constructor.Statements.Add(assignment);
		}

		public void CreatePropertyObject(Type type, string varName)
		{
			debug();
			bool isDefaultName;
			if (varName == null) {
				isDefaultName = true;
				varName = Char.ToLower(type.Name[0]) + type.Name.Substring(1);
				// make sure something sensible happens when class
				// names start with a lowercase letter
				if (varName == type.Name)
					varName = "_" + varName;
			} else {
				isDefaultName = false;
			}

			if (isDefaultName) {
				if (!nameClashes.ContainsKey(varName))
					nameClashes[varName] = 0;
				nameClashes[varName] = 1 + (int)nameClashes[varName];
				varName += (int)nameClashes[varName];
			}


			if (isDefaultName) {
				CodeVariableDeclarationStatement declaration = 
						new CodeVariableDeclarationStatement(type, 
								varName,
								new CodeObjectCreateExpression(type));
				constructor.Statements.Add(declaration);
			} else {
				CodeMemberField declaration = new CodeMemberField(type, varName);
				declaration.InitExpression = new CodeObjectCreateExpression(type);
				this.type.Members.Add(declaration);
			}
			CodeVariableReferenceExpression varRef = new CodeVariableReferenceExpression(varName);

			push(type);
			push(varRef);
		
		}

		public void EndPropertyObject(Type destType)
		{
			debug();
			CodeExpression varRef = (CodeExpression)pop();
			Type sourceType = (Type)pop();

			Debug.WriteLine("CodeWriter: " + destType + "->" + sourceType);

			
			CodeExpression expr;
			if (sourceType == destType || sourceType.IsSubclassOf(destType))
				expr = varRef;
			else
				expr = new CodeCastExpression(
						new CodeTypeReference(destType),
						new CodeMethodInvokeExpression(
								fetchConverter(sourceType),
								"ConvertTo",
								varRef,
								new CodeTypeOfExpression(destType)));
			CodeAssignStatement assignment = new CodeAssignStatement(
					(CodeExpression)peek(),
					expr);
			constructor.Statements.Add(assignment);
		}
		
		public void EndObject()
		{
			debug();
			pop();
		}

		public void EndProperty()
		{
			debug();
			pop();
		}
		
		public void EndEvent()
		{
			debug();
			pop();
		}

		public void Finish()
		{
			debug();
			generator.GenerateCodeFromCompileUnit(code, writer, null);
			writer.Close();
		}

		public void CreateCode(string code)
		{
			debug();
			type.Members.Add(new CodeSnippetTypeMember(code));
		}

		private void debug()
		{
			Debug.WriteLine("CodeWriter: " + new System.Diagnostics.StackTrace());
		}
		
		private object pop()
		{
			object v = objects[objects.Count - 1];
			objects.RemoveAt(objects.Count - 1);
			Debug.WriteLine("CodeWriter: POPPING");
			return v;
		}
		private void push(object v)
		{
			Debug.WriteLine("CodeWriter: PUSHING " + v);
			objects.Add(v);
		}
		private object peek()
		{
			return peek(0);
		}
		private object peek(int i)
		{
			return objects[objects.Count - 1 - i];
		}
	}
}