// Copyright (c) AlphaSierraPapa for the SharpDevelop Team (for details please see \doc\copyright.txt)
// This code is distributed under MIT X11 license (for details please see \doc\license.txt)

using System;
using System.Collections.Generic;
using System.Linq;

using ICSharpCode.Decompiler;
using ICSharpCode.Decompiler.ILAst;
using ICSharpCode.NRefactory.CSharp;
using Mono.Cecil;

namespace ICSharpCode.Decompiler.Ast
{
	public class TextOutputFormatter : IOutputFormatter
	{
		readonly ITextOutput output;
		readonly Stack<AstNode> nodeStack = new Stack<AstNode>();
		int braceLevelWithinType = -1;
		
		public TextOutputFormatter(ITextOutput output)
		{
			if (output == null)
				throw new ArgumentNullException("output");
			this.output = output;
		}
		
		public void WriteIdentifier(string identifier)
		{
			MemberReference memberRef = GetCurrentMemberReference();
			
			if (memberRef != null)
				output.WriteReference(identifier, memberRef);
			else
				output.Write(identifier);
		}

		MemberReference GetCurrentMemberReference()
		{
			AstNode node = nodeStack.Peek();
			MemberReference memberRef = node.Annotation<MemberReference>();
			if (memberRef == null && node.Role == AstNode.Roles.TargetExpression && (node.Parent is InvocationExpression || node.Parent is ObjectCreateExpression)) {
				memberRef = node.Parent.Annotation<MemberReference>();
			}
			return memberRef;
		}
		
		public void WriteKeyword(string keyword)
		{
			output.Write(keyword);
		}
		
		public void WriteToken(string token)
		{
			// Attach member reference to token only if there's no identifier in the current node.
			MemberReference memberRef = GetCurrentMemberReference();
			if (memberRef != null && nodeStack.Peek().GetChildByRole(AstNode.Roles.Identifier).IsNull)
				output.WriteReference(token, memberRef);
			else
				output.Write(token);
		}
		
		public void Space()
		{
			output.Write(' ');
		}
		
		public void OpenBrace(BraceStyle style)
		{
			if (braceLevelWithinType >= 0 || nodeStack.Peek() is TypeDeclaration)
				braceLevelWithinType++;
			if (nodeStack.OfType<BlockStatement>().Count() <= 1) {
				output.MarkFoldStart(defaultCollapsed: braceLevelWithinType == 1);
			}
			output.WriteLine();
			output.WriteLine("{");
			output.Indent();
		}
		
		public void CloseBrace(BraceStyle style)
		{
			output.Unindent();
			output.Write('}');
			if (nodeStack.OfType<BlockStatement>().Count() <= 1)
				output.MarkFoldEnd();
			if (braceLevelWithinType >= 0)
				braceLevelWithinType--;
		}
		
		public void Indent()
		{
			output.Indent();
		}
		
		public void Unindent()
		{
			output.Unindent();
		}
		
		public void NewLine()
		{
			output.WriteLine();
		}
		
		public void WriteComment(CommentType commentType, string content)
		{
			switch (commentType) {
				case CommentType.SingleLine:
					output.Write("//");
					output.WriteLine(content);
					break;
				case CommentType.MultiLine:
					output.Write("/*");
					output.Write(content);
					output.Write("*/");
					break;
				case CommentType.Documentation:
					output.Write("///");
					output.WriteLine(content);
					break;
			}
		}
		
		public void StartNode(AstNode node)
		{
			// code mappings
			var ranges = node.Annotation<List<ILRange>>();
			if (ranges != null && ranges.Count > 0) {
				// find the ancestor that has method mapping as annotation
				if (node.Ancestors != null && node.Ancestors.Count() > 0) {
					var n = node.Ancestors.FirstOrDefault(a => a.Annotation<MemberMapping>() != null);
					if (n != null) {
						MemberMapping mapping = n.Annotation<MemberMapping>();

						// add all ranges
						foreach (var range in ranges) {
							mapping.MemberCodeMappings.Add(new SourceCodeMapping {
							                               	ILInstructionOffset = range,
							                               	SourceCodeLine = output.CurrentLine,
							                               	MemberMapping = mapping
							                               });
						}
					}
				}
			}
			
			// definitions of types and their members
			Predicate<AstNode> predicate = n => n is TypeDeclaration || n is DelegateDeclaration ||
				n is FieldDeclaration || n is PropertyDeclaration || n is EventDeclaration ||n is MethodDeclaration || n is ConstructorDeclaration ||
				n is IndexerDeclaration || n is OperatorDeclaration;
			
			if (predicate(node)) {
				var n = node as AttributedNode;
				int c = 0;
				if (n != null)
					c = n.Attributes.Count;
				node.AddAnnotation(Tuple.Create(output.CurrentLine + c, 0));
			}
			
			nodeStack.Push(node);
		}
		
		public void EndNode(AstNode node)
		{
			if (nodeStack.Pop() != node)
				throw new InvalidOperationException();
		}
	}
}