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using System;
using System.IO;
using ICSharpCode.NRefactory.Editor;
using ICSharpCode.NRefactory.TypeSystem;
using NUnit.Framework;

namespace ICSharpCode.NRefactory.CSharp.Parser
{
	/// <summary>
	/// Test fixture that parses NRefactory itself,
	/// ensures that there are no parser crashes while doing so,
	/// and that the returned positions are consistent.
	/// </summary>
	[TestFixture]
	public class ParseSelfTests
	{
		string[] fileNames;
		
		[TestFixtureSetUp]
		public void SetUp()
		{
			string path = Path.GetFullPath (Path.Combine ("..", ".."));
			if (!File.Exists(Path.Combine(path, "NRefactory.sln")))
				throw new InvalidOperationException("Test cannot find the NRefactory source code in " + path);
			fileNames = Directory.GetFiles(path, "*.cs", SearchOption.AllDirectories);
		}
		
		[Test]
		public void GenerateTypeSystem()
		{
			IProjectContent pc = new CSharpProjectContent();
			CSharpParser parser = new CSharpParser();
			parser.GenerateTypeSystemMode = true;
			foreach (string fileName in fileNames) {
				SyntaxTree syntaxTree;
				using (var fs = new FileStream(fileName, FileMode.Open, FileAccess.Read, FileShare.Read, 4096, FileOptions.SequentialScan)) {
					syntaxTree = parser.Parse(fs, fileName);
				}
				var unresolvedFile = syntaxTree.ToTypeSystem();
				foreach (var td in unresolvedFile.GetAllTypeDefinitions()) {
					Assert.AreSame(unresolvedFile, td.UnresolvedFile);
					foreach (var member in td.Members) {
						Assert.AreSame(unresolvedFile, member.UnresolvedFile);
						Assert.AreSame(td, member.DeclaringTypeDefinition);
					}
				}
				pc = pc.AddOrUpdateFiles(unresolvedFile);
			}
		}
		
		#region ParseAndCheckPositions
		string currentFileName;
		ReadOnlyDocument currentDocument;
		
		[Test, Ignore("Positions still are incorrect in several cases")]
		public void ParseAndCheckPositions()
		{
			CSharpParser parser = new CSharpParser();
			foreach (string fileName in fileNames) {
				this.currentDocument = new ReadOnlyDocument(File.ReadAllText(fileName));
				SyntaxTree syntaxTree = parser.Parse(currentDocument, fileName);
				if (parser.HasErrors)
					continue;
				this.currentFileName = fileName;
				CheckPositionConsistency(syntaxTree);
				CheckMissingTokens(syntaxTree);
			}
		}

		void PrintNode (AstNode node)
		{
			Console.WriteLine ("Parent:" + node.GetType ());
			Console.WriteLine ("Children:");
			foreach (var c in node.Children)
				Console.WriteLine (c.GetType () +" at:"+ c.StartLocation +"-"+ c.EndLocation + " Role: "+ c.Role);
			Console.WriteLine ("----");
		}
		
		void CheckPositionConsistency (AstNode node)
		{
			string comment = "(" + node.GetType ().Name + " at " + node.StartLocation + " in " + currentFileName + ")";
			var pred = node.StartLocation <= node.EndLocation;
			if (!pred)
				PrintNode (node);
			Assert.IsTrue(pred, "StartLocation must be before EndLocation " + comment);
			var prevNodeEnd = node.StartLocation;
			var prevNode = node;
			for (AstNode child = node.FirstChild; child != null; child = child.NextSibling) {
				bool assertion = child.StartLocation >= prevNodeEnd;
				if (!assertion) {
					PrintNode (prevNode);
					PrintNode (node);
					
				}
				Assert.IsTrue(assertion, currentFileName + ": Child " + child.GetType () +" (" + child.StartLocation  + ")" +" must start after previous sibling " + prevNode.GetType () + "(" + prevNode.StartLocation + ")");
				CheckPositionConsistency(child);
				prevNodeEnd = child.EndLocation;
				prevNode = child;
			}
			Assert.IsTrue(prevNodeEnd <= node.EndLocation, "Last child must end before parent node ends " + comment);
		}
		
		void CheckMissingTokens(AstNode node)
		{
			if (node is CSharpTokenNode) {
				Assert.IsNull(node.FirstChild, "Token nodes should not have children");
			} else {
				var prevNodeEnd = node.StartLocation;
				var prevNode = node;
				for (AstNode child = node.FirstChild; child != null; child = child.NextSibling) {
					CheckWhitespace(prevNode, prevNodeEnd, child, child.StartLocation);
					CheckMissingTokens(child);
					prevNode = child;
					prevNodeEnd = child.EndLocation;
				}
				CheckWhitespace(prevNode, prevNodeEnd, node, node.EndLocation);
			}
		}
		
		void CheckWhitespace(AstNode startNode, TextLocation whitespaceStart, AstNode endNode, TextLocation whitespaceEnd)
		{
			if (whitespaceStart == whitespaceEnd || startNode == endNode)
				return;
			int start = currentDocument.GetOffset(whitespaceStart.Line, whitespaceStart.Column);
			int end = currentDocument.GetOffset(whitespaceEnd.Line, whitespaceEnd.Column);
			string text = currentDocument.GetText(start, end - start);
			bool assertion = string.IsNullOrWhiteSpace(text);
			if (!assertion) {
				if (startNode.Parent != endNode.Parent)
					PrintNode (startNode.Parent);
				PrintNode (endNode.Parent);
			}
			Assert.IsTrue(assertion, "Expected whitespace between " + startNode.GetType () +":" + whitespaceStart + " and " + endNode.GetType () + ":" + whitespaceEnd
			              + ", but got '" + text + "' (in " + currentFileName + " parent:" + startNode.Parent.GetType () +")");
		}
		#endregion
	}
}