// Copyright (c) 2010 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 NUnit.Framework;
using ICSharpCode.NRefactory.TypeSystem;

namespace ICSharpCode.NRefactory.CSharp.Resolver
{
	[TestFixture]
	public class SimpleNameLookupTests : ResolverTestBase
	{
		[Test]
		public void SimpleNameLookupWithoutContext()
		{
			// nothing should be found without specifying any UsingScope - however, the resolver also must not crash
			resolver.UsingScope = null;
			Assert.IsTrue(resolver.ResolveSimpleName("System", new IType[0]).IsError);
		}
		
		[Test]
		public void SimpleNamespaceLookup()
		{
			NamespaceResolveResult nrr = (NamespaceResolveResult)resolver.ResolveSimpleName("System", new IType[0]);
			Assert.AreEqual("System", nrr.NamespaceName);
			Assert.AreSame(SharedTypes.UnknownType, nrr.Type);
		}
		
		[Test]
		public void NamespaceInParentNamespaceLookup()
		{
			resolver.UsingScope = MakeUsingScope("System.Collections.Generic");
			NamespaceResolveResult nrr = (NamespaceResolveResult)resolver.ResolveSimpleName("Text", new IType[0]);
			Assert.AreEqual("System.Text", nrr.NamespaceName);
		}
		
		[Test]
		public void NamespacesAreNotImported()
		{
			AddUsing("System");
			Assert.IsTrue(resolver.ResolveSimpleName("Collections", new IType[0]).IsError);
		}
		
		[Test]
		public void ImportedType()
		{
			AddUsing("System");
			TypeResolveResult trr = (TypeResolveResult)resolver.ResolveSimpleName("String", new IType[0]);
			Assert.AreEqual("System.String", trr.Type.FullName);
		}
		
		[Test]
		public void UnknownIdentifierTest()
		{
			UnknownIdentifierResolveResult uirr = (UnknownIdentifierResolveResult)resolver.ResolveSimpleName("xyz", new IType[0]);
			Assert.IsTrue(uirr.IsError);
			Assert.AreEqual("xyz", uirr.Identifier);
		}
		
		[Test]
		public void GlobalIsUnknownIdentifier()
		{
			Assert.IsTrue(resolver.ResolveSimpleName("global", new IType[0]).IsError);
		}
		
		[Test]
		public void GlobalIsAlias()
		{
			NamespaceResolveResult nrr = (NamespaceResolveResult)resolver.ResolveAlias("global");
			Assert.AreEqual("", nrr.NamespaceName);
		}
		
		[Test]
		public void AliasToImportedType()
		{
			AddUsing("System");
			AddUsingAlias("x", "String");
			TypeResolveResult trr = (TypeResolveResult)resolver.ResolveSimpleName("x", new IType[0]);
			// Unknown type (as String isn't looked up in System)
			Assert.AreSame(SharedTypes.UnknownType, trr.Type);
		}
		
		[Test]
		public void AliasToImportedType2()
		{
			AddUsing("System");
			resolver.UsingScope = new UsingScope(resolver.UsingScope, "SomeNamespace");
			AddUsingAlias("x", "String");
			TypeResolveResult trr = (TypeResolveResult)resolver.ResolveSimpleName("x", new IType[0]);
			Assert.AreEqual("System.String", trr.Type.FullName);
		}
		
		[Test]
		public void AliasOperatorOnTypeAlias()
		{
			AddUsingAlias("x", "System.String");
			Assert.IsTrue(resolver.ResolveAlias("x").IsError);
		}
		
		[Test]
		public void AliasOperatorOnNamespaceAlias()
		{
			AddUsingAlias("x", "System.Collections.Generic");
			NamespaceResolveResult nrr = (NamespaceResolveResult)resolver.ResolveAlias("x");
			Assert.AreEqual("System.Collections.Generic", nrr.NamespaceName);
		}
		
		[Test]
		public void AliasOperatorOnNamespace()
		{
			Assert.IsTrue(resolver.ResolveAlias("System").IsError);
		}
		
		[Test]
		public void FindClassInCurrentNamespace()
		{
			resolver.UsingScope = MakeUsingScope("System.Collections");
			TypeResolveResult trr = (TypeResolveResult)resolver.ResolveSimpleName("String", new IType[0]);
			Assert.AreEqual("System.String", trr.Type.FullName);
		}
		
		[Test]
		public void FindNeighborNamespace()
		{
			resolver.UsingScope = MakeUsingScope("System.Collections");
			NamespaceResolveResult nrr = (NamespaceResolveResult)resolver.ResolveSimpleName("Text", new IType[0]);
			Assert.AreEqual("System.Text", nrr.NamespaceName);
		}
		
		[Test]
		public void FindTypeParameters()
		{
			resolver.UsingScope = MakeUsingScope("System.Collections.Generic");
			resolver.CurrentTypeDefinition = context.GetClass(typeof(List<>));
			resolver.CurrentMember = resolver.CurrentTypeDefinition.Methods.Single(m => m.Name == "ConvertAll");
			
			TypeResolveResult trr;
			trr = (TypeResolveResult)resolver.ResolveSimpleName("TOutput", new IType[0]);
			Assert.AreSame(((IMethod)resolver.CurrentMember).TypeParameters[0], trr.Type);
			
			trr = (TypeResolveResult)resolver.ResolveSimpleName("T", new IType[0]);
			Assert.AreSame(resolver.CurrentTypeDefinition.TypeParameters[0], trr.Type);
		}
		
		[Test]
		public void SimpleParameter()
		{
			string program = @"class A {
	void Method(string a) {
		string b = $a$;
	}
}
";
			VariableResolveResult result = Resolve<VariableResolveResult>(program);
			Assert.AreEqual("a", result.Variable.Name);
			Assert.IsTrue(result.IsParameter);
			Assert.AreEqual("System.String", result.Type.FullName);
		}
		
		[Test]
		public void SimpleLocalVariable()
		{
			string program = @"class A {
	void Method() {
		string a;
		string b = $a$;
	}
}
";
			VariableResolveResult result = Resolve<VariableResolveResult>(program);
			Assert.AreEqual("a", result.Variable.Name);
			Assert.IsFalse(result.IsParameter);
			
			Assert.AreEqual("System.String", result.Type.FullName);
		}
		
		[Test]
		public void UnknownTypeTest()
		{
			string program = @"class A {
	void Method($StringBuilder$ b) {
	}
}
";
			UnknownIdentifierResolveResult result = Resolve<UnknownIdentifierResolveResult>(program);
			Assert.AreEqual("StringBuilder", result.Identifier);
			
			Assert.AreSame(SharedTypes.UnknownType, result.Type);
		}
		
		[Test, Ignore("not yet implemented (depends on distuishing types and expressions in the DOM)")]
		public void PropertyNameAmbiguousWithTypeName()
		{
			string program = @"class A {
	public Color Color { get; set; }
	
	void Method() {
		$
	}
}
class Color { public static readonly Color Empty = null; }
";
			TypeResolveResult trr = Resolve<TypeResolveResult>(program.Replace("$", "$Color$ c;"));
			Assert.AreEqual("Color", trr.Type.Name);
			
			MemberResolveResult mrr = Resolve<MemberResolveResult>(program.Replace("$", "x = $Color$;"));
			Assert.AreEqual("Color", mrr.Member.Name);
			
			Resolve<MemberResolveResult>(program.Replace("$", "$Color$ = Color.Empty;"));
			Resolve<TypeResolveResult>(program.Replace("$", "Color = $Color$.Empty;"));
			Resolve<MemberResolveResult>(program.Replace("$", "x = $Color$.ToString();"));
		}
	}
}