// Copyright (c) AlphaSierraPapa for the SharpDevelop Team
// 
// 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.Linq;
using ICSharpCode.NRefactory.Semantics;
using ICSharpCode.NRefactory.TypeSystem;
using ICSharpCode.NRefactory.TypeSystem.Implementation;
using NUnit.Framework;

namespace ICSharpCode.NRefactory.CSharp.Resolver
{
	[TestFixture]
	public class InvocationTests : ResolverTestBase
	{
		[Test]
		public void MethodCallTest()
		{
			string program = @"class A {
	void Method() {
		$TargetMethod()$;
	}
	
	int TargetMethod() {
		return 3;
	}
}
";
			InvocationResolveResult result = Resolve<CSharpInvocationResolveResult>(program);
			Assert.AreEqual("A.TargetMethod", result.Member.FullName);
			Assert.AreEqual("System.Int32", result.Type.ReflectionName);
		}
		
		[Test]
		public void InvalidMethodCall()
		{
			string program = @"class A {
	void Method(string b) {
		$b.ThisMethodDoesNotExistOnString(b)$;
	}
}
";
			UnknownMethodResolveResult result = Resolve<UnknownMethodResolveResult>(program);
			Assert.AreEqual("ThisMethodDoesNotExistOnString", result.MemberName);
			Assert.AreEqual("System.String", result.TargetType.FullName);
			Assert.AreEqual(1, result.Parameters.Count);
			Assert.AreEqual("b", result.Parameters[0].Name);
			Assert.AreEqual("System.String", result.Parameters[0].Type.ReflectionName);
			
			Assert.AreSame(SpecialType.UnknownType, result.Type);
		}
		
		[Test]
		public void OverriddenMethodCall()
		{
			string program = @"class A {
	void Method() {
		$new B().GetRandomNumber()$;
	}
	
	public abstract int GetRandomNumber();
}
class B : A {
	public override int GetRandomNumber() {
		return 4; // chosen by fair dice roll.
		          // guaranteed to be random
	}
}
";
			InvocationResolveResult result = Resolve<CSharpInvocationResolveResult>(program);
			Assert.AreEqual("B.GetRandomNumber", result.Member.FullName);
		}
		
		[Test]
		public void OverriddenMethodCall2()
		{
			string program = @"class A {
	void Method() {
		$new B().GetRandomNumber(""x"", this)$;
	}
	
	public abstract int GetRandomNumber(string a, A b);
}
class B : A {
	public override int GetRandomNumber(string b, A a) {
		return 4;
	}
}
";
			InvocationResolveResult result = Resolve<CSharpInvocationResolveResult>(program);
			Assert.AreEqual("B.GetRandomNumber", result.Member.FullName);
		}
		
		[Test]
		public void ThisMethodCallTest()
		{
			string program = @"class A {
	void Method() {
		$this.TargetMethod()$;
	}
	
	int TargetMethod() {
		return 3;
	}
}
";
			InvocationResolveResult result = Resolve<CSharpInvocationResolveResult>(program);
			Assert.AreEqual("A.TargetMethod", result.Member.FullName);
			Assert.AreEqual("System.Int32", result.Type.ReflectionName);
		}
		
		[Test]
		public void VoidTest()
		{
			string program = @"using System;
class A {
	void TestMethod() {
		$TestMethod()$;
	}
}
";
			Assert.AreEqual("System.Void", Resolve(program).Type.ReflectionName);
		}
		
		[Test]
		public void EventCallTest()
		{
			string program = @"using System;
class A {
	void Method() {
		$TestEvent(this, EventArgs.Empty)$;
	}
	
	public event EventHandler TestEvent;
}
";
			Assert.AreEqual("System.Void", Resolve(program).Type.ReflectionName);
		}
		
		[Test]
		public void DelegateCallTest()
		{
			string program = @"using System; using System.Reflection;
class A {
	void Method(ModuleResolveEventHandler eh) {
		$eh(this, new ResolveEventArgs())$;
	}
}
";
			Assert.AreEqual("System.Reflection.Module", Resolve(program).Type.ReflectionName);
		}
		
		[Test]
		public void DelegateReturnedFromMethodCallTest()
		{
			string program = @"using System;
class A {
	void Method() {
		$GetHandler()(abc)$;
	}
	abstract Predicate<string> GetHandler();
}
";
			Assert.AreEqual("System.Boolean", Resolve(program).Type.ReflectionName);
		}
		
		/* TODO
		[Test]
		public void MethodGroupResolveTest()
		{
			string program = @"class A {
	void Method() {
		
	}
	
	void TargetMethod(int a) { }
	void TargetMethod<T>(T a) { }
}
";
			MethodGroupResolveResult result = Resolve<MethodGroupResolveResult>(program, "TargetMethod", 3);
			Assert.AreEqual("TargetMethod", result.Name);
			Assert.AreEqual(2, result.Methods.Count);
			
			result = Resolve<MethodGroupResolveResult>(program, "TargetMethod<string>", 3);
			Assert.AreEqual("TargetMethod", result.Name);
			Assert.AreEqual(1, result.Methods[0].Count);
			Assert.AreEqual("System.String", result.GetMethodIfSingleOverload().Parameters[0].ReturnType.FullyQualifiedName);
		}
		 */
		
		[Test]
		public void TestOverloadingByRef()
		{
			string program = @"using System;
class Program {
	public static void Main() {
		int a = 42;
		T(a);
		T(ref a);
	}
	static void T(int x) {}
	static void T(ref int y) {}
}";
			
			InvocationResolveResult mrr = Resolve<CSharpInvocationResolveResult>(program.Replace("T(a)", "$T(a)$"));
			Assert.IsFalse(mrr.Member.Parameters[0].IsRef);
			
			mrr = Resolve<CSharpInvocationResolveResult>(program.Replace("T(ref a)", "$T(ref a)$"));
			Assert.IsTrue(mrr.Member.Parameters[0].IsRef);
		}
		
		[Test]
		public void AddedOverload()
		{
			string program = @"class BaseClass {
	static void Main(DerivedClass d) {
		$d.Test(3)$;
	}
	public void Test(int a) { }
}
class DerivedClass : BaseClass {
	public void Test(object a) { }
}";
			InvocationResolveResult mrr = Resolve<CSharpInvocationResolveResult>(program);
			Assert.AreEqual("DerivedClass.Test", mrr.Member.FullName);
		}
		
		[Test]
		public void AddedOverloadOnInterface()
		{
			string program = @"
interface IBase { void Method(int a); }
interface IDerived { void Method(object a); }
class Test {
	static void Main(IDerived d) {
		$d.Method(3)$;
	}
}";
			InvocationResolveResult mrr = Resolve<CSharpInvocationResolveResult>(program);
			Assert.AreEqual("IDerived.Method", mrr.Member.FullName);
		}
		
		[Test]
		public void AddedNonApplicableOverload()
		{
			string program = @"class BaseClass {
	static void Main(DerivedClass d) {
		$d.Test(3)$;
	}
	public void Test(int a) { }
}
class DerivedClass : BaseClass {
	public void Test(string a) { }
}";
			InvocationResolveResult mrr = Resolve<CSharpInvocationResolveResult>(program);
			Assert.AreEqual("BaseClass.Test", mrr.Member.FullName);
			
			mrr = Resolve<CSharpInvocationResolveResult>(program.Replace("(3)", "(\"3\")"));
			Assert.AreEqual("DerivedClass.Test", mrr.Member.FullName);
		}
		
		[Test]
		public void OverrideShadowed()
		{
			string program = @"using System;
class BaseClass {
	static void Main() {
		$new DerivedClass().Test(3)$;
	}
	public virtual void Test(int a) { }
}
class MiddleClass : BaseClass {
	public void Test(object a) { }
}
class DerivedClass : MiddleClass {
	public override void Test(int a) { }
}";
			
			InvocationResolveResult mrr = Resolve<CSharpInvocationResolveResult>(program);
			Assert.AreEqual("MiddleClass.Test", mrr.Member.FullName);
		}
		
		[Test]
		public void SubstituteClassAndMethodTypeParametersAtOnce()
		{
			string program = @"class C<X> { static void M<T>(X a, T b) { $C<T>.M(b, a)$; } }";
			var rr = Resolve<CSharpInvocationResolveResult>(program);
			Assert.IsFalse(rr.IsError);
			
			var m = (SpecializedMethod)rr.Member;
			Assert.AreEqual("X", m.TypeArguments.Single().Name);
			Assert.AreEqual("T", m.Parameters[0].Type.Name);
			Assert.AreEqual("X", m.Parameters[1].Type.Name);
		}
		
		[Test]
		public void MemberHiddenOnOneAccessPath()
		{
			// If a member is hidden in any access path, it is hidden in all access paths
			string program = @"
interface IBase { int F { get; } }
interface ILeft: IBase { new int F { get; } }
interface IRight: IBase { void G(); }
interface IDerived: ILeft, IRight {}
class A {
   void Test(IDerived d) { var a = $d.F$; }
}";
			var rr = Resolve<MemberResolveResult>(program);
			Assert.AreEqual("ILeft.F", rr.Member.FullName);
		}
		
		[Test]
		public void PropertyClashesWithMethod()
		{
			string program = @"
interface IList { int Count { get; set; } }
interface ICounter { void Count(int i); }
interface IListCounter: IList, ICounter {}
class A {
 	void Test(IListCounter x) { var a = $x.Count$; }
}";
			var rr = Resolve<MethodGroupResolveResult>(program);
			Assert.IsFalse(rr.IsError);
			Assert.AreEqual("ICounter.Count", rr.Methods.Single().FullName);
		}
		
		[Test]
		public void OverloadAmbiguousWithMethodInTwoInterfaces()
		{
			string program = @"
interface ILeft { void Method(); }
interface IRight { void Method(); }
interface IBoth : ILeft, IRight {}
class A {
 	void Test(IBoth x) { $x.Method()$; }
}";
			var rr = Resolve<CSharpInvocationResolveResult>(program);
			Assert.IsTrue(rr.IsError);
			Assert.AreEqual(OverloadResolutionErrors.AmbiguousMatch, rr.OverloadResolutionErrors);
		}
		
		[Test]
		public void AddedOverloadInOneInterfaceAndBetterOverloadInOtherInterface1()
		{
			string program = @"
interface IBase { void Method(int x); }
interface ILeft : IBase { void Method(object x); }
interface IRight { void Method(int x); }
interface IBoth : ILeft, IRight {}
class A {
 	void Test(IBoth x) { $x.Method(1)$; }
}";
			// IBase.Method is "hidden" because ILeft.Method is also applicable,
			// so IRight.Method is unambiguously the chosen overload.
			var rr = Resolve<CSharpInvocationResolveResult>(program);
			Assert.IsFalse(rr.IsError);
			Assert.AreEqual("IRight.Method", rr.Member.FullName);
		}
		
		[Test]
		public void AddedOverloadInOneInterfaceAndBetterOverloadInOtherInterface2()
		{
			// repeat the above test with Left/Right swapped to make sure we aren't order-sensitive
			string program = @"
interface IBase { void Method(int x); }
interface ILeft : IBase { void Method(object x); }
interface IRight { void Method(int x); }
interface IBoth : IRight, ILeft {}
class A {
 	void Test(IBoth x) { $x.Method(1)$; }
}";
			var rr = Resolve<CSharpInvocationResolveResult>(program);
			Assert.IsFalse(rr.IsError);
			Assert.AreEqual("IRight.Method", rr.Member.FullName);
		}
		
		[Test]
		public void AddedOverloadHidesCommonBaseMethod_Generic1()
		{
			string program = @"
interface IBase<T> {
	void Method(int x);
}
interface ILeft : IBase<int> { void Method(object x); }
interface IRight : IBase<int> { }
interface IBoth : ILeft, IRight {}
class A {
	void Test(IBoth x) { $x.Method(1)$; }
}";
			var rr = Resolve<CSharpInvocationResolveResult>(program);
			Assert.IsFalse(rr.IsError);
			Assert.AreEqual("ILeft.Method", rr.Member.FullName);
		}
		
		[Test]
		public void AddedOverloadHidesCommonBaseMethod_Generic2()
		{
			string program = @"
interface IBase<T> {
	void Method(int x);
}
interface ILeft : IBase<int> { void Method(object x); }
interface IRight : IBase<int> { }
interface IBoth : ILeft, IRight {}
class A {
	void Test(IBoth x) { $x.Method(1)$; }
}";
			var rr = Resolve<CSharpInvocationResolveResult>(program);
			Assert.IsFalse(rr.IsError);
			Assert.AreEqual("ILeft.Method", rr.Member.FullName);
		}
		
		[Test]
		public void AddedOverloadDoesNotHideCommonBaseMethodWithDifferentTypeArgument1()
		{
			string program = @"
interface IBase<T> {
	void Method(int x);
}
interface ILeft : IBase<int> { void Method(object x); }
interface IRight : IBase<long> { }
interface IBoth : IRight, ILeft {}
class A {
	void Test(IBoth x) { $x.Method(1)$; }
}";
			var rr = Resolve<CSharpInvocationResolveResult>(program);
			Assert.IsFalse(rr.IsError);
			Assert.AreEqual("IBase`1[[System.Int64]]", rr.Member.DeclaringType.ReflectionName);
		}
		
		[Test]
		public void AddedOverloadDoesNotHideCommonBaseMethodWithDifferentTypeArgument2()
		{
			string program = @"
interface IBase<T> {
	void Method(int x);
}
interface ILeft : IBase<int> { void Method(object x); }
interface IRight : IBase<long> { }
interface IBoth : IRight, ILeft {}
class A {
	void Test(IBoth x) { $x.Method(1)$; }
}";
			var rr = Resolve<CSharpInvocationResolveResult>(program);
			Assert.IsFalse(rr.IsError);
			Assert.AreEqual("IBase`1[[System.Int64]]", rr.Member.DeclaringType.ReflectionName);
		}
		
		[Test]
		public void AmbiguityBetweenMemberAndMethodIsNotAnError()
		{
			string program = @"
interface ILeft { void Method(object x); }
interface IRight { Action<object> Method { get; } }
interface IBoth : ILeft, IRight {}
class A {
	void Test(IBoth x) { $x.Method(null)$; }
}";
			var rr = Resolve<CSharpInvocationResolveResult>(program);
			Assert.IsFalse(rr.IsError);
			Assert.AreEqual("ILeft.Method", rr.Member.FullName);
		}
		
		[Test]
		public void AcceptVisitor()
		{
			string program = @"
interface IVisitor<in T, out S> { }
class Test : IVisitor<object, object> {
	void M() {
		$Accept(this, null)$;
	}
	S Accept<T, S>(IVisitor<T, S> v, T input) { }
}";
			var rr = Resolve<CSharpInvocationResolveResult>(program);
			Assert.IsFalse(rr.IsError);
			var typeArguments = ((SpecializedMethod)rr.Member).TypeArguments;
			Assert.AreEqual("System.Object", typeArguments[0].ReflectionName);
			Assert.AreEqual("System.Object", typeArguments[1].ReflectionName);
		}
		
		[Test]
		public void FirstParameterToExtensionMethod()
		{
			string program = @"
public class X {}
public static class Ex {
	public static void F(this X x, int y, int z) {}
}
class C {
	public void M() {
		X a = null;
		int b = 0, c = 0;
		$a.F(b, c)$;
	}
}";
			var rr = Resolve<CSharpInvocationResolveResult>(program);
			Assert.IsFalse(rr.IsError);
			Assert.That(rr.IsExtensionMethodInvocation, Is.True);
			Assert.That(rr.Arguments[0], Is.InstanceOf<LocalResolveResult>());
			Assert.That(((LocalResolveResult)rr.Arguments[0]).Variable.Name, Is.EqualTo("a"));
			Assert.That(rr.Arguments[1], Is.InstanceOf<LocalResolveResult>());
			Assert.That(((LocalResolveResult)rr.Arguments[1]).Variable.Name, Is.EqualTo("b"));
			Assert.That(rr.Arguments[2], Is.InstanceOf<LocalResolveResult>());
			Assert.That(((LocalResolveResult)rr.Arguments[2]).Variable.Name, Is.EqualTo("c"));
			
			Assert.That(rr.TargetResult, Is.InstanceOf<TypeResolveResult>());
		}
		
		[Test]
		public void BaseInvocation()
		{
			string program = @"
class B {
	public virtual void F(int x, int y) {}
}
class D : B {
	public override void F(int x, int y) {}
	public void M() {
		$base.F(0, 1)$;
	}
}";
			var rr = Resolve<CSharpInvocationResolveResult>(program);
			Assert.IsFalse(rr.IsError);
			Assert.IsFalse(rr.IsVirtualCall);
		}
		
		[Test]
		public void NamedArgument()
		{
			string program = @"
class Test {
	public void F(int x) {}
	public void Test() {
		F($x: 0$);
	}
}";
			var narr = Resolve<NamedArgumentResolveResult>(program);
			Assert.IsInstanceOf<ConstantResolveResult>(narr.Argument);
			Assert.AreEqual("x", narr.ParameterName);
			Assert.AreEqual("Test.F", narr.Member.FullName);
			Assert.AreSame(narr.Member.Parameters.Single(), narr.Parameter);
		}
		
		[Test]
		public void NamedArgumentInInvocation()
		{
			string program = @"
class Test {
	public void F(int x) {}
	public void Test() {
		$F(x: 0)$;
	}
}";
			var rr = Resolve<CSharpInvocationResolveResult>(program);
			Assert.IsInstanceOf<NamedArgumentResolveResult>(rr.Arguments.Single());
			var narr = (NamedArgumentResolveResult)rr.Arguments.Single();
			Assert.IsInstanceOf<ConstantResolveResult>(narr.Argument);
			Assert.AreEqual("x", narr.ParameterName);
			Assert.AreEqual("Test.F", narr.Member.FullName);
			Assert.AreSame(narr.Member.Parameters.Single(), narr.Parameter);
			
			// but GetArgumentsForCall() should directly return the constant:
			Assert.IsInstanceOf<ConstantResolveResult>(rr.GetArgumentsForCall().Single());
		}
		
		[Test]
		public void UnknownNamedArgument()
		{
			string program = @"
class Test {
	public void F(int x) {}
	public void Test() {
		F($y: 0$);
	}
}";
			var narr = Resolve<NamedArgumentResolveResult>(program);
			Assert.IsInstanceOf<ConstantResolveResult>(narr.Argument);
			Assert.AreEqual("y", narr.ParameterName);
			Assert.IsNull(narr.Parameter);
		}
		
		[Test]
		public void NamedArgumentInMissingMethod()
		{
			string program = @"
class Test {
	public void Test() {
		Missing($x: 0$);
	}
}";
			var narr = Resolve<NamedArgumentResolveResult>(program);
			Assert.IsInstanceOf<ConstantResolveResult>(narr.Argument);
			Assert.AreEqual("x", narr.ParameterName);
			Assert.IsNull(narr.Parameter);
		}
		
		[Test]
		public void GenericMethodInvocationWithConstraintMismatch()
		{
			string program = @"
interface IA
{
}
class Test
{
    void F()
    {
        string o = null;
        $M(o)$;
    }

    void M<T>(T arg) where T : IA
    {
    }
    void M(object arg) {
	}
}";
			var rr = Resolve<CSharpInvocationResolveResult>(program);
			Assert.AreEqual(OverloadResolutionErrors.MethodConstraintsNotSatisfied, rr.OverloadResolutionErrors);
			Assert.IsTrue(rr.IsError);
		}

		[Test]
		public void MethodCanBeInvokedWithNullableTypeArgument1() {
			string program = @"
public class C {
	static T F<T>() {
		return default(T);
	}

	void M() {
		$F<int?>()$;
	}
}";

			var rr = Resolve<CSharpInvocationResolveResult>(program);
			Assert.IsFalse(rr.IsError);
		}

		[Test]
		public void MethodCanBeInvokedWithNullableTypeArgument2() {
			string program = @"
public class C {
	static T F<T>(T t) {
		return default(T);
	}

	void M() {
		$F((int?)null)$;
	}
}";

			var rr = Resolve<CSharpInvocationResolveResult>(program);
			Assert.IsFalse(rr.IsError);
		}

		[Test]
		public void MethodCanBeInvokedWithNullableTypeArgument3() {
			string program = @"
public class C {
	static T F<T, U>() where T : U {
		return default(T);
	}

	void M() {
		$F<int?, object>()$;
	}
}";

			var rr = Resolve<CSharpInvocationResolveResult>(program);
			Assert.IsFalse(rr.IsError);
		}
		
		[Test]
		public void MethodWithStructContraintCanBeInvokedWithValueType() {
			string program = @"
public class C {
	static T F<T>() where T : struct {
		return default(T);
	}

	void M() {
		$F<int>()$;
	}
}";

			var rr = Resolve<CSharpInvocationResolveResult>(program);
			Assert.IsFalse(rr.IsError);
		}
		
		[Test]
		public void MethodWithStructContraintCannotBeInvokedWithNullableValueType() {
			string program = @"
public class C {
	static T F<T>() where T : struct {
		return default(T);
	}

	void M() {
		$F<int?>()$;
	}
}";

			var rr = Resolve<CSharpInvocationResolveResult>(program);
			Assert.IsTrue(rr.IsError);
			Assert.AreEqual(OverloadResolutionErrors.MethodConstraintsNotSatisfied, rr.OverloadResolutionErrors);
		}
		
		[Test]
		public void CanConstructGenericTypeWithNullableTypeArgument() {
			string program = @"
public class X<T> {}
public class C {
	void M() {
		$new X<int?>()$;
	}
}";

			var rr = Resolve<CSharpInvocationResolveResult>(program);
			Assert.IsFalse(rr.IsError);
		}
		
		[Test]
		public void OverloadResolutionIsAmbiguousEvenIfNotDelegateCompatible() {
			string program = @"
class Test {
	static void M(Func<int> o) {}
	static void M(Action o) {}
	
	static int K() { return 0; }
	
	static void Main() {
		$M(K)$;
	}
}";
			// K is only delegate-compatible with one of the overloads; yet we get an invalid match.
			// This is because the conversion exists even though it is invalid.
			var rr = Resolve<CSharpInvocationResolveResult>(program);
			Assert.AreEqual(OverloadResolutionErrors.AmbiguousMatch, rr.OverloadResolutionErrors);
		}
		
		[Test]
		public void IndexerWithMoreSpecificParameterTypesIsPreferred()
		{
			string program = @"
class A {
	public static void Test(B<object> b) {
		x = $b[4]$;
	}
}
public class B<T> {
	public string this[T key] {
		get { return ""1""; }
	}
	public int this[object key] {
		get { return 2; }
	}
}";
			var rr = Resolve<CSharpInvocationResolveResult>(program);
			Assert.IsFalse(rr.IsError);
			Assert.AreEqual("System.Int32", rr.Member.ReturnType.FullName);
		}
		
		[Test]
		public void MethodWithMoreSpecificParameterTypesIsPreferred()
		{
			string program = @"
class A {
	public static void Test(B<object> b) {
		$b.M(4)$;
	}
}
public class B<T> {
	public string M(T key) {
		return ""1"";
	}
	public int M(object key) {
		return 2;
	}
}";
			var rr = Resolve<CSharpInvocationResolveResult>(program);
			Assert.IsFalse(rr.IsError);
			Assert.AreEqual("System.Int32", rr.Member.ReturnType.FullName);
		}
	}
}