// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.
// See the LICENSE file in the project root for more information.
 
#nullable disable
 
using Microsoft.CodeAnalysis.Editor.UnitTests.AutomaticCompletion;
using Microsoft.CodeAnalysis.Test.Utilities;
using Roslyn.Test.Utilities;
using Xunit;
using static Microsoft.CodeAnalysis.BraceCompletion.AbstractBraceCompletionService;
 
namespace Microsoft.CodeAnalysis.Editor.CSharp.UnitTests.AutomaticCompletion;
 
[Trait(Traits.Feature, Traits.Features.AutomaticCompletion)]
public class AutomaticLessAndGreaterThanCompletionTests : AbstractAutomaticBraceCompletionTests
{
    [WpfFact]
    public void Creation()
    {
        using var session = CreateSession("$$");
        Assert.NotNull(session);
    }
 
    [WpfFact]
    public void InvalidLocation_TopLevel()
    {
        using var session = CreateSession("$$");
        Assert.NotNull(session);
    }
 
    [WpfFact]
    public void InvalidLocation_TopLevel2()
    {
        using var session = CreateSession("using System;$$");
        Assert.NotNull(session);
        CheckStart(session.Session, expectValidSession: false);
    }
 
    [WpfFact]
    public void Class_TypeParameter()
    {
        var code = @"class C$$";
 
        using var session = CreateSession(code);
        Assert.NotNull(session);
        CheckStart(session.Session);
    }
 
    [WpfFact]
    public void Method_TypeParameter()
    {
        var code = """
            class C
            {
                void Method$$
            }
            """;
 
        using var session = CreateSession(code);
        Assert.NotNull(session);
        CheckStart(session.Session);
    }
 
    [WpfFact]
    public void Class_TypeParameter_Delete()
    {
        var code = @"class C$$";
 
        using var session = CreateSession(code);
        Assert.NotNull(session);
        CheckStart(session.Session);
        CheckBackspace(session.Session);
    }
 
    [WpfFact]
    public void Class_TypeParameter_Tab()
    {
        var code = @"class C$$";
 
        using var session = CreateSession(code);
        Assert.NotNull(session);
        CheckStart(session.Session);
        CheckTab(session.Session);
    }
 
    [WpfFact]
    public void Class_TypeParameter_GreaterThan()
    {
        var code = @"class C$$";
 
        using var session = CreateSession(code);
        Assert.NotNull(session);
        CheckStart(session.Session);
        CheckOverType(session.Session);
    }
 
    [WpfFact]
    public void Multiple_Invalid()
    {
        var code = @"class C<$$>";
 
        using var session = CreateSession(code);
        Assert.NotNull(session);
        CheckStart(session.Session, expectValidSession: false);
    }
 
    [WpfFact]
    public void Multiple_Nested()
    {
        var code = """
            class C<T>
            {
                C<C$$>
            }
            """;
 
        using var session = CreateSession(code);
        Assert.NotNull(session);
        CheckStart(session.Session);
    }
 
    [WpfFact]
    public void TypeArgument_Invalid()
    {
        var code = """
            class C
            {
                void Method()
                {
                    var i = 1;
                    var b = i $$
                }
            }
            """;
        using var session = CreateSession(code);
        Assert.NotNull(session);
        CheckStart(session.Session, expectValidSession: false);
    }
 
    [WpfFact]
    public void TypeArgument1()
    {
        var code = """
            class C
            {
                void Method()
                {
                    var a = new List$$
                }
            }
            """;
        using var session = CreateSession(code);
        Assert.NotNull(session);
        CheckStart(session.Session);
    }
 
    [WpfFact]
    public void TypeArgument2()
    {
        var code = """
            class C
            {
                void Method()
                {
                    var a = typeof(List$$
                }
            }
            """;
        using var session = CreateSession(code);
        Assert.NotNull(session);
        CheckStart(session.Session);
    }
 
    [WpfFact, WorkItem("http://vstfdevdiv:8080/DevDiv2/DevDiv/_workitems/edit/531637")]
    public void TypeParameterReturnType()
    {
        var code = """
            class C
            {
                List$$
            }
            """;
        using var session = CreateSession(code);
        Assert.NotNull(session);
        CheckStart(session.Session);
        Type(session.Session, "int");
        CheckOverType(session.Session);
    }
 
    [WpfFact, WorkItem("http://vstfdevdiv:8080/DevDiv2/DevDiv/_workitems/edit/531637")]
    public void TypeParameterInDecl()
    {
        var code = """
            class C
            {
                void List$$
            }
            """;
        using var session = CreateSession(code);
        Assert.NotNull(session);
        CheckStart(session.Session);
        Type(session.Session, "T");
        CheckOverType(session.Session);
    }
 
    [WpfFact, WorkItem("http://vstfdevdiv:8080/DevDiv2/DevDiv/_workitems/edit/531637")]
    public void TypeParameterInDeclWith()
    {
        var code = """
            class C
            {
                async Task$$
            }
            """;
        using var session = CreateSession(code);
        Assert.NotNull(session);
        CheckStart(session.Session);
        Type(session.Session, "int");
        CheckOverType(session.Session);
    }
 
    [WpfFact, WorkItem("http://vstfdevdiv:8080/DevDiv2/DevDiv/_workitems/edit/530864")]
    public void TypeArgumentWithUsing()
    {
        var code = """
            using System.Collections.Generic;
 
            class C
            {
                void Test()
                {
                    List$$
                }
            }
            """;
        using var session = CreateSession(code);
        Assert.NotNull(session);
        CheckStart(session.Session);
        Type(session.Session, "int");
        CheckOverType(session.Session);
    }
 
    [WpfFact, WorkItem("http://vstfdevdiv:8080/DevDiv2/DevDiv/_workitems/edit/530864")]
    public void TypeArgumentNoUsing()
    {
        var code = """
            class C
            {
                void Test()
                {
                    List$$
                }
            }
            """;
        using var session = CreateSession(code);
        Assert.NotNull(session);
        CheckStart(session.Session, expectValidSession: false);
    }
 
    [WpfFact, WorkItem("https://github.com/dotnet/roslyn/issues/1628")]
    public void NotInLessThanComparisonOperation()
    {
        var code = """
            using System.Linq;
            class C
            {
                void Test(int[] args)
                {
                    var a = args[0]$$
                }
            }
            """;
        using var session = CreateSession(code);
        Assert.NotNull(session);
        CheckStart(session.Session, expectValidSession: false);
    }
 
    [WpfFact, WorkItem("https://github.com/dotnet/roslyn/issues/1628")]
    public void NotInLessThanComparisonOperationAfterConditionalAccessExpression()
    {
        var code = """
            using System.Linq;
            class C
            {
                void Test(object[] args, object[] other)
                {
                    var a = args?.First()$$
                }
            }
            """;
        using var session = CreateSession(code);
        Assert.NotNull(session);
        CheckStart(session.Session, expectValidSession: false);
    }
 
    [WpfFact, WorkItem("https://github.com/dotnet/roslyn/issues/1628")]
    public void TypeArgumentInConditionalAccessExpressionSimple()
    {
        var code = """
            using System.Linq;
            class C
            {
                void Test(object[] args)
                {
                    args?.OfType$$
                }
            }
            """;
        using var session = CreateSession(code);
        Assert.NotNull(session);
        CheckStart(session.Session);
    }
 
    [WpfFact, WorkItem("https://github.com/dotnet/roslyn/issues/1628")]
    public void TypeArgumentInConditionalAccessExpressionNested()
    {
        var code = """
            class C
            {
                void Test()
                {
                    Outer<int> t = new Outer<int>();
                    t?.GetInner<int>()?.Method$$
                }
            }
            class Outer<T>
            {
                public Inner<U> GetInner<U>()
                {
                    return new Inner<U>();
                }
            }
            class Inner<V>
            {
                public void Method<X>() { }
            }
            """;
        using var session = CreateSession(code);
        Assert.NotNull(session);
        CheckStart(session.Session);
        Type(session.Session, "int");
        CheckOverType(session.Session);
    }
 
    [WpfFact, WorkItem("https://github.com/dotnet/roslyn/issues/1628")]
    public void TypeArgumentInConditionalAccessExpressionDeeplyNested()
    {
        var code = """
            class C
            {
                void Test()
                {
                    new Outer1<int>()?.GetInner<int>()?.GetInner().DoSomething$$
                }
            }
            internal class Outer1<T>
            {
                public Outer2<U> GetInner<U>()
                {
                    return new Outer2<U>();
                }
            }
            internal class Outer2<U>
            {
                public Outer2() { }
                public Inner GetInner()
                {
                    return new Inner();
                }
            }
            internal class Inner
            {
                public Inner() { }
                public void DoSomething<V>() { }
            }
            """;
        using var session = CreateSession(code);
        Assert.NotNull(session);
        CheckStart(session.Session);
    }
 
    [WpfFact, WorkItem("https://github.com/dotnet/roslyn/issues/1628")]
    public void TypeArgumentInConditionalAccessExpressionWithLambdas()
    {
        var code = """
            using System;
            using System.Collections.Generic;
            using System.Linq;
 
            class Program
            {
                void Goo(object[] args)
                {
                    var a = new Outer();
                    a?.M(x => x?.ToString())?.Method$$
                }
            }
 
            public class Outer
            {
                internal Inner M(Func<object, object> p)
                {
                    throw new NotImplementedException();
                }
            }
 
            public class Inner
            {
                public void Method<U>() { }
            }
            """;
        using var session = CreateSession(code);
        Assert.NotNull(session);
        CheckStart(session.Session);
    }
 
    [WpfFact]
    public void FunctionPointerStartSession()
    {
        var code = """
            class C
            {
                delegate*$$
            """;
 
        using var session = CreateSession(code);
        Assert.NotNull(session);
        CheckStart(session.Session);
        Type(session.Session, "int");
        CheckOverType(session.Session);
    }
 
    internal static Holder CreateSession(string code)
    {
        return CreateSession(
            EditorTestWorkspace.CreateCSharp(code),
            LessAndGreaterThan.OpenCharacter, LessAndGreaterThan.CloseCharacter);
    }
}