﻿// 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.

using System.Threading.Tasks;
using Microsoft.CodeAnalysis.Test.Utilities;
using Roslyn.Test.Utilities;
using Xunit;

namespace Microsoft.CodeAnalysis.Editor.CSharp.UnitTests.Recommendations
{
    [Trait(Traits.Feature, Traits.Features.KeywordRecommending)]
    public class UsingKeywordRecommenderTests : KeywordRecommenderTests
    {
        [Fact]
        public async Task TestNotInUsingAlias()
        {
            await VerifyAbsenceAsync(
@"using Goo = $$");
        }

        [Fact]
        public async Task TestNotInGlobalUsingAlias()
        {
            await VerifyAbsenceAsync(
@"global using Goo = $$");
        }

        [Fact]
        public async Task TestAfterClass()
        {
            await VerifyKeywordAsync(
@"class C { }
$$");
        }

        [Fact]
        public async Task TestAfterGlobalStatement_Interactive()
        {
            await VerifyKeywordAsync(SourceCodeKind.Script,
@"System.Console.WriteLine();
$$");
        }

        [Fact]
        public async Task TestAfterGlobalVariableDeclaration_Interactive()
        {
            await VerifyKeywordAsync(SourceCodeKind.Script,
@"int i = 0;
$$");
        }

        [Theory]
        [CombinatorialData]
        public async Task TestInEmptyStatement(bool topLevelStatement)
        {
            await VerifyKeywordAsync(AddInsideMethod(
@"$$", topLevelStatement: topLevelStatement), options: CSharp9ParseOptions);
        }

        [Fact]
        public async Task TestAfterAwait()
        {
            await VerifyKeywordAsync(
@"class C
{
    async void M()
    {
        await $$
    }
}");
        }

        [Fact]
        public async Task TestAfterAwaitInAssignment()
        {
            await VerifyAbsenceAsync(
@"class C
{
    async void M()
    {
        _ = await $$
    }
}");
        }

        [Fact]
        public async Task TestAtRoot()
        {
            await VerifyKeywordAsync(
@"$$");
        }

        [Fact]
        public async Task TestNotAfterUsingKeyword()
            => await VerifyAbsenceAsync(@"using $$");

        [Fact]
        public async Task TestAfterPreviousUsing()
        {
            await VerifyKeywordAsync(
@"using Goo;
$$");
        }

        [Fact]
        public async Task TestAfterPreviousGlobalUsing()
        {
            await VerifyKeywordAsync(
@"global using Goo;
$$");
        }

        [Fact]
        public async Task TestAfterExtern()
        {
            await VerifyKeywordAsync(
@"extern alias goo;
$$");
        }

        [Fact]
        public async Task TestAfterGlobalAfterExtern()
        {
            await VerifyKeywordAsync(
@"extern alias goo;
global $$");
        }

        [Fact]
        public async Task TestAfterGlobalAfterExternBeforeUsing_01()
        {
            await VerifyKeywordAsync(
@"extern alias goo;
global $$
using Goo;");
        }

        [Fact]
        public async Task TestAfterGlobalAfterExternBeforeUsing_02()
        {
            await VerifyKeywordAsync(
@"extern alias goo;
global $$
global using Goo;");
        }

        [Fact]
        public async Task TestBeforeUsing()
        {
            await VerifyKeywordAsync(
@"$$
using Goo;");
        }

        [Fact]
        public async Task TestBeforeUsingAfterGlobal()
        {
            await VerifyKeywordAsync(
@"global $$
using Goo;");
        }

        [Fact]
        public async Task TestAfterUsingAlias()
        {
            await VerifyKeywordAsync(
@"using Goo = Bar;
$$");
        }

        [Fact]
        public async Task TestAfterGlobalUsingAlias()
        {
            await VerifyKeywordAsync(
@"global using Goo = Bar;
$$");
        }

        [Fact]
        public async Task TestNotAfterNestedTypeDeclaration()
        {
            await VerifyAbsenceAsync(@"class A {
    class C {}
    $$");
        }

        [Fact]
        public async Task TestInsideNamespace()
        {
            await VerifyKeywordAsync(
@"namespace N {
    $$");
        }

        [Fact]
        public async Task TestAfterFileScopedNamespace()
        {
            await VerifyKeywordAsync(
@"namespace N;
$$");
        }

        [Fact]
        public async Task TestNotAfterUsingKeyword_InsideNamespace()
        {
            await VerifyAbsenceAsync(@"namespace N {
    using $$");
        }

        [Fact]
        public async Task TestAfterPreviousUsing_InsideNamespace()
        {
            await VerifyKeywordAsync(
@"namespace N {
   using Goo;
   $$");
        }

        [Fact]
        public async Task TestBeforeUsing_InsideNamespace()
        {
            await VerifyKeywordAsync(
@"namespace N {
    $$
    using Goo;");
        }

        [Fact]
        public async Task TestNotAfterMember_InsideNamespace()
        {
            await VerifyAbsenceAsync(@"namespace N {
    class C {}
    $$");
        }

        [Fact]
        public async Task TestNotAfterNestedMember_InsideNamespace()
        {
            await VerifyAbsenceAsync(@"namespace N {
    class A {
      class C {}
      $$");
        }

        [Fact]
        public async Task TestNotBeforeExtern()
        {
            await VerifyAbsenceAsync(SourceCodeKind.Regular,
@"$$
extern alias Goo;");
        }

        [Fact(Skip = "https://github.com/dotnet/roslyn/issues/9880")]
        public async Task TestNotBeforeExtern_Interactive()
        {
            await VerifyAbsenceAsync(SourceCodeKind.Script,
@"$$
extern alias Goo;");
        }

        [Fact]
        public async Task TestNotBeforeExternAfterGlobal()
        {
            await VerifyAbsenceAsync(SourceCodeKind.Regular,
@"global $$
extern alias Goo;");
        }

        [Fact(Skip = "https://github.com/dotnet/roslyn/issues/9880")]
        public async Task TestNotBeforeExternAfterGlobal_Interactive()
        {
            await VerifyAbsenceAsync(SourceCodeKind.Script,
@"global $$
extern alias Goo;");
        }

        [Theory]
        [CombinatorialData]
        public async Task TestBeforeStatement(bool topLevelStatement)
        {
            await VerifyKeywordAsync(AddInsideMethod(
@"$$
return true;", topLevelStatement: topLevelStatement), options: CSharp9ParseOptions);
        }

        [Theory]
        [CombinatorialData]
        public async Task TestAfterStatement(bool topLevelStatement)
        {
            await VerifyKeywordAsync(AddInsideMethod(
@"return true;
$$", topLevelStatement: topLevelStatement), options: CSharp9ParseOptions);
        }

        [Theory]
        [CombinatorialData]
        public async Task TestAfterBlock(bool topLevelStatement)
        {
            await VerifyKeywordAsync(AddInsideMethod(
@"if (true) {
}
$$", topLevelStatement: topLevelStatement), options: CSharp9ParseOptions);
        }

        [Theory]
        [CombinatorialData]
        public async Task TestAfterIf(bool topLevelStatement)
        {
            await VerifyKeywordAsync(AddInsideMethod(
@"if (true) 
    $$", topLevelStatement: topLevelStatement), options: CSharp9ParseOptions);
        }

        [Theory]
        [CombinatorialData]
        public async Task TestAfterDo(bool topLevelStatement)
        {
            await VerifyKeywordAsync(AddInsideMethod(
@"do 
    $$", topLevelStatement: topLevelStatement), options: CSharp9ParseOptions);
        }

        [Theory]
        [CombinatorialData]
        public async Task TestAfterWhile(bool topLevelStatement)
        {
            await VerifyKeywordAsync(AddInsideMethod(
@"while (true) 
    $$", topLevelStatement: topLevelStatement), options: CSharp9ParseOptions);
        }

        [Theory]
        [CombinatorialData]
        public async Task TestAfterFor(bool topLevelStatement)
        {
            await VerifyKeywordAsync(AddInsideMethod(
@"for (int i = 0; i < 10; i++) 
    $$", topLevelStatement: topLevelStatement), options: CSharp9ParseOptions);
        }

        [Theory]
        [CombinatorialData]
        public async Task TestAfterForeach(bool topLevelStatement)
        {
            await VerifyKeywordAsync(AddInsideMethod(
@"foreach (var v in bar)
    $$", topLevelStatement: topLevelStatement), options: CSharp9ParseOptions);
        }

        [Fact]
        public async Task TestNotAfterUsing()
        {
            await VerifyAbsenceAsync(
@"using $$");
        }

        [Fact]
        public async Task TestNotAfterGlobalUsing()
        {
            await VerifyAbsenceAsync(
@"global using $$");
        }

        [Fact]
        public async Task TestNotInClass()
        {
            await VerifyAbsenceAsync(@"class C
{
  $$
}");
        }

        [Fact]
        public async Task TestBetweenUsings_01()
        {
            await VerifyKeywordAsync(
@"using Goo;
$$
using Bar;");
        }

        [Fact]
        public async Task TestBetweenUsings_02()
        {
            await VerifyKeywordAsync(
@"global using Goo;
$$
using Bar;");
        }

        [Fact]
        public async Task TestAfterGlobalBetweenUsings_01()
        {
            await VerifyKeywordAsync(
@"global using Goo;
global $$
using Bar;");
        }

        [Fact]
        public async Task TestAfterGlobalBetweenUsings_02()
        {
            await VerifyKeywordAsync(
@"global using Goo;
global $$
global using Bar;");
        }

        [Fact]
        public async Task TestAfterGlobal()
        {
            await VerifyKeywordAsync(
@"global $$");
        }

        [Fact]
        public async Task TestBeforeNamespace()
        {
            await VerifyKeywordAsync(
@"$$
namespace NS
{}");
        }

        [Fact]
        public async Task TestBeforeFileScopedNamespace()
        {
            await VerifyKeywordAsync(
@"$$
namespace NS;");
        }

        [Fact]
        public async Task TestBeforeClass()
        {
            await VerifyKeywordAsync(
@"$$
class C1
{}");
        }

        [Fact]
        public async Task TestBeforeAttribute_01()
        {
            await VerifyKeywordAsync(
@"$$
[Call()]");
        }

        [Fact]
        public async Task TestBeforeAttribute_02()
        {
            await VerifyKeywordAsync(
@"$$
[assembly: Call()]");
        }

        [Fact]
        public async Task TestBeforeNamespaceAfterGlobal()
        {
            await VerifyKeywordAsync(
@"global $$
namespace NS
{}");
        }

        [Fact]
        public async Task TestBeforeClassAfterGlobal()
        {
            await VerifyKeywordAsync(
@"global $$
class C1
{}");
        }

        [Fact]
        public async Task TestBeforeStatementAfterGlobal()
        {
            await VerifyKeywordAsync(
@"global $$
Call();");
        }

        [Fact]
        public async Task TestBeforeAttributeAfterGlobal_01()
        {
            await VerifyKeywordAsync(
@"global $$
[Call()]");
        }

        [Fact]
        public async Task TestBeforeAttributeAfterGlobal_02()
        {
            await VerifyKeywordAsync(
@"global $$
[assembly: Call()]");
        }
    }
}
