// 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 Xunit;
 
namespace Microsoft.CodeAnalysis.Editor.CSharp.UnitTests.Recommendations;
 
[Trait(Traits.Feature, Traits.Features.KeywordRecommending)]
public sealed 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()
    {
        await VerifyKeywordAsync(
            """
            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()]
            """);
    }
 
    [Fact]
    public async Task TestWithinExtension()
    {
        await VerifyAbsenceAsync(
            """
            static class C
            {
                extension(string s)
                {
                    $$
                }
            }
            """,
            CSharpNextParseOptions,
            CSharpNextScriptParseOptions);
    }
}