// 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.CodeFixes;
using Microsoft.CodeAnalysis.CSharp.UseExplicitTypeForConst;
using Microsoft.CodeAnalysis.Diagnostics;
using Microsoft.CodeAnalysis.Editor.CSharp.UnitTests.Diagnostics;
using Microsoft.CodeAnalysis.Test.Utilities;
using Xunit;
using Xunit.Abstractions;
 
namespace Microsoft.CodeAnalysis.Editor.CSharp.UnitTests.UseExplicitTypeForConst
{
    [Trait(Traits.Feature, Traits.Features.CodeActionsUseExplicitTypeForConst)]
    public sealed class UseExplicitTypeForConstTests : AbstractCSharpDiagnosticProviderBasedUserDiagnosticTest
    {
        public UseExplicitTypeForConstTests(ITestOutputHelper logger)
            : base(logger)
        {
        }
 
        internal override (DiagnosticAnalyzer?, CodeFixProvider) CreateDiagnosticProviderAndFixer(Workspace workspace)
            => (null, new UseExplicitTypeForConstCodeFixProvider());
 
        [Fact]
        public async Task TestWithIntLiteral()
        {
            await TestInRegularAndScriptAsync(
                """
                class C
                {
                    void M()
                    {
                        const [|var|] v = 0;
                    }
                }
                """,
                """
                class C
                {
                    void M()
                    {
                        const int v = 0;
                    }
                }
                """);
        }
 
        [Fact]
        public async Task TestWithStringConstant()
        {
            await TestInRegularAndScriptAsync(
                """
                class C
                {
                    const string s = null;
                    void M()
                    {
                        const [|var|] v = s;
                    }
                }
                """,
                """
                class C
                {
                    const string s = null;
                    void M()
                    {
                        const string v = s;
                    }
                }
                """);
        }
 
        [Fact]
        public async Task TestWithQualifiedType()
        {
            await TestInRegularAndScriptAsync(
                """
                class C
                {
                    void M()
                    {
                        const [|var|] v = default(System.Action);
                    }
                }
                """,
                """
                class C
                {
                    void M()
                    {
                        const System.Action v = default(System.Action);
                    }
                }
                """);
        }
 
        [Fact]
        public async Task TestWithNonConstantInitializer()
        {
            await TestInRegularAndScriptAsync(
                """
                class C
                {
                    void M()
                    {
                        const [|var|] v = System.Console.ReadLine();
                    }
                }
                """,
                """
                class C
                {
                    void M()
                    {
                        const string v = System.Console.ReadLine();
                    }
                }
                """);
        }
 
        [Fact]
        public async Task TestWithNonConstantTupleType()
        {
            await TestInRegularAndScriptAsync(
                """
                class C
                {
                    void M()
                    {
                        const [|var|] v = (0, true);
                    }
                }
                """,
                """
                class C
                {
                    void M()
                    {
                        const (int, bool) v = (0, true);
                    }
                }
                """);
        }
 
        [Fact]
        public async Task TestNotWithNullLiteral()
        {
            await TestMissingInRegularAndScriptAsync(
                """
                class C
                {
                    void M()
                    {
                        const [|var|] v = null;
                    }
                }
                """);
        }
 
        [Fact]
        public async Task TestNotWithDefaultLiteral()
        {
            await TestMissingInRegularAndScriptAsync(
                """
                class C
                {
                    void M()
                    {
                        const [|var|] v = default;
                    }
                }
                """);
        }
 
        [Fact]
        public async Task TestWithLambda()
        {
            await TestInRegularAndScriptAsync(
                """
                class C
                {
                    void M()
                    {
                        const [|var|] v = () => { };
                    }
                }
                """,
                """
                class C
                {
                    void M()
                    {
                        const System.Action v = () => { };
                    }
                }
                """);
        }
 
        [Fact]
        public async Task TestNotWithAnonymousType()
        {
            await TestMissingInRegularAndScriptAsync(
                """
                class C
                {
                    void M()
                    {
                        const [|var|] v = new { a = 0 };
                    }
                }
                """);
        }
 
        [Fact]
        public async Task TestNotWithArrayInitializer()
        {
            await TestMissingInRegularAndScriptAsync(
                """
                class C
                {
                    void M()
                    {
                        const [|var|] v = { 0, 1 };
                    }
                }
                """);
        }
 
        [Fact]
        public async Task TestNotWithMissingInitializer()
        {
            await TestMissingInRegularAndScriptAsync(
                """
                class C
                {
                    void M()
                    {
                        const [|var|] v =
                    }
                }
                """);
        }
 
        [Fact]
        public async Task TestNotWithClassVar()
        {
            await TestMissingInRegularAndScriptAsync(
                """
                class C
                {
                    class var { }
                    void M()
                    {
                        const [|var|] v = 0;
                    }
                }
                """);
        }
 
        [Fact]
        public async Task TestNotOnField()
        {
            await TestMissingInRegularAndScriptAsync(
                """
                class C
                {
                    const [|var|] v = 0;
                }
                """);
        }
 
        [Fact]
        public async Task TestNotWithMultipleDeclarators()
        {
            await TestMissingInRegularAndScriptAsync(
                """
                class C
                {
                    void M()
                    {
                        const [|var|] a = 0, b = 0;
                    }
                }
                """);
        }
    }
}