// 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.CodeStyle;
using Microsoft.CodeAnalysis.CSharp.CodeStyle;
using Microsoft.CodeAnalysis.CSharp.UseExpressionBody;
using Microsoft.CodeAnalysis.Editor.UnitTests.CodeActions;
using Microsoft.CodeAnalysis.Test.Utilities;
using Xunit;
 
namespace Microsoft.CodeAnalysis.Editor.CSharp.UnitTests.UseExpressionBody
{
    using VerifyCS = CSharpCodeFixVerifier<
        UseExpressionBodyDiagnosticAnalyzer,
        UseExpressionBodyCodeFixProvider>;
 
    [Trait(Traits.Feature, Traits.Features.CodeActionsUseExpressionBody)]
    public class UseExpressionBodyForOperatorsAnalyzerTests
    {
        private static async Task TestWithUseExpressionBody(string code, string fixedCode)
        {
            await new VerifyCS.Test
            {
                TestCode = code,
                FixedCode = fixedCode,
                Options = { { CSharpCodeStyleOptions.PreferExpressionBodiedOperators, ExpressionBodyPreference.WhenPossible } }
            }.RunAsync();
        }
 
        private static async Task TestWithUseBlockBody(string code, string fixedCode)
        {
            await new VerifyCS.Test
            {
                TestCode = code,
                FixedCode = fixedCode,
                Options = { { CSharpCodeStyleOptions.PreferExpressionBodiedOperators, ExpressionBodyPreference.Never } }
            }.RunAsync();
        }
 
        [Fact]
        public async Task TestUseExpressionBody1()
        {
            var code = """
                class C
                {
                    private static C Bar() { return new C(); }
 
                    {|IDE0024:public static C operator {|CS0161:+|}(C c1, C c2)
                    {
                        Bar();
                    }|}
                }
                """;
            var fixedCode = """
                class C
                {
                    private static C Bar() { return new C(); }
 
                    public static C operator +(C c1, C c2) => Bar();
                }
                """;
            await TestWithUseExpressionBody(code, fixedCode);
        }
 
        [Fact]
        public async Task TestUseExpressionBody2()
        {
            var code = """
                class C
                {
                    private static C Bar() { return new C(); }
 
                    {|IDE0024:public static C operator +(C c1, C c2)
                    {
                        return Bar();
                    }|}
                }
                """;
            var fixedCode = """
                class C
                {
                    private static C Bar() { return new C(); }
 
                    public static C operator +(C c1, C c2) => Bar();
                }
                """;
            await TestWithUseExpressionBody(code, fixedCode);
        }
 
        [Fact]
        public async Task TestUseExpressionBody3()
        {
            var code = """
                using System;
 
                class C
                {
                    {|IDE0024:public static C operator +(C c1, C c2)
                    {
                        throw new NotImplementedException();
                    }|}
                }
                """;
            var fixedCode = """
                using System;
 
                class C
                {
                    public static C operator +(C c1, C c2) => throw new NotImplementedException();
                }
                """;
            await TestWithUseExpressionBody(code, fixedCode);
        }
 
        [Fact]
        public async Task TestUseExpressionBody4()
        {
            var code = """
                using System;
 
                class C
                {
                    {|IDE0024:public static C operator +(C c1, C c2)
                    {
                        throw new NotImplementedException(); // comment
                    }|}
                }
                """;
            var fixedCode = """
                using System;
 
                class C
                {
                    public static C operator +(C c1, C c2) => throw new NotImplementedException(); // comment
                }
                """;
            await TestWithUseExpressionBody(code, fixedCode);
        }
 
        [Fact]
        public async Task TestUseBlockBody1()
        {
            var code = """
                class C
                {
                    private static C Bar() { return new C(); }
 
                    {|IDE0024:public static C operator +(C c1, C c2) => Bar();|}
                }
                """;
            var fixedCode = """
                class C
                {
                    private static C Bar() { return new C(); }
 
                    public static C operator +(C c1, C c2)
                    {
                        return Bar();
                    }
                }
                """;
            await TestWithUseBlockBody(code, fixedCode);
        }
 
        [Fact]
        public async Task TestUseBlockBody3()
        {
            var code = """
                using System;
 
                class C
                {
                    {|IDE0024:public static C operator +(C c1, C c2) => throw new NotImplementedException();|}
                }
                """;
            var fixedCode = """
                using System;
 
                class C
                {
                    public static C operator +(C c1, C c2)
                    {
                        throw new NotImplementedException();
                    }
                }
                """;
            await TestWithUseBlockBody(code, fixedCode);
        }
 
        [Fact]
        public async Task TestUseBlockBody4()
        {
            var code = """
                using System;
 
                class C
                {
                    {|IDE0024:public static C operator +(C c1, C c2) => throw new NotImplementedException();|} // comment
                }
                """;
            var fixedCode = """
                using System;
 
                class C
                {
                    public static C operator +(C c1, C c2)
                    {
                        throw new NotImplementedException(); // comment
                    }
                }
                """;
            await TestWithUseBlockBody(code, fixedCode);
        }
    }
}