// 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.Collections.Immutable;
using Microsoft.CodeAnalysis.CodeStyle;
using Microsoft.CodeAnalysis.CSharp.Analyzers.ConvertProgram;
using Microsoft.CodeAnalysis.CSharp.CodeStyle;
using Microsoft.CodeAnalysis.CSharp.Syntax;
using Microsoft.CodeAnalysis.Diagnostics;

namespace Microsoft.CodeAnalysis.CSharp.TopLevelStatements;

using static ConvertProgramAnalysis;

[DiagnosticAnalyzer(LanguageNames.CSharp)]
internal sealed class ConvertToProgramMainDiagnosticAnalyzer : AbstractBuiltInCodeStyleDiagnosticAnalyzer
{
    public ConvertToProgramMainDiagnosticAnalyzer()
        : base(
              IDEDiagnosticIds.UseProgramMainId,
              EnforceOnBuildValues.UseProgramMain,
              CSharpCodeStyleOptions.PreferTopLevelStatements,
              new LocalizableResourceString(nameof(CSharpAnalyzersResources.Convert_to_Program_Main_style_program), CSharpAnalyzersResources.ResourceManager, typeof(CSharpAnalyzersResources)))
    {
    }

    public override DiagnosticAnalyzerCategory GetAnalyzerCategory()
        => DiagnosticAnalyzerCategory.SemanticDocumentAnalysis;

    protected override void InitializeWorker(AnalysisContext context)
    {
        context.RegisterCompilationStartAction(context =>
        {
            if (!IsApplication(context.Compilation))
                return;

            context.RegisterSyntaxNodeAction(ProcessCompilationUnit, SyntaxKind.CompilationUnit);
        });
    }

    private void ProcessCompilationUnit(SyntaxNodeAnalysisContext context)
    {
        var root = (CompilationUnitSyntax)context.Node;
        var option = context.GetCSharpAnalyzerOptions().PreferTopLevelStatements;

        if (ShouldSkipAnalysis(context, option.Notification)
            || !CanOfferUseProgramMain(option, root, context.Compilation, forAnalyzer: true))
        {
            return;
        }

        var severity = option.Notification.Severity;

        context.ReportDiagnostic(DiagnosticHelper.Create(
            this.Descriptor,
            GetUseProgramMainDiagnosticLocation(
                root, isHidden: severity.WithDefaultSeverity(DiagnosticSeverity.Hidden) == ReportDiagnostic.Hidden),
            option.Notification,
            context.Options,
            [],
            ImmutableDictionary<string, string?>.Empty));
    }
}