// 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 Microsoft.CodeAnalysis.CodeStyle;
using Microsoft.CodeAnalysis.Diagnostics;
using Microsoft.CodeAnalysis.PooledObjects;
 
namespace Microsoft.CodeAnalysis.CSharp.RemoveUnnecessaryUnsafeModifier;
 
[DiagnosticAnalyzer(LanguageNames.CSharp)]
internal sealed partial class CSharpRemoveUnnecessaryUnsafeModifierDiagnosticAnalyzer()
    : AbstractBuiltInUnnecessaryCodeStyleDiagnosticAnalyzer(
        IDEDiagnosticIds.RemoveUnnecessaryUnsafeModifier,
        EnforceOnBuildValues.RemoveUnnecessaryUnsafeModifier,
        option: null,
        new LocalizableResourceString(nameof(AnalyzersResources.Remove_unnecessary_unsafe_modifier), AnalyzersResources.ResourceManager, typeof(AnalyzersResources)),
        new LocalizableResourceString(nameof(AnalyzersResources.unsafe_modifier_is_unnecessary), AnalyzersResources.ResourceManager, typeof(CompilerExtensionsResources)))
{
    public override DiagnosticAnalyzerCategory GetAnalyzerCategory()
        => DiagnosticAnalyzerCategory.SemanticDocumentAnalysis;
 
    protected override void InitializeWorker(AnalysisContext context)
        => context.RegisterCompilationStartAction(context =>
        {
            var compilation = context.Compilation;
            var options = (CSharpCompilationOptions)compilation.Options;
            if (!options.AllowUnsafe)
                return;
 
            context.RegisterSemanticModelAction(AnalyzeSemanticModel);
        });
 
    private void AnalyzeSemanticModel(SemanticModelAnalysisContext context)
    {
        if (ShouldSkipAnalysis(context, notification: null))
            return;
 
        using var _ = ArrayBuilder<SyntaxNode>.GetInstance(out var unnecessaryNodes);
        UnnecessaryUnsafeModifierUtilities.AddUnnecessaryNodes(context.SemanticModel, unnecessaryNodes, context.CancellationToken);
 
        foreach (var declaration in unnecessaryNodes)
        {
            context.ReportDiagnostic(Diagnostic.Create(
                Descriptor,
                UnnecessaryUnsafeModifierUtilities.GetUnsafeModifier(declaration).GetLocation(),
                [declaration.GetLocation()]));
        }
    }
}