// 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.Generic;
using Microsoft.CodeAnalysis.CodeStyle;
using Microsoft.CodeAnalysis.Diagnostics;
using Microsoft.CodeAnalysis.LanguageService;
using Microsoft.CodeAnalysis.Options;
using Microsoft.CodeAnalysis.Text;
 
namespace Microsoft.CodeAnalysis.OrderModifiers;
 
internal abstract class AbstractOrderModifiersDiagnosticAnalyzer : AbstractBuiltInCodeStyleDiagnosticAnalyzer
{
    private readonly ISyntaxFacts _syntaxFacts;
    private readonly AbstractOrderModifiersHelpers _helpers;
 
    protected AbstractOrderModifiersDiagnosticAnalyzer(
        ISyntaxFacts syntaxFacts,
        Option2<CodeStyleOption2<string>> option,
        AbstractOrderModifiersHelpers helpers)
        : base(IDEDiagnosticIds.OrderModifiersDiagnosticId,
               EnforceOnBuildValues.OrderModifiers,
               option,
               new LocalizableResourceString(nameof(AnalyzersResources.Order_modifiers), AnalyzersResources.ResourceManager, typeof(AnalyzersResources)),
               new LocalizableResourceString(nameof(AnalyzersResources.Modifiers_are_not_ordered), AnalyzersResources.ResourceManager, typeof(AnalyzersResources)))
    {
        _syntaxFacts = syntaxFacts;
        _helpers = helpers;
    }
 
    public override DiagnosticAnalyzerCategory GetAnalyzerCategory()
        => DiagnosticAnalyzerCategory.SyntaxTreeWithoutSemanticsAnalysis;
 
    protected override void InitializeWorker(AnalysisContext context)
        => context.RegisterCompilationStartAction(context =>
            context.RegisterSyntaxTreeAction(treeContext => AnalyzeSyntaxTree(treeContext, context.Compilation.Options)));
 
    protected abstract CodeStyleOption2<string> GetPreferredOrderStyle(SyntaxTreeAnalysisContext context);
 
    private void AnalyzeSyntaxTree(SyntaxTreeAnalysisContext context, CompilationOptions compilationOptions)
    {
        var option = GetPreferredOrderStyle(context);
        if (ShouldSkipAnalysis(context, compilationOptions, option.Notification)
            || !_helpers.TryGetOrComputePreferredOrder(option.Value, out var preferredOrder))
        {
            return;
        }
 
        var analysisRoot = context.GetAnalysisRoot(findInTrivia: false);
 
        // Check the root node first to see if it has any modifiers that need reordering.
        CheckModifiers(context, preferredOrder, option.Notification, analysisRoot);
 
        // Recurse to check the child nodes.
        Recurse(context, preferredOrder, option.Notification, analysisRoot);
    }
 
    protected abstract void Recurse(
        SyntaxTreeAnalysisContext context,
        Dictionary<int, int> preferredOrder,
        NotificationOption2 notificationOption,
        SyntaxNode root);
 
    protected void CheckModifiers(
        SyntaxTreeAnalysisContext context,
        Dictionary<int, int> preferredOrder,
        NotificationOption2 notificationOption,
        SyntaxNode memberDeclaration)
    {
        var modifiers = _syntaxFacts.GetModifiers(memberDeclaration);
        if (!AbstractOrderModifiersHelpers.IsOrdered(preferredOrder, modifiers))
        {
            if (notificationOption.Severity.WithDefaultSeverity(DiagnosticSeverity.Hidden) == ReportDiagnostic.Hidden)
            {
                // If the severity is hidden, put the marker on all the modifiers so that the
                // user can bring up the fix anywhere in the modifier list.
                context.ReportDiagnostic(
                    DiagnosticHelper.Create(
                        Descriptor,
                        context.Tree.GetLocation(TextSpan.FromBounds(modifiers.First().SpanStart, modifiers.Last().Span.End)),
                        notificationOption,
                        context.Options,
                        additionalLocations: null,
                        properties: null));
            }
            else
            {
                // If the Severity is not hidden, then just put the user visible portion on the
                // first token.  That way we don't 
                context.ReportDiagnostic(
                    DiagnosticHelper.Create(Descriptor, modifiers.First().GetLocation(), notificationOption, context.Options, additionalLocations: null, properties: null));
            }
        }
    }
}