// 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 Roslyn.Utilities;
 
namespace Microsoft.CodeAnalysis.Diagnostics
{
    internal static partial class DiagnosticAnalyzerExtensions
    {
        public static DiagnosticAnalyzerCategory GetDiagnosticAnalyzerCategory(this DiagnosticAnalyzer analyzer)
            => analyzer switch
            {
                FileContentLoadAnalyzer _ => DiagnosticAnalyzerCategory.SyntaxTreeWithoutSemanticsAnalysis,
                DocumentDiagnosticAnalyzer _ => DiagnosticAnalyzerCategory.SyntaxTreeWithoutSemanticsAnalysis | DiagnosticAnalyzerCategory.SemanticDocumentAnalysis,
                ProjectDiagnosticAnalyzer _ => DiagnosticAnalyzerCategory.ProjectAnalysis,
                IBuiltInAnalyzer builtInAnalyzer => builtInAnalyzer.GetAnalyzerCategory(),
 
                // Compiler analyzer supports syntax diagnostics, span-based semantic diagnostics and project level diagnostics.
                // For a public analyzer it is not possible to know the diagnostic categorization, so return a worst-case categorization.
                _ => analyzer.IsCompilerAnalyzer()
                    ? DiagnosticAnalyzerCategory.SyntaxTreeWithoutSemanticsAnalysis | DiagnosticAnalyzerCategory.SemanticSpanAnalysis | DiagnosticAnalyzerCategory.ProjectAnalysis
                    : DiagnosticAnalyzerCategory.SyntaxTreeWithoutSemanticsAnalysis | DiagnosticAnalyzerCategory.SemanticDocumentAnalysis | DiagnosticAnalyzerCategory.ProjectAnalysis
            };
 
        public static bool SupportAnalysisKind(this DiagnosticAnalyzer analyzer, AnalysisKind kind)
            => kind switch
            {
                AnalysisKind.Syntax => analyzer.SupportsSyntaxDiagnosticAnalysis(),
                AnalysisKind.Semantic => analyzer.SupportsSemanticDiagnosticAnalysis(),
                _ => throw ExceptionUtilities.UnexpectedValue(kind)
            };
 
        public static bool SupportsSyntaxDiagnosticAnalysis(this DiagnosticAnalyzer analyzer)
        {
            var category = analyzer.GetDiagnosticAnalyzerCategory();
            return (category & DiagnosticAnalyzerCategory.SyntaxTreeWithoutSemanticsAnalysis) != 0;
        }
 
        public static bool SupportsSemanticDiagnosticAnalysis(this DiagnosticAnalyzer analyzer)
        {
            var category = analyzer.GetDiagnosticAnalyzerCategory();
            return (category & (DiagnosticAnalyzerCategory.SemanticSpanAnalysis | DiagnosticAnalyzerCategory.SemanticDocumentAnalysis)) != 0;
        }
 
        public static bool SupportsSpanBasedSemanticDiagnosticAnalysis(this DiagnosticAnalyzer analyzer)
        {
            var category = analyzer.GetDiagnosticAnalyzerCategory();
            return (category & DiagnosticAnalyzerCategory.SemanticSpanAnalysis) != 0;
        }
 
        public static bool SupportsProjectDiagnosticAnalysis(this DiagnosticAnalyzer analyzer)
        {
            var category = analyzer.GetDiagnosticAnalyzerCategory();
            return (category & DiagnosticAnalyzerCategory.ProjectAnalysis) != 0;
        }
    }
}