// Copyright (c) .NET Foundation and contributors. All rights reserved.
// Licensed under the MIT license. See LICENSE file in the project root for full license information.

using System;
using System.Diagnostics;
using ILLink.RoslynAnalyzer.DataFlow;
using ILLink.Shared.TrimAnalysis;
using Microsoft.CodeAnalysis;

namespace ILLink.RoslynAnalyzer.TrimAnalysis
{
    internal readonly record struct TrimAnalysisReflectionAccessPattern
    {
        public IMethodSymbol ReferencedMethod { get; init; }
        public IOperation Operation { get; init; }
        public ISymbol OwningSymbol { get; init; }
        public FeatureContext FeatureContext { get; init; }

        public TrimAnalysisReflectionAccessPattern(
            IMethodSymbol referencedMethod,
            IOperation operation,
            ISymbol owningSymbol,
            FeatureContext feature)
        {
            ReferencedMethod = referencedMethod;
            Operation = operation;
            OwningSymbol = owningSymbol;
            FeatureContext = feature.DeepCopy();
        }

        public TrimAnalysisReflectionAccessPattern Merge(
            FeatureContextLattice featureContextLattice,
            TrimAnalysisReflectionAccessPattern other)
        {
            Debug.Assert(SymbolEqualityComparer.Default.Equals(ReferencedMethod, other.ReferencedMethod));
            Debug.Assert(Operation == other.Operation);
            Debug.Assert(SymbolEqualityComparer.Default.Equals(OwningSymbol, other.OwningSymbol));

            return new TrimAnalysisReflectionAccessPattern(
                ReferencedMethod,
                Operation,
                OwningSymbol,
                featureContextLattice.Meet(FeatureContext, other.FeatureContext));
        }

        public void ReportDiagnostics(DataFlowAnalyzerContext context, Action<Diagnostic> reportDiagnostic)
        {
            var location = Operation.Syntax.GetLocation();
            var typeNameResolver = new TypeNameResolver(context.Compilation);
            var reflectionAccessAnalyzer = new ReflectionAccessAnalyzer(reportDiagnostic, typeNameResolver, typeHierarchyType: null);
            if (context.TrimAnalyzer is not null &&
                !OwningSymbol.IsInRequiresUnreferencedCodeAttributeScope(out _) &&
                !FeatureContext.IsEnabled(RequiresUnreferencedCodeAnalyzer.FullyQualifiedRequiresUnreferencedCodeAttribute))
            {
                reflectionAccessAnalyzer.GetDiagnosticsForReflectionAccessToDAMOnMethod(location, ReferencedMethod);
            }

            DiagnosticContext diagnosticContext = new(location, reportDiagnostic);
            foreach (var requiresAnalyzer in context.EnabledRequiresAnalyzers)
                requiresAnalyzer.CheckAndCreateRequiresDiagnostic(Operation, ReferencedMethod, OwningSymbol, context, FeatureContext, diagnosticContext);
        }
    }
}