// 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.CodeAnalysis;
using ILLink.RoslynAnalyzer.TrimAnalysis;
using ILLink.Shared;
using ILLink.Shared.TrimAnalysis;
using Microsoft.CodeAnalysis;

namespace ILLink.RoslynAnalyzer
{
    sealed class DynamicallyAccessedMembersTypeHierarchy
    {
        public static void ApplyDynamicallyAccessedMembersToTypeHierarchy(
            TypeNameResolver typeNameResolver,
            Location typeLocation,
            INamedTypeSymbol type,
            Action<Diagnostic> reportDiagnostic)
        {
            var annotation = FlowAnnotations.GetTypeAnnotation(type);

            // We need to apply annotations to this type, and its base/interface types (recursively)
            // But the annotations on base/interfaces may already be applied so we don't need to apply those
            // again (and should avoid doing so as it would produce extra warnings).
            var reflectionAccessAnalyzer = new ReflectionAccessAnalyzer(reportDiagnostic, typeNameResolver, type);
            if (type.BaseType is INamedTypeSymbol baseType)
            {
                var baseAnnotation = FlowAnnotations.GetTypeAnnotation(baseType);
                var annotationToApplyToBase = Annotations.GetMissingMemberTypes(annotation, baseAnnotation);

                // Apply any annotations that didn't exist on the base type to the base type.
                // This may produce redundant warnings when the annotation is DAMT.All or DAMT.PublicConstructors and the base already has a
                // subset of those annotations.
                reflectionAccessAnalyzer.GetReflectionAccessDiagnostics(typeLocation, baseType, annotationToApplyToBase, declaredOnly: false);
            }

            // Most of the DynamicallyAccessedMemberTypes don't select members on interfaces. We only need to apply
            // annotations to interfaces separately if dealing with DAMT.All or DAMT.Interfaces.
            if (annotation.HasFlag(DynamicallyAccessedMemberTypes.Interfaces))
            {
                var annotationToApplyToInterfaces = annotation == DynamicallyAccessedMemberTypes.All ? annotation : DynamicallyAccessedMemberTypes.Interfaces;
                foreach (var iface in type.AllInterfaces)
                {
                    if (FlowAnnotations.GetTypeAnnotation(iface).HasFlag(annotationToApplyToInterfaces))
                        continue;

                    // Apply All or Interfaces to the interface type.
                    // DAMT.All may produce redundant warnings from implementing types, when the interface type already had some annotations.
                    reflectionAccessAnalyzer.GetReflectionAccessDiagnostics(typeLocation, iface, annotationToApplyToInterfaces, declaredOnly: false);
                }
            }

            // The annotations this type inherited from its base types or interfaces should not produce
            // warnings on the respective base/interface members, since those are already covered by applying
            // the annotations to those types. So we only need to handle the members directly declared on this type.
            reflectionAccessAnalyzer.GetReflectionAccessDiagnostics(typeLocation, type, annotation, declaredOnly: true);
        }
    }
}