// 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.Collections.Generic;
using ILLink.Shared.DataFlow;
using Mono.Linker.Steps;
using Mono.Cecil;

namespace Mono.Linker.Dataflow
{
    public readonly struct TrimAnalysisPatternStore
    {
        readonly Dictionary<(MessageOrigin, int?), TrimAnalysisAssignmentPattern> AssignmentPatterns;
        readonly Dictionary<MessageOrigin, TrimAnalysisMethodCallPattern> MethodCallPatterns;
        readonly Dictionary<(MessageOrigin, MemberReference), TrimAnalysisGenericInstantiationAccessPattern> GenericInstantiations;
        readonly ValueSetLattice<SingleValue> Lattice;
        readonly LinkContext _context;

        public TrimAnalysisPatternStore(ValueSetLattice<SingleValue> lattice, LinkContext context)
        {
            AssignmentPatterns = new Dictionary<(MessageOrigin, int?), TrimAnalysisAssignmentPattern>();
            MethodCallPatterns = new Dictionary<MessageOrigin, TrimAnalysisMethodCallPattern>();
            GenericInstantiations = new Dictionary<(MessageOrigin, MemberReference), TrimAnalysisGenericInstantiationAccessPattern>();
            Lattice = lattice;
            _context = context;
        }

        public void Add(TrimAnalysisAssignmentPattern pattern)
        {
            var key = (pattern.Origin, pattern.ParameterIndex);
            if (!AssignmentPatterns.TryGetValue(key, out var existingPattern))
            {
                AssignmentPatterns.Add(key, pattern);
                return;
            }

            AssignmentPatterns[key] = pattern.Merge(Lattice, existingPattern);
        }

        public void Add(TrimAnalysisMethodCallPattern pattern)
        {
            if (!MethodCallPatterns.TryGetValue(pattern.Origin, out var existingPattern))
            {
                MethodCallPatterns.Add(pattern.Origin, pattern);
                return;
            }

            MethodCallPatterns[pattern.Origin] = pattern.Merge(Lattice, existingPattern);
        }

        public void Add(TrimAnalysisGenericInstantiationAccessPattern pattern)
        {
            GenericInstantiations.TryAdd((pattern.Origin, pattern.MemberReference), pattern);

            // No Merge - there's nothing to merge since this pattern is uniquely identified by both the origin and the member reference
            // and there's only one way to "access" a generic instantiation.
        }

        public void MarkAndProduceDiagnostics(ReflectionMarker reflectionMarker, MarkStep markStep)
        {
            foreach (var pattern in AssignmentPatterns.Values)
                pattern.MarkAndProduceDiagnostics(reflectionMarker, _context);

            foreach (var pattern in MethodCallPatterns.Values)
                pattern.MarkAndProduceDiagnostics(reflectionMarker, markStep, _context);

            foreach (var pattern in GenericInstantiations.Values)
                pattern.MarkAndProduceDiagnostics(reflectionMarker, markStep, _context);
        }
    }
}