// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.

using System.Collections.Immutable;
using System.Diagnostics;
using ILCompiler.Logging;
using ILLink.Shared.DataFlow;
using ILLink.Shared.TrimAnalysis;
using Internal.IL;
using Internal.TypeSystem;
using MultiValue = ILLink.Shared.DataFlow.ValueSet<ILLink.Shared.DataFlow.SingleValue>;

#nullable enable

namespace ILCompiler.Dataflow
{
    public readonly record struct TrimAnalysisMethodCallPattern
    {
        public readonly MethodIL MethodBody;
        public readonly ILOpcode Operation;
        public readonly int Offset;
        public readonly MethodDesc CalledMethod;
        public readonly MultiValue Instance;
        public readonly ImmutableArray<MultiValue> Arguments;
        public readonly MessageOrigin Origin;

        public TrimAnalysisMethodCallPattern(
            MethodIL methodBody,
            ILOpcode operation,
            int offset,
            MethodDesc calledMethod,
            MultiValue instance,
            ImmutableArray<MultiValue> arguments,
            MessageOrigin origin)
        {
            Debug.Assert(origin.MemberDefinition is MethodDesc);
            MethodBody = methodBody;
            Operation = operation;
            Offset = offset;
            CalledMethod = calledMethod;
            Instance = instance.DeepCopy();
            if (arguments.IsEmpty)
            {
                Arguments = ImmutableArray<MultiValue>.Empty;
            }
            else
            {
                var builder = ImmutableArray.CreateBuilder<MultiValue>();
                foreach (var argument in arguments)
                    builder.Add(argument.DeepCopy());
                Arguments = builder.ToImmutableArray();
            }
            Origin = origin;
        }

        public TrimAnalysisMethodCallPattern Merge(ValueSetLattice<SingleValue> lattice, TrimAnalysisMethodCallPattern other)
        {
            Debug.Assert(MethodBody.OwningMethod == other.MethodBody.OwningMethod);
            Debug.Assert(Operation == other.Operation);
            Debug.Assert(Offset == other.Offset);
            Debug.Assert(Origin == other.Origin);
            Debug.Assert(CalledMethod == other.CalledMethod);
            Debug.Assert(Arguments.Length == other.Arguments.Length);

            var argumentsBuilder = ImmutableArray.CreateBuilder<MultiValue>();
            for (int i = 0; i < Arguments.Length; i++)
                argumentsBuilder.Add(lattice.Meet(Arguments[i], other.Arguments[i]));

            return new TrimAnalysisMethodCallPattern(
                MethodBody,
                Operation,
                Offset,
                CalledMethod,
                lattice.Meet(Instance, other.Instance),
                argumentsBuilder.ToImmutable(),
                Origin);
        }

        public void MarkAndProduceDiagnostics(ReflectionMarker reflectionMarker, Logger logger)
        {
            var diagnosticContext = new DiagnosticContext(
                Origin,
                logger.ShouldSuppressAnalysisWarningsForRequires(Origin.MemberDefinition, DiagnosticUtilities.RequiresUnreferencedCodeAttribute),
                logger.ShouldSuppressAnalysisWarningsForRequires(Origin.MemberDefinition, DiagnosticUtilities.RequiresDynamicCodeAttribute),
                logger.ShouldSuppressAnalysisWarningsForRequires(Origin.MemberDefinition, DiagnosticUtilities.RequiresAssemblyFilesAttribute),
                logger);
            ReflectionMethodBodyScanner.HandleCall(MethodBody, CalledMethod, Operation, Instance, Arguments,
                diagnosticContext,
                reflectionMarker);
        }
    }
}