// 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 System.Collections.Generic;
using System.Collections.Immutable;
using System.Linq;
using System.Threading;
using System.Threading.Tasks;
using Microsoft.CodeAnalysis.CodeActions;
using Microsoft.CodeAnalysis.CodeGeneration;
using Microsoft.CodeAnalysis.GenerateFromMembers;
using Microsoft.CodeAnalysis.Options;
using Microsoft.CodeAnalysis.PickMembers;
using Microsoft.CodeAnalysis.Shared.Extensions;
using Microsoft.CodeAnalysis.Shared.Utilities;
using Microsoft.CodeAnalysis.Text;
using Roslyn.Utilities;
 
namespace Microsoft.CodeAnalysis.GenerateConstructorFromMembers
{
    internal abstract partial class AbstractGenerateConstructorFromMembersCodeRefactoringProvider : AbstractGenerateFromMembersCodeRefactoringProvider
    {
        private class GenerateConstructorWithDialogCodeAction : CodeActionWithOptions
        {
            private readonly Document _document;
            private readonly INamedTypeSymbol _containingType;
            private readonly Accessibility? _desiredAccessibility;
            private readonly AbstractGenerateConstructorFromMembersCodeRefactoringProvider _service;
            private readonly TextSpan _textSpan;
            private readonly CleanCodeGenerationOptionsProvider _fallbackOptions;
 
            internal ImmutableArray<ISymbol> ViableMembers { get; }
            internal ImmutableArray<PickMembersOption> PickMembersOptions { get; }
 
            public override string Title => FeaturesResources.Generate_constructor;
 
            public GenerateConstructorWithDialogCodeAction(
                AbstractGenerateConstructorFromMembersCodeRefactoringProvider service,
                Document document,
                TextSpan textSpan,
                INamedTypeSymbol containingType,
                Accessibility? desiredAccessibility,
                ImmutableArray<ISymbol> viableMembers,
                ImmutableArray<PickMembersOption> pickMembersOptions,
                CleanCodeGenerationOptionsProvider fallbackOptions)
            {
                _service = service;
                _document = document;
                _textSpan = textSpan;
                _containingType = containingType;
                _desiredAccessibility = desiredAccessibility;
                ViableMembers = viableMembers;
                PickMembersOptions = pickMembersOptions;
                _fallbackOptions = fallbackOptions;
            }
 
            public override object GetOptions(CancellationToken cancellationToken)
            {
                var service = _service._pickMembersService_forTesting ?? _document.Project.Solution.Services.GetRequiredService<IPickMembersService>();
 
                return service.PickMembers(
                    FeaturesResources.Pick_members_to_be_used_as_constructor_parameters,
                    ViableMembers, PickMembersOptions);
            }
 
            protected override async Task<IEnumerable<CodeActionOperation>> ComputeOperationsAsync(
                object options, CancellationToken cancellationToken)
            {
                var result = (PickMembersResult)options;
                if (result.IsCanceled)
                {
                    return SpecializedCollections.EmptyEnumerable<CodeActionOperation>();
                }
 
                var addNullChecksOption = result.Options.FirstOrDefault(o => o.Id == AddNullChecksId);
                if (addNullChecksOption != null)
                {
                    // If we presented the 'Add null check' option, then persist whatever value
                    // the user chose.  That way we'll keep that as the default for the next time
                    // the user opens the dialog.
                    var globalOptions = _document.Project.Solution.Services.GetRequiredService<ILegacyGlobalOptionsWorkspaceService>();
                    globalOptions.SetGenerateEqualsAndGetHashCodeFromMembersGenerateOperators(_document.Project.Language, addNullChecksOption.Value);
                }
 
                var addNullChecks = (addNullChecksOption?.Value ?? false);
                var state = await State.TryGenerateAsync(
                    _service, _document, _textSpan, _containingType, _desiredAccessibility,
                    result.Members, _fallbackOptions, cancellationToken).ConfigureAwait(false);
 
                if (state == null)
                {
                    return SpecializedCollections.EmptyEnumerable<CodeActionOperation>();
                }
 
                // There was an existing constructor that matched what the user wants to create.
                // Generate it if it's the implicit, no-arg, constructor, otherwise just navigate
                // to the existing constructor
                var solution = _document.Project.Solution;
                if (state.MatchingConstructor != null)
                {
                    if (state.MatchingConstructor.IsImplicitlyDeclared)
                    {
                        var codeAction = new FieldDelegatingCodeAction(_service, _document, state, addNullChecks, _fallbackOptions);
                        return await codeAction.GetOperationsAsync(solution, new ProgressTracker(), cancellationToken).ConfigureAwait(false);
                    }
 
                    var constructorReference = state.MatchingConstructor.DeclaringSyntaxReferences[0];
                    var constructorSyntax = await constructorReference.GetSyntaxAsync(cancellationToken).ConfigureAwait(false);
                    var constructorTree = constructorSyntax.SyntaxTree;
                    var constructorDocument = solution.GetRequiredDocument(constructorTree);
                    return ImmutableArray.Create<CodeActionOperation>(new DocumentNavigationOperation(
                        constructorDocument.Id, constructorSyntax.SpanStart));
                }
                else
                {
                    var codeAction = state.DelegatedConstructor != null
                        ? new ConstructorDelegatingCodeAction(_service, _document, state, addNullChecks, _fallbackOptions)
                        : (CodeAction)new FieldDelegatingCodeAction(_service, _document, state, addNullChecks, _fallbackOptions);
 
                    return await codeAction.GetOperationsAsync(solution, new ProgressTracker(), cancellationToken).ConfigureAwait(false);
                }
            }
        }
    }
}