// 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;
using System.Collections.Generic;
using System.Collections.Immutable;
using System.Threading;
using System.Threading.Tasks;
using Microsoft.CodeAnalysis.Options;
using Microsoft.CodeAnalysis.Shared.Extensions;
using Microsoft.CodeAnalysis.Shared.Extensions.ContextQuery;
 
namespace Microsoft.CodeAnalysis.Recommendations
{
    public static class Recommender
    {
        [Obsolete("Use GetRecommendedSymbolsAtPositionAsync(Document, ...)")]
        public static IEnumerable<ISymbol> GetRecommendedSymbolsAtPosition(
            SemanticModel semanticModel,
            int position,
            Workspace workspace,
            OptionSet? options = null,
            CancellationToken cancellationToken = default)
        {
            var solution = workspace.CurrentSolution;
            var document = solution.GetRequiredDocument(semanticModel.SyntaxTree);
            var context = document.GetRequiredLanguageService<ISyntaxContextService>().CreateContext(document, semanticModel, position, cancellationToken);
 
            var languageRecommender = document.GetRequiredLanguageService<IRecommendationService>();
            return languageRecommender.GetRecommendedSymbolsInContext(context, GetOptions(options, document.Project), cancellationToken).NamedSymbols;
        }
 
        [Obsolete("Use GetRecommendedSymbolsAtPositionAsync(Document, ...)")]
        public static Task<IEnumerable<ISymbol>> GetRecommendedSymbolsAtPositionAsync(
             SemanticModel semanticModel,
             int position,
             Workspace workspace,
             OptionSet? options = null,
             CancellationToken cancellationToken = default)
        {
            return Task.FromResult(GetRecommendedSymbolsAtPosition(semanticModel, position, workspace, options, cancellationToken));
        }
 
        public static async Task<ImmutableArray<ISymbol>> GetRecommendedSymbolsAtPositionAsync(
            Document document,
            int position,
            OptionSet? options = null,
            CancellationToken cancellationToken = default)
        {
            var semanticModel = await document.GetRequiredSemanticModelAsync(cancellationToken).ConfigureAwait(false);
            var context = document.GetRequiredLanguageService<ISyntaxContextService>().CreateContext(document, semanticModel, position, cancellationToken);
            var languageRecommender = document.GetRequiredLanguageService<IRecommendationService>();
            return languageRecommender.GetRecommendedSymbolsInContext(context, GetOptions(options, document.Project), cancellationToken).NamedSymbols;
        }
 
#pragma warning disable RS0030 // Do not used banned APIs: RecommendationOptions
        private static RecommendationServiceOptions GetOptions(OptionSet? options, Project project)
        {
            options ??= project.Solution.Options;
            var language = project.Language;
 
            return new RecommendationServiceOptions()
            {
                HideAdvancedMembers = options.GetOption(RecommendationOptions.HideAdvancedMembers, language),
                FilterOutOfScopeLocals = options.GetOption(RecommendationOptions.FilterOutOfScopeLocals, language),
            };
        }
#pragma warning restore
    }
}