// 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 Microsoft.CodeAnalysis.Host.Mef;
 
namespace Microsoft.CodeAnalysis.Host
{
    /// <summary>
    /// Per solution services provided by the host environment.
    /// </summary>
    public sealed class SolutionServices
    {
        /// <remarks>
        /// Note: do not expose publicly.  <see cref="HostWorkspaceServices"/> exposes a <see
        /// cref="HostWorkspaceServices.Workspace"/> which we want to avoid doing from our immutable snapshots.
        /// </remarks>
        private readonly HostWorkspaceServices _services;
 
        // This ensures a single instance of this type associated with each HostWorkspaceServices.
        [Obsolete("Do not call directly.  Use HostWorkspaceServices.SolutionServices to acquire an instance")]
        internal SolutionServices(HostWorkspaceServices services)
        {
            _services = services;
        }
 
        [Obsolete("Only use to implement obsolete public API")]
        internal HostWorkspaceServices WorkspaceServices => _services;
 
        internal IMefHostExportProvider ExportProvider => (IMefHostExportProvider)_services.HostServices;
 
        /// <inheritdoc cref="HostWorkspaceServices.GetService"/>
        public TWorkspaceService? GetService<TWorkspaceService>() where TWorkspaceService : IWorkspaceService
            => _services.GetService<TWorkspaceService>();
 
        /// <inheritdoc cref="HostWorkspaceServices.GetRequiredService"/>
        public TWorkspaceService GetRequiredService<TWorkspaceService>() where TWorkspaceService : IWorkspaceService
            => _services.GetRequiredService<TWorkspaceService>();
 
        /// <inheritdoc cref="HostWorkspaceServices.SupportedLanguages"/>
        public IEnumerable<string> SupportedLanguages
            => _services.SupportedLanguages;
 
        /// <inheritdoc cref="HostWorkspaceServices.IsSupported"/>
        public bool IsSupported(string languageName)
            => _services.IsSupported(languageName);
 
        /// <summary>
        /// Gets the <see cref="LanguageServices"/> for the language name.
        /// </summary>
        /// <exception cref="NotSupportedException">Thrown if the language isn't supported.</exception>
        public LanguageServices GetLanguageServices(string languageName)
            => _services.GetLanguageServices(languageName).LanguageServices;
 
        public TLanguageService GetRequiredLanguageService<TLanguageService>(string language) where TLanguageService : ILanguageService
            => this.GetLanguageServices(language).GetRequiredService<TLanguageService>();
 
        internal IEnumerable<T> FindLanguageServices<T>(HostWorkspaceServices.MetadataFilter filter)
            => _services.FindLanguageServices<T>(filter);
    }
}