﻿// 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.

#nullable disable

using System.Collections.Generic;
using System.Collections.Immutable;
using System.Linq;
using Microsoft.CodeAnalysis.PooledObjects;
using Microsoft.CodeAnalysis;
using Microsoft.VisualStudio.Language.Intellisense;
using Microsoft.VisualStudio.Shell.Interop;

namespace Microsoft.VisualStudio.LanguageServices.Implementation.Preview
{
    internal abstract partial class ReferenceChange : AbstractChange
    {
        private readonly ProjectId _projectId;
        private readonly string _projectName;
        private readonly bool _isAddedReference;

        protected ReferenceChange(ProjectId projectId, string projectName, bool isAddedReference, PreviewEngine engine)
            : base(engine)
        {
            _projectId = projectId;
            _projectName = projectName;
            _isAddedReference = isAddedReference;
        }

        public static void AppendReferenceChanges(IEnumerable<ProjectChanges> projectChangesList, PreviewEngine engine, ArrayBuilder<AbstractChange> builder)
        {
            foreach (var projectChanges in projectChangesList)
            {
                var projectId = projectChanges.ProjectId;
                var oldSolution = projectChanges.OldProject.Solution;
                var newSolution = projectChanges.NewProject.Solution;
                var projectName = oldSolution.GetProject(projectId).Name;

                // Metadata references
                var addedMetadataReferenceChanges = projectChanges
                    .GetAddedMetadataReferences()
                    .Select(r => new MetadataReferenceChange(r, projectId, projectName, isAdded: true, engine: engine));
                builder.AddRange(addedMetadataReferenceChanges);

                var removedMetadataReferenceChanges = projectChanges
                    .GetRemovedMetadataReferences()
                    .Select(r => new MetadataReferenceChange(r, projectId, projectName, isAdded: false, engine: engine));
                builder.AddRange(removedMetadataReferenceChanges);

                // Project references
                var addedProjectReferenceChanges = projectChanges
                    .GetAddedProjectReferences()
                    .Select(r => new ProjectReferenceChange(r, newSolution.GetProject(r.ProjectId).Name, projectId, projectName, isAdded: true, engine: engine));
                builder.AddRange(addedProjectReferenceChanges);

                var removedProjectReferenceChanges = projectChanges
                    .GetRemovedProjectReferences()
                    .Select(r => new ProjectReferenceChange(r, oldSolution.GetProject(r.ProjectId).Name, projectId, projectName, isAdded: false, engine: engine));
                builder.AddRange(removedProjectReferenceChanges);

                // Analyzer references
                var addedAnalyzerReferenceChanges = projectChanges
                    .GetAddedAnalyzerReferences()
                    .Select(r => new AnalyzerReferenceChange(r, projectId, projectName, isAdded: true, engine: engine));
                builder.AddRange(addedAnalyzerReferenceChanges);

                var removedAnalyzerReferenceChanges = projectChanges
                    .GetRemovedAnalyzerReferences()
                    .Select(r => new AnalyzerReferenceChange(r, projectId, projectName, isAdded: false, engine: engine));
                builder.AddRange(removedAnalyzerReferenceChanges);
            }
        }

        protected ProjectId ProjectId { get { return _projectId; } }
        internal bool IsAddedReference { get { return _isAddedReference; } }
        protected string ProjectName { get { return _projectName; } }

        protected abstract string GetDisplayText();
        internal abstract Solution AddToSolution(Solution solution);
        internal abstract Solution RemoveFromSolution(Solution solution);

        public override int GetText(out VSTREETEXTOPTIONS tto, out string pbstrText)
        {
            var displayText = GetDisplayText();
            if (IsAddedReference)
            {
                pbstrText = ServicesVSResources.bracket_plus_bracket + displayText;
            }
            else
            {
                pbstrText = ServicesVSResources.bracket_bracket + displayText;
            }

            tto = VSTREETEXTOPTIONS.TTO_DEFAULT;
            return VSConstants.S_OK;
        }

        public sealed override int GetTipText(out VSTREETOOLTIPTYPE eTipType, out string pbstrText)
        {
            eTipType = VSTREETOOLTIPTYPE.TIPTYPE_DEFAULT;
            pbstrText = null;
            return VSConstants.E_FAIL;
        }

        public sealed override int OnRequestSource(object pIUnknownTextView)
        {
            // When adding a project reference `Children` can be null, so check before looking at `Changes`
            if (pIUnknownTextView != null && Children?.Changes != null && Children.Changes.Length > 0)
            {
                engine.SetTextView(pIUnknownTextView);
                UpdatePreview();
            }

            return VSConstants.S_OK;
        }

        public sealed override void UpdatePreview()
        {
            // Don't need any preview updates for reference changes.
        }

        internal sealed override void GetDisplayData(VSTREEDISPLAYDATA[] pData)
            => pData[0].Image = pData[0].SelectedImage = (ushort)StandardGlyphGroup.GlyphReference;
    }
}
