// Copyright (c) .NET Foundation. All rights reserved.
// Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.

using System;
using System.Collections.Generic;
using Microsoft.CodeAnalysis;
using Microsoft.CodeAnalysis.Razor;
using Microsoft.CodeAnalysis.Razor.Editor;
using Microsoft.CodeAnalysis.Razor.ProjectSystem;
using Microsoft.VisualStudio.Text;
using Microsoft.VisualStudio.Text.Editor;
using Microsoft.VisualStudio.Utilities;
using Moq;
using Xunit;

namespace Microsoft.VisualStudio.Editor.Razor
{
    public class DefaultVisualStudioDocumentTrackerTest : ForegroundDispatcherTestBase
    {
        private IContentType RazorCoreContentType { get; } = Mock.Of<IContentType>(c => c.IsOfType(RazorLanguage.CoreContentType) == true);

        private ITextBuffer TextBuffer => Mock.Of<ITextBuffer>(b => b.ContentType == RazorCoreContentType);

        private string FilePath => "C:/Some/Path/TestDocumentTracker.cshtml";

        private string ProjectPath => "C:/Some/Path/TestProject.csproj";

        private ProjectSnapshotManager ProjectManager => Mock.Of<ProjectSnapshotManager>(p => p.Projects == new List<ProjectSnapshot>());

        private EditorSettingsManagerInternal EditorSettingsManager => new DefaultEditorSettingsManagerInternal(Dispatcher);

        private Workspace Workspace => TestWorkspace.Create();

        private ImportDocumentManager ImportDocumentManager => Mock.Of<ImportDocumentManager>();

        [Fact]
        public void EditorSettingsManager_Changed_TriggersContextChanged()
        {
            // Arrange
            var documentTracker = new DefaultVisualStudioDocumentTracker(Dispatcher, FilePath, ProjectPath, ProjectManager, EditorSettingsManager, Workspace, TextBuffer, ImportDocumentManager);
            var called = false;
            documentTracker.ContextChanged += (sender, args) =>
            {
                Assert.Equal(ContextChangeKind.EditorSettingsChanged, args.Kind);
                called = true;
                Assert.Equal(ContextChangeKind.EditorSettingsChanged, args.Kind);
            };

            // Act
            documentTracker.EditorSettingsManager_Changed(null, null);

            // Assert
            Assert.True(called);
        }

        [Fact]
        public void ProjectManager_Changed_ProjectChanged_TriggersContextChanged()
        {
            // Arrange
            Project project = null;
            var workspace = TestWorkspace.Create(ws =>
            {
                project = ws.AddProject(ProjectInfo.Create(ProjectId.CreateNewId(), new VersionStamp(), "Test1", "TestAssembly", LanguageNames.CSharp, filePath: "C:/Some/Path/TestProject.csproj"));
            });
            var documentTracker = new DefaultVisualStudioDocumentTracker(Dispatcher, FilePath, ProjectPath, ProjectManager, EditorSettingsManager, workspace, TextBuffer, ImportDocumentManager);

            var projectSnapshot = new DefaultProjectSnapshot(project);
            var projectChangedArgs = new ProjectChangeEventArgs(projectSnapshot, ProjectChangeKind.Changed);

            var called = false;
            documentTracker.ContextChanged += (sender, args) =>
            {
                Assert.Equal(ContextChangeKind.ProjectChanged, args.Kind);
                called = true;
            };

            // Act
            documentTracker.ProjectManager_Changed(null, projectChangedArgs);

            // Assert
            Assert.True(called);
        }

        [Fact]
        public void ProjectManager_Changed_TagHelpersChanged_TriggersContextChanged()
        {
            // Arrange
            Project project = null;
            var workspace = TestWorkspace.Create(ws =>
            {
                project = ws.AddProject(ProjectInfo.Create(ProjectId.CreateNewId(), new VersionStamp(), "Test1", "TestAssembly", LanguageNames.CSharp, filePath: "C:/Some/Path/TestProject.csproj"));
            });
            var documentTracker = new DefaultVisualStudioDocumentTracker(Dispatcher, FilePath, ProjectPath, ProjectManager, EditorSettingsManager, workspace, TextBuffer, ImportDocumentManager);

            var projectSnapshot = new DefaultProjectSnapshot(project);
            var projectChangedArgs = new ProjectChangeEventArgs(projectSnapshot, ProjectChangeKind.TagHelpersChanged);

            var called = false;
            documentTracker.ContextChanged += (sender, args) =>
            {
                Assert.Equal(ContextChangeKind.TagHelpersChanged, args.Kind);
                called = true;
            };

            // Act
            documentTracker.ProjectManager_Changed(null, projectChangedArgs);

            // Assert
            Assert.True(called);
        }

        [Fact]
        public void ProjectManager_Changed_IgnoresUnknownProject()
        {
            // Arrange
            Project project = null;
            var workspace = TestWorkspace.Create(ws =>
            {
                project = ws.AddProject(ProjectInfo.Create(ProjectId.CreateNewId(), new VersionStamp(), "Test1", "TestAssembly", LanguageNames.CSharp, filePath: "C:/Some/Other/Path/TestProject.csproj"));
            });
            var documentTracker = new DefaultVisualStudioDocumentTracker(Dispatcher, FilePath, ProjectPath, ProjectManager, EditorSettingsManager, workspace, TextBuffer, ImportDocumentManager);

            var projectSnapshot = new DefaultProjectSnapshot(project);
            var projectChangedArgs = new ProjectChangeEventArgs(projectSnapshot, ProjectChangeKind.Changed);

            var called = false;
            documentTracker.ContextChanged += (sender, args) =>
            {
                called = true;
            };

            // Act
            documentTracker.ProjectManager_Changed(null, projectChangedArgs);

            // Assert
            Assert.False(called);
        }

        [Fact]
        public void Import_Changed_ImportAssociatedWithDocument_TriggersContextChanged()
        {
            // Arrange
            var documentTracker = new DefaultVisualStudioDocumentTracker(Dispatcher, FilePath, ProjectPath, ProjectManager, EditorSettingsManager, Workspace, TextBuffer, ImportDocumentManager);

            var called = false;
            documentTracker.ContextChanged += (sender, args) =>
            {
                Assert.Equal(ContextChangeKind.ImportsChanged, args.Kind);
                called = true;
            };

            var importChangedArgs = new ImportChangedEventArgs("path/to/import", FileChangeKind.Changed, new[] { FilePath });

            // Act
            documentTracker.Import_Changed(null, importChangedArgs);

            // Assert
            Assert.True(called);
        }

        [Fact]
        public void Import_Changed_UnrelatedImport_DoesNothing()
        {
            // Arrange
            var documentTracker = new DefaultVisualStudioDocumentTracker(Dispatcher, FilePath, ProjectPath, ProjectManager, EditorSettingsManager, Workspace, TextBuffer, ImportDocumentManager);

            documentTracker.ContextChanged += (sender, args) =>
            {
                throw new InvalidOperationException();
            };

            var importChangedArgs = new ImportChangedEventArgs("path/to/import", FileChangeKind.Changed, new[] { "path/to/differentfile" });

            // Act & Assert (Does not throw)
            documentTracker.Import_Changed(null, importChangedArgs);
        }

        [Fact]
        public void Subscribe_SetsSupportedProjectAndTriggersContextChanged()
        {
            // Arrange
            var documentTracker = new DefaultVisualStudioDocumentTracker(Dispatcher, FilePath, ProjectPath, ProjectManager, EditorSettingsManager, Workspace, TextBuffer, ImportDocumentManager);
            var called = false;
            documentTracker.ContextChanged += (sender, args) =>
            {
                called = true;
                Assert.Equal(ContextChangeKind.ProjectChanged, args.Kind);
            };

            // Act
            documentTracker.Subscribe();

            // Assert
            Assert.True(called);
            Assert.True(documentTracker.IsSupportedProject);
        }

        [Fact]
        public void Unsubscribe_ResetsSupportedProjectAndTriggersContextChanged()
        {
            // Arrange
            var documentTracker = new DefaultVisualStudioDocumentTracker(Dispatcher, FilePath, ProjectPath, ProjectManager, EditorSettingsManager, Workspace, TextBuffer, ImportDocumentManager);

            // Subscribe once to set supported project
            documentTracker.Subscribe();

            var called = false;
            documentTracker.ContextChanged += (sender, args) =>
            {
                called = true;
                Assert.Equal(ContextChangeKind.ProjectChanged, args.Kind);
            };

            // Act
            documentTracker.Unsubscribe();

            // Assert
            Assert.False(documentTracker.IsSupportedProject);
            Assert.True(called);
        }

        [Fact]
        public void AddTextView_AddsToTextViewCollection()
        {
            // Arrange
            var documentTracker = new DefaultVisualStudioDocumentTracker(Dispatcher, FilePath, ProjectPath, ProjectManager, EditorSettingsManager, Workspace, TextBuffer, ImportDocumentManager);
            var textView = Mock.Of<ITextView>();

            // Act
            documentTracker.AddTextView(textView);

            // Assert
            Assert.Collection(documentTracker.TextViews, v => Assert.Same(v, textView));
        }

        [Fact]
        public void AddTextView_DoesNotAddDuplicateTextViews()
        {
            // Arrange
            var documentTracker = new DefaultVisualStudioDocumentTracker(Dispatcher, FilePath, ProjectPath, ProjectManager, EditorSettingsManager, Workspace, TextBuffer, ImportDocumentManager);
            var textView = Mock.Of<ITextView>();

            // Act
            documentTracker.AddTextView(textView);
            documentTracker.AddTextView(textView);

            // Assert
            Assert.Collection(documentTracker.TextViews, v => Assert.Same(v, textView));
        }

        [Fact]
        public void AddTextView_AddsMultipleTextViewsToCollection()
        {
            // Arrange
            var documentTracker = new DefaultVisualStudioDocumentTracker(Dispatcher, FilePath, ProjectPath, ProjectManager, EditorSettingsManager, Workspace, TextBuffer, ImportDocumentManager);
            var textView1 = Mock.Of<ITextView>();
            var textView2 = Mock.Of<ITextView>();

            // Act
            documentTracker.AddTextView(textView1);
            documentTracker.AddTextView(textView2);

            // Assert
            Assert.Collection(
                documentTracker.TextViews,
                v => Assert.Same(v, textView1),
                v => Assert.Same(v, textView2));
        }

        [Fact]
        public void RemoveTextView_RemovesTextViewFromCollection_SingleItem()
        {
            // Arrange
            var documentTracker = new DefaultVisualStudioDocumentTracker(Dispatcher, FilePath, ProjectPath, ProjectManager, EditorSettingsManager, Workspace, TextBuffer, ImportDocumentManager);
            var textView = Mock.Of<ITextView>();
            documentTracker.AddTextView(textView);

            // Act
            documentTracker.RemoveTextView(textView);

            // Assert
            Assert.Empty(documentTracker.TextViews);
        }

        [Fact]
        public void RemoveTextView_RemovesTextViewFromCollection_MultipleItems()
        {
            // Arrange
            var documentTracker = new DefaultVisualStudioDocumentTracker(Dispatcher, FilePath, ProjectPath, ProjectManager, EditorSettingsManager, Workspace, TextBuffer, ImportDocumentManager);
            var textView1 = Mock.Of<ITextView>();
            var textView2 = Mock.Of<ITextView>();
            var textView3 = Mock.Of<ITextView>();
            documentTracker.AddTextView(textView1);
            documentTracker.AddTextView(textView2);
            documentTracker.AddTextView(textView3);

            // Act
            documentTracker.RemoveTextView(textView2);

            // Assert
            Assert.Collection(
                documentTracker.TextViews,
                v => Assert.Same(v, textView1),
                v => Assert.Same(v, textView3));
        }

        [Fact]
        public void RemoveTextView_NoopsWhenRemovingTextViewNotInCollection()
        {
            // Arrange
            var documentTracker = new DefaultVisualStudioDocumentTracker(Dispatcher, FilePath, ProjectPath, ProjectManager, EditorSettingsManager, Workspace, TextBuffer, ImportDocumentManager);
            var textView1 = Mock.Of<ITextView>();
            documentTracker.AddTextView(textView1);
            var textView2 = Mock.Of<ITextView>();

            // Act
            documentTracker.RemoveTextView(textView2);

            // Assert
            Assert.Collection(documentTracker.TextViews, v => Assert.Same(v, textView1));
        }
    }
}