// 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 Microsoft.AspNetCore.Razor.Language;
using Microsoft.AspNetCore.Razor.Language.Intermediate;
using Xunit;

namespace Microsoft.AspNetCore.Mvc.Razor.Extensions
{
    public class MvcViewDocumentClassifierPassTest
    {
        [Fact]
        public void MvcViewDocumentClassifierPass_SetsDocumentKind()
        {
            // Arrange
            var codeDocument = RazorCodeDocument.Create(RazorSourceDocument.Create("some-content", "Test.cshtml"));

            var engine = CreateEngine();
            var irDocument = CreateIRDocument(engine, codeDocument);
            var pass = new MvcViewDocumentClassifierPass
            {
                Engine = engine
            };

            // Act
            pass.Execute(codeDocument, irDocument);

            // Assert
            Assert.Equal("mvc.1.0.view", irDocument.DocumentKind);
        }

        [Fact]
        public void MvcViewDocumentClassifierPass_NoOpsIfDocumentKindIsAlreadySet()
        {
            // Arrange
            var codeDocument = RazorCodeDocument.Create(RazorSourceDocument.Create("some-content", "Test.cshtml"));

            var engine = CreateEngine();
            var irDocument = CreateIRDocument(engine, codeDocument);
            irDocument.DocumentKind = "some-value";
            var pass = new MvcViewDocumentClassifierPass
            {
                Engine = engine
            };

            // Act
            pass.Execute(codeDocument, irDocument);

            // Assert
            Assert.Equal("some-value", irDocument.DocumentKind);
        }

        [Fact]
        public void MvcViewDocumentClassifierPass_SetsNamespace()
        {
            // Arrange
            var codeDocument = RazorCodeDocument.Create(RazorSourceDocument.Create("some-content", "Test.cshtml"));

            var engine = CreateEngine();
            var irDocument = CreateIRDocument(engine, codeDocument);
            var pass = new MvcViewDocumentClassifierPass
            {
                Engine = engine
            };

            // Act
            pass.Execute(codeDocument, irDocument);
            var visitor = new Visitor();
            visitor.Visit(irDocument);

            // Assert
            Assert.Equal("AspNetCore", visitor.Namespace.Content);
        }

        [Fact]
        public void MvcViewDocumentClassifierPass_SetsClass()
        {
            // Arrange
            var properties = new RazorSourceDocumentProperties(filePath: "ignored", relativePath: "Test.cshtml");
            var codeDocument = RazorCodeDocument.Create(RazorSourceDocument.Create("some-content", properties));

            var engine = CreateEngine();
            var irDocument = CreateIRDocument(engine, codeDocument);
            var pass = new MvcViewDocumentClassifierPass
            {
                Engine = engine
            };

            // Act
            pass.Execute(codeDocument, irDocument);
            var visitor = new Visitor();
            visitor.Visit(irDocument);

            // Assert
            Assert.Equal("global::Microsoft.AspNetCore.Mvc.Razor.RazorPage<TModel>", visitor.Class.BaseType);
            Assert.Equal(new[] { "public" }, visitor.Class.Modifiers);
            Assert.Equal("Test", visitor.Class.ClassName);
        }

        [Theory]
        [InlineData("/Views/Home/Index.cshtml", "_Views_Home_Index")]
        [InlineData("/Areas/MyArea/Views/Home/About.cshtml", "_Areas_MyArea_Views_Home_About")]
        public void MvcViewDocumentClassifierPass_UsesRelativePathToGenerateTypeName(string relativePath, string expected)
        {
            // Arrange
            var properties = new RazorSourceDocumentProperties(filePath: "ignored", relativePath: relativePath);
            var codeDocument = RazorCodeDocument.Create(RazorSourceDocument.Create("some-content", properties));

            var engine = CreateEngine();
            var irDocument = CreateIRDocument(engine, codeDocument);
            var pass = new MvcViewDocumentClassifierPass
            {
                Engine = engine
            };

            // Act
            pass.Execute(codeDocument, irDocument);
            var visitor = new Visitor();
            visitor.Visit(irDocument);

            // Assert
            Assert.Equal(expected, visitor.Class.ClassName);
        }

        [Fact]
        public void MvcViewDocumentClassifierPass_UsesAbsolutePath_IfRelativePathIsNotSet()
        {
            // Arrange
            var properties = new RazorSourceDocumentProperties(filePath: @"x::\application\Views\Home\Index.cshtml", relativePath: null);
            var codeDocument = RazorCodeDocument.Create(RazorSourceDocument.Create("some-content", properties));

            var engine = CreateEngine();
            var irDocument = CreateIRDocument(engine, codeDocument);
            var pass = new MvcViewDocumentClassifierPass
            {
                Engine = engine
            };

            // Act
            pass.Execute(codeDocument, irDocument);
            var visitor = new Visitor();
            visitor.Visit(irDocument);

            // Assert
            Assert.Equal("x___application_Views_Home_Index", visitor.Class.ClassName);
        }

        [Fact]
        public void MvcViewDocumentClassifierPass_SanitizesClassName()
        {
            // Arrange
            var properties = new RazorSourceDocumentProperties(filePath: @"x:\Test.cshtml", relativePath: "path.with+invalid-chars");
            var codeDocument = RazorCodeDocument.Create(RazorSourceDocument.Create("@page", properties));

            var engine = CreateEngine();
            var irDocument = CreateIRDocument(engine, codeDocument);
            var pass = new MvcViewDocumentClassifierPass
            {
                Engine = engine
            };

            // Act
            pass.Execute(codeDocument, irDocument);
            var visitor = new Visitor();
            visitor.Visit(irDocument);

            // Assert
            Assert.Equal("path_with_invalid_chars", visitor.Class.ClassName);
        }

        [Fact]
        public void MvcViewDocumentClassifierPass_SetsUpExecuteAsyncMethod()
        {
            // Arrange
            var codeDocument = RazorCodeDocument.Create(RazorSourceDocument.Create("some-content", "Test.cshtml"));

            var engine = CreateEngine();
            var irDocument = CreateIRDocument(engine, codeDocument);
            var pass = new MvcViewDocumentClassifierPass
            {
                Engine = engine
            };

            // Act
            pass.Execute(codeDocument, irDocument);
            var visitor = new Visitor();
            visitor.Visit(irDocument);

            // Assert
            Assert.Equal("ExecuteAsync", visitor.Method.MethodName);
            Assert.Equal("global::System.Threading.Tasks.Task", visitor.Method.ReturnType);
            Assert.Equal(new[] { "public", "async", "override" }, visitor.Method.Modifiers);
        }

        private static RazorEngine CreateEngine() => RazorEngine.Create();

        private static DocumentIntermediateNode CreateIRDocument(RazorEngine engine, RazorCodeDocument codeDocument)
        {
            for (var i = 0; i < engine.Phases.Count; i++)
            {
                var phase = engine.Phases[i];
                phase.Execute(codeDocument);

                if (phase is IRazorIntermediateNodeLoweringPhase)
                {
                    break;
                }
            }

            return codeDocument.GetDocumentIntermediateNode();
        }

        private class Visitor : IntermediateNodeWalker
        {
            public NamespaceDeclarationIntermediateNode Namespace { get; private set; }

            public ClassDeclarationIntermediateNode Class { get; private set; }

            public MethodDeclarationIntermediateNode Method { get; private set; }

            public override void VisitMethodDeclaration(MethodDeclarationIntermediateNode node)
            {
                Method = node;
            }

            public override void VisitNamespaceDeclaration(NamespaceDeclarationIntermediateNode node)
            {
                Namespace = node;
                base.VisitNamespaceDeclaration(node);
            }

            public override void VisitClassDeclaration(ClassDeclarationIntermediateNode node)
            {
                Class = node;
                base.VisitClassDeclaration(node);
            }
        }
    }
}