// 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.IO;
using System.Linq;
using Microsoft.AspNetCore.Testing;
using Xunit;

namespace Microsoft.AspNetCore.Razor.Language
{
    public class FileSystemRazorProjectTest
    {
        private static string TestFolder { get; } = Path.Combine(
            TestProject.GetProjectDirectory(typeof(FileSystemRazorProjectTest)),
            "TestFiles", 
            "FileSystemRazorProject");

        [Theory]
        [InlineData(null)]
        [InlineData("")]
        public void NormalizeAndEnsureValidPath_ThrowsIfPathIsNullOrEmpty(string path)
        {
            // Arrange
            var project = new TestFileSystemRazorProject("C:/some/test/path/root");

            // Act and Assert
            ExceptionAssert.ThrowsArgumentNullOrEmptyString(() => project.NormalizeAndEnsureValidPath(path), "path");
        }

        [Fact]
        public void NormalizeAndEnsureValidPath_NormalizesToAbsolutePath()
        {
            // Arrange
            var project = new TestFileSystemRazorProject("C:/some/test/path/root");

            // Act
            var absolutePath = project.NormalizeAndEnsureValidPath("file.cshtml");

            // Assert
            Assert.Equal("C:/some/test/path/root/file.cshtml", absolutePath);
        }

        [Fact]
        public void NormalizeAndEnsureValidPath_NormalizesToAbsolutePathWithoutForwardSlash()
        {
            // Arrange
            var project = new TestFileSystemRazorProject("C:/some/test/path/root");

            // Act
            var absolutePath = project.NormalizeAndEnsureValidPath("/file.cshtml");

            // Assert
            Assert.Equal("C:/some/test/path/root/file.cshtml", absolutePath);
        }

        [Fact]
        public void NormalizeAndEnsureValidPath_NormalizesToForwardSlashes()
        {
            // Arrange
            var project = new TestFileSystemRazorProject(@"C:\some\test\path\root");

            // Act
            var absolutePath = project.NormalizeAndEnsureValidPath(@"something\file.cshtml");

            // Assert
            Assert.Equal("C:/some/test/path/root/something/file.cshtml", absolutePath);
        }

        [Fact]
        public void EnumerateItems_DiscoversAllCshtmlFiles()
        {
            // Arrange
            var fileSystemProject = new FileSystemRazorProject(TestFolder);

            // Act
            var files = fileSystemProject.EnumerateItems("/");

            // Assert
            Assert.Collection(files.OrderBy(f => f.Path),
                file =>
                {
                    Assert.Equal("/Home.cshtml", file.Path);
                    Assert.Equal("/", file.BasePath);
                },
                file =>
                {
                    Assert.Equal("/Views/About/About.cshtml", file.Path);
                    Assert.Equal("/", file.BasePath);
                },
                file =>
                {
                    Assert.Equal("/Views/Home/Index.cshtml", file.Path);
                    Assert.Equal("/", file.BasePath);
                });
        }

        [Fact]
        public void EnumerateItems_DiscoversAllCshtmlFiles_UnderSpecifiedBasePath()
        {
            // Arrange
            var fileSystemProject = new FileSystemRazorProject(TestFolder);

            // Act
            var files = fileSystemProject.EnumerateItems("/Views");

            // Assert
            Assert.Collection(files.OrderBy(f => f.Path),
                file =>
                {
                    Assert.Equal("/About/About.cshtml", file.Path);
                    Assert.Equal("/Views", file.BasePath);
                },
                file =>
                {
                    Assert.Equal("/Home/Index.cshtml", file.Path);
                    Assert.Equal("/Views", file.BasePath);
                });
        }

        [Fact]
        public void EnumerateItems_ReturnsEmptySequence_WhenBasePathDoesNotExist()
        {
            // Arrange
            var fileSystemProject = new FileSystemRazorProject(TestFolder);

            // Act
            var files = fileSystemProject.EnumerateItems("/Does-Not-Exist");

            // Assert
            Assert.Empty(files);
        }

        [Fact]
        public void GetItem_ReturnsFileFromDisk()
        {
            // Arrange
            var path = "/Views/About/About.cshtml";
            var fileSystemProject = new FileSystemRazorProject(TestFolder);

            // Act
            var file = fileSystemProject.GetItem(path);

            // Assert
            Assert.True(file.Exists);
            Assert.Equal(path, file.Path);
        }

        [Fact]
        public void GetItem_ReturnsNotFoundResult()
        {
            // Arrange
            var path = "/NotFound.cshtml";
            var fileSystemProject = new FileSystemRazorProject(TestFolder);

            // Act
            var file = fileSystemProject.GetItem(path);

            // Assert
            Assert.False(file.Exists);
        }

        private class TestFileSystemRazorProject : FileSystemRazorProject
        {
            public TestFileSystemRazorProject(string root) : base(root)
            {
            }

            public new string NormalizeAndEnsureValidPath(string path) => base.NormalizeAndEnsureValidPath(path);
        }
    }
}
