using System;

using System.Collections.Generic;

using System.IO;

using System.Linq;

using NUnitLite;

using NUnit.Framework;

​

public class VideoFileSearcher

{

    /// <summary>

    /// Searches a directory and its subdirectories for video files.

    /// </summary>

    /// <param name="directoryPath">The path to the directory to search.</param>

    /// <returns>A list of strings, where each string is the full path to a video file.</returns>

    public static List<string> FindVideoFiles(string directoryPath)

    {

        List<string> videoFiles = new List<string>();

        string[] videoExtensions = { ".mp4", ".avi", ".mov", ".wmv", ".flv" };

​

        try

        {

            if (!Directory.Exists(directoryPath))

            {

                Console.WriteLine($"Error: Directory not found: {directoryPath}");

                return new List<string>(); // Return empty list if directory doesn't exist

            }

​

            // Get all files in the directory and its subdirectories

            string[] allFiles = Directory.GetFiles(directoryPath, "*.*", SearchOption.AllDirectories);

​

            // Filter files based on video extensions

            foreach (string file in allFiles)

            {

                if (videoExtensions.Contains(Path.GetExtension(file).ToLower()))

                {

                    videoFiles.Add(file);

                }

            }

        }

        catch (Exception ex)

        {

            Console.WriteLine($"Error: An exception occurred: {ex.Message}");

            return new List<string>(); // Return empty list in case of an exception

        }

​

        return videoFiles;

    }

    public static void CreateDirectory(string folderPath)

    {

        try

        {

            // Create the folder if it does not exist

            if (!Directory.Exists(folderPath))

            {

                Directory.CreateDirectory(folderPath);

                Console.WriteLine("Folder created: " + folderPath);

            }

            else

            {

                Console.WriteLine("Folder already exists: " + folderPath);

            }

        }

        catch (Exception ex)

        {

            Console.WriteLine("Error creating folder: " + ex.Message);

        }

    }

    public static int Main(string[] args)

    {

        return new AutoRun().Execute(args);

    }

}   

​

[TestFixture]

public class VideoFileSearcherTests

{

    private string _testDirectory;

​

    [SetUp]

    public void Setup()

    {

        // Create a temporary directory for testing

        _testDirectory = Path.Combine(Path.GetTempPath(), Guid.NewGuid().ToString());

        Directory.CreateDirectory(_testDirectory);

​

        // Create some dummy files

        File.WriteAllText(Path.Combine(_testDirectory, "test1.mp4"), "dummy content");

        File.WriteAllText(Path.Combine(_testDirectory, "test2.avi"), "dummy content");

        File.WriteAllText(Path.Combine(_testDirectory, "test3.txt"), "dummy content");

​

        // Create a subdirectory and add a video file there

        string subDirectory = Path.Combine(_testDirectory, "subdir");

        Directory.CreateDirectory(subDirectory);

        File.WriteAllText(Path.Combine(subDirectory, "test4.mov"), "dummy content");

    }

​

    [TearDown]

    public void TearDown()

    {

        // Delete the temporary directory and its contents

        if (Directory.Exists(_testDirectory))

        {

            Directory.Delete(_testDirectory, true);

        }

    }

​

    [Test]

    public void FindVideoFiles_ValidDirectory_ReturnsListOfVideoFiles()

    {

        // Act

        List<string> videoFiles = VideoFileSearcher.FindVideoFiles(_testDirectory);

​

        // Assert

        Assert.AreEqual(3, videoFiles.Count);

        Assert.IsTrue(videoFiles.Any(f => Path.GetFileName(f) == "test1.mp4"));

        Assert.IsTrue(videoFiles.Any(f => Path.GetFileName(f) == "test2.avi"));

        Assert.IsTrue(videoFiles.Any(f => Path.GetFileName(f) == "test4.mov"));

    }

​

    [Test]

    public void FindVideoFiles_DirectoryNotFound_ReturnsEmptyList()

    {

        // Arrange

        string nonExistentDirectory = Path.Combine(Path.GetTempPath(), Guid.NewGuid().ToString());

​

        // Act

        List<string> videoFiles = VideoFileSearcher.FindVideoFiles(nonExistentDirectory);

​

        // Assert

        Assert.IsEmpty(videoFiles);

    }

​

    [Test]

    public void FindVideoFiles_NoVideoFiles_ReturnsEmptyList()

    {

        // Arrange

        string emptyDirectory = Path.Combine(Path.GetTempPath(), Guid.NewGuid().ToString());

        Directory.CreateDirectory(emptyDirectory);

​

        // Act

        List<string> videoFiles = VideoFileSearcher.FindVideoFiles(emptyDirectory);

​

        // Assert

        Assert.IsEmpty(videoFiles);

​

        // Cleanup

        Directory.Delete(emptyDirectory);

    }

​

    [Test]

    public void FindVideoFiles_EmptyDirectoryPath_ReturnsEmptyList()

    {

        // Arrange

        string emptyDirectoryPath = "";

​

        // Act

        List<string> videoFiles = VideoFileSearcher.FindVideoFiles(emptyDirectoryPath);

​

        // Assert

        Assert.IsEmpty(videoFiles);

    }

​

     [Test]

    public void FindVideoFiles_DirectoryWithMixedCaseExtensions_ReturnsListOfVideoFiles()

    {

        // Arrange

        string mixedCaseDirectory = Path.Combine(Path.GetTempPath(), Guid.NewGuid().ToString());

        Directory.CreateDirectory(mixedCaseDirectory);

​

        // Create files with mixed case extensions

        File.WriteAllText(Path.Combine(mixedCaseDirectory, "test.Mp4"), "dummy content");

        File.WriteAllText(Path.Combine(mixedCaseDirectory, "test.aVi"), "dummy content");

        File.WriteAllText(Path.Combine(mixedCaseDirectory, "test.MOV"), "dummy content");

​

        // Act

        List<string> videoFiles = VideoFileSearcher.FindVideoFiles(mixedCaseDirectory);

​

        // Assert

        Assert.AreEqual(3, videoFiles.Count);

        Assert.IsTrue(videoFiles.Any(f => Path.GetFileName(f) == "test.Mp4"));

        Assert.IsTrue(videoFiles.Any(f => Path.GetFileName(f) == "test.aVi"));

        Assert.IsTrue(videoFiles.Any(f => Path.GetFileName(f) == "test.MOV"));

​

         // Cleanup

        Directory.Delete(mixedCaseDirectory, true);

    }

}