using System.IO.Compression;
using System.Text;
using StellaOps.Scanner.Analyzers.Lang.Python.Internal;

namespace StellaOps.Scanner.Analyzers.Lang.Python.Tests.Container;

public sealed class PythonZipappAdapterTests : IDisposable
{
    private readonly string _tempDir;

    public PythonZipappAdapterTests()
    {
        _tempDir = Path.Combine(Path.GetTempPath(), $"zipapp-tests-{Guid.NewGuid():N}");
        Directory.CreateDirectory(_tempDir);
    }

    public void Dispose()
    {
        try
        {
            Directory.Delete(_tempDir, recursive: true);
        }
        catch
        {
            // Ignore cleanup errors
        }
    }

    [Fact]
    public void DiscoverZipapps_FindsPyzFiles()
    {
        // Arrange
        var pyzPath = Path.Combine(_tempDir, "app.pyz");
        CreateMinimalZipapp(pyzPath, "#!/usr/bin/env python3\n");

        // Act
        var discovered = PythonZipappAdapter.DiscoverZipapps(_tempDir);

        // Assert
        Assert.Single(discovered);
        Assert.Contains(discovered, p => p.EndsWith("app.pyz"));
    }

    [Fact]
    public void DiscoverZipapps_FindsPyzwFiles()
    {
        // Arrange
        var pyzwPath = Path.Combine(_tempDir, "app.pyzw");
        CreateMinimalZipapp(pyzwPath, "#!/usr/bin/env pythonw\n");

        // Act
        var discovered = PythonZipappAdapter.DiscoverZipapps(_tempDir);

        // Assert
        Assert.Single(discovered);
        Assert.Contains(discovered, p => p.EndsWith("app.pyzw"));
    }

    [Fact]
    public void DiscoverZipapps_FindsInContainerLayers()
    {
        // Arrange
        var layersDir = Path.Combine(_tempDir, "layers", "layer1", "fs", "app");
        Directory.CreateDirectory(layersDir);
        var pyzPath = Path.Combine(layersDir, "container-app.pyz");
        CreateMinimalZipapp(pyzPath, "#!/usr/bin/python3.11\n");

        // Act
        var discovered = PythonZipappAdapter.DiscoverZipapps(_tempDir);

        // Assert
        Assert.Single(discovered);
        Assert.Contains(discovered, p => p.EndsWith("container-app.pyz"));
    }

    [Fact]
    public void AnalyzeZipapp_ExtractsShebang()
    {
        // Arrange
        var pyzPath = Path.Combine(_tempDir, "app.pyz");
        CreateMinimalZipapp(pyzPath, "#!/usr/bin/python3.11\n");

        // Act
        var info = PythonZipappAdapter.AnalyzeZipapp(pyzPath);

        // Assert
        Assert.NotNull(info);
        Assert.Equal("/usr/bin/python3.11", info.Shebang);
        Assert.Equal("3.11", info.PythonVersion);
    }

    [Fact]
    public void AnalyzeZipapp_ExtractsEnvShebang()
    {
        // Arrange
        var pyzPath = Path.Combine(_tempDir, "app.pyz");
        CreateMinimalZipapp(pyzPath, "#!/usr/bin/env python3.10\n");

        // Act
        var info = PythonZipappAdapter.AnalyzeZipapp(pyzPath);

        // Assert
        Assert.NotNull(info);
        Assert.Contains("/usr/bin/env python3.10", info.Shebang);
        Assert.Equal("3.10", info.PythonVersion);
    }

    [Fact]
    public void AnalyzeZipapp_DetectsMainPy()
    {
        // Arrange
        var pyzPath = Path.Combine(_tempDir, "app.pyz");
        CreateZipappWithMain(pyzPath, "#!/usr/bin/python3\n", "print('Hello')");

        // Act
        var info = PythonZipappAdapter.AnalyzeZipapp(pyzPath);

        // Assert
        Assert.NotNull(info);
        Assert.True(info.HasMainPy);
    }

    [Fact]
    public void AnalyzeZipapp_DetectsMissingMain_GeneratesWarning()
    {
        // Arrange
        var pyzPath = Path.Combine(_tempDir, "app.pyz");
        CreateMinimalZipapp(pyzPath, "#!/usr/bin/python3\n");

        // Act
        var info = PythonZipappAdapter.AnalyzeZipapp(pyzPath);

        // Assert
        Assert.NotNull(info);
        Assert.False(info.HasMainPy);
        Assert.Contains(info.Warnings, w => w.Contains("missing __main__.py"));
    }

    [Fact]
    public void AnalyzeZipapp_DetectsWindowsApp()
    {
        // Arrange
        var pyzwPath = Path.Combine(_tempDir, "app.pyzw");
        CreateZipappWithMain(pyzwPath, "#!/usr/bin/pythonw\n", "print('Hello')");

        // Act
        var info = PythonZipappAdapter.AnalyzeZipapp(pyzwPath);

        // Assert
        Assert.NotNull(info);
        Assert.True(info.IsWindowsApp);
        Assert.Contains(info.Warnings, w => w.Contains("Windows-specific"));
    }

    [Fact]
    public void AnalyzeZipapp_DetectsEnvShebangWarning()
    {
        // Arrange
        var pyzPath = Path.Combine(_tempDir, "app.pyz");
        CreateZipappWithMain(pyzPath, "#!/usr/bin/env python3\n", "print('Hello')");

        // Act
        var info = PythonZipappAdapter.AnalyzeZipapp(pyzPath);

        // Assert
        Assert.NotNull(info);
        Assert.Contains(info.Warnings, w => w.Contains("/usr/bin/env") && w.Contains("may vary"));
    }

    [Fact]
    public void AnalyzeZipapp_ExtractsEmbeddedRequirements()
    {
        // Arrange
        var pyzPath = Path.Combine(_tempDir, "app.pyz");
        var requirements = "requests>=2.0\nflask==2.1.0\n# Comment\nnumpy";
        CreateZipappWithRequirements(pyzPath, "#!/usr/bin/python3\n", requirements);

        // Act
        var info = PythonZipappAdapter.AnalyzeZipapp(pyzPath);

        // Assert
        Assert.NotNull(info);
        Assert.Contains("requests", info.EmbeddedDependencies);
        Assert.Contains("flask", info.EmbeddedDependencies);
        Assert.Contains("numpy", info.EmbeddedDependencies);
    }

    [Fact]
    public void AnalyzeAll_ReturnsAnalysisForMultipleZipapps()
    {
        // Arrange
        var pyz1 = Path.Combine(_tempDir, "app1.pyz");
        var pyz2 = Path.Combine(_tempDir, "app2.pyz");
        CreateZipappWithMain(pyz1, "#!/usr/bin/python3.10\n", "print('App1')");
        CreateZipappWithMain(pyz2, "#!/usr/bin/python3.11\n", "print('App2')");

        // Act
        var analysis = PythonZipappAdapter.AnalyzeAll(_tempDir);

        // Assert
        Assert.Equal(2, analysis.Zipapps.Count);
        Assert.True(analysis.HasZipapps);
        Assert.Contains(analysis.Warnings, w => w.Contains("Multiple zipapps"));
    }

    [Fact]
    public void AnalyzeAll_CollectsVersionsFromShebangs()
    {
        // Arrange
        var pyz1 = Path.Combine(_tempDir, "app1.pyz");
        var pyz2 = Path.Combine(_tempDir, "app2.pyz");
        CreateZipappWithMain(pyz1, "#!/usr/bin/python3.10\n", "print('App1')");
        CreateZipappWithMain(pyz2, "#!/usr/bin/python3.11\n", "print('App2')");

        // Act
        var analysis = PythonZipappAdapter.AnalyzeAll(_tempDir);

        // Assert
        var versioned = analysis.Zipapps.Where(z => z.PythonVersion != null).ToList();
        Assert.Equal(2, versioned.Count);
        Assert.Contains(versioned, z => z.PythonVersion == "3.10");
        Assert.Contains(versioned, z => z.PythonVersion == "3.11");
    }

    [Fact]
    public void AnalyzeZipapp_ExtractsEntryModuleFromRunpy()
    {
        // Arrange
        var pyzPath = Path.Combine(_tempDir, "app.pyz");
        var mainContent = @"
import runpy
runpy.run_module('mypackage.main')
";
        CreateZipappWithMain(pyzPath, "#!/usr/bin/python3\n", mainContent);

        // Act
        var info = PythonZipappAdapter.AnalyzeZipapp(pyzPath);

        // Assert
        Assert.NotNull(info);
        Assert.Equal("mypackage.main", info.EntryModule);
    }

    [Fact]
    public void ToMetadata_GeneratesExpectedKeys()
    {
        // Arrange
        var pyzPath = Path.Combine(_tempDir, "app.pyz");
        CreateZipappWithMain(pyzPath, "#!/usr/bin/python3.11\n", "print('Hello')");
        var info = PythonZipappAdapter.AnalyzeZipapp(pyzPath);

        // Act
        var metadata = info!.ToMetadata();

        // Assert
        Assert.Contains(metadata, m => m.Key == "zipapp.path");
        Assert.Contains(metadata, m => m.Key == "zipapp.hasMain" && m.Value == "true");
        Assert.Contains(metadata, m => m.Key == "zipapp.shebang");
        Assert.Contains(metadata, m => m.Key == "zipapp.pythonVersion" && m.Value == "3.11");
    }

    [Fact]
    public void AnalyzeZipapp_ReturnsNull_ForNonExistentFile()
    {
        // Act
        var info = PythonZipappAdapter.AnalyzeZipapp(Path.Combine(_tempDir, "nonexistent.pyz"));

        // Assert
        Assert.Null(info);
    }

    [Fact]
    public void AnalyzeZipapp_HandlesCorruptedArchive()
    {
        // Arrange
        var pyzPath = Path.Combine(_tempDir, "corrupt.pyz");
        File.WriteAllText(pyzPath, "#!/usr/bin/python3\nNot a valid zip archive");

        // Act
        var info = PythonZipappAdapter.AnalyzeZipapp(pyzPath);

        // Assert - should return null for corrupted archives
        Assert.Null(info);
    }

    private static void CreateMinimalZipapp(string path, string shebang)
    {
        using var fileStream = File.Create(path);
        // Write shebang
        var shebangBytes = Encoding.UTF8.GetBytes(shebang);
        fileStream.Write(shebangBytes);

        // Write minimal zip archive
        using var archive = new ZipArchive(fileStream, ZipArchiveMode.Create, leaveOpen: true);
        var entry = archive.CreateEntry("placeholder.txt");
        using var entryStream = entry.Open();
        using var writer = new StreamWriter(entryStream);
        writer.Write("placeholder");
    }

    private static void CreateZipappWithMain(string path, string shebang, string mainContent)
    {
        using var fileStream = File.Create(path);
        // Write shebang
        var shebangBytes = Encoding.UTF8.GetBytes(shebang);
        fileStream.Write(shebangBytes);

        // Write zip archive with __main__.py
        using var archive = new ZipArchive(fileStream, ZipArchiveMode.Create, leaveOpen: true);
        var entry = archive.CreateEntry("__main__.py");
        using var entryStream = entry.Open();
        using var writer = new StreamWriter(entryStream);
        writer.Write(mainContent);
    }

    private static void CreateZipappWithRequirements(string path, string shebang, string requirements)
    {
        using var fileStream = File.Create(path);
        // Write shebang
        var shebangBytes = Encoding.UTF8.GetBytes(shebang);
        fileStream.Write(shebangBytes);

        // Write zip archive with __main__.py and requirements.txt
        using var archive = new ZipArchive(fileStream, ZipArchiveMode.Create, leaveOpen: true);

        var mainEntry = archive.CreateEntry("__main__.py");
        using (var mainStream = mainEntry.Open())
        using (var mainWriter = new StreamWriter(mainStream))
        {
            mainWriter.Write("print('Hello')");
        }

        var reqEntry = archive.CreateEntry("requirements.txt");
        using var reqStream = reqEntry.Open();
        using var reqWriter = new StreamWriter(reqStream);
        reqWriter.Write(requirements);
    }
}