using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Text;
using System.Threading;
using System.Threading.Tasks;
using SharpCompress.Readers;
using Xunit;

namespace SharpCompress.Test;

public class TestBase : IAsyncDisposable
{
    private static readonly string SOLUTION_BASE_PATH;
    public static readonly string TEST_ARCHIVES_PATH;
    public static readonly string ORIGINAL_FILES_PATH;
    public static readonly string MISC_TEST_FILES_PATH;
    private static readonly string SCRATCH_BASE_PATH;

    private static readonly string SCRATCH_DIRECTORY;
    private static readonly string SCRATCH2_DIRECTORY;

    static TestBase()
    {
        var index = AppDomain.CurrentDomain.BaseDirectory.IndexOf(
            "SharpCompress.Test",
            StringComparison.OrdinalIgnoreCase
        );
        var path = AppDomain.CurrentDomain.BaseDirectory.Substring(0, index);
        SOLUTION_BASE_PATH = Path.GetDirectoryName(path) ?? throw new ArgumentNullException();

        TEST_ARCHIVES_PATH = Path.Combine(SOLUTION_BASE_PATH, "TestArchives", "Archives");
        ORIGINAL_FILES_PATH = Path.Combine(SOLUTION_BASE_PATH, "TestArchives", "Original");
        MISC_TEST_FILES_PATH = Path.Combine(SOLUTION_BASE_PATH, "TestArchives", "MiscTest");

        SCRATCH_BASE_PATH = Path.Combine(SOLUTION_BASE_PATH, "TestArchives");
        SCRATCH_DIRECTORY = Path.Combine(SCRATCH_BASE_PATH, "Scratch");
        SCRATCH2_DIRECTORY = Path.Combine(SCRATCH_BASE_PATH, "Scratch2");

        Directory.CreateDirectory(SCRATCH_DIRECTORY);
        Directory.CreateDirectory(SCRATCH2_DIRECTORY);
    }

    private readonly Guid _testGuid = Guid.NewGuid();
    protected readonly string SCRATCH_FILES_PATH;
    protected readonly string SCRATCH2_FILES_PATH;

    protected TestBase()
    {
        SCRATCH_FILES_PATH = Path.Combine(SCRATCH_DIRECTORY, _testGuid.ToString());
        SCRATCH2_FILES_PATH = Path.Combine(SCRATCH2_DIRECTORY, _testGuid.ToString());

        Directory.CreateDirectory(SCRATCH_FILES_PATH);
        Directory.CreateDirectory(SCRATCH2_FILES_PATH);
    }

    //always use async dispose since we have I/O and sync Dispose doesn't wait when using xunit
    public async ValueTask DisposeAsync()
    {
        await Task.CompletedTask;
        Directory.Delete(SCRATCH_FILES_PATH, true);
        Directory.Delete(SCRATCH2_FILES_PATH, true);
    }

    public void VerifyFiles()
    {
        if (UseExtensionInsteadOfNameToVerify)
        {
            VerifyFilesByExtension();
        }
        else
        {
            VerifyFilesByName();
        }
    }

    /// <summary>
    /// Verifies the files also check modified time and attributes.
    /// </summary>
    public void VerifyFilesEx()
    {
        if (UseExtensionInsteadOfNameToVerify)
        {
            VerifyFilesByExtensionEx();
        }
        else
        {
            VerifyFilesByNameEx();
        }
    }

    protected void VerifyFilesByName()
    {
        var extracted = Directory
            .EnumerateFiles(SCRATCH_FILES_PATH, "*.*", SearchOption.AllDirectories)
            .ToLookup(path => path.Substring(SCRATCH_FILES_PATH.Length));
        var original = Directory
            .EnumerateFiles(ORIGINAL_FILES_PATH, "*.*", SearchOption.AllDirectories)
            .ToLookup(path => path.Substring(ORIGINAL_FILES_PATH.Length));

        Assert.Equal(extracted.Count, original.Count);

        foreach (var orig in original)
        {
            Assert.True(extracted.Contains(orig.Key));

            CompareFilesByPath(orig.Single(), extracted[orig.Key].Single());
        }
    }

    /// <summary>
    /// Verifies the files by name also check modified time and attributes.
    /// </summary>
    protected void VerifyFilesByNameEx()
    {
        var extracted = Directory
            .EnumerateFiles(SCRATCH_FILES_PATH, "*.*", SearchOption.AllDirectories)
            .ToLookup(path => path.Substring(SCRATCH_FILES_PATH.Length));
        var original = Directory
            .EnumerateFiles(ORIGINAL_FILES_PATH, "*.*", SearchOption.AllDirectories)
            .ToLookup(path => path.Substring(ORIGINAL_FILES_PATH.Length));

        Assert.Equal(extracted.Count, original.Count);

        foreach (var orig in original)
        {
            Assert.True(extracted.Contains(orig.Key));

            CompareFilesByPath(orig.Single(), extracted[orig.Key].Single());
            CompareFilesByTimeAndAttribute(orig.Single(), extracted[orig.Key].Single());
        }
    }

    /// <summary>
    /// Verifies the files by extension also check modified time and attributes.
    /// </summary>
    private void VerifyFilesByExtensionEx()
    {
        var extracted = Directory
            .EnumerateFiles(SCRATCH_FILES_PATH, "*.*", SearchOption.AllDirectories)
            .ToLookup(path => Path.GetExtension(path));
        var original = Directory
            .EnumerateFiles(ORIGINAL_FILES_PATH, "*.*", SearchOption.AllDirectories)
            .ToLookup(path => Path.GetExtension(path));

        Assert.Equal(extracted.Count, original.Count);

        foreach (var orig in original)
        {
            Assert.True(extracted.Contains(orig.Key));

            CompareFilesByPath(orig.Single(), extracted[orig.Key].Single());
            CompareFilesByTimeAndAttribute(orig.Single(), extracted[orig.Key].Single());
        }
    }

    protected bool UseExtensionInsteadOfNameToVerify { get; set; }
    protected bool UseCaseInsensitiveToVerify { get; set; }

    protected void VerifyFilesByExtension()
    {
        ILookup<string, string> extracted;
        if (UseCaseInsensitiveToVerify)
        {
            extracted = Directory
                .EnumerateFiles(SCRATCH_FILES_PATH, "*.*", SearchOption.AllDirectories)
                .ToLookup(path => Path.GetExtension(path).ToLowerInvariant());
        }
        else
        {
            extracted = Directory
                .EnumerateFiles(SCRATCH_FILES_PATH, "*.*", SearchOption.AllDirectories)
                .ToLookup(path => Path.GetExtension(path));
        }
        var original = Directory
            .EnumerateFiles(ORIGINAL_FILES_PATH, "*.*", SearchOption.AllDirectories)
            .ToLookup(path => Path.GetExtension(path));

        Assert.Equal(extracted.Count, original.Count);

        foreach (var orig in original)
        {
            Assert.True(extracted.Contains(orig.Key));

            CompareFilesByPath(orig.Single(), extracted[orig.Key].Single());
        }
    }

    protected void CompareFilesByPath(string file1, string file2)
    {
        //TODO: fix line ending issues with the text file
        if (file1.EndsWith("txt", StringComparison.OrdinalIgnoreCase))
        {
            return;
        }

        using var file1Stream = File.OpenRead(file1);
        using var file2Stream = File.OpenRead(file2);
        Assert.Equal(file1Stream.Length, file2Stream.Length);
        var byte1 = 0;
        var byte2 = 0;
        for (var counter = 0; byte1 != -1; counter++)
        {
            byte1 = file1Stream.ReadByte();
            byte2 = file2Stream.ReadByte();
            if (byte1 != byte2)
            {
                //string.Format("Byte {0} differ between {1} and {2}", counter, file1, file2)
                Assert.Equal(byte1, byte2);
            }
        }
    }

    private void CompareFilesByTimeAndAttribute(string file1, string file2)
    {
        var fi1 = new FileInfo(file1);
        var fi2 = new FileInfo(file2);
        Assert.NotEqual(fi1.LastWriteTime, fi2.LastWriteTime);
        Assert.Equal(fi1.Attributes, fi2.Attributes);
    }

    protected void CompareArchivesByPath(string file1, string file2, Encoding? encoding = null)
    {
        var readerOptions = new ReaderOptions { LeaveStreamOpen = false };
        readerOptions.ArchiveEncoding.Default = encoding ?? Encoding.Default;

        //don't compare the order.  OS X reads files from the file system in a different order therefore makes the archive ordering different
        var archive1Entries = new List<string>();
        var archive2Entries = new List<string>();
        using (var archive1 = ReaderFactory.OpenReader(File.OpenRead(file1), readerOptions))
        using (var archive2 = ReaderFactory.OpenReader(File.OpenRead(file2), readerOptions))
        {
            while (archive1.MoveToNextEntry())
            {
                Assert.True(archive2.MoveToNextEntry());
                archive1Entries.Add(archive1.Entry.Key.NotNull());
                archive2Entries.Add(archive2.Entry.Key.NotNull());
            }
            Assert.False(archive2.MoveToNextEntry());
        }
        archive1Entries.Sort();
        archive2Entries.Sort();
        for (var i = 0; i < archive1Entries.Count; i++)
        {
            Assert.Equal(archive1Entries[i], archive2Entries[i]);
        }
    }
}