using System;
using System.Collections.Concurrent;
using System.IO;
using BurnOutSharp.Interfaces;
using BurnOutSharp.Tools;
using WixToolset.Dtf.Compression.Cab;

namespace BurnOutSharp.FileType
{
    // Specification available at http://download.microsoft.com/download/5/0/1/501ED102-E53F-4CE0-AA6B-B0F93629DDC6/Exchange/%5BMS-CAB%5D.pdf
    public class MicrosoftCAB : IScannable
    {
        /// <inheritdoc/>
        public bool ShouldScan(byte[] magic)
        {
            if (magic.StartsWith(new byte?[] { 0x4d, 0x53, 0x43, 0x46 }))
                return true;

            return false;
        }

        /// <inheritdoc/>
        public ConcurrentDictionary<string, ConcurrentQueue<string>> Scan(Scanner scanner, string file)
        {
            if (!File.Exists(file))
                return null;

            using (var fs = File.OpenRead(file))
            {
                return Scan(scanner, fs, file);
            }
        }

        /// <inheritdoc/>
        public ConcurrentDictionary<string, ConcurrentQueue<string>> Scan(Scanner scanner, Stream stream, string file)
        {
            // If the cab file itself fails
            try
            {
                string tempPath = Path.Combine(Path.GetTempPath(), Guid.NewGuid().ToString());
                Directory.CreateDirectory(tempPath);

                CabInfo cabInfo = new CabInfo(file);
                cabInfo.Unpack(tempPath);

                // Collect and format all found protections
                var protections = scanner.GetProtections(tempPath);

                // If temp directory cleanup fails
                try
                {
                    Directory.Delete(tempPath, true);
                }
                catch (Exception ex)
                {
                    if (scanner.IncludeDebug) Console.WriteLine(ex);
                }

                // Remove temporary path references
                Utilities.StripFromKeys(protections, tempPath);

                return protections;
            }
            catch (Exception ex)
            {
                if (scanner.IncludeDebug) Console.WriteLine(ex);
            }

            return null;
        }

        #region LibMSPackSharp

        // TODO: Add stream opening support
        /// <inheritdoc/>
        //public ConcurrentDictionary<string, ConcurrentQueue<string>> Scan(Scanner scanner, Stream stream, string file)
        //{
        //    // If the cab file itself fails
        //    try
        //    {
        //        string tempPath = Path.Combine(Path.GetTempPath(), Guid.NewGuid().ToString());
        //        Directory.CreateDirectory(tempPath);

        //        // Create the decompressor
        //        var decompressor = Library.CreateCABDecompressor(null);
        //        decompressor.Debug = scanner.IncludeDebug;

        //        // Open the cab file
        //        var cabFile = decompressor.Open(file);
        //        if (cabFile == null)
        //        {
        //            if (scanner.IncludeDebug) Console.WriteLine($"Error occurred opening of '{file}': {decompressor.Error}");
        //            return null;
        //        }

        //        // If we have a previous CAB and it exists, don't try scanning
        //        string directory = Path.GetDirectoryName(file);
        //        if (!string.IsNullOrWhiteSpace(cabFile.PreviousCabinetName))
        //        {
        //            if (File.Exists(Path.Combine(directory, cabFile.PreviousCabinetName)))
        //                return null;
        //        }

        //        // If there are additional next CABs, add those
        //        string fileName = Path.GetFileName(file);
        //        CABExtract.LoadSpanningCabinets(cabFile, fileName);

        //        // Loop through the found internal files
        //        var sub = cabFile.Files;
        //        while (sub != null)
        //        {
        //            // If an individual entry fails
        //            try
        //            {
        //                // The trim here is for some very odd and stubborn files
        //                string tempFile = Path.Combine(tempPath, sub.Filename.TrimEnd('\0', ' ', '.'));
        //                Error error = decompressor.Extract(sub, tempFile);
        //                if (error != Error.MSPACK_ERR_OK)
        //                {
        //                    if (scanner.IncludeDebug) Console.WriteLine($"Error occurred during extraction of '{sub.Filename}': {error}");
        //                }
        //            }
        //            catch (Exception ex)
        //            {
        //                if (scanner.IncludeDebug) Console.WriteLine(ex);
        //            }

        //            sub = sub.Next;
        //        }

        //        // Destroy the decompressor
        //        Library.DestroyCABDecompressor(decompressor);

        //        // Collect and format all found protections
        //        var protections = scanner.GetProtections(tempPath);

        //        // If temp directory cleanup fails
        //        try
        //        {
        //            Directory.Delete(tempPath, true);
        //        }
        //        catch (Exception ex)
        //        {
        //            if (scanner.IncludeDebug) Console.WriteLine(ex);
        //        }

        //        // Remove temporary path references
        //        Utilities.StripFromKeys(protections, tempPath);

        //        return protections;
        //    }
        //    catch (Exception ex)
        //    {
        //        if (scanner.IncludeDebug) Console.WriteLine(ex);
        //    }

        //    return null;
        //}

        #endregion
    }
}