using System.Collections.Concurrent;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using BurnOutSharp.ExecutableType.Microsoft;
using BurnOutSharp.Matching;

namespace BurnOutSharp.PackerType
{
    // The official website for CExe also includes the source code (which does have to be retrieved by the Wayback Machine)
    // http://www.scottlu.com/Content/CExe.html
    public class CExe : IContentCheck, IScannable
    {
        /// <inheritdoc/>
        public bool ShouldScan(byte[] magic) => true;
        
        /// <inheritdoc/>
        private List<ContentMatchSet> GetContentMatchSets()
        {
            // TODO: Obtain a sample to find where this string is in a typical executable
            return new List<ContentMatchSet>
            {
                // %Wo�a6.�a6.�a6.�a6.�{6.�.).�f6.��).�`6.��0.�`6.�
                new ContentMatchSet(
                    new ContentMatch(new byte?[]
                    {
                        0x25, 0x57, 0x6F, 0xC1, 0x61, 0x36, 0x01, 0x92,
                        0x61, 0x36, 0x01, 0x92, 0x61, 0x36, 0x01, 0x92,
                        0x61, 0x36, 0x00, 0x92, 0x7B, 0x36, 0x01, 0x92,
                        0x03, 0x29, 0x12, 0x92, 0x66, 0x36, 0x01, 0x92,
                        0x89, 0x29, 0x0A, 0x92, 0x60, 0x36, 0x01, 0x92,
                        0xD9, 0x30, 0x07, 0x92, 0x60, 0x36, 0x01, 0x92
                    }, end: 200), "CExe"),
            };
        }

        /// <inheritdoc/>
        public string CheckContents(string file, byte[] fileContent, bool includeDebug, PortableExecutable pex, NewExecutable nex)
        {
            var contentMatchSets = GetContentMatchSets();
            if (contentMatchSets != null && contentMatchSets.Any())
                return MatchUtil.GetFirstMatch(file, fileContent, contentMatchSets, includeDebug);

            return null;
        }

        /// <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/>
        // TODO: Add extraction if viable
        public ConcurrentDictionary<string, ConcurrentQueue<string>> Scan(Scanner scanner, Stream stream, string file)
        {
            return null;
        }
    }
}