using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.IO;
using System.Linq;
using System.Text;

namespace BurnOutSharp.ProtectionType
{
    public class SafeDisc : IPathCheck
    {
        public static string CheckContents(string file, byte[] fileContent, bool includePosition = false)
        {
            // "BoG_ *90.0&!!  Yy>"
            byte[] check = new byte[] { 0x42, 0x6F, 0x47, 0x5F, 0x20, 0x2A, 0x39, 0x30, 0x2E, 0x30, 0x26, 0x21, 0x21, 0x20, 0x20, 0x59, 0x79, 0x3E };
            if (fileContent.Contains(check, out int position))
            {
                // "product activation library"
                byte[] check2 = new byte[] { 0x70, 0x72, 0x6F, 0x64, 0x75, 0x63, 0x74, 0x20, 0x61, 0x63, 0x74, 0x69, 0x76, 0x61, 0x74, 0x69, 0x6F, 0x6E, 0x20, 0x6C, 0x69, 0x62, 0x72, 0x61, 0x72, 0x79 };
                if (fileContent.Contains(check2, out int position2))
                    return $"SafeCast {GetVersion(fileContent, position)}" + (includePosition ? $" (Index {position}, {position2})" : string.Empty);
                else
                    return $"SafeDisc {GetVersion(fileContent, position)}" + (includePosition ? $" (Index {position})" : string.Empty);
            }

            // (char)0x00 + (char)0x00 + "BoG_"
            check = new byte[] { 0x00, 0x00, 0x42, 0x6F, 0x47, 0x5F };
            if (fileContent.Contains(check, out position))
            {
                string version = SearchSafeDiscVersion(file, fileContent);
                if (version.Length > 0)
                    return $"SafeDisc {version}" + (includePosition ? $" (Index {position})" : string.Empty);

                return "SafeDisc 3.20-4.xx (version removed)" + (includePosition ? $" (Index {position})" : string.Empty);
            }

            // "stxt774"
            check = new byte[] { 0x73, 0x74, 0x78, 0x74, 0x37, 0x37, 0x34 };
            if (fileContent.Contains(check, out position))
            {
                string version = SearchSafeDiscVersion(file, fileContent);
                if (version.Length > 0)
                    return $"SafeDisc {version}" + (includePosition ? $" (Index {position})" : string.Empty);

                return "SafeDisc 3.20-4.xx (version removed)" + (includePosition ? $" (Index {position})" : string.Empty);
            }

            // "stxt371"
            check = new byte[] { 0x73, 0x74, 0x78, 0x74, 0x33, 0x37, 0x31 };
            if (fileContent.Contains(check, out position))
            {
                string version = SearchSafeDiscVersion(file, fileContent);
                if (version.Length > 0)
                    return $"SafeDisc {version}" + (includePosition ? $" (Index {position})" : string.Empty);

                return "SafeDisc 3.20-4.xx (version removed)" + (includePosition ? $" (Index {position})" : string.Empty);
            }

            return null;
        }

        /// <inheritdoc/>
        public string CheckPath(string path, IEnumerable<string> files, bool isDirectory)
        {
            if (isDirectory)
            {
                // TODO: These are all cop-outs that don't check the existence of the other files
                if (files.Any(f => Path.GetFileName(f).Equals("DPLAYERX.DLL", StringComparison.OrdinalIgnoreCase)))
                {
                    string file = files.First(f => Path.GetFileName(f).Equals("DPLAYERX.DLL", StringComparison.OrdinalIgnoreCase));
                    return GetDPlayerXVersion(file);
                }
                else if (files.Any(f => Path.GetFileName(f).Equals("drvmgt.dll", StringComparison.OrdinalIgnoreCase)))
                {
                    string file = files.First(f => Path.GetFileName(f).Equals("drvmgt.dll", StringComparison.OrdinalIgnoreCase));
                    return GetDrvmgtVersion(file);
                }
                else if (files.Any(f => Path.GetFileName(f).Equals("secdrv.sys", StringComparison.OrdinalIgnoreCase)))
                {
                    string file = files.First(f => Path.GetFileName(f).Equals("secdrv.sys", StringComparison.OrdinalIgnoreCase));
                    return GetSecdrvVersion(file);
                }
                else if (path.EndsWith(".SafeDiscDVD.bundle", StringComparison.OrdinalIgnoreCase))
                {
                    return "SafeDisc for Macintosh";
                }
            }
            else
            {
                // V1
                if (Path.GetFileName(path).Equals("CLCD16.DLL", StringComparison.OrdinalIgnoreCase)
                    || Path.GetFileName(path).Equals("CLCD32.DLL", StringComparison.OrdinalIgnoreCase)
                    || Path.GetFileName(path).Equals("CLOKSPL.EXE", StringComparison.OrdinalIgnoreCase)
                    || Path.GetExtension(path).Trim('.').Equals("icd", StringComparison.OrdinalIgnoreCase))
                {
                    return "SafeDisc 1";
                }

                // V1 or greater
                else if (Path.GetFileName(path).Equals("00000001.TMP", StringComparison.OrdinalIgnoreCase)
                    || Path.GetExtension(path).Trim('.').Equals("016", StringComparison.OrdinalIgnoreCase)
                    || Path.GetExtension(path).Trim('.').Equals("256", StringComparison.OrdinalIgnoreCase))
                {
                    return "SafeDisc 1 or greater";
                }

                // V2 or greater
                else if (Path.GetFileName(path).Equals("00000002.TMP", StringComparison.OrdinalIgnoreCase))
                {
                    return "SafeDisc 2 or greater";
                }

                // Specific Versions
                else if (Path.GetFileName(path).Equals("DPLAYERX.DLL", StringComparison.OrdinalIgnoreCase))
                {
                    return GetDPlayerXVersion(path);
                }
                else if (Path.GetFileName(path).Equals("drvmgt.dll", StringComparison.OrdinalIgnoreCase))
                {
                    return GetDrvmgtVersion(path);
                }
                else if (Path.GetFileName(path).Equals("secdrv.sys", StringComparison.OrdinalIgnoreCase))
                {
                    return GetSecdrvVersion(path);
                }
            }

            return null;
        }

        private static string GetDPlayerXVersion(string file)
        {
            if (file == null || !File.Exists(file))
                return string.Empty;

            FileInfo fi = new FileInfo(file);
            if (fi.Length == 81408)
                return "SafeDisc 1.0x";
            else if (fi.Length == 155648)
                return "SafeDisc 1.1x";
            else if (fi.Length == 156160)
                return "SafeDisc 1.1x-1.2x";
            else if (fi.Length == 163328)
                return "SafeDisc 1.3x";
            else if (fi.Length == 165888)
                return "SafeDisc 1.35";
            else if (fi.Length == 172544)
                return "SafeDisc 1.40";
            else if (fi.Length == 173568)
                return "SafeDisc 1.4x";
            else if (fi.Length == 136704)
                return "SafeDisc 1.4x";
            else if (fi.Length == 138752)
                return "SafeDisc 1.5x";
            else
                return "SafeDisc 1";
        }

        private static string GetDrvmgtVersion(string file)
        {
            if (file == null || !File.Exists(file))
                return string.Empty;

            FileInfo fi = new FileInfo(file);
            if (fi.Length == 34816)
                return "SafeDisc 1.0x";
            else if (fi.Length == 32256)
                return "SafeDisc 1.1x-1.3x";
            else if (fi.Length == 31744)
                return "SafeDisc 1.4x";
            else if (fi.Length == 34304)
                return "SafeDisc 1.5x-2.40";
            else if (fi.Length == 35840)
                return "SafeDisc 2.51-2.60";
            else if (fi.Length == 40960)
                return "SafeDisc 2.70";
            else if (fi.Length == 23552)
                return "SafeDisc 2.80";
            else if (fi.Length == 41472)
                return "SafeDisc 2.90-3.10";
            else if (fi.Length == 24064)
                return "SafeDisc 3.15-3.20";
            else
                return "SafeDisc 1 or greater";
        }

        private static string GetSecdrvVersion(string file)
        {
            if (file == null || !File.Exists(file))
                return string.Empty;

            FileInfo fi = new FileInfo(file);
            if (fi.Length == 20128)
                return "SafeDisc 2.10";
            else if (fi.Length == 27440)
                return "SafeDisc 2.30";
            else if (fi.Length == 28624)
                return "SafeDisc 2.40";
            else if (fi.Length == 18768)
                return "SafeDisc 2.50";
            else if (fi.Length == 28400)
                return "SafeDisc 2.51";
            else if (fi.Length == 29392)
                return "SafeDisc 2.60";
            else if (fi.Length == 11376)
                return "SafeDisc 2.70";
            else if (fi.Length == 12464)
                return "SafeDisc 2.80";
            else if (fi.Length == 12400)
                return "SafeDisc 2.90";
            else if (fi.Length == 12528)
                return "SafeDisc 3.10";
            else if (fi.Length == 12528)
                return "SafeDisc 3.15";
            else if (fi.Length == 11973)
                return "SafeDisc 3.20";
            else
                return "SafeDisc 1 or greater";
        }

        private static string GetVersion(byte[] fileContent, int position)
        {
            int index = position + 20; // Begin reading after "BoG_ *90.0&!!  Yy>" for old SafeDisc
            int version = BitConverter.ToInt32(fileContent, index);
            index += 4;
            int subVersion = BitConverter.ToInt32(fileContent, index);
            index += 4;
            int subsubVersion = BitConverter.ToInt32(fileContent, index);

            if (version != 0)
                return $"{version}.{subVersion:00}.{subsubVersion:000}";

            index = position + 18 + 14; // Begin reading after "BoG_ *90.0&!!  Yy>" for newer SafeDisc
            version = BitConverter.ToInt32(fileContent, index);
            index += 4;
            subVersion = BitConverter.ToInt32(fileContent, index);
            index += 4;
            subsubVersion = BitConverter.ToInt32(fileContent, index);

            if (version == 0)
                return "";

            return $"{version}.{subVersion:00}.{subsubVersion:000}";
        }
    
        // TODO: Analyze this method and figure out if this can be done without attempting execution
        private static string SearchSafeDiscVersion(string file, byte[] fileContent)
        {
            Process exe;
            string version = "";
            DateTime timestart;
            if (!EVORE.IsEXE(fileContent))
                return "";

            string tempexe = EVORE.MakeTempFile(fileContent);
            string[] DependentDlls = EVORE.CopyDependentDlls(file, fileContent);
            try
            {
                Directory.Delete(Path.Combine(Path.GetTempPath(), "~e*"), true);
            }
            catch { }
            try
            {
                File.Delete(Path.Combine(Path.GetTempPath(), "~e*"));
            }
            catch { }

            exe = EVORE.StartSafe(tempexe);
            if (exe == null)
                return "";

            timestart = DateTime.Now;
            do
            {
                if (Directory.GetDirectories(Path.GetTempPath(), "~e*").Length > 0)
                {
                    string[] files = Directory.GetFiles(Directory.GetDirectories(Path.GetTempPath(), "~e*")[0], "~de*.tmp");
                    if (files.Length > 0)
                    {
                        StreamReader sr;
                        try
                        {
                            sr = new StreamReader(files[0], Encoding.Default);
                            string FileContent = sr.ReadToEnd();
                            sr.Close();
                            int position = FileContent.IndexOf("%ld.%ld.%ld, %ld, %s,") - 1;
                            if (position > -1)
                                version = FileContent.Substring(position + 28, 12);
                            break;
                        }
                        catch { }
                    }
                }
            } while (!exe.HasExited && DateTime.Now.Subtract(timestart).TotalSeconds < 20);

            if (!exe.HasExited)
                exe.Kill();
            exe.Close();

            try
            {
                Directory.Delete(Path.Combine(Path.GetTempPath(), "~e*"), true);
            }
            catch { }
            try
            {
                File.Delete(Path.Combine(Path.GetTempPath(), "~e*"));
                File.Delete(tempexe);
            }
            catch { }

            if (DependentDlls != null)
            {
                for (int i = 0; i < DependentDlls.Length; i--)
                {
                    try
                    {
                        File.Delete(DependentDlls[i]);
                    }
                    catch (Exception ex)
                    {
                        Console.WriteLine("!error while deleting file " + DependentDlls[i] + "; " + ex.Message);
                    }
                }
            }

            return version;
        }
    }
}