using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.IO;
using System.Linq;
using System.Threading;
using BurnOutSharp.Matching;
using BurnOutSharp.Tools;

namespace BurnOutSharp.ProtectionType
{
    public class ProtectDisc : IContentCheck
    {
        /// <inheritdoc/>
        public List<ContentMatchSet> GetContentMatchSets()
        {
            return new List<ContentMatchSet>
            {
                // HúMETINF
                new ContentMatchSet(new byte?[] { 0x48, 0xFA, 0x4D, 0x45, 0x54, 0x49, 0x4E, 0x46 }, GetVersion76till10, "ProtectDisc"),

                // ACE-PCD
                new ContentMatchSet(new byte?[] { 0x41, 0x43, 0x45, 0x2D, 0x50, 0x43, 0x44 }, GetVersion6till8, "ProtectDisc"),
            };
        }

        /// <inheritdoc/>
        public string CheckContents(string file, byte[] fileContent, bool includeDebug = false) => null;

        public static string GetVersion6till8(string file, byte[] fileContent, List<int> positions)
        {
            string version = SearchProtectDiscVersion(file, fileContent);
            if (version.Length > 0)
            {
                string[] astrVersionArray = version.Split('.');
                return $"{astrVersionArray[0]}.{astrVersionArray[1]}.{astrVersionArray[2]} (Build {astrVersionArray[3]})";
            }

            return $"{GetVersionBuild6till8(fileContent, positions[0])}";
        }

        public static string GetVersion76till10(string file, byte[] fileContent, List<int> positions)
        {
            string version = SearchProtectDiscVersion(file, fileContent);
            if (version.Length > 0)
            {
                string[] astrVersionArray = version.Split('.');
                if (astrVersionArray[0] == "9")
                {
                    if (GetVersionBuild76till10(fileContent, positions[0], out int ibuild).Length > 0)
                        return $"{astrVersionArray[0]}.{astrVersionArray[1]}{astrVersionArray[2]}.{astrVersionArray[3]} (Build {ibuild})";
                }
                else
                {
                    return $"{astrVersionArray[0]}.{astrVersionArray[1]}.{astrVersionArray[2]} (Build {astrVersionArray[3]})";
                }
            }

            return null;
        }

        private static string GetVersionBuild6till8(byte[] fileContent, int position)
        {
            string version;
            string strBuild;

            int index = position - 12;
            if (new ArraySegment<byte>(fileContent, index, 4).SequenceEqual(new byte[] { 0x0A, 0x0D, 0x0A, 0x0D })) // ProtectDisc 6-7 with Build Number in plain text
            {
                index = position - 12 - 6;

                // ProtectDisc 7
                if (new string(new ArraySegment<byte>(fileContent, index, 6).Select(b => (char)b).ToArray()) == "Henrik")
                {
                    version = "7.1-7.5";
                    index = position - 12 - 6 - 6;
                }

                // ProtectDisc 6
                else
                {
                    version = "6";
                    index = position - 12 - 10;
                    while (true) //search for e.g. "Build 050913 -  September 2005"
                    {
                        if (Char.IsNumber((char)fileContent[index]))
                            break;

                        index -= 1; //search upwards
                    }

                    index -= 5;
                }
            }
            else
            {
                index = position + 28;
                if (fileContent[index] == 0xFB)
                    return "7.6-7.x";
                else
                    return "8.0";
            }

            strBuild = new string(new ArraySegment<byte>(fileContent, index, 5).Select(b => (char)b).ToArray());
            return $"{version} (Build {strBuild})";
        }

        private static string GetVersionBuild76till10(byte[] fileContent, int position, out int irefBuild)
        {
            int index = position + 37;
            byte subversion = fileContent[index];
            index++;
            index++;
            byte version = fileContent[index];
            index = position + 49;
            irefBuild = BitConverter.ToInt32(fileContent, index);
            index = position + 53;
            byte versionindicatorPD9 = fileContent[index];
            index = position + 0x40;
            byte subsubversionPD9x = fileContent[index];
            index++;
            byte subversionPD9x2 = fileContent[index];
            index++;
            byte subversionPD9x1 = fileContent[index];

            // version 7
            if (version == 0xAC)
                return $"7.{subversion ^ 0x43} (Build {irefBuild})";

            // version 8
            else if (version == 0xA2)
            {
                if (subversion == 0x46)
                {
                    if ((irefBuild & 0x3A00) == 0x3A00)
                        return $"8.2 (Build {irefBuild})";
                    else
                        return $"8.1 (Build {irefBuild})";
                }

                return $"8.{subversion ^ 0x47} (Build {irefBuild})";
            }

            // version 9
            else if (version == 0xA3)
            {
                // version removed or not given
                if ((subversionPD9x2 == 0x5F && subversionPD9x1 == 0x61) || (subversionPD9x1 == 0 && subversionPD9x2 == 0))
                {
                    if (versionindicatorPD9 == 0xB)
                    {
                        return $"9.0-9.4 (Build {irefBuild})";
                    }
                    else if (versionindicatorPD9 == 0xC)
                    {
                        if (subversionPD9x2 == 0x5F && subversionPD9x1 == 0x61)
                            return $"9.5-9.11 (Build {irefBuild})";
                        else if (subversionPD9x1 == 0 && subversionPD9x2 == 0)
                            return $"9.11-9.20 (Build {irefBuild})";
                    }
                    else
                    {
                        return $"9.{subversionPD9x1}{subversionPD9x2}.{subsubversionPD9x} (Build {irefBuild})";
                    }
                }
            }

            // version 10
            else if (version == 0xA0)
            {
                // version removed
                if (subversionPD9x1 != 0 || subversionPD9x2 != 0)
                    return $"10.{subversionPD9x1}.{subsubversionPD9x} (Build {irefBuild})";
                else
                    return $"10.x (Build {irefBuild})";
            }

            // unknown version
            else
            {
                return $"7.6-10.x (Build {irefBuild})";
            }

            return string.Empty;
        }
    
        // TODO: Analyze this method and figure out if this can be done without attempting execution
        private static string SearchProtectDiscVersion(string file, byte[] fileContent)
        {
            // If the file isn't executable, don't even bother
            if (!EVORE.IsPEExecutable(fileContent))
                return string.Empty;

            // Get some of the required paths
            string tempexe = EVORE.MakeTempFile(fileContent);
            string[] dependentDlls = EVORE.CopyDependentDlls(file, fileContent);
            string pdPath = Path.Combine(Environment.GetFolderPath(Environment.SpecialFolder.ApplicationData), "ProtectDisc");

            // Clean up any temp files before attempting to run
            Utilities.SafeTempDelete("a*.tmp");
            Utilities.SafeTempDelete("PCD*.sys");
            if (Directory.Exists(pdPath))
                Utilities.SafeDelete(Path.Combine(pdPath, "p*.dll"));

            // Try to safely start the temp executable
            Process exe = EVORE.StartSafe(tempexe);
            if (exe == null)
                return string.Empty;

            string version = "";
            Process[] processes = new Process[0];
            DateTime timestart = DateTime.Now;
            do
            {
                exe.Refresh();
                string[] files = new string[0];

                // Check for ProtectDisc 8.2-x
                if (Directory.Exists(pdPath))
                    files = Directory.GetFiles(pdPath, "p*.dll");

                if (files.Any())
                {
                    string fileVersion = Utilities.GetFileVersion(files[0]);
                    if (!string.IsNullOrWhiteSpace(fileVersion))
                    {
                        version = fileVersion;

                        // ProtectDisc 9 uses a ProtectDisc-Core dll version 8.0.x
                        if (version.StartsWith("8.0"))
                            version = string.Empty;

                        break;
                    }
                }

                //check for ProtectDisc 7.1-8.1
                files = Directory.GetFiles(Path.GetTempPath(), "a*.tmp");
                if (files.Any())
                {
                    string fileVersion = Utilities.GetFileVersion(files[0]);
                    if (!string.IsNullOrWhiteSpace(fileVersion))
                    {
                        version = fileVersion;
                        break;
                    }
                }

                if (exe.HasExited)
                    break;

                processes = Process.GetProcessesByName(exe.ProcessName);
                if (processes.Length == 2)
                {
                    processes[0].Refresh();
                    processes[1].Refresh();
                    if (processes[1].WorkingSet64 > exe.WorkingSet64)
                        exe = processes[1];
                    else if (processes[0].WorkingSet64 > exe.WorkingSet64) //else if (processes[0].Modules.Count > exe.Modules.Count)
                        exe = processes[0];
                }
            } while (processes.Length > 0 && DateTime.Now.Subtract(timestart).TotalSeconds < 20);

            Thread.Sleep(500);
            if (!exe.HasExited)
            {
                processes = Process.GetProcessesByName(exe.ProcessName);
                if (processes.Length == 2)
                {
                    try
                    {
                        processes[0].Kill();
                    }
                    catch { }
                    processes[0].Close();
                    try
                    {
                        processes[1].Kill();
                    }
                    catch { }
                }
                else
                {
                    exe.Refresh();
                    try
                    {
                        exe.Kill();
                    }
                    catch { }
                }
            }

            exe.Close();
            Thread.Sleep(500);

            // Clean up any temp files after running
            Utilities.SafeDelete(tempexe);
            Utilities.SafeTempDelete("a*.tmp");
            Utilities.SafeTempDelete("PCD*.sys");
            if (Directory.Exists(pdPath))
                Utilities.SafeDelete(Path.Combine(pdPath, "p*.dll"));

            if (dependentDlls != null)
            {
                foreach (string dll in dependentDlls)
                {
                    Utilities.SafeDelete(dll);
                }
            }

            return version;
        }
    }
}