using nspector.Common.Helper;
using nspector.Native.NVAPI2;
using System.Text.RegularExpressions;

namespace nspector.Common
{


    public class DrsScannerService : DrsSettingsServiceBase
    {

        public DrsScannerService(DrsSettingsMetaService metaService, DrsDecrypterService decrpterService)
            : base(metaService, decrpterService)
        { }


        internal List<CachedSettings> CachedSettings = new List<CachedSettings>();
        internal List<string> ModifiedProfiles = new List<string>();
        internal HashSet<string> UserProfiles = new HashSet<string>();
        private bool _scannedPredefinedSettings = false;

        // most common setting ids as start pattern for the heuristic scan
        private readonly uint[] _commonSettingIds = new uint[] { 0x1095DEF8, 0x1033DCD2, 0x1033CEC1,
                            0x10930F46, 0x00A06946, 0x10ECDB82, 0x20EBD7B8, 0x0095DEF9, 0x00D55F7D,
                            0x1033DCD3, 0x1033CEC2, 0x2072F036, 0x00664339, 0x002C7F45, 0x209746C1,
                            0x0076E164, 0x20FF7493, 0x204CFF7B };

        private bool CheckCommonSetting(IntPtr hSession, IntPtr hProfile, NVDRS_PROFILE profile,
            ref int checkedSettingsCount, uint checkSettingId, bool addToScanResult,
            ref List<uint> alreadyCheckedSettingIds, ref NVDRS_SETTING providedSetting)
        {

            if (checkedSettingsCount >= profile.numOfSettings)
                return false;

            //var setting = new NVDRS_SETTING
            //{
            //    version = nvw.NVDRS_SETTING_VER
            //};

            var setting = providedSetting;
            //if (nvw.DRS_GetSetting(hSession, hProfile, checkSettingId, ref setting) != NvAPI_Status.NVAPI_OK)
            //    return false;

            if (setting.settingLocation != NVDRS_SETTING_LOCATION.NVDRS_CURRENT_PROFILE_LOCATION)
                return false;

            if (!addToScanResult && setting.isCurrentPredefined == 1)
            {
                checkedSettingsCount++;
            }
            else if (addToScanResult)
            {
                if (decrypter != null)
                {
                    decrypter.DecryptSettingIfNeeded(profile.profileName, ref setting);
                }

                checkedSettingsCount++;
                AddScannedSettingToCache(profile, setting);
                alreadyCheckedSettingIds.Add(setting.settingId);
                return (setting.isCurrentPredefined != 1);
            }
            else if (setting.isCurrentPredefined != 1)
            {
                return true;
            }

            return false;
        }


        private int CalcPercent(int current, int max)
        {
            return (current > 0) ? (int)Math.Round((current * 100f) / max) : 0; ;
        }

        public void ScanProfileSettings(bool justModified, IProgress<int> progress, CancellationToken token = default(CancellationToken))
        {
            if (!justModified && _scannedPredefinedSettings)
            {
                justModified = true;
            }

            ModifiedProfiles = new List<string>();
            UserProfiles = new HashSet<string>();

            DrsSession((hSession) =>
            {
                IntPtr hBaseProfile = GetProfileHandle(hSession, "");
                var profileHandles = EnumProfileHandles(hSession);

                var maxProfileCount = profileHandles.Count;
                int curProfilePos = 0;

                var knownPredefines = new HashSet<uint>(600);
                knownPredefines.UnionWith(_commonSettingIds);
                var alreadyChecked = new List<uint>();
                var doubles = new List<uint>();

                foreach (IntPtr hProfile in profileHandles)
                {
                    if (token.IsCancellationRequested) break;

                    progress?.Report(CalcPercent(curProfilePos++, maxProfileCount));

                    var profile = GetProfileInfo(hSession, hProfile);

                    int checkedSettingsCount = 0;

                    bool foundModifiedProfile = false;
                    if (profile.isPredefined == 0)
                    {
                        ModifiedProfiles.Add(profile.profileName);
                        UserProfiles.Add(profile.profileName);
                        foundModifiedProfile = true;
                        if (justModified) continue;
                    }

                    alreadyChecked.Clear();

                    var settings = GetProfileSettings(hSession, hProfile, profile);
                    foreach (var setting in settings.Where(s => knownPredefines.Contains(s.settingId)))
                    {
                        var outSetting = setting;

                        if (CheckCommonSetting(hSession, hProfile, profile,
                           ref checkedSettingsCount, setting.settingId, !justModified, ref alreadyChecked, ref outSetting))
                        {
                            if (!foundModifiedProfile)
                            {
                                foundModifiedProfile = true;
                                ModifiedProfiles.Add(profile.profileName);
                                if (justModified) break;
                            }
                        }
                    }

                    if ((foundModifiedProfile && justModified) || checkedSettingsCount >= profile.numOfSettings)
                        continue;


                    foreach (var setting in settings)
                    {
                        if (!knownPredefines.Contains(setting.settingId))
                        {
                            knownPredefines.Add(setting.settingId);
                        }

                        if (!justModified && alreadyChecked.IndexOf(setting.settingId) < 0)
                            AddScannedSettingToCache(profile, setting);

                        if (setting.isCurrentPredefined != 1)
                        {
                            if (!foundModifiedProfile)
                            {
                                foundModifiedProfile = true;
                                ModifiedProfiles.Add(profile.profileName);
                                if (justModified) break;
                            }
                        }
                    }
                }
            });


            if (!justModified)
            {
                _scannedPredefinedSettings = true;
            }
        }

        public async Task ScanProfileSettingsAsync(bool justModified, IProgress<int> progress, CancellationToken token = default(CancellationToken))
        {
            await Task.Run(() => ScanProfileSettings(justModified, progress, token));
        }


        private void AddScannedSettingToCache(NVDRS_PROFILE profile, NVDRS_SETTING setting)
        {
            // Skip 3D Vision string values here for improved scan performance
            bool allowAddValue = setting.settingId < 0x70000000 || setting.settingType == NVDRS_SETTING_TYPE.NVDRS_DWORD_TYPE;

            //bool allowAddValue = true;

            var cachedSetting = CachedSettings
                .FirstOrDefault(x => x.SettingId.Equals(setting.settingId));

            bool cacheEntryExists = true;
            if (cachedSetting == null)
            {
                cacheEntryExists = false;
                cachedSetting = new CachedSettings(setting.settingId, setting.settingType);
            }

            if (setting.isPredefinedValid == 1)
            {
                if (allowAddValue)
                {
                    if (setting.settingType == NVDRS_SETTING_TYPE.NVDRS_WSTRING_TYPE)
                        cachedSetting.AddStringValue(setting.predefinedValue.stringValue, profile.profileName);
                    else if (setting.settingType == NVDRS_SETTING_TYPE.NVDRS_DWORD_TYPE)
                        cachedSetting.AddDwordValue(setting.predefinedValue.dwordValue, profile.profileName);
                    else if (setting.settingType == NVDRS_SETTING_TYPE.NVDRS_BINARY_TYPE)
                        cachedSetting.AddBinaryValue(setting.predefinedValue.binaryValue, profile.profileName);
                }
                else
                    cachedSetting.ProfileCount++;

                if (!cacheEntryExists)
                    CachedSettings.Add(cachedSetting);
            }

        }

        public string FindProfilesUsingApplication(string applicationName)
        {
            string lowerApplicationName = applicationName.ToLowerInvariant();
            string tmpfile = TempFile.GetTempFileName();

            try
            {
                var matchingProfiles = new List<string>();

                DrsSession((hSession) =>
                {
                    SaveSettingsFileEx(hSession, tmpfile);
                });

                if (File.Exists(tmpfile))
                {
                    string content = File.ReadAllText(tmpfile);
                    string pattern = "\\sProfile\\s\\\"(?<profile>.*?)\\\"(?<scope>.*?Executable.*?)EndProfile";
                    foreach (Match m in Regex.Matches(content, pattern, RegexOptions.Singleline))
                    {
                        string scope = m.Result("${scope}");
                        foreach (Match ms in Regex.Matches(scope, "Executable\\s\\\"(?<app>.*?)\\\"", RegexOptions.Singleline))
                        {
                            if (ms.Result("${app}").ToLowerInvariant() == lowerApplicationName)
                            {
                                matchingProfiles.Add(m.Result("${profile}"));
                            }
                        }
                    }
                }

                return string.Join(";", matchingProfiles);
            }
            finally
            {
                if (File.Exists(tmpfile))
                    File.Delete(tmpfile);
            }
        }

    }
}