/src/Kweh.Core/Win32/RegistryUtil.cs

using Microsoft.Win32;
using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Threading.Tasks;

namespace BadMishka.Kweh.Win32
{
    public static class RegistryUtil
    {


        public static RegistryKey FindUninstallKey(string displayName, Func<string, string, bool> comparison = null, string sid = null)
        {
            if (comparison == null)
                comparison = (left, right) =>
                {
                    if (string.IsNullOrWhiteSpace(right))
                        return false;

                    return left.StartsWith(right);
                };

            var list = new List<string>()
            {
                 @"HKLM:\SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall",
                 @"HKLM:\SOFTWARE\WOW6432Node\Microsoft\Windows\CurrentVersion\Uninstall",
                 @"HKCU:\SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall",
                 @"HKCU:\SOFTWARE\WOW6432Node\Microsoft\Windows\CurrentVersion\Uninstall",
                 $"HKU:\\{sid}\\SOFTWARE\\Microsoft\\Windows\\CurrentVersion\\Uninstall",
                 $"HKU:\\{sid}\\SOFTWARE\\WOW6432Node\\Microsoft\\Windows\\CurrentVersion\\Uninstall",
            };

            var noSid = string.IsNullOrWhiteSpace(sid);

            foreach(var subKeyName in list)
            {
                if (subKeyName.StartsWith("HKU") && noSid)
                    continue;

                var subKey = OpenSubKey(subKeyName);
                if (subKey == null)
                    continue;

                var subKeyNames = subKey.GetSubKeyNames();

                foreach(var guidSubKeyName in subKeyNames)
                {
                    var guidSubKey = subKey.OpenSubKey(guidSubKeyName);
                    var productDisplayName = guidSubKey.GetValue("DisplayName") as string;
                    if (productDisplayName == null)
                        continue;

                    if (comparison(productDisplayName, displayName))
                        return guidSubKey;
                }
            }

            return null;
        }


        public static RegistryKey FindUninstallKey(Guid productId, Func<string, string, bool> comparison = null, string sid = null)
        {
            if (comparison == null)
                comparison = (left, right) =>
                {
                    if (string.IsNullOrWhiteSpace(right))
                        return false;

                    return left.StartsWith(right);
                };

            var list = new List<string>()
            {
                 @"HKLM:\SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall",
                 @"HKLM:\SOFTWARE\WOW6432Node\Microsoft\Windows\CurrentVersion\Uninstall",
                 @"HKCU:\SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall",
                 @"HKCU:\SOFTWARE\WOW6432Node\Microsoft\Windows\CurrentVersion\Uninstall",
                 $"HKU:\\{sid}\\SOFTWARE\\Microsoft\\Windows\\CurrentVersion\\Uninstall",
                 $"HKU:\\{sid}\\SOFTWARE\\WOW6432Node\\Microsoft\\Windows\\CurrentVersion\\Uninstall",
            };

            var noSid = string.IsNullOrWhiteSpace(sid);

            foreach (var subKeyName in list)
            {
                if (subKeyName.StartsWith("HKU") && noSid)
                    continue;

                var subKey = OpenSubKey(subKeyName + "\\" + productId.ToString());
                if (subKey != null)
                    return subKey;
            }

            return null;
        }

        public static RegistryKey OpenSubKey(string registryPath)
        {
            if (string.IsNullOrWhiteSpace(registryPath))
                throw new ArgumentNullException(nameof(registryPath));

            if(!registryPath.Contains(":"))
                throw new ArgumentException("registryPath is missing registry drive", nameof(registryPath));

            var delimiterIndex = registryPath.IndexOf(":");
            var drive = registryPath.Substring(0, delimiterIndex);
            var subKey = registryPath.Substring(delimiterIndex + 2);

            Console.WriteLine(drive);
            Console.WriteLine(subKey);

            switch (drive)
            {
                case "HKU":
                    return Registry.Users.OpenSubKey(subKey);
                case "HKCU":
                    return Registry.CurrentUser.OpenSubKey(subKey);
                case "HKLM":
                    return Registry.LocalMachine.OpenSubKey(subKey);

                default:
                    throw new NotSupportedException($"Unknown registry drive {drive}");
            }
        }

        public static string FindEnvironmentVariableForUser(string variableName, string sid = null)
        {
            var normalizedName = variableName.ToLowerInvariant();
            RegistryKey sidKey = null;
            RegistryKey subKey = null;
            var mapped = new Dictionary<string, string>()
            {
                { "localappdata", "Local AppData"},
                { "local appdata", "Local AppData"},
                { "documents", "Personal" }
            };


            if (sid == null)
            {
                switch (normalizedName)
                {
                    case "tmp":
                        return Environment.GetEnvironmentVariable("TEMP");

                    case "local appdata":
                        return Environment.GetEnvironmentVariable("LOCALAPPDATA");

                    case "onedrive":
                        subKey = Registry.CurrentUser.OpenSubKey(@"SOFTWARE\Microsoft\OneDrive\Accounts");
                        if (subKey == null)
                            return null;
                        subKey = subKey.OpenSubKey("Personal");
                        if (subKey == null)
                            return null;

                        return subKey.GetValue("UserFolder") as string;
                    case "onedrivebusiness":
                        subKey = Registry.CurrentUser.OpenSubKey(@"SOFTWARE\Microsoft\OneDrive\Accounts");
                        if (subKey == null)
                            return null;
                        subKey = subKey.OpenSubKey("Business1");
                        if (subKey == null)
                            return null;

                        return subKey.GetValue("UserFolder") as string;
                    case "documents":
                    case "my music":
                    case "my pictures":
                    case "my video":
                    case "personal":
                    case "cache":
                    case "cookies":
                    case "fonts":
                    case "history":
                    case "favorites":
                    case "desktop":
                    case "programs":
                        var localName = variableName;

                        if (mapped.ContainsKey(normalizedName))
                            localName = mapped[normalizedName];


                        subKey = Registry.CurrentUser.OpenSubKey(@"SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer\Shell Folders");
                        if (subKey == null)
                            return null;

                        return subKey.GetValue(localName) as string;
                }

                return Environment.GetEnvironmentVariable(variableName);
            }

            switch (normalizedName)
            {
                case "userprofile":
                    subKey = Registry.LocalMachine.OpenSubKey(@"SOFTWARE\Microsoft\Windows NT\CurrentVersion\ProfileList\" + sid);
                    if (subKey == null)
                        return null;

                    return subKey.GetValue("ProfileImagePath") as string;
                case "onedrive":
                    sidKey = Registry.Users.OpenSubKey(sid);
                    if (sidKey == null)
                        return null;

                    subKey = sidKey.OpenSubKey(@"SOFTWARE\Microsoft\OneDrive\Accounts");
                    if (subKey == null)
                        return null;
                    subKey = subKey.OpenSubKey("Personal");
                    if (subKey == null)
                        return null;

                    return subKey.GetValue("UserFolder") as string;
                case "onedrivebusiness":
                    sidKey = Registry.Users.OpenSubKey(sid);
                    if (sidKey == null)
                        return null;

                    subKey = sidKey.OpenSubKey(@"SOFTWARE\Microsoft\OneDrive\Accounts");
                    if (subKey == null)
                        return null;
                    subKey = subKey.OpenSubKey("Business1");
                    if (subKey == null)
                        return null;

                    return subKey.GetValue("UserFolder") as string;
                case "temp":
                case "tmp":
                case "local appdata":
                case "localappdata":
                case "appdata":
                case "documents":
                case "personal":
                case "cache":
                case "cookies":
                case "my music":
                case "my pictures":
                case "my video":
                case "favorites":
                case "fonts":
                case "history":
                case "desktop":
                case "programs":
                    var localName = variableName;

                    if (mapped.ContainsKey(normalizedName))
                        localName = mapped[normalizedName];


                    sidKey = Registry.Users.OpenSubKey(sid);
                    if (sidKey == null)
                        return null;

                    subKey = sidKey.OpenSubKey(@"SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer\Shell Folders");
                    if (subKey == null)
                        return null;

                    var value = subKey.GetValue(localName) as string;
                    if (value != null && normalizedName == "temp" || normalizedName == "tmp")
                        return Path.Combine(value , "Temp");

                    return value;

                default:

                    subKey = Registry.Users.OpenSubKey(sid);
                  
                    if (subKey != null)
                    {
                        subKey = subKey.OpenSubKey(@"Environment");
                        if (subKey != null)
                        {
                            var keys = subKey.GetSubKeyNames();
                            foreach (var key in keys)
                            {
                                if (normalizedName == key.ToLowerInvariant())
                                {
                                    var path = subKey.GetValue(key) as string;
                                    if (path.Contains("%USERPROFILE%"))
                                    {
                                        subKey = Registry.LocalMachine.OpenSubKey(@"SOFTWARE\Microsoft\Windows NT\CurrentVersion\ProfileList\" + sid);
                                        if (subKey != null)
                                        {
                                            var userProfile = subKey.GetValue("ProfileImagePath") as string;
                                            path = path.Replace("%USERPROFILE%", userProfile ?? "");
                                        }
                                    }

                                    if (path.Contains("%"))
                                    {
                                        //TODO handle other values;
                                    }

                                    return path;
                                }
                            }
                        }
                    }


                    var globalVariables = Environment.GetEnvironmentVariables();
                    foreach (string key in globalVariables.Keys)
                    {
                        if (key.ToLowerInvariant() == normalizedName)
                        {
                            return Environment.GetEnvironmentVariable(key);
                        }
                    }

                    return null;
            }

        }
    }
}