using System;
using System.Collections.Generic;
using System.IO;
using System.Security.AccessControl;
using System.Security.Principal;
using Microsoft.Win32;
using NitroxModel.Platforms.OS.Shared;
using NitroxModel.Platforms.OS.Windows.Internal;

namespace NitroxModel.Platforms.OS.Windows;


#if NET5_0_OR_GREATER
[System.Runtime.Versioning.SupportedOSPlatform("windows")]
#endif
internal class WinFileSystem : FileSystem
{
    public override IEnumerable<string> ExecutableFileExtensions { get; } = ["exe", "cmd", "bat"];
    public override string TextEditor => GetFullPath("notepad.exe");

    public override IEnumerable<string> GetDefaultPrograms(string file)
    {
        string SearchExecutableInSameDirectory(string path)
        {
            if (Path.GetExtension(path) != "")
            {
                return path;
            }

            foreach (string ext in ExecutableFileExtensions)
            {
                string newPath = Path.ChangeExtension(path, ext);
                if (File.Exists(newPath))
                {
                    return newPath;
                }
            }

            return path;
        }

        string extension = Path.GetExtension(file);
        if (string.IsNullOrWhiteSpace(extension))
        {
            yield break;
        }

        string defaultProgramOnDblClick = Win32Native.AssocQueryString(Win32Native.AssocStr.Executable, extension);
        if (!string.IsNullOrWhiteSpace(defaultProgramOnDblClick) && File.Exists(defaultProgramOnDblClick))
        {
            yield return Path.GetFullPath(defaultProgramOnDblClick);
        }

        string baseKey = $@"Software\Microsoft\Windows\CurrentVersion\Explorer\FileExts\{extension}";
        using RegistryKey rk = Registry.CurrentUser.OpenSubKey($@"{baseKey}\OpenWithList");
        if (rk?.GetValue("MRUList") is not string mruList)
        {
            yield break;
        }

        foreach (char c in mruList)
        {
            string fullPath = SearchExecutableInSameDirectory(GetFullPath(rk.GetValue(c.ToString()).ToString()));
            if (fullPath == null)
            {
                continue;
            }

            yield return fullPath;
        }
    }

    /// <summary>
    ///     Adds full access flag to the directory (and sub files/directories) for the current user.
    /// </summary>
    /// <param name="directory"></param>
    /// <returns>True if set, false if program is not allowed to change permissions.</returns>
    public override bool SetFullAccessToCurrentUser(string directory)
    {
        try
        {
            string identity = WindowsIdentity.GetCurrent().Name;

            DirectoryInfo dir = new(directory);
            DirectorySecurity flags = dir.GetAccessControl();
            flags.AddAccessRule(new(identity, FileSystemRights.FullControl, InheritanceFlags.None, PropagationFlags.InheritOnly, AccessControlType.Allow));
            flags.AddAccessRule(new (identity, FileSystemRights.FullControl, InheritanceFlags.ContainerInherit, PropagationFlags.InheritOnly, AccessControlType.Allow));
            flags.AddAccessRule(new (identity, FileSystemRights.FullControl, InheritanceFlags.ObjectInherit, PropagationFlags.InheritOnly, AccessControlType.Allow));
            dir.SetAccessControl(flags);
            return true;
        }
        catch (UnauthorizedAccessException)
        {
            return false;
        }
    }

    public override bool IsTrustedFile(string file) => Win32Native.IsTrusted(file);
}