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

class Program
{
    private class KernelMenuItem
    {
        public string Name { get; set; }
        public bool IsSelected { get; set; }
        public bool IsInitiallyInstalled { get; set; }
    }

    static void Main(string[] args)
    {
        Console.CursorVisible = false;
        Console.Clear();

        Console.WriteLine("CachyOS Kernel Manager");
        Console.WriteLine("----------------------");

        List<KernelMenuItem> menuItems = InitializeKernelMenuItems();
        int selectedIndex = 0;

        while (true)
        {
            DrawMenu(menuItems, selectedIndex);

            ConsoleKeyInfo key = Console.ReadKey(true);

            switch (key.Key)
            {
                case ConsoleKey.UpArrow:
                    selectedIndex = (selectedIndex == 0) ? menuItems.Count - 1 : selectedIndex - 1;
                    break;
                case ConsoleKey.DownArrow:
                    selectedIndex = (selectedIndex == menuItems.Count - 1) ? 0 : selectedIndex + 1;
                    break;
                case ConsoleKey.Spacebar:
                    menuItems[selectedIndex].IsSelected = !menuItems[selectedIndex].IsSelected;
                    break;
                case ConsoleKey.Enter:
                    Console.Clear();
                    Console.WriteLine("Processing kernel changes...");
                    foreach (var item in menuItems.Where(item => !item.IsInitiallyInstalled && item.IsSelected))
                    {
                        Console.WriteLine($"\nPreparing to install {item.Name}...");
                        if (InstallKernel(item.Name))
                        {
                            Console.WriteLine($"Kernel {item.Name} installed successfully.");
                        }
                        else
                        {
                            Console.WriteLine($"Failed to install {item.Name}. Please check the output above for errors.");
                        }
                    }
                    foreach (var item in menuItems.Where(item => item.IsInitiallyInstalled && !item.IsSelected))
                    {
                        Console.WriteLine($"\nPreparing to uninstall {item.Name}...");
                        if (UninstallKernel(item.Name))
                        {
                            Console.WriteLine($"Kernel {item.Name} uninstalled successfully.");
                        }
                        else
                        {
                            Console.WriteLine($"Failed to uninstall {item.Name}. Please check the output above for errors.");
                        }
                    }
                    Console.WriteLine("\nAll selected operations complete. Please reboot to apply changes. Press any key to exit.");
                    Console.ReadKey(true);
                    return;
                case ConsoleKey.Q:
                    return;
            }
        }
    }

    static void DrawMenu(List<KernelMenuItem> menuItems, int selectedIndex)
    {
        Console.SetCursorPosition(0, 3);
        for (int i = 0; i < menuItems.Count; i++)
        {
            Console.SetCursorPosition(0, 3 + i);
            if (i == selectedIndex)
            {
                Console.BackgroundColor = ConsoleColor.White;
                Console.ForegroundColor = ConsoleColor.Black;
            }
            Console.Write($"{(menuItems[i].IsSelected ? "[X]" : "[ ]")}" + " " + $"{menuItems[i].Name}");
            Console.ResetColor();
            Console.WriteLine(new string(' ', Console.WindowWidth - Console.CursorLeft));
        }
        Console.SetCursorPosition(0, 3 + menuItems.Count);
        Console.WriteLine("\nUse \u2191\u2193 to navigate, SPACE to select/deselect, ENTER to apply, Q to quit.");
    }

    static List<KernelMenuItem> InitializeKernelMenuItems()
    {
        var installedKernels = GetInstalledKernels();
        var availableCachyosKernels = new List<string>
        {
            "linux-cachyos-bmq",
            "linux-cachyos-bore",
            "linux-cachyos-deckify",
            "linux-cachyos-eevdf",
            "linux-cachyos-hardened",
            "linux-cachyos-lts",
            "linux-cachyos-rc",
            "linux-cachyos-rt-bore",
            "linux-cachyos-server",
            "linux-cachyos"
        };

        var commonArchKernels = new List<string>
        {
            "linux",
            "linux-lts",
            "linux-zen",
            "linux-hardened",
            "linux-rt"
        };

        var allKernelNames = availableCachyosKernels
            .Concat(commonArchKernels)
            .Distinct()
            .OrderBy(k => k)
            .ToList();

        var menuItems = new List<KernelMenuItem>();
        foreach (var kernelName in allKernelNames)
        {
            bool isInstalled = installedKernels.Contains(kernelName);
            menuItems.Add(new KernelMenuItem
            {
                Name = kernelName,
                IsSelected = isInstalled,
                IsInitiallyInstalled = isInstalled
            });
        }
        return menuItems;
    }

    static HashSet<string> GetInstalledKernels()
    {
        var installed = new HashSet<string>();
        var process = new Process
        {
            StartInfo = new ProcessStartInfo
            {
                FileName = "pacman",
                Arguments = "-Q",
                RedirectStandardOutput = true,
                UseShellExecute = false,
                CreateNoWindow = true,
            }
        };

        try
        {
            process.Start();
            string output = process.StandardOutput.ReadToEnd();
            process.WaitForExit();

            if (process.ExitCode == 0)
            {
                foreach (var line in output.Split(new[] { '\n' }, StringSplitOptions.RemoveEmptyEntries))
                {
                    var parts = line.Split(' ');
                    if (parts.Length > 0)
                    {
                        string packageName = parts[0];
                        if (packageName.StartsWith("linux") || packageName.StartsWith("cachyos-linux"))
                        {
                            installed.Add(packageName);
                        }
                    }
                }
            }
        }
        catch (Exception ex)
        {
            Console.WriteLine($"Error getting installed kernels: {ex.Message}");
        }
        return installed;
    }

    static bool InstallKernel(string kernelName)
    {
        string headersPackageName = kernelName + "-headers";
        Console.WriteLine($"Running: sudo pacman -S --noconfirm {kernelName} {headersPackageName}");
        Console.WriteLine("You may be prompted for your password.");
        
        var process = new Process
        {
            StartInfo = new ProcessStartInfo
            {
                FileName = "sudo",
                Arguments = $"pacman -S --noconfirm {kernelName} {headersPackageName}",
                UseShellExecute = true,
            }
        };

        try
        {
            process.Start();
            process.WaitForExit();
            return process.ExitCode == 0;
        }
        catch (Exception ex)
        {
            Console.WriteLine($"Error installing kernel: {ex.Message}");
            return false;
        }
    }

    static bool UninstallKernel(string kernelName)
    {
        string headersPackageName = kernelName + "-headers";
        Console.WriteLine($"Running: sudo pacman -Rns --noconfirm {kernelName} {headersPackageName}");
        Console.WriteLine("You may be prompted for your password.");
        
        var process = new Process
        {
            StartInfo = new ProcessStartInfo
            {
                FileName = "sudo",
                Arguments = $"pacman -Rns --noconfirm {kernelName} {headersPackageName}",
                UseShellExecute = true,
            }
        };

        try
        {
            process.Start();
            process.WaitForExit();
            return process.ExitCode == 0;
        }
        catch (Exception ex)
        {
            Console.WriteLine($"Error uninstalling kernel: {ex.Message}");
            return false;
        }
    }
}