using Renci.SshNet;

namespace AiQ_GUI
{
    internal class SSH
    {
        public const string SSHUsername = "mav";
        public const string SSHPassword = "mavPA$$";

        // Connects to camera over SSH and collects the Vaxtor packages, filesystem name, filesystem size, and tailscale status.
        public static SSHData CollectSSHData(string IPAddress)
        {
            SSHData Data = new();

            try
            {
                using SshClient client = new SshClient(IPAddress, SSHUsername, SSHPassword);
                client.Connect();

                try
                {
                    Data.packages = GetVaxtorPackages(client);
                }
                catch (Exception ex)
                {
                    MainForm.Instance.AddToActionsList($"Failed to get Vaxtor packages: {ex.Message}");
                    Data.packages = "Error";
                }

                try
                {
                    (Data.FilesystemName, Data.FilesystemSize) = GetRootFilesystemInfo(client);
                }
                catch (Exception ex)
                {
                    MainForm.Instance.AddToActionsList($"Failed to get filesystem info: {ex.Message}");
                    Data.FilesystemName = "Unknown";
                    Data.FilesystemSize = "Unknown";
                }

                try
                {
                    Data.tailscale = IsTailscaleInstalled(client);
                }
                catch (Exception ex)
                {
                    MainForm.Instance.AddToActionsList($"Failed to check Tailscale: {ex.Message}");
                    Data.tailscale = false;
                }

                client.Disconnect();
            }
            catch (Exception ex)
            {
                MainForm.Instance.AddToActionsList($"SSH connection failed: {ex.Message}. Check password or network.");
            }

            string LogMssg = string.Join(" | ", typeof(SSHData).GetProperties().Select(p => $"{p.Name}: {p.GetValue(Data)}"));
            Logging.LogMessage(LogMssg); // Log all of Data

            return Data;
        }

        // Gets a list of packages with Vaxtor in the name
        public static string GetVaxtorPackages(SshClient client)
        {
            try
            {
                SshCommand cmd = client.RunCommand("dpkg -l | grep vaxtor");
                if (!string.IsNullOrWhiteSpace(cmd.Error))
                    throw new Exception(cmd.Error);

                string result = cmd.Result;
                if (string.IsNullOrWhiteSpace(result))
                    return "No Vaxtor packages found.";

                string[] lines = result.Split(['\r', '\n'], StringSplitOptions.RemoveEmptyEntries);
                List<string> packages = [];

                foreach (string line in lines)
                {
                    string[] parts = line.Split([' '], StringSplitOptions.RemoveEmptyEntries);

                    if (parts.Length >= 3)
                        packages.Add($"{parts[1]} - {parts[2]}"); // Package name - Version
                }

                return packages.Count > 0 ? string.Join("\n", packages) : "No Vaxtor packages found.";
            }
            catch (Exception ex)
            {
                MainForm.Instance.AddToActionsList($"Error getting Vaxtor packages: {ex.Message}");
                return "Error";
            }
        }

        // Returns true if Tailscale is installed on the camera
        public static bool IsTailscaleInstalled(SshClient client)
        {
            try
            {
                SshCommand cmd = client.RunCommand("dpkg -l | grep '^ii' | grep tailscale");
                if (!string.IsNullOrWhiteSpace(cmd.Error))
                    throw new Exception(cmd.Error);

                string command = cmd.Result;
                if (string.IsNullOrWhiteSpace(command))
                    return false;

                string[] lines = command.Split(['\r', '\n'], StringSplitOptions.RemoveEmptyEntries);

                foreach (string line in lines)
                {
                    string[] parts = line.Split([' '], StringSplitOptions.RemoveEmptyEntries);

                    if (parts.Length >= 3 && parts[1].Equals("tailscale", StringComparison.OrdinalIgnoreCase))
                        return true; // Return true if any line contains "tailscale" as the package name
                }

                return false;
            }
            catch (Exception ex)
            {
                MainForm.Instance.AddToActionsList($"Error checking Tailscale: {ex.Message}");
                return false;
            }
        }

        // Connects to camera over SSH and collects the Vaxtor packages, filesystem name, filesystem size, and tailscale status.
        public static (string filesystem, string size) CollectFSData(string IPAddress)
        {
            try
            {
                using SshClient client = new SshClient(IPAddress, SSHUsername, SSHPassword);
                client.Connect();

                try
                {
                    return GetRootFilesystemInfo(client);
                }
                catch (Exception ex)
                {
                    MainForm.Instance.AddToActionsList($"Failed to get filesystem info: {ex.Message}");
                }

                client.Disconnect();
            }
            catch (Exception ex)
            {
                MainForm.Instance.AddToActionsList($"SSH connection failed: {ex.Message}. Check password or network.");
            }

            return (string.Empty, string.Empty);
        }

        // Gets the filesystem size and partition name
        public static (string filesystem, string size) GetRootFilesystemInfo(SshClient client)
        {
            try
            {
                SshCommand cmd = client.RunCommand("df -h");
                if (!string.IsNullOrWhiteSpace(cmd.Error))
                    throw new Exception(cmd.Error);

                string result = cmd.Result;
                if (string.IsNullOrWhiteSpace(result))
                    return ("Unknown", "Unknown");

                IEnumerable<string> lines = result.Split(['\r', '\n'], StringSplitOptions.RemoveEmptyEntries).Skip(1);

                foreach (string line in lines)
                {
                    string[] parts = line.Split([' '], StringSplitOptions.RemoveEmptyEntries);

                    // Long enough & Filesystem name isn't tmpfs varient or none & Mountpoint is root
                    if (parts.Length >= 6 && !parts[0].Contains("tmpfs") && parts[0] != "none" && parts[5] == "/")
                        return (parts[0], parts[1]); // Return name & size of partition
                }

                return ("Unknown", "Unknown");
            }
            catch (Exception ex)
            {
                MainForm.Instance.AddToActionsList($"Error getting filesystem info: {ex.Message}");
                return ("Unknown", "Unknown");
            }
        }

        // Sorts the SSH client for the filesystem call
        public static (string filesystem, string size) GetRootFilesystemInfo(string IPAddress)
        {
            try
            {
                using SshClient client = new(IPAddress, SSHUsername, SSHPassword);
                client.Connect();
                (string FilesystemName, string FilesystemSize) = GetRootFilesystemInfo(client);
                client.Disconnect();
                return (FilesystemName, FilesystemSize);
            }
            catch (Exception ex)
            {
                MainForm.Instance.AddToActionsList($"Error getting root filesystem info: {ex.Message}");
                return ("Unknown", "Unknown");
            }
        }

        // Checks the filesystem size and expands it if necessary, displays on the label how big the SD card is.
        public static async Task<SSHData> CheckFSSize(string IPAddress, Label LblFSSize, SSHData sshData)
        {
            const double MinGoodSize = 100.0; // 100GB
            const double MaxGoodSize = 150.0; // 150GB

            double currentSize = NormaliseFSSize(sshData.FilesystemSize);
            LblFSSize.Text = $"Filesystem Size = {currentSize}GB";

            if (currentSize >= MinGoodSize && currentSize <= MaxGoodSize)
            {
                LblFSSize.ForeColor = Color.LightGreen;
                return sshData;
            }

            if (currentSize < MinGoodSize)
            {
                try
                {
                    if (await ExpandFS(sshData.FilesystemName, IPAddress))
                    {
                        (sshData.FilesystemName, sshData.FilesystemSize) = GetRootFilesystemInfo(IPAddress);

                        double newSize = NormaliseFSSize(sshData.FilesystemSize);
                        LblFSSize.Text = $"Filesystem Size = {newSize}GB";

                        if (newSize >= MinGoodSize && newSize <= MaxGoodSize)
                        {
                            LblFSSize.ForeColor = Color.LightGreen;
                            return sshData;
                        }
                    }
                }
                catch (Exception ex)
                {
                    MainForm.Instance.AddToActionsList($"Error expanding filesystem: {ex.Message}");
                }

                LblFSSize.ForeColor = Color.Red;
                MainForm.Instance.AddToActionsList("Size is too small, failed to expand FS, please try manually.");
                return sshData;
            }

            LblFSSize.ForeColor = Color.Red;
            LblFSSize.Text += " Size is too big.";
            return sshData;
        }

        // Makes sure the units given are accounted for when calcualting the size of the SD card.
        public static double NormaliseFSSize(string rootSize)
        {
            try
            {
                if (string.IsNullOrWhiteSpace(rootSize)) return 0;

                // Extract value & unit
                System.Text.RegularExpressions.Match match = RegexCache.FileSizeRegex().Match(rootSize.Trim());
                if (!match.Success)
                    return 0;

                if (!double.TryParse(match.Groups["value"].Value, out double value))
                    return 0;

                string unit = match.Groups["unit"].Value.ToUpperInvariant();

                switch (unit) // Normalize to gigabytes
                {
                    case "T": value *= 1024; break;
                    case "G": break;
                    case "M": value /= 1024; break;
                    case "K": value /= 1024 * 1024; break;
                    case "": value /= 1024 * 1024 * 1024; break; // assume bytes
                    default: value = 0; break;
                }

                return value;
            }
            catch (Exception ex)
            {
                MainForm.Instance.AddToActionsList($"Error normalizing FS size: {ex.Message}");
            }
            return 0;
        }

        // Expands the filesystem to max 
        public async static Task<bool> ExpandFS(string device, string IPAddress)
        {
            try
            {
                using SshClient ssh = new SshClient(IPAddress, SSHUsername, SSHPassword);
                ssh.Connect();

                SshCommand checkDevice = ssh.RunCommand($"[ -b {device} ] && echo OK || echo NOT_FOUND");
                if (!string.IsNullOrWhiteSpace(checkDevice.Error))
                    throw new Exception(checkDevice.Error);

                if (checkDevice.Result.Trim() != "OK") // Device not found
                {
                    MainForm.Instance.AddToActionsList($"Block device {device} not found.");
                    return false;
                }

                SshCommand umountCmd = ssh.RunCommand($"sudo umount {device}");
                if (!string.IsNullOrWhiteSpace(umountCmd.Error) && !umountCmd.Error.Contains("not mounted"))
                {
                    MainForm.Instance.AddToActionsList($"Unmount error: {umountCmd.Error}");
                    return false;
                }

                await Task.Delay(1000); // Wait for mount to settle

                SshCommand fsckCmd = ssh.RunCommand($"sudo e2fsck -f -y -v -C 0 {device}");
                if (!string.IsNullOrWhiteSpace(fsckCmd.Error))
                {
                    MainForm.Instance.AddToActionsList($"e2fsck error: {fsckCmd.Error}");
                    return false;
                }

                SshCommand resizeFs = ssh.RunCommand($"sudo resize2fs {device}");
                ssh.Disconnect();

                if (!string.IsNullOrWhiteSpace(resizeFs.Error))
                {
                    MainForm.Instance.AddToActionsList($"resize2fs error: {resizeFs.Error}");
                    return false;
                }

                if (resizeFs.ExitStatus == 0)
                    return true;

                MainForm.Instance.AddToActionsList($"resize2fs failed with exit code {resizeFs.ExitStatus}");
                return false;
            }
            catch (Exception ex)
            {
                MainForm.Instance.AddToActionsList($"Error expanding filesystem: {ex.Message}");
                return false;
            }
        }

        public static void Sync(string IPAddress)
        {
            try
            {
                using SshClient ssh = new SshClient(IPAddress, SSHUsername, SSHPassword);
                ssh.Connect();

                SshCommand checkDevice = ssh.RunCommand("sync");
                if (!string.IsNullOrWhiteSpace(checkDevice.Error))
                    throw new Exception(checkDevice.Error);

                if (checkDevice.Result.Trim().Length > 1) // Device not found
                {
                    MainForm.Instance.AddToActionsList($"Cannot sync files to disk. Replied: {checkDevice.Result}. DO NOT TURN OFF, GET SUPERVISOR");
                    return;
                }
            }
            catch (Exception ex)
            {
                MainForm.Instance.AddToActionsList($"Cannot sync becuase: {ex.Message}. DO NOT TURN OFF, GET SUPERVISOR");
            }
        }
    }

    public class SSHData
    {
        public string packages { get; set; } = string.Empty;
        public string FilesystemName { get; set; } = string.Empty;
        public string FilesystemSize { get; set; } = string.Empty;
        public bool tailscale { get; set; }
    }
}