using System.Collections.ObjectModel;
using System.Security.Cryptography;
using CommunityToolkit.Mvvm.ComponentModel;
using CommunityToolkit.Mvvm.Input;
using Microsoft.EntityFrameworkCore;
using Microsoft.Extensions.DependencyInjection;
using OTSSignsOrchestrator.Core.Data;
using OTSSignsOrchestrator.Core.Models.DTOs;
using OTSSignsOrchestrator.Core.Models.Entities;
using OTSSignsOrchestrator.Core.Services;
using OTSSignsOrchestrator.Desktop.Services;

namespace OTSSignsOrchestrator.Desktop.ViewModels;

/// <summary>
/// ViewModel for the Create Instance form.
/// Simplified: Customer Name, Abbreviation, SSH Host, and optional Newt credentials.
/// All other config comes from the Settings page.
/// </summary>
public partial class CreateInstanceViewModel : ObservableObject
{
    private readonly IServiceProvider _services;

    [ObservableProperty] private string _statusMessage = string.Empty;
    [ObservableProperty] private bool _isBusy;
    [ObservableProperty] private string _deployOutput = string.Empty;
    [ObservableProperty] private double _progressPercent;
    [ObservableProperty] private string _progressStep = string.Empty;

    // Core form fields — only these two are required from the user
    [ObservableProperty] private string _customerName = string.Empty;
    [ObservableProperty] private string _customerAbbrev = string.Empty;

    // Optional Pangolin/Newt credentials (per-instance)
    [ObservableProperty] private string _newtId = string.Empty;
    [ObservableProperty] private string _newtSecret = string.Empty;

    // CIFS / SMB credentials (per-instance, defaults loaded from global settings)
    [ObservableProperty] private string _cifsServer = string.Empty;
    [ObservableProperty] private string _cifsShareBasePath = string.Empty;
    [ObservableProperty] private string _cifsUsername = string.Empty;
    [ObservableProperty] private string _cifsPassword = string.Empty;
    [ObservableProperty] private string _cifsExtraOptions = string.Empty;

    // SSH host selection
    [ObservableProperty] private ObservableCollection<SshHost> _availableHosts = new();
    [ObservableProperty] private SshHost? _selectedSshHost;

    // ── Derived preview properties ───────────────────────────────────────────

    public string PreviewStackName      => Valid ? $"{Abbrev}-cms-stack"      : "—";
    public string PreviewServiceWeb     => Valid ? $"{Abbrev}-web"            : "—";
    public string PreviewServiceCache   => Valid ? $"{Abbrev}-memcached"      : "—";
    public string PreviewServiceChart   => Valid ? $"{Abbrev}-quickchart"     : "—";
    public string PreviewServiceNewt    => Valid ? $"{Abbrev}-newt"           : "—";
    public string PreviewNetwork        => Valid ? $"{Abbrev}-net"            : "—";
    public string PreviewVolCustom      => Valid ? $"{Abbrev}-cms-custom"     : "—";
    public string PreviewVolBackup      => Valid ? $"{Abbrev}-cms-backup"     : "—";
    public string PreviewVolLibrary     => Valid ? $"{Abbrev}-cms-library"    : "—";
    public string PreviewVolUserscripts => Valid ? $"{Abbrev}-cms-userscripts": "—";
    public string PreviewVolCaCerts     => Valid ? $"{Abbrev}-cms-ca-certs"   : "—";
    public string PreviewSecret         => Valid ? $"{Abbrev}-cms-db-password": "—";
    public string PreviewMySqlDb        => Valid ? $"{Abbrev}_cms_db"         : "—";
    public string PreviewMySqlUser      => Valid ? $"{Abbrev}_cms"            : "—";
    public string PreviewCmsUrl         => Valid ? $"https://{Abbrev}.ots-signs.com" : "—";

    private string Abbrev => CustomerAbbrev.Trim().ToLowerInvariant();
    private bool Valid => Abbrev.Length == 3 && System.Text.RegularExpressions.Regex.IsMatch(Abbrev, "^[a-z]{3}$");

    // ─────────────────────────────────────────────────────────────────────────

    public CreateInstanceViewModel(IServiceProvider services)
    {
        _services = services;
        _ = LoadHostsAsync();
        _ = LoadCifsDefaultsAsync();
    }

    partial void OnCustomerAbbrevChanged(string value) => RefreshPreview();

    private void RefreshPreview()
    {
        OnPropertyChanged(nameof(PreviewStackName));
        OnPropertyChanged(nameof(PreviewServiceWeb));
        OnPropertyChanged(nameof(PreviewServiceCache));
        OnPropertyChanged(nameof(PreviewServiceChart));
        OnPropertyChanged(nameof(PreviewServiceNewt));
        OnPropertyChanged(nameof(PreviewNetwork));
        OnPropertyChanged(nameof(PreviewVolCustom));
        OnPropertyChanged(nameof(PreviewVolBackup));
        OnPropertyChanged(nameof(PreviewVolLibrary));
        OnPropertyChanged(nameof(PreviewVolUserscripts));
        OnPropertyChanged(nameof(PreviewVolCaCerts));
        OnPropertyChanged(nameof(PreviewSecret));
        OnPropertyChanged(nameof(PreviewMySqlDb));
        OnPropertyChanged(nameof(PreviewMySqlUser));
        OnPropertyChanged(nameof(PreviewCmsUrl));
    }

    private async Task LoadHostsAsync()
    {
        using var scope = _services.CreateScope();
        var db = scope.ServiceProvider.GetRequiredService<XiboContext>();
        var hosts = await db.SshHosts.OrderBy(h => h.Label).ToListAsync();
        AvailableHosts = new ObservableCollection<SshHost>(hosts);
    }

    private async Task LoadCifsDefaultsAsync()
    {
        using var scope = _services.CreateScope();
        var settings = scope.ServiceProvider.GetRequiredService<SettingsService>();
        CifsServer = await settings.GetAsync(SettingsService.CifsServer) ?? string.Empty;
        CifsShareBasePath = await settings.GetAsync(SettingsService.CifsShareBasePath) ?? string.Empty;
        CifsUsername = await settings.GetAsync(SettingsService.CifsUsername) ?? string.Empty;
        CifsPassword = await settings.GetAsync(SettingsService.CifsPassword) ?? string.Empty;
        CifsExtraOptions = await settings.GetAsync(SettingsService.CifsOptions, "file_mode=0777,dir_mode=0777");
    }

    [RelayCommand]
    private async Task DeployAsync()
    {
        // ── Validation ───────────────────────────────────────────────────
        if (SelectedSshHost == null)
        {
            StatusMessage = "Select an SSH host first.";
            return;
        }
        if (string.IsNullOrWhiteSpace(CustomerName))
        {
            StatusMessage = "Customer Name is required.";
            return;
        }
        if (!Valid)
        {
            StatusMessage = "Abbreviation must be exactly 3 lowercase letters (a-z).";
            return;
        }

        IsBusy = true;
        StatusMessage = "Starting deployment...";
        DeployOutput = string.Empty;
        ProgressPercent = 0;

        try
        {
            // Wire SSH host into docker services
            var dockerCli = _services.GetRequiredService<SshDockerCliService>();
            dockerCli.SetHost(SelectedSshHost);
            var dockerSecrets = _services.GetRequiredService<SshDockerSecretsService>();
            dockerSecrets.SetHost(SelectedSshHost);
            var ssh = _services.GetRequiredService<SshConnectionService>();

            using var scope = _services.CreateScope();
            var instanceSvc = scope.ServiceProvider.GetRequiredService<InstanceService>();

            // ── Step 1: Clone template repo ────────────────────────────────
            SetProgress(10, "Cloning template repository...");
            // Handled inside InstanceService.CreateInstanceAsync

            // ── Step 2: Generate MySQL password → Docker secret ────────────
            SetProgress(20, "Generating secrets...");
            var mysqlPassword = GenerateRandomPassword(32);

            // ── Step 3: Create MySQL database + user via SSH ───────────────
            SetProgress(35, "Creating MySQL database and user...");
            var (mysqlOk, mysqlMsg) = await instanceSvc.CreateMySqlDatabaseAsync(
                Abbrev,
                mysqlPassword,
                cmd => ssh.RunCommandAsync(SelectedSshHost, cmd));

            AppendOutput($"[MySQL] {mysqlMsg}");
            if (!mysqlOk)
            {
                StatusMessage = mysqlMsg;
                return;
            }

            // ── Step 4: Create Docker Swarm secret ────────────────────────
            SetProgress(50, "Creating Docker Swarm secrets...");
            var secretName = $"{Abbrev}-cms-db-password";
            var (_, secretId) = await dockerSecrets.EnsureSecretAsync(secretName, mysqlPassword);
            AppendOutput($"[Secret] {secretName} → {secretId}");

            // Password is now ONLY on the Swarm — clear from memory
            mysqlPassword = string.Empty;

            // ── Step 5: Deploy stack ──────────────────────────────────────
            SetProgress(70, "Rendering compose & deploying stack...");

            var dto = new CreateInstanceDto
            {
                CustomerName   = CustomerName.Trim(),
                CustomerAbbrev = Abbrev,
                SshHostId      = SelectedSshHost.Id,
                NewtId         = string.IsNullOrWhiteSpace(NewtId) ? null : NewtId.Trim(),
                NewtSecret     = string.IsNullOrWhiteSpace(NewtSecret) ? null : NewtSecret.Trim(),
                CifsServer     = string.IsNullOrWhiteSpace(CifsServer) ? null : CifsServer.Trim(),
                CifsShareBasePath = string.IsNullOrWhiteSpace(CifsShareBasePath) ? null : CifsShareBasePath.Trim(),
                CifsUsername   = string.IsNullOrWhiteSpace(CifsUsername) ? null : CifsUsername.Trim(),
                CifsPassword   = string.IsNullOrWhiteSpace(CifsPassword) ? null : CifsPassword.Trim(),
                CifsExtraOptions = string.IsNullOrWhiteSpace(CifsExtraOptions) ? null : CifsExtraOptions.Trim(),
            };

            var result = await instanceSvc.CreateInstanceAsync(dto);

            AppendOutput(result.Output ?? string.Empty);
            SetProgress(100, result.Success ? "Deployment complete!" : "Deployment failed.");

            StatusMessage = result.Success
                ? $"Instance '{Abbrev}-cms-stack' deployed in {result.DurationMs}ms!"
                : $"Deploy failed: {result.ErrorMessage}";
        }
        catch (Exception ex)
        {
            StatusMessage = $"Error: {ex.Message}";
            AppendOutput(ex.ToString());
            SetProgress(0, "Failed.");
        }
        finally
        {
            IsBusy = false;
        }
    }

    private void SetProgress(double pct, string step)
    {
        ProgressPercent = pct;
        ProgressStep = step;
        AppendOutput($"[{pct:0}%] {step}");
    }

    private void AppendOutput(string text)
    {
        if (!string.IsNullOrWhiteSpace(text))
            DeployOutput += (DeployOutput.Length > 0 ? "\n" : "") + text;
    }

    private static string GenerateRandomPassword(int length)
    {
        const string chars = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789!@#$%^&*";
        return RandomNumberGenerator.GetString(chars, length);
    }
}