using System.Diagnostics;
using System.Reflection;
using Microsoft.Win32;

namespace StudioE5.SetupWizard;

public partial class MainForm : Form
{
    private readonly InstallerState _state;
    private readonly Panel _contentPanel;
    private readonly Button _btnBack;
    private readonly Button _btnNext;
    private readonly Button _btnCancel;
    private readonly Label _titleLabel;
    private readonly Label _subtitleLabel;

    private WizardStep _currentStep = WizardStep.Welcome;
    private PrerequisiteResult? _lastCheck;

    public MainForm(bool startInUninstallMode = false)
    {
        _state = InstallerState.Load();
        Text = startInUninstallMode ? "Désinstallation studioE5" : "Installateur studioE5 Agent";
        Size = new Size(700, 520);
        StartPosition = FormStartPosition.CenterScreen;
        FormBorderStyle = FormBorderStyle.FixedDialog;
        MaximizeBox = false;
        MinimizeBox = false;

        _titleLabel = new Label
        {
            Left = 24,
            Top = 18,
            Width = 640,
            Height = 32,
            Font = new Font("Segoe UI", 14, FontStyle.Bold),
            Text = "Installateur studioE5 Agent"
        };

        _subtitleLabel = new Label
        {
            Left = 24,
            Top = 50,
            Width = 640,
            Height = 24,
            Font = new Font("Segoe UI", 9),
            ForeColor = Color.Gray
        };

        _contentPanel = new Panel
        {
            Left = 24,
            Top = 84,
            Width = 640,
            Height = 320,
            BorderStyle = BorderStyle.None
        };

        var separator = new Panel
        {
            Left = 0,
            Top = 416,
            Width = 700,
            Height = 1,
            BackColor = Color.LightGray,
            Anchor = AnchorStyles.Left | AnchorStyles.Right | AnchorStyles.Bottom
        };

        _btnBack = new Button
        {
            Left = 360,
            Top = 440,
            Width = 100,
            Height = 30,
            Text = "< Précédent",
            Visible = false
        };
        _btnBack.Click += (s, e) => GoBack();

        _btnNext = new Button
        {
            Left = 470,
            Top = 440,
            Width = 100,
            Height = 30,
            Text = "Suivant >"
        };
        _btnNext.Click += (s, e) => GoNext();

        _btnCancel = new Button
        {
            Left = 584,
            Top = 440,
            Width = 80,
            Height = 30,
            Text = "Annuler"
        };
        _btnCancel.Click += (s, e) => Application.Exit();

        Controls.Add(_titleLabel);
        Controls.Add(_subtitleLabel);
        Controls.Add(_contentPanel);
        Controls.Add(separator);
        Controls.Add(_btnBack);
        Controls.Add(_btnNext);
        Controls.Add(_btnCancel);

        if (startInUninstallMode)
        {
            GoToStep(WizardStep.Uninstall);
            return;
        }

        ResumeAfterReboot();
    }

    private void ResumeAfterReboot()
    {
        // If we are resuming after a reboot, skip directly to the relevant step.
        if (_state.VirtualEnvironmentInstalled && !_state.PodmanInstalled)
        {
            GoToStep(WizardStep.InstallPodman);
            return;
        }
        if (_state.PodmanInstalled && !_state.PodmanConfigured)
        {
            GoToStep(WizardStep.ConfigurePodman);
            return;
        }
        if (_state.PodmanConfigured && !_state.AgentInstalled)
        {
            GoToStep(WizardStep.InstallAgent);
            return;
        }

        GoToStep(WizardStep.Welcome);
    }

    private void GoBack()
    {
        switch (_currentStep)
        {
            case WizardStep.Prerequisites:
                GoToStep(WizardStep.Welcome);
                break;
            case WizardStep.InstallVirtualEnvironment:
            case WizardStep.RestartRequired:
                GoToStep(WizardStep.Prerequisites);
                break;
            case WizardStep.InstallPodman:
                GoToStep(WizardStep.Prerequisites);
                break;
            case WizardStep.ConfigurePodman:
                GoToStep(WizardStep.InstallPodman);
                break;
            case WizardStep.InstallAgent:
                GoToStep(WizardStep.ConfigurePodman);
                break;
        }
    }

    private void GoNext()
    {
        switch (_currentStep)
        {
            case WizardStep.Welcome:
                GoToStep(WizardStep.Prerequisites);
                break;
            case WizardStep.Prerequisites:
                if (_lastCheck?.VirtualEnvironmentInstalled == true)
                    GoToStep(WizardStep.InstallPodman);
                else
                    GoToStep(WizardStep.InstallVirtualEnvironment);
                break;
            case WizardStep.InstallVirtualEnvironment:
                InstallVirtualEnvironment();
                break;
            case WizardStep.RestartRequired:
                Application.Exit();
                break;
            case WizardStep.InstallPodman:
                InstallPodman();
                break;
            case WizardStep.ConfigurePodman:
                ConfigurePodman();
                break;
            case WizardStep.InstallAgent:
                InstallAgent();
                break;
            case WizardStep.Finished:
                Application.Exit();
                break;
            case WizardStep.Uninstall:
                RunUninstall();
                break;
        }
    }

    private void GoToStep(WizardStep step)
    {
        _currentStep = step;
        _state.Step = step;
        _state.Save();
        _contentPanel.Controls.Clear();

        switch (step)
        {
            case WizardStep.Welcome:
                ShowWelcome();
                break;
            case WizardStep.Prerequisites:
                ShowPrerequisites();
                break;
            case WizardStep.InstallVirtualEnvironment:
                ShowInstallVirtualEnvironment();
                break;
            case WizardStep.RestartRequired:
                ShowRestartRequired();
                break;
            case WizardStep.InstallPodman:
                ShowInstallPodman();
                break;
            case WizardStep.ConfigurePodman:
                ShowConfigurePodman();
                break;
            case WizardStep.InstallAgent:
                ShowInstallAgent();
                break;
            case WizardStep.Finished:
                ShowFinished();
                break;
            case WizardStep.Uninstall:
                ShowUninstall();
                break;
        }
    }

    private void ShowWelcome()
    {
        _titleLabel.Text = "Bienvenue dans l'installateur studioE5";
        _subtitleLabel.Text = "Cet assistant va vous guider pour installer studioE5 Agent sur votre poste.";

        var label = new Label
        {
            Left = 0,
            Top = 20,
            Width = _contentPanel.Width,
            Height = 200,
            Text = "L'installation se déroule en plusieurs étapes :\n\n" +
                   "1. Vérification des prérequis\n" +
                   "2. Installation de l'environnement virtuel (si nécessaire)\n" +
                   "3. Installation de Podman\n" +
                   "4. Configuration de Podman\n" +
                   "5. Installation de studioE5 Agent\n\n" +
                   "Cliquez sur 'Suivant' pour commencer.",
            Font = new Font("Segoe UI", 10)
        };

        _contentPanel.Controls.Add(label);

        _btnBack.Visible = false;
        _btnNext.Text = "Suivant >";
        _btnNext.Enabled = true;
        _btnCancel.Text = "Annuler";
    }

    private void ShowPrerequisites()
    {
        _titleLabel.Text = "Vérification des prérequis";
        _subtitleLabel.Text = "Assurez-vous que votre poste est prêt avant de continuer.";

        _lastCheck = PrerequisiteChecker.Check();
        var result = _lastCheck;

        var text = $"Système d'exploitation : {(result.WindowsCompatible ? "✅ Compatible" : "❌ Non compatible (Windows 10 2004+ requis)")}\n" +
                   $"Mémoire vive (RAM) : {(result.RamMB >= 8192 ? "✅" : result.RamMB >= 4096 ? "⚠️" : "❌")} {result.RamMB} Mo (8 Go recommandés)\n" +
                   $"Espace disque disponible : {(result.FreeDiskMB >= 10240 ? "✅" : result.FreeDiskMB >= 5120 ? "⚠️" : "❌")} {result.FreeDiskMB} Mo (10 Go recommandés)\n" +
                   $"Environnement virtuel : {(result.VirtualEnvironmentInstalled ? "✅ Installé" : "❌ Non installé")}\n" +
                   $"Podman : {(result.PodmanInstalled ? "✅ Installé" : "❌ Non installé")}\n" +
                   $"Machine Podman : {(result.PodmanMachineReady ? "✅ Prête" : "❌ Non prête")}\n\n";

        if (result.AllReady)
        {
            text += "Tous les prérequis sont satisfaits. Vous pouvez continuer.";
        }
        else
        {
            text += "Ordre d'installation recommandé :\n" +
                    "1. Installer l'environnement virtuel\n" +
                    "2. Installer Podman\n" +
                    "3. Configurer Podman\n" +
                    "4. Installer studioE5 Agent";
        }

        var label = new Label
        {
            Left = 0,
            Top = 20,
            Width = _contentPanel.Width,
            Height = 240,
            Text = text,
            Font = new Font("Consolas", 10),
            ForeColor = Color.Black
        };

        _contentPanel.Controls.Add(label);

        _btnBack.Visible = true;
        _btnNext.Text = result.AllReady ? "Suivant >" : (result.VirtualEnvironmentInstalled ? "Installer Podman" : "Installer l'environnement virtuel");
        _btnNext.Enabled = true;
    }

    private void ShowInstallVirtualEnvironment()
    {
        _titleLabel.Text = "Installation de l'environnement virtuel";
        _subtitleLabel.Text = "L'environnement virtuel permet de faire tourner Podman sur Windows.";

        var label = new Label
        {
            Left = 0,
            Top = 20,
            Width = _contentPanel.Width,
            Height = 120,
            Text = "L'environnement virtuel (WSL2) n'est pas installé.\n\n" +
                   "Cliquez sur 'Installer' pour lancer l'installation.\n" +
                   "Un redémarrage de l'ordinateur sera nécessaire. L'installateur se relancera automatiquement.",
            Font = new Font("Segoe UI", 10)
        };

        _contentPanel.Controls.Add(label);

        _btnBack.Visible = true;
        _btnNext.Text = "Installer";
        _btnNext.Enabled = true;
    }

    private void InstallVirtualEnvironment()
    {
        _btnNext.Enabled = false;
        _btnBack.Enabled = false;

        try
        {
            RunCommand("wsl.exe", "--install --no-distribution", "Installation de l'environnement virtuel en cours...");
            _state.VirtualEnvironmentInstalled = true;
            _state.Save();
            RegisterRunOnce();
            GoToStep(WizardStep.RestartRequired);
        }
        catch (Exception ex)
        {
            MessageBox.Show($"Erreur lors de l'installation de l'environnement virtuel : {ex.Message}", "Erreur", MessageBoxButtons.OK, MessageBoxIcon.Error);
        }
        finally
        {
            _btnNext.Enabled = true;
            _btnBack.Enabled = true;
        }
    }

    private void ShowRestartRequired()
    {
        _titleLabel.Text = "Redémarrage nécessaire";
        _subtitleLabel.Text = "L'environnement virtuel a été installé.";

        var label = new Label
        {
            Left = 0,
            Top = 20,
            Width = _contentPanel.Width,
            Height = 120,
            Text = "Veuillez redémarrer votre ordinateur pour finaliser l'installation de l'environnement virtuel.\n\n" +
                   "L'installateur se relancera automatiquement après le redémarrage pour continuer l'installation.",
            Font = new Font("Segoe UI", 10)
        };

        _contentPanel.Controls.Add(label);

        _btnBack.Visible = false;
        _btnNext.Text = "Redémarrer maintenant";
        _btnNext.Enabled = true;
        _btnCancel.Text = "Redémarrer plus tard";
    }

    private void ShowInstallPodman()
    {
        _titleLabel.Text = "Installation de Podman";
        _subtitleLabel.Text = "Podman est le moteur de conteneurs utilisé par studioE5.";

        var label = new Label
        {
            Left = 0,
            Top = 20,
            Width = _contentPanel.Width,
            Height = 120,
            Text = "Podman va être installé sur votre poste.\n\n" +
                   "Cliquez sur 'Installer' pour lancer l'installation silencieuse.",
            Font = new Font("Segoe UI", 10)
        };

        _contentPanel.Controls.Add(label);

        _btnBack.Visible = true;
        _btnNext.Text = "Installer Podman";
        _btnNext.Enabled = true;
    }

    private void InstallPodman()
    {
        _btnNext.Enabled = false;
        _btnBack.Enabled = false;

        try
        {
            var msiPath = Path.Combine(Path.GetDirectoryName(Assembly.GetExecutingAssembly().Location) ?? ".", "Resources", "podman-setup.msi");
            if (!File.Exists(msiPath))
                throw new FileNotFoundException("Le fichier podman-setup.msi est introuvable. Vérifiez qu'il est bien inclus dans le package.");

            RunCommand("msiexec.exe", $"/i \"{msiPath}\" /qn /norestart", "Installation de Podman en cours...");
            _state.PodmanInstalled = true;
            _state.Save();
            GoToStep(WizardStep.ConfigurePodman);
        }
        catch (Exception ex)
        {
            MessageBox.Show($"Erreur lors de l'installation de Podman : {ex.Message}", "Erreur", MessageBoxButtons.OK, MessageBoxIcon.Error);
        }
        finally
        {
            _btnNext.Enabled = true;
            _btnBack.Enabled = true;
        }
    }

    private void ShowConfigurePodman()
    {
        _titleLabel.Text = "Configuration de Podman";
        _subtitleLabel.Text = "Initialisation de la machine Podman.";

        var label = new Label
        {
            Left = 0,
            Top = 20,
            Width = _contentPanel.Width,
            Height = 120,
            Text = "La machine virtuelle Podman va être créée et démarrée.\n\n" +
                   "Cette opération peut prendre plusieurs minutes la première fois.",
            Font = new Font("Segoe UI", 10)
        };

        _contentPanel.Controls.Add(label);

        _btnBack.Visible = true;
        _btnNext.Text = "Configurer Podman";
        _btnNext.Enabled = true;
    }

    private void ConfigurePodman()
    {
        _btnNext.Enabled = false;
        _btnBack.Enabled = false;

        try
        {
            RunCommand("podman.exe", "machine init", "Initialisation de la machine Podman...");
            RunCommand("podman.exe", "machine start", "Démarrage de la machine Podman...");
            _state.PodmanConfigured = true;
            _state.Save();
            GoToStep(WizardStep.InstallAgent);
        }
        catch (Exception ex)
        {
            MessageBox.Show($"Erreur lors de la configuration de Podman : {ex.Message}", "Erreur", MessageBoxButtons.OK, MessageBoxIcon.Error);
        }
        finally
        {
            _btnNext.Enabled = true;
            _btnBack.Enabled = true;
        }
    }

    private void ShowInstallAgent()
    {
        _titleLabel.Text = "Installation de studioE5 Agent";
        _subtitleLabel.Text = "L'environnement est prêt. Il ne reste plus qu'à installer l'agent.";

        var label = new Label
        {
            Left = 0,
            Top = 20,
            Width = _contentPanel.Width,
            Height = 120,
            Text = "Cliquez sur 'Installer studioE5 Agent' pour lancer le package d'installation.\n\n" +
                   "Une fois l'installation terminée, fermez cet assistant.",
            Font = new Font("Segoe UI", 10)
        };

        _contentPanel.Controls.Add(label);

        _btnBack.Visible = true;
        _btnNext.Text = "Installer studioE5 Agent";
        _btnNext.Enabled = true;
    }

    private void InstallAgent()
    {
        try
        {
            var setupPath = Path.Combine(Path.GetDirectoryName(Assembly.GetExecutingAssembly().Location) ?? ".", "Resources", "studioE5-agent-setup.exe");
            if (!File.Exists(setupPath))
                throw new FileNotFoundException("Le fichier studioE5-agent-setup.exe est introuvable. Vérifiez qu'il est bien inclus dans le package.");

            var psi = new ProcessStartInfo(setupPath)
            {
                UseShellExecute = true,
                Verb = "runas"
            };
            Process.Start(psi);

            _state.AgentInstalled = true;
            _state.Save();
            GoToStep(WizardStep.Finished);
        }
        catch (Exception ex)
        {
            MessageBox.Show($"Erreur lors du lancement de l'installation de l'agent : {ex.Message}", "Erreur", MessageBoxButtons.OK, MessageBoxIcon.Error);
        }
    }

    private void ShowFinished()
    {
        _titleLabel.Text = "Installation terminée";
        _subtitleLabel.Text = "studioE5 Agent est prêt à être utilisé.";

        var label = new Label
        {
            Left = 0,
            Top = 20,
            Width = _contentPanel.Width,
            Height = 120,
            Text = "L'installation est terminée.\n\n" +
                   "Vous pouvez lancer studioE5 Agent depuis le menu Démarrer ou le bureau.",
            Font = new Font("Segoe UI", 10)
        };

        _contentPanel.Controls.Add(label);

        _btnBack.Visible = false;
        _btnNext.Text = "Terminer";
        _btnCancel.Text = "Fermer";
    }

    private void ShowUninstall()
    {
        _titleLabel.Text = "Désinstallation de studioE5";
        _subtitleLabel.Text = "Suppression complète de studioE5 Agent et des composants associés.";

        var label = new Label
        {
            Left = 0,
            Top = 20,
            Width = _contentPanel.Width,
            Height = 200,
            Text = "Cette opération va :\n\n" +
                   "- Arrêter studioE5 Agent\n" +
                   "- Désinstaller studioE5 Agent\n" +
                   "- Supprimer les données élèves\n" +
                   "- Désinstaller Podman\n" +
                   "- Proposer de désactiver l'environnement virtuel\n\n" +
                   "Cliquez sur 'Désinstaller' pour commencer.",
            Font = new Font("Segoe UI", 10)
        };

        _contentPanel.Controls.Add(label);

        _btnBack.Visible = false;
        _btnNext.Text = "Désinstaller";
        _btnCancel.Text = "Annuler";
    }

    private void RunUninstall()
    {
        _btnNext.Enabled = false;

        try
        {
            // 1. Kill agent
            RunCommand("taskkill.exe", "/f /im studioE5-agent.exe", "Arrêt de studioE5 Agent...");

            // 2. Uninstall agent via Inno Setup uninstaller
            var agentUninstaller = Path.Combine(Environment.GetFolderPath(Environment.SpecialFolder.ProgramFiles), "studioE5-agent", "unins000.exe");
            if (File.Exists(agentUninstaller))
                RunCommand(agentUninstaller, "/SILENT", "Désinstallation de studioE5 Agent...");

            // 3. Delete student data
            var dataDir = Path.Combine(Environment.GetFolderPath(Environment.SpecialFolder.LocalApplicationData), "studioE5-agent");
            if (Directory.Exists(dataDir))
            {
                Directory.Delete(dataDir, true);
            }

            // 4. Uninstall Podman
            var podmanMsiPath = Path.Combine(Path.GetDirectoryName(Assembly.GetExecutingAssembly().Location) ?? ".", "Resources", "podman-setup.msi");
            if (File.Exists(podmanMsiPath))
            {
                RunCommand("msiexec.exe", $"/x \"{podmanMsiPath}\" /qn /norestart", "Désinstallation de Podman...");
            }
            else
            {
                MessageBox.Show("Le MSI de Podman n'a pas été trouvé dans le package. Veuillez désinstaller Podman manuellement via Ajouter/Supprimer des programmes.", "Information", MessageBoxButtons.OK, MessageBoxIcon.Information);
            }

            // 5. Optionally disable WSL2
            var result = MessageBox.Show("Voulez-vous désactiver l'environnement virtuel (WSL2) ?", "Environnement virtuel", MessageBoxButtons.YesNo, MessageBoxIcon.Question);
            if (result == DialogResult.Yes)
            {
                RunCommand("wsl.exe", "--uninstall", "Désactivation de l'environnement virtuel...");
            }

            InstallerState.Delete();
            MessageBox.Show("Désinstallation terminée.", "Terminé", MessageBoxButtons.OK, MessageBoxIcon.Information);
            Application.Exit();
        }
        catch (Exception ex)
        {
            MessageBox.Show($"Erreur lors de la désinstallation : {ex.Message}", "Erreur", MessageBoxButtons.OK, MessageBoxIcon.Error);
        }
        finally
        {
            _btnNext.Enabled = true;
        }
    }

    private void RunCommand(string fileName, string arguments, string description)
    {
        var psi = new ProcessStartInfo(fileName, arguments)
        {
            UseShellExecute = false,
            CreateNoWindow = true,
            RedirectStandardOutput = true,
            RedirectStandardError = true
        };

        using var process = Process.Start(psi);
        if (process == null)
            throw new InvalidOperationException($"Impossible de démarrer {fileName}");

        process.WaitForExit();
        if (process.ExitCode != 0)
        {
            var error = process.StandardError.ReadToEnd();
            throw new InvalidOperationException($"{description} a échoué (code {process.ExitCode}) : {error}");
        }
    }

    private void RegisterRunOnce()
    {
        var executablePath = Application.ExecutablePath;
        var key = Registry.CurrentUser.OpenSubKey("Software\\Microsoft\\Windows\\CurrentVersion\\RunOnce", true);
        key?.SetValue("StudioE5SetupWizard", $"\"{executablePath}\"");
    }
}