#include "ui/accountsetupdialog.h"
#include <QMessageBox>
#include <QScrollArea>
#include <QFrame>
#include <QDebug>
#include <QRegularExpression>
#include <QRegularExpressionValidator>
#include <QIntValidator>
#include <QTimer>

// ─────────────────────── Constructor ───────────────────────
AccountSetupDialog::AccountSetupDialog(AccountService *accountService, QWidget *parent)
    : QDialog(parent)
    , m_accountService(accountService)
    , m_selectedProvider(0)
    , m_accountCreatedOk(false)
    , m_editingAccountId(-1)
    , m_isEditing(false)
{
    m_authTimeoutTimer = new QTimer(this);
    m_authTimeoutTimer->setSingleShot(true);
    connect(m_authTimeoutTimer, &QTimer::timeout, this, &AccountSetupDialog::onAuthTimeout);

    if (m_accountService) {
        connect(m_accountService, &AccountService::accountAdded,
                this, &AccountSetupDialog::onAccountAdded);
    }

    setupUI();
}

// ─────────────────────── Public API ───────────────────────
void AccountSetupDialog::loadAccountForEditing(const Account &account)
{
    // Only support editing IMAP accounts for simplicity
    if (account.type() != AccountType::IMAP) {
        QMessageBox::information(this, tr("Edit Account"),
                                 tr("Editing of OAuth (Gmail/Outlook) accounts is not supported in this version.\n"
                                    "You can add a new account instead."));
        m_isEditing = false;
        return;
    }

    m_isEditing = true;
    m_editingAccountId = account.id();

    // Set window title
    setWindowTitle(tr("Edit Email Account – Wino Mail"));

    // Fill IMAP fields
    m_imapEmailEdit->setText(account.email());
    m_imapNameEdit->setText(account.displayName());

    // Password field left blank for security; user must re-enter
    m_imapPasswordEdit->clear();

    const Account::ConnectionSettings &settings = account.connectionSettings();
    m_imapHostEdit->setText(settings.incomingHost);
    m_imapPortEdit->setText(QString::number(settings.incomingPort));
    m_smtpHostEdit->setText(settings.outgoingHost);
    m_smtpPortEdit->setText(QString::number(settings.outgoingPort));
    m_sslCheckbox->setChecked(settings.incomingSsl); // assuming same for SMTP

    // Switch to IMAP page
    m_selectedProvider = 2; // IMAP
    goToPage(PageImap);
}

// ─────────────────────── UI Setup ───────────────────────
void AccountSetupDialog::setupUI()
{
    setWindowTitle("Añadir Cuenta de Correo — Wino Mail");
    setMinimumSize(600, 500);
    resize(660, 520);

    // ── Global stylesheet ──
    setStyleSheet(
        "AccountSetupDialog { background: #f5f5f7; }"
        "QLabel { color: #1d1d1f; }"
        "QLineEdit {"
        "  background: #fff; border: 1px solid #d1d1d6; border-radius: 6px;"
        "  padding: 8px 12px; font-size: 13px; color: #1d1d1f;"
        "}"
        "QLineEdit:focus { border: 2px solid #0071e3; }"
        "QRadioButton { font-size: 14px; padding: 6px 0; }"
        "QCheckBox { font-size: 13px; }"
        "QPushButton {"
        "  font-weight: 600; font-size: 13px; padding: 8px 20px; border-radius: 6px;"
        "}"
    );

    QVBoxLayout *root = new QVBoxLayout(this);
    root->setContentsMargins(24, 24, 24, 18);
    root->setSpacing(16);

    // ── Stacked pages ──
    m_stack = new QStackedWidget(this);
    m_stack->addWidget(createProviderPage());   // 0
    m_stack->addWidget(createOAuthPage());       // 1
    m_stack->addWidget(createImapPage());        // 2
    m_stack->addWidget(createProgressPage());    // 3
    root->addWidget(m_stack, 1);

    // ── Separator ──
    QFrame *sep = new QFrame();
    sep->setFrameShape(QFrame::HLine);
    sep->setStyleSheet("color: #d1d1d6;");
    root->addWidget(sep);

    // ── Navigation buttons ──
    QHBoxLayout *nav = new QHBoxLayout();

    m_btnBack = new QPushButton("← Atrás");
    m_btnBack->setStyleSheet(
        "QPushButton { background: #fff; color: #0071e3; border: 1px solid #0071e3; }"
        "QPushButton:hover { background: #e8f0fe; }"
    );

    m_btnCancel = new QPushButton("Cancelar");
    m_btnCancel->setStyleSheet(
        "QPushButton { background: #e5e5ea; color: #1d1d1f; border: none; }"
        "QPushButton:hover { background: #d1d1d6; }"
    );

    m_btnNext = new QPushButton("Siguiente →");
    m_btnNext->setStyleSheet(
        "QPushButton { background: #0071e3; color: white; border: none; }"
        "QPushButton:hover { background: #005bb5; }"
        "QPushButton:disabled { background: #a0c4ff; color: #e0e0e0; }"
    );

    nav->addWidget(m_btnBack);
    nav->addStretch();
    nav->addWidget(m_btnCancel);
    nav->addSpacing(8);
    nav->addWidget(m_btnNext);
    root->addLayout(nav);

    connect(m_btnBack, &QPushButton::clicked, this, &AccountSetupDialog::onBackClicked);
    connect(m_btnNext, &QPushButton::clicked, this, &AccountSetupDialog::onNextClicked);
    connect(m_btnCancel, &QPushButton::clicked, this, &AccountSetupDialog::onCancelClicked);

    goToPage(PageProvider);
}

// ─────────────────── Page 0: Provider ───────────────────
QWidget* AccountSetupDialog::createProviderPage()
{
    QWidget *page = new QWidget();
    QVBoxLayout *lay = new QVBoxLayout(page);
    lay->setContentsMargins(10, 10, 10, 10);
    lay->setSpacing(20);

    // Title
    QLabel *title = new QLabel("Añadir nueva cuenta");
    title->setStyleSheet("font-size: 22px; font-weight: 700; color: #1d1d1f;");
    title->setAlignment(Qt::AlignCenter);

    QLabel *subtitle = new QLabel("Selecciona el tipo de cuenta que deseas configurar:");
    subtitle->setStyleSheet("font-size: 14px; color: #8e8e93;");
    subtitle->setWordWrap(true);
    subtitle->setAlignment(Qt::AlignCenter);

    lay->addWidget(title);
    lay->addWidget(subtitle);
    lay->addSpacing(10);

    // Provider cards
    m_providerGroup = new QButtonGroup(this);

    auto makeRadio = [&](const QString &text, const QString &desc, int id) -> QWidget* {
        QWidget *card = new QWidget();
        card->setStyleSheet(
            "QWidget { background: #fff; border: 1px solid #e0e0e5; border-radius: 10px; }"
            "QWidget:hover { border-color: #0071e3; }"
        );
        QHBoxLayout *h = new QHBoxLayout(card);
        h->setContentsMargins(16, 12, 16, 12);

        QRadioButton *radio = new QRadioButton(text);
        radio->setStyleSheet("font-size: 15px; font-weight: 600;");
        m_providerGroup->addButton(radio, id);

        QLabel *descLabel = new QLabel(desc);
        descLabel->setStyleSheet("font-size: 12px; color: #8e8e93;");
        descLabel->setAlignment(Qt::AlignRight | Qt::AlignVCenter);

        h->addWidget(radio, 1);
        h->addWidget(descLabel);
        return card;
    };

    lay->addWidget(makeRadio("🔴  Google / Gmail",         "OAuth2 seguro",           0));
    lay->addWidget(makeRadio("🔵  Microsoft / Outlook",    "OAuth2 seguro",           1));
    lay->addWidget(makeRadio("⚙️  IMAP / SMTP",            "Servidor personalizado",  2));

    m_providerGroup->button(0)->setChecked(true);
    connect(m_providerGroup, QOverload<int>::of(&QButtonGroup::idClicked),
            this, &AccountSetupDialog::onProviderSelected);

    lay->addStretch();
    return page;
}

// ─────────────────── Page 1: OAuth ───────────────────
QWidget* AccountSetupDialog::createOAuthPage()
{
    QWidget *page = new QWidget();
    QVBoxLayout *lay = new QVBoxLayout(page);
    lay->setContentsMargins(10, 10, 10, 10);
    lay->setSpacing(14);

    QLabel *title = new QLabel("Autenticación OAuth2");
    title->setStyleSheet("font-size: 18px; font-weight: 700;");
    lay->addWidget(title);

    QLabel *info = new QLabel(
        "Se abrirá tu navegador web para que inicies sesión de forma segura.\\n"
        "Wino Mail no almacena tu contraseña, solo el token de acceso autorizado.\\n\\n"
        "Pasos:\\n"
        "  1. Introduce tu dirección de correo.\\n"
        "  2. Pulsa «Autenticar en Navegador».\\n"
        "  3. Completa el inicio de sesión en la ventana del navegador.\\n"
        "  4. Al terminar, esta ventana se actualizará automáticamente."
    );
    info->setWordWrap(true);
    info->setStyleSheet("font-size: 13px; color: #555; line-height: 1.5;");
    lay->addWidget(info);

    lay->addSpacing(6);

    QLabel *emailLabel = new QLabel("Correo electrónico:");
    emailLabel->setStyleSheet("font-weight: 600; font-size: 13px;");
    lay->addWidget(emailLabel);

    m_oauthEmailEdit = new QLineEdit();
    m_oauthEmailEdit->setPlaceholderText("tu-correo@gmail.com");
    QRegularExpression rx(R"([a-zA-Z0-9._%+-]+@[a-zA-Z0-9.-]+\.[a-zA-Z]{2,})");
    m_oauthEmailEdit->setValidator(new QRegularExpressionValidator(rx, this));
    lay->addWidget(m_oauthEmailEdit);

    lay->addSpacing(8);

    m_btnOAuthStart = new QPushButton("🔑  Autenticar en Navegador");
    m_btnOAuthStart->setMinimumHeight(40);
    m_btnOAuthStart->setStyleSheet(
        "QPushButton { background: #34a853; color: white; border: none; font-size: 14px; font-weight: 700; border-radius: 8px; }"
        "QPushButton:hover { background: #2d9249; }"
        "QPushButton:disabled { background: #a8d5b8; color: #e0e0e0; }"
    );
    connect(m_btnOAuthStart, &QPushButton::clicked, this, &AccountSetupDialog::startOAuthAuthentication);
    lay->addWidget(m_btnOAuthStart);

    m_oauthStatusLabel = new QLabel("Esperando…");
    m_oauthStatusLabel->setStyleSheet("font-size: 12px; color: #8e8e93; font-style: italic;");
    m_oauthStatusLabel->setAlignment(Qt::AlignCenter);
    lay->addWidget(m_oauthStatusLabel);

    lay->addStretch();
    return page;
}

// ─────────────────── Page 2: IMAP ───────────────────
QWidget* AccountSetupDialog::createImapPage()
{
    QWidget *page = new QWidget();
    QVBoxLayout *outerLay = new QVBoxLayout(page);
    outerLay->setContentsMargins(10, 10, 10, 10);

    QLabel *title = new QLabel("Configuración IMAP / SMTP");
    title->setStyleSheet("font-size: 18px; font-weight: 700;");
    outerLay->addWidget(title);

    QLabel *info = new QLabel("Introduce los datos de tu servidor de correo. "
                              "Consulta a tu proveedor si no conoces los datos del servidor.");
    info->setWordWrap(true);
    info->setStyleSheet("font-size: 12px; color: #8e8e93; margin-bottom: 8px;");
    outerLay->addWidget(info);

    // Scrollable form
    QScrollArea *scroll = new QScrollArea();
    scroll->setWidgetResizable(true);
    scroll->setFrameShape(QFrame::NoFrame);

    QWidget *formWidget = new QWidget();
    QFormLayout *form = new QFormLayout(formWidget);
    form->setSpacing(10);
    form->setContentsMargins(0, 8, 12, 8);
    form->setLabelAlignment(Qt::AlignRight);

    m_imapEmailEdit = new QLineEdit();
    m_imapEmailEdit->setPlaceholderText("usuario@empresa.com");

    m_imapNameEdit = new QLineEdit();
    m_imapNameEdit->setPlaceholderText("Nombre a mostrar (ej. Javier)");

    m_imapPasswordEdit = new QLineEdit();
    m_imapPasswordEdit->setEchoMode(QLineEdit::Password);
    m_imapPasswordEdit->setPlaceholderText("Contraseña");

    m_imapHostEdit = new QLineEdit();
    m_imapHostEdit->setPlaceholderText("imap.empresa.com");

    m_imapPortEdit = new QLineEdit();
    m_imapPortEdit->setPlaceholderText("993");
    m_imapPortEdit->setValidator(new QIntValidator(1, 65535, this));
    m_imapPortEdit->setMaximumWidth(100);

    m_smtpHostEdit = new QLineEdit();
    m_smtpHostEdit->setPlaceholderText("smtp.empresa.com");

    m_smtpPortEdit = new QLineEdit();
    m_smtpPortEdit->setPlaceholderText("587");
    m_smtpPortEdit->setValidator(new QIntValidator(1, 65535, this));
    m_smtpPortEdit->setMaximumWidth(100);

    m_sslCheckbox = new QCheckBox("Usar conexión segura (SSL/TLS)");
    m_sslCheckbox->setChecked(true);

    form->addRow("Correo:", m_imapEmailEdit);
    form->addRow("Nombre:", m_imapNameEdit);
    form->addRow("Contraseña:", m_imapPasswordEdit);

    // Visual separator
    QFrame *line = new QFrame();
    line->setFrameShape(QFrame::HLine);
    line->setStyleSheet("color: #e0e0e5;");
    form->addRow(line);

    QLabel *serverHeader = new QLabel("Servidores");
    serverHeader->setStyleSheet("font-weight: 700; font-size: 13px; color: #0071e3;");
    form->addRow(serverHeader);

    form->addRow("Servidor IMAP:", m_imapHostEdit);
    form->addRow("Puerto IMAP:", m_imapPortEdit);
    form->addRow("Servidor SMTP:", m_smtpHostEdit);
    form->addRow("Puerto SMTP:", m_smtpPortEdit);
    form->addRow("", m_sslCheckbox);

    scroll->setWidget(formWidget);
    outerLay->addWidget(scroll, 1);

    return page;
}

// ─────────────────── Page 3: Progress ───────────────────
QWidget* AccountSetupDialog::createProgressPage()
{
    QWidget *page = new QWidget();
    QVBoxLayout *lay = new QVBoxLayout(page);
    lay->setContentsMargins(20, 40, 20, 20);
    lay->setAlignment(Qt::AlignCenter);

    m_progressIcon = new QLabel("⏳");
    m_progressIcon->setStyleSheet("font-size: 56px;");
    m_progressIcon->setAlignment(Qt::AlignCenter);

    m_progressText = new QLabel("Conectando al servidor…");
    m_progressText->setStyleSheet("font-size: 16px; font-weight: 600; color: #1d1d1f;");
    m_progressText->setAlignment(Qt::AlignCenter);

    m_progressDetail = new QLabel("Validando credenciales y configuración del servidor de correo.");
    m_progressDetail->setWordWrap(true);
    m_progressDetail->setStyleSheet("font-size: 13px; color: #8e8e93;");
    m_progressDetail->setAlignment(Qt::AlignCenter);

    lay->addWidget(m_progressIcon);
    lay->addSpacing(16);
    lay->addWidget(m_progressText);
    lay->addSpacing(8);
    lay->addWidget(m_progressDetail);
    lay->addStretch();

    return page;
}

// ─────────────────── Navigation ───────────────────
void AccountSetupDialog::goToPage(int page)
{
    m_stack->setCurrentIndex(page);
    updateNavButtons();
}

void AccountSetupDialog::updateNavButtons()
{
    int page = m_stack->currentIndex();

    m_btnBack->setVisible(page > 0 && page != PageProgress);
    m_btnCancel->setVisible(page != PageProgress || !m_accountCreatedOk);

    switch (page) {
    case PageProvider:
        m_btnNext->setText("Siguiente →");
        m_btnNext->setEnabled(true);
        m_btnNext->setVisible(true);
        break;
    case PageOAuth:
        m_btnNext->setVisible(false); // OAuth flow is driven by the authenticate button
        break;
    case PageImap:
        m_btnNext->setText(m_isEditing ? "Guardar cambios" : "Conectar");
        m_btnNext->setEnabled(true);
        m_btnNext->setVisible(true);
        break;
    case PageProgress:
        if (m_accountCreatedOk) {
            m_btnNext->setText("Finalizar ✓");
            m_btnNext->setEnabled(true);
            m_btnNext->setVisible(true);
            m_btnBack->setVisible(false);
            m_btnCancel->setVisible(false);
        } else {
            m_btnNext->setVisible(false);
        }
        break;
    }
}

void AccountSetupDialog::onProviderSelected(int id)
{
    m_selectedProvider = id;
}

void AccountSetupDialog::onNextClicked()
{
    int page = m_stack->currentIndex();

    if (page == PageProvider) {
        if (m_selectedProvider == 2) {
            goToPage(PageImap);
        } else {
            // Update OAuth page subtitle based on provider
            goToPage(PageOAuth);
        }
    }
    else if (page == PageImap) {
        submitImapAccount();
    }
    else if (page == PageProgress) {
        accept(); // Finalizar
    }
}

void AccountSetupDialog::onBackClicked()
{
    int page = m_stack->currentIndex();
    if (page == PageOAuth || page == PageImap) {
        m_authTimeoutTimer->stop();
        goToPage(PageProvider);
    }
}

void AccountSetupDialog::onCancelClicked()
{
    m_authTimeoutTimer->stop();
    reject();
}

// ─────────────────── OAuth Flow ───────────────────
void AccountSetupDialog::startOAuthAuthentication()
{
    QString email = m_oauthEmailEdit->text().trimmed();
    if (email.isEmpty()) {
        QMessageBox::warning(this, "Validación",
            "Introduce tu dirección de correo electrónico.");
        return;
    }

    m_btnOAuthStart->setEnabled(false);
    m_oauthStatusLabel->setText("Abriendo navegador… Completa el inicio de sesión allí.");
    m_oauthStatusLabel->setStyleSheet("font-size: 12px; color: #0071e3; font-weight: 600;");

    QString provider = (m_selectedProvider == 0) ? "gmail" : "outlook";

    // Start authentication via AccountService (opens browser)
    m_accountService->startAuthentication(email, provider);

    // Start timeout timer (120 seconds to complete OAuth)
    m_authTimeoutTimer->start(120000);

    qDebug() << "[AccountSetupDialog] OAuth started for" << email << "provider:" << provider;
}

void AccountSetupDialog::onAuthTimeout()
{
    if (m_stack->currentIndex() == PageOAuth) {
        m_btnOAuthStart->setEnabled(true);
        m_oauthStatusLabel->setText("⚠️ Tiempo de espera agotado. Inténtalo de nuevo.");
        m_oauthStatusLabel->setStyleSheet("font-size: 12px; color: #ff3b30; font-weight: 600;");
    }
}

// ─────────────────── IMAP Flow ───────────────────
void AccountSetupDialog::submitImapAccount()
{
    QString email    = m_imapEmailEdit->text().trimmed();
    QString name     = m_imapNameEdit->text().trimmed();
    QString password = m_imapPasswordEdit->text().trimmed();
    QString imapHost = m_imapHostEdit->text().trimmed();
    QString imapPort = m_imapPortEdit->text().trimmed();
    QString smtpHost = m_smtpHostEdit->text().trimmed();
    QString smtpPort = m_smtpPortEdit->text().trimmed();

    // Validation
    if (email.isEmpty()) {
        QMessageBox::warning(this, "Campo requerido", "Introduce tu dirección de correo.");
        return;
    }
    if (password.isEmpty()) {
        QMessageBox::warning(this, "Campo requerido", "Introduce tu contraseña.");
        return;
    }
    if (imapHost.isEmpty()) {
        QMessageBox::warning(this, "Campo requerido", "Introduce el servidor IMAP.");
        return;
    }

    // Use defaults if ports are empty
    if (imapPort.isEmpty()) imapPort = m_sslCheckbox->isChecked() ? "993" : "143";
    if (smtpPort.isEmpty()) smtpPort = m_sslCheckbox->isChecked() ? "465" : "587";
    if (smtpHost.isEmpty()) smtpHost = imapHost.replace("imap.", "smtp.");
    if (name.isEmpty()) name = email.split("@").first();

    // Create account with connection settings
    Account account;
    account.setEmail(email);
    account.setDisplayName(name);
    account.setType(AccountType::IMAP);

    Account::ConnectionSettings settings;
    settings.type = "imap";
    settings.incomingHost = imapHost;
    settings.incomingPort = imapPort.toInt();
    settings.incomingSsl = m_sslCheckbox->isChecked();
    settings.outgoingHost = smtpHost;
    settings.outgoingPort = smtpPort.toInt();
    settings.outgoingSsl = m_sslCheckbox->isChecked();
    settings.username = email;
    settings.password = password;
    settings.authMethod = "plain";

    account.setConnectionSettings(settings);

    // Show progress
    m_accountCreatedOk = false;
    goToPage(PageProgress);
    m_progressIcon->setText("⏳");
    m_progressText->setText("Conectando al servidor...");
    m_progressDetail->setText(
        QString("Servidor IMAP: %1:%2\\nServidor SMTP: %3:%4\\nSSL: %5")
            .arg(imapHost, imapPort, smtpHost, smtpPort,
                 m_sslCheckbox->isChecked() ? "Sí" : "No")
    );

     // Disable UI during connection attempt
     m_btnBack->setEnabled(false);
     m_btnNext->setEnabled(false);
     m_btnCancel->setEnabled(false);
     QString errorMsg;
     bool success = m_accountService->testConnection(account.connectionSettings(), errorMsg);
     if (success) {
         if (m_isEditing) {
             account.setId(m_editingAccountId);
             m_accountService->updateAccount(account);
         } else {
             m_accountService->addAccount(account);
         }
    m_btnCancel->setEnabled(true);
     } else {
         QMessageBox::warning(this, tr("Connection failed"), tr("Could not connect to IMAP server: %1").arg(errorMsg));
         // Re-enable UI
         m_btnBack->setEnabled(true);
         m_btnNext->setEnabled(true);
         m_btnCancel->setEnabled(true);
     }
}

// ─────────────────── Account Result ───────────────────
void AccountSetupDialog::onAccountAdded(const Account &account)
{
    m_authTimeoutTimer->stop();
    m_accountCreatedOk = true;

    qDebug() << "[AccountSetupDialog] Account" << (m_isEditing ? "updated" : "created") << "successfully:" << account.email();

    // If we were on the OAuth page, move to progress first
    if (m_stack->currentIndex() == PageOAuth) {
        goToPage(PageProgress);
    }

    showSuccess(QString(m_isEditing ? "¡Cuenta «%1» actualizada con éxito!\\n\\n"
                                    "Los cambios se aplicarán inmediatamente."
                                    : "¡Cuenta «%1» configurada con éxito!\\n\\n"
                                      "La sincronización de correos comenzará automáticamente en segundo plano.")
                    .arg(account.email()));

    emit accountCreated(account);
}

void AccountSetupDialog::showSuccess(const QString &message)
{
    m_progressIcon->setText("✅");
    m_progressText->setText("¡Cuenta añadida!");
    m_progressDetail->setText(message);
    updateNavButtons();
}

void AccountSetupDialog::showError(const QString &message)
{
    m_accountCreatedOk = false;
    m_progressIcon->setText("❌");
    m_progressText->setText("Error de conexión");
    m_progressDetail->setText(message);

    // Allow going back
    m_btnBack->setVisible(true);
    m_btnCancel->setVisible(true);
    m_btnNext->setVisible(false);
}

#include "accountsetupdialog.moc"