// McpServersSection.cpp — MCP external server management panel (Qt port)

#include "screens/settings/McpServersSection.h"

#include "core/logging/Logger.h"
#include "mcp/McpManager.h"
#include "mcp/McpService.h"
#include "storage/repositories/McpServerRepository.h"
#include "ui/theme/Theme.h"
#include "ui/theme/ThemeManager.h"

#include <QCheckBox>
#include <QDialog>
#include <QDialogButtonBox>
#include <QFormLayout>
#include <QFrame>
#include <QHBoxLayout>
#include <QHeaderView>
#include <QInputDialog>
#include <QLabel>
#include <QLineEdit>
#include <QMessageBox>
#include <QPointer>
#include <QPushButton>
#include <QScrollArea>
#include <QTimer>
#include <QVBoxLayout>
#include <QtConcurrent/QtConcurrent>

namespace fincept::screens {

using mcp::McpManager;
using mcp::McpServerConfig;
using mcp::McpService;
using mcp::ServerStatus;

static constexpr const char* TAG = "McpServersSection";

// ============================================================================
// Construction
// ============================================================================

McpServersSection::McpServersSection(QWidget* parent) : QWidget(parent) {
    build_ui();
    load_servers();

    connect(&ui::ThemeManager::instance(), &ui::ThemeManager::theme_changed, this, [this](const ui::ThemeTokens&) {
        setStyleSheet(QString("background:%1;color:%2;").arg(ui::colors::BG_BASE(), ui::colors::TEXT_PRIMARY()));
    });
    setStyleSheet(QString("background:%1;color:%2;").arg(ui::colors::BG_BASE(), ui::colors::TEXT_PRIMARY()));
}

void McpServersSection::reload() {
    if (!tab_stack_)
        return;
    load_servers();
    if (tab_stack_->currentIndex() == 1)
        load_tools();
    if (tools_badge_)
        tools_badge_->setText(tr("%1 internal tools active").arg(McpService::instance().tool_count()));
}

void McpServersSection::showEvent(QShowEvent* e) {
    QWidget::showEvent(e);
    reload();
}

void McpServersSection::build_ui() {
    auto* root = new QVBoxLayout(this);
    root->setContentsMargins(0, 0, 0, 0);
    root->setSpacing(0);

    // Title bar
    auto* title_bar = new QWidget(this);
    title_bar->setFixedHeight(44);
    title_bar->setStyleSheet("background:" + QString(ui::colors::BG_SURFACE()) + ";border-bottom:1px solid " +
                             QString(ui::colors::BORDER_DIM()) + ";");
    auto* tbl = new QHBoxLayout(title_bar);
    tbl->setContentsMargins(16, 0, 16, 0);
    title_lbl_ = new QLabel(tr("MCP SERVERS"));
    title_lbl_->setStyleSheet("color:" + QString(ui::colors::AMBER()) + ";font-weight:700;letter-spacing:1px;");
    tbl->addWidget(title_lbl_);
    tbl->addStretch();

    // Internal tools count badge
    tools_badge_ = new QLabel;
    tools_badge_->setObjectName("McpToolsBadge");
    tools_badge_->setStyleSheet("color:" + QString(ui::colors::TEXT_SECONDARY()) + ";");
    tbl->addWidget(tools_badge_);

    root->addWidget(title_bar);

    // Tab buttons
    auto* tab_bar = new QWidget(this);
    tab_bar->setFixedHeight(36);
    tab_bar->setStyleSheet("background:" + QString(ui::colors::BG_BASE()) + ";border-bottom:1px solid " +
                           QString(ui::colors::BORDER_DIM()) + ";");
    auto* tbbl = new QHBoxLayout(tab_bar);
    tbbl->setContentsMargins(8, 0, 8, 0);
    tbbl->setSpacing(4);

    auto make_tab = [&](const QString& text, int idx) {
        auto* btn = new QPushButton(text);
        btn->setCheckable(true);
        btn->setFixedHeight(28);
        btn->setStyleSheet("QPushButton{background:transparent;color:" + QString(ui::colors::TEXT_SECONDARY()) +
                           ";border:none;"
                           "border-bottom:2px solid transparent;padding:0 12px;}"
                           "QPushButton:checked{color:" +
                           QString(ui::colors::AMBER()) + ";border-bottom:2px solid " + QString(ui::colors::AMBER()) +
                           ";}"
                           "QPushButton:hover:!checked{color:" +
                           QString(ui::colors::TEXT_PRIMARY()) + ";}");
        connect(btn, &QPushButton::clicked, this, [this, idx]() { on_tab_changed(idx); });
        tbbl->addWidget(btn);
        if (idx == 0)
            btn->setChecked(true);
        return btn;
    };
    servers_tab_btn_ = make_tab(tr("Installed Servers"), 0);
    tools_tab_btn_ = make_tab(tr("Tools"), 1);
    tbbl->addStretch();
    root->addWidget(tab_bar);

    tab_stack_ = new QStackedWidget;
    tab_stack_->addWidget(build_servers_tab());
    tab_stack_->addWidget(build_tools_tab());
    root->addWidget(tab_stack_, 1);

    // Update badge
    std::size_t n = McpService::instance().tool_count();
    if (tools_badge_)
        tools_badge_->setText(tr("%1 internal tools active").arg(n));
}

// ============================================================================
// Servers tab
// ============================================================================

QWidget* McpServersSection::build_servers_tab() {
    auto* page = new QWidget(this);
    page->setStyleSheet("background:" + QString(ui::colors::BG_BASE()) + ";");
    auto* hl = new QHBoxLayout(page);
    hl->setContentsMargins(0, 0, 0, 0);
    hl->setSpacing(0);

    // Left: server list
    auto* left = new QWidget(this);
    left->setFixedWidth(240);
    left->setStyleSheet("background:" + QString(ui::colors::BG_BASE()) + ";border-right:1px solid " +
                        QString(ui::colors::BORDER_DIM()) + ";");
    auto* lvl = new QVBoxLayout(left);
    lvl->setContentsMargins(8, 8, 8, 8);
    lvl->setSpacing(6);

    server_list_lbl_ = new QLabel(tr("External Servers"));
    server_list_lbl_->setStyleSheet("color:" + QString(ui::colors::TEXT_SECONDARY()) +
                                    ";font-weight:700;letter-spacing:1px;");
    lvl->addWidget(server_list_lbl_);

    server_list_ = new QListWidget;
    server_list_->setStyleSheet(
        "QListWidget{background:transparent;border:none;color:" + QString(ui::colors::TEXT_PRIMARY()) +
        ";}"
        "QListWidget::item{padding:10px 8px;border-radius:3px;border-bottom:1px solid " +
        QString(ui::colors::BG_RAISED()) +
        ";}"
        "QListWidget::item:selected{background:" +
        QString(ui::colors::BG_RAISED()) + ";color:" + QString(ui::colors::AMBER()) +
        ";}"
        "QListWidget::item:hover{background:" +
        QString(ui::colors::BG_RAISED()) + ";}");
    connect(server_list_, &QListWidget::currentRowChanged, this, &McpServersSection::on_server_selected);
    lvl->addWidget(server_list_, 1);

    // Action buttons
    auto* btns = new QHBoxLayout;
    add_btn_ = new QPushButton(tr("+ Add"));
    add_btn_->setStyleSheet("QPushButton{background:" + QString(ui::colors::BG_RAISED()) + ";color:" +
                            QString(ui::colors::AMBER()) + ";border:1px solid " + QString(ui::colors::AMBER()) +
                            ";"
                            "border-radius:3px;padding:5px 10px;font-weight:600;}"
                            "QPushButton:hover{background:" +
                            QString(ui::colors::BG_RAISED()) + ";}");
    connect(add_btn_, &QPushButton::clicked, this, &McpServersSection::on_add_server);

    remove_btn_ = new QPushButton(tr("Remove"));
    remove_btn_->setEnabled(false);
    remove_btn_->setStyleSheet(
        "QPushButton{background:" + QString(ui::colors::BG_RAISED()) + ";color:" + QString(ui::colors::NEGATIVE()) +
        ";border:1px solid " + QString(ui::colors::BG_RAISED()) +
        ";"
        "border-radius:3px;padding:5px 10px;}"
        "QPushButton:hover{background:" +
        QString(ui::colors::BG_RAISED()) +
        ";}"
        "QPushButton:disabled{color:" +
        QString(ui::colors::BORDER_BRIGHT()) + ";border-color:" + QString(ui::colors::BORDER_MED()) + ";}");
    connect(remove_btn_, &QPushButton::clicked, this, &McpServersSection::on_remove_server);

    btns->addWidget(add_btn_);
    btns->addWidget(remove_btn_);
    lvl->addLayout(btns);

    hl->addWidget(left);

    // Right: detail panel
    auto* right = new QScrollArea;
    right->setWidgetResizable(true);
    right->setFrameShape(QFrame::NoFrame);
    right->setStyleSheet("QScrollArea{background:" + QString(ui::colors::BG_BASE()) +
                         ";border:none;}"
                         "QScrollBar:vertical{background:" +
                         QString(ui::colors::BG_RAISED()) +
                         ";width:6px;}"
                         "QScrollBar::handle:vertical{background:" +
                         QString(ui::colors::BORDER_BRIGHT()) +
                         ";border-radius:3px;}"
                         "QScrollBar::add-line:vertical,QScrollBar::sub-line:vertical{height:0;}");

    auto* detail_page = new QWidget(this);
    detail_page->setStyleSheet("background:" + QString(ui::colors::BG_BASE()) + ";");
    auto* dvl = new QVBoxLayout(detail_page);
    dvl->setContentsMargins(24, 20, 24, 20);
    dvl->setSpacing(12);

    detail_lbl_ = new QLabel(tr("Select a server to view details."));
    detail_lbl_->setWordWrap(true);
    detail_lbl_->setStyleSheet("color:" + QString(ui::colors::TEXT_TERTIARY()) + ";");
    dvl->addWidget(detail_lbl_);

    // Start/Stop buttons
    auto* server_btns = new QHBoxLayout;
    start_btn_ = new QPushButton(tr("▶  Start"));
    start_btn_->setEnabled(false);
    start_btn_->setFixedHeight(32);
    start_btn_->setStyleSheet(
        "QPushButton{background:" + QString(ui::colors::BG_RAISED()) + ";color:" + QString(ui::colors::POSITIVE()) +
        ";border:1px solid " + QString(ui::colors::POSITIVE()) +
        ";"
        "border-radius:4px;font-weight:600;padding:0 16px;}"
        "QPushButton:hover{background:" +
        QString(ui::colors::BG_RAISED()) +
        ";}"
        "QPushButton:disabled{color:" +
        QString(ui::colors::BORDER_BRIGHT()) + ";border-color:" + QString(ui::colors::BORDER_MED()) +
        ";background:" + QString(ui::colors::BG_BASE()) + ";}");
    connect(start_btn_, &QPushButton::clicked, this, &McpServersSection::on_start_server);

    stop_btn_ = new QPushButton(tr("■  Stop"));
    stop_btn_->setEnabled(false);
    stop_btn_->setFixedHeight(32);
    // Was red text on a red background — the label was invisible in the enabled
    // state. Now the Obsidian danger-button spec: tinted surface, red label,
    // solid red on hover.
    stop_btn_->setStyleSheet(
        "QPushButton{background:rgba(220,38,38,0.1);color:" + QString(ui::colors::NEGATIVE()) + ";border:1px solid " +
        QString(ui::colors::NEGATIVE_DIM()) +
        ";"
        "border-radius:4px;font-weight:600;padding:0 16px;}"
        "QPushButton:hover{background:" +
        QString(ui::colors::NEGATIVE()) + ";color:" + QString(ui::colors::TEXT_PRIMARY()) +
        ";}"
        "QPushButton:disabled{color:" +
        QString(ui::colors::BORDER_BRIGHT()) + ";border-color:" + QString(ui::colors::BORDER_MED()) +
        ";background:" + QString(ui::colors::BG_BASE()) + ";}");
    connect(stop_btn_, &QPushButton::clicked, this, &McpServersSection::on_stop_server);

    server_btns->addWidget(start_btn_);
    server_btns->addWidget(stop_btn_);
    server_btns->addStretch();
    dvl->addLayout(server_btns);

    status_lbl_ = new QLabel;
    status_lbl_->setStyleSheet("");
    status_lbl_->hide();
    dvl->addWidget(status_lbl_);

    dvl->addStretch();
    right->setWidget(detail_page);
    hl->addWidget(right, 1);

    return page;
}

// ============================================================================
// Tools tab
// ============================================================================

QWidget* McpServersSection::build_tools_tab() {
    auto* page = new QWidget(this);
    page->setStyleSheet("background:" + QString(ui::colors::BG_BASE()) + ";");
    auto* vl = new QVBoxLayout(page);
    vl->setContentsMargins(16, 12, 16, 12);
    vl->setSpacing(8);

    tools_info_lbl_ =
        new QLabel(tr("All registered MCP tools — both internal (built-in) and external (from connected servers)."));
    tools_info_lbl_->setStyleSheet("color:" + QString(ui::colors::TEXT_SECONDARY()) + ";");
    tools_info_lbl_->setWordWrap(true);
    vl->addWidget(tools_info_lbl_);

    tools_table_ = new QTableWidget;
    tools_table_->setColumnCount(4);
    tools_table_->setHorizontalHeaderLabels({tr("Tool Name"), tr("Server"), tr("Category"), tr("Description")});
    tools_table_->horizontalHeader()->setStretchLastSection(true);
    tools_table_->horizontalHeader()->setSectionResizeMode(0, QHeaderView::ResizeToContents);
    tools_table_->horizontalHeader()->setSectionResizeMode(1, QHeaderView::ResizeToContents);
    tools_table_->horizontalHeader()->setSectionResizeMode(2, QHeaderView::ResizeToContents);
    tools_table_->setSelectionBehavior(QAbstractItemView::SelectRows);
    tools_table_->setEditTriggers(QAbstractItemView::NoEditTriggers);
    tools_table_->setAlternatingRowColors(true);
    tools_table_->verticalHeader()->hide();
    tools_table_->setStyleSheet("QTableWidget{background:" + QString(ui::colors::BG_BASE()) +
                                ";color:" + QString(ui::colors::TEXT_PRIMARY()) + ";border:1px solid " +
                                QString(ui::colors::BORDER_DIM()) +
                                ";"
                                "gridline-color:" +
                                QString(ui::colors::BG_RAISED()) +
                                ";}"
                                "QTableWidget::item{padding:6px;}"
                                "QTableWidget::item:selected{background:" +
                                QString(ui::colors::BG_RAISED()) + ";color:" + QString(ui::colors::AMBER()) +
                                ";}"
                                "QHeaderView::section{background:" +
                                QString(ui::colors::BG_SURFACE()) + ";color:" + QString(ui::colors::TEXT_SECONDARY()) +
                                ";border:none;"
                                "border-bottom:1px solid " +
                                QString(ui::colors::BORDER_DIM()) +
                                ";padding:6px;font-weight:600;}"
                                "QTableWidget{alternate-background-color:" +
                                QString(ui::colors::BG_BASE()) + ";}");
    vl->addWidget(tools_table_, 1);

    return page;
}

// ============================================================================
// Add Server Dialog
// ============================================================================

void McpServersSection::on_add_server() {
    auto* dlg = new QDialog(this);
    dlg->setWindowTitle(tr("Add MCP Server"));
    dlg->setMinimumWidth(480);
    dlg->setStyleSheet("background:" + QString(ui::colors::BG_SURFACE()) +
                       ";color:" + QString(ui::colors::TEXT_PRIMARY()) + ";");

    auto* vl = new QVBoxLayout(dlg);
    vl->setSpacing(12);
    vl->setContentsMargins(16, 16, 16, 16);

    auto* title = new QLabel(tr("Add External MCP Server"));
    title->setStyleSheet("color:" + QString(ui::colors::AMBER()) + ";font-weight:700;");
    vl->addWidget(title);

    auto* form = new QFormLayout;
    form->setSpacing(8);

    auto fe = [](const QString& ph) {
        auto* e = new QLineEdit;
        e->setPlaceholderText(ph);
        e->setStyleSheet("QLineEdit{background:" + QString(ui::colors::BG_RAISED()) +
                         ";color:" + QString(ui::colors::TEXT_PRIMARY()) + ";border:1px solid " +
                         QString(ui::colors::BORDER_MED()) +
                         ";"
                         "border-radius:3px;padding:6px;}"
                         "QLineEdit:focus{border:1px solid " +
                         QString(ui::colors::AMBER()) + ";}");
        return e;
    };
    auto fl = [](const QString& t) {
        auto* l = new QLabel(t);
        l->setStyleSheet("color:" + QString(ui::colors::TEXT_SECONDARY()) + ";");
        return l;
    };

    auto* name_edit = fe(tr("e.g. My Database Server"));
    auto* cmd_edit = fe(tr("e.g. npx, uvx, python"));
    auto* args_edit = fe(tr("e.g. -y @modelcontextprotocol/server-postgres"));
    auto* env_edit = fe(tr("KEY=VALUE KEY2=VALUE2 (space-separated)"));
    auto* cat_edit = fe(tr("e.g. data, tools, analytics"));

    form->addRow(fl(tr("Name")), name_edit);
    form->addRow(fl(tr("Command")), cmd_edit);
    form->addRow(fl(tr("Arguments")), args_edit);
    form->addRow(fl(tr("Environment")), env_edit);
    form->addRow(fl(tr("Category")), cat_edit);

    vl->addLayout(form);

    // Auto-start checkbox
    auto* auto_start_row = new QHBoxLayout;
    auto* as_lbl = new QLabel(tr("Auto-start on launch"));
    as_lbl->setStyleSheet("color:" + QString(ui::colors::TEXT_SECONDARY()) + ";");
    auto* as_cb = new QCheckBox;
    as_cb->setChecked(false);
    auto_start_row->addWidget(as_lbl);
    auto_start_row->addWidget(as_cb);
    auto_start_row->addStretch();
    vl->addLayout(auto_start_row);

    auto* btns = new QDialogButtonBox(QDialogButtonBox::Ok | QDialogButtonBox::Cancel);
    btns->setStyleSheet("QPushButton{background:" + QString(ui::colors::BG_RAISED()) +
                        ";color:" + QString(ui::colors::TEXT_PRIMARY()) + ";border:1px solid " +
                        QString(ui::colors::BORDER_BRIGHT()) +
                        ";"
                        "border-radius:3px;padding:6px 16px;}"
                        "QPushButton:hover{background:" +
                        QString(ui::colors::BG_HOVER()) +
                        ";}"
                        "QPushButton[text='OK']{background:" +
                        QString(ui::colors::AMBER()) + ";color:" + QString(ui::colors::BG_BASE()) +
                        ";border:none;}"
                        "QPushButton[text='OK']:hover{background:" +
                        QString(ui::colors::AMBER_DIM()) + ";}");
    connect(btns, &QDialogButtonBox::accepted, dlg, &QDialog::accept);
    connect(btns, &QDialogButtonBox::rejected, dlg, &QDialog::reject);
    vl->addWidget(btns);

    if (dlg->exec() != QDialog::Accepted) {
        dlg->deleteLater();
        return;
    }

    QString name = name_edit->text().trimmed();
    QString cmd = cmd_edit->text().trimmed();
    if (name.isEmpty() || cmd.isEmpty()) {
        show_status(tr("Name and Command are required"), true);
        dlg->deleteLater();
        return;
    }

    McpServerConfig cfg;
    cfg.name = name;
    cfg.command = cmd;
    cfg.args = args_edit->text().trimmed().split(' ', Qt::SkipEmptyParts);
    cfg.category = cat_edit->text().trimmed();
    cfg.auto_start = as_cb->isChecked();
    cfg.enabled = true;

    // Parse env pairs
    for (const auto& pair : env_edit->text().trimmed().split(' ', Qt::SkipEmptyParts)) {
        int eq = pair.indexOf('=');
        if (eq > 0)
            cfg.env[pair.left(eq)] = pair.mid(eq + 1);
    }

    auto r = McpManager::instance().save_server(cfg);
    if (r.is_err()) {
        show_status(tr("Failed to save server: ") + QString::fromStdString(r.error()), true);
    } else {
        show_status(tr("Server added: ") + name, false);
        load_servers();
        LOG_INFO(TAG, "Added MCP server: " + name);
    }

    dlg->deleteLater();
}

// ============================================================================
// Data Loading
// ============================================================================

void McpServersSection::load_servers() {
    server_list_->blockSignals(true);
    server_list_->clear();

    auto servers = McpManager::instance().get_servers();
    for (const auto& cfg : servers) {
        QString status_icon;
        if (cfg.status == ServerStatus::Running)
            status_icon = "● ";
        else if (cfg.status == ServerStatus::Error)
            status_icon = "✕ ";
        else
            status_icon = "○ ";

        auto* item = new QListWidgetItem(status_icon + cfg.name);
        item->setData(Qt::UserRole, cfg.id);

        if (cfg.status == ServerStatus::Running)
            item->setForeground(QColor("" + QString(ui::colors::POSITIVE()) + ""));
        else if (cfg.status == ServerStatus::Error)
            item->setForeground(QColor("" + QString(ui::colors::NEGATIVE()) + ""));
        else
            item->setForeground(QColor(ui::colors::TEXT_SECONDARY.get()));

        item->setToolTip(cfg.command + " " + cfg.args.join(' '));
        server_list_->addItem(item);
    }

    server_list_->blockSignals(false);
    remove_btn_->setEnabled(false);
    start_btn_->setEnabled(false);
    stop_btn_->setEnabled(false);

    if (server_list_->count() > 0)
        server_list_->setCurrentRow(0);
    else
        detail_lbl_->setText(tr("No external servers configured.\nClick '+ Add' to add one."));
}

void McpServersSection::load_tools() {
    auto tools = McpService::instance().get_all_tools();
    tools_table_->setRowCount(0);
    tools_table_->setRowCount(static_cast<int>(tools.size()));

    int row = 0;
    for (const auto& t : tools) {
        auto* name_item = new QTableWidgetItem(t.name);
        auto* server_item = new QTableWidgetItem(t.server_name);
        auto* cat_item = new QTableWidgetItem(t.is_internal ? tr("internal") : tr("external"));
        auto* desc_item = new QTableWidgetItem(t.description);

        if (t.is_internal) {
            server_item->setForeground(QColor("" + QString(ui::colors::AMBER()) + ""));
            cat_item->setForeground(QColor(ui::colors::TEXT_SECONDARY.get()));
        } else {
            server_item->setForeground(QColor("" + QString(ui::colors::POSITIVE()) + ""));
            cat_item->setForeground(QColor("" + QString(ui::colors::INFO()) + ""));
        }

        tools_table_->setItem(row, 0, name_item);
        tools_table_->setItem(row, 1, server_item);
        tools_table_->setItem(row, 2, cat_item);
        tools_table_->setItem(row, 3, desc_item);
        ++row;
    }
}

void McpServersSection::refresh_server_detail(const QString& server_id) {
    auto servers = McpManager::instance().get_servers();
    for (const auto& cfg : servers) {
        if (cfg.id != server_id)
            continue;

        QString status_str;
        if (cfg.status == ServerStatus::Running)
            status_str = tr("Running");
        else if (cfg.status == ServerStatus::Error)
            status_str = tr("Error");
        else
            status_str = tr("Stopped");

        detail_lbl_->setText(QString("<b style='color:" + QString(ui::colors::TEXT_PRIMARY()) +
                                     "'>%1</b><br>"
                                     "<span style='color:" +
                                     QString(ui::colors::TEXT_SECONDARY()) + ";'>" + tr("Status: %2") +
                                     "</span><br>"
                                     "<span style='color:" +
                                     QString(ui::colors::TEXT_TERTIARY()) + ";'>" + tr("Command: %3 %4") +
                                     "</span><br>"
                                     "<span style='color:" +
                                     QString(ui::colors::TEXT_TERTIARY()) + ";'>" + tr("Category: %5") +
                                     "</span><br>"
                                     "<span style='color:" +
                                     QString(ui::colors::TEXT_TERTIARY()) + ";'>" + tr("Auto-start: %6") + "</span>")
                                 // Server name / command / args are user-supplied and land in a
                                 // rich-text QLabel — escape them so a stray '<' doesn't swallow
                                 // the rest of the detail panel.
                                 .arg(cfg.name.toHtmlEscaped(), status_str, cfg.command.toHtmlEscaped(),
                                      cfg.args.join(' ').toHtmlEscaped(),
                                      cfg.category.isEmpty() ? QStringLiteral("-") : cfg.category.toHtmlEscaped(),
                                      cfg.auto_start ? tr("Yes") : tr("No")));

        bool running = (cfg.status == ServerStatus::Running);
        start_btn_->setEnabled(!running);
        stop_btn_->setEnabled(running);
        return;
    }
}

// ============================================================================
// Slots
// ============================================================================

void McpServersSection::on_server_selected(int row) {
    if (row < 0 || row >= server_list_->count()) {
        remove_btn_->setEnabled(false);
        start_btn_->setEnabled(false);
        stop_btn_->setEnabled(false);
        return;
    }

    selected_server_id_ = server_list_->item(row)->data(Qt::UserRole).toString();
    remove_btn_->setEnabled(true);
    refresh_server_detail(selected_server_id_);
}

void McpServersSection::on_remove_server() {
    if (selected_server_id_.isEmpty())
        return;

    auto reply = QMessageBox::question(this, tr("Remove Server"), tr("Remove this MCP server configuration?"),
                                       QMessageBox::Yes | QMessageBox::No);
    if (reply != QMessageBox::Yes)
        return;

    McpManager::instance().remove_server(selected_server_id_);
    selected_server_id_.clear();
    load_servers();
}

void McpServersSection::on_start_server() {
    if (selected_server_id_.isEmpty())
        return;
    show_status(tr("Starting server..."), false);
    start_btn_->setEnabled(false);

    QPointer<McpServersSection> self = this;
    QString id = selected_server_id_;
    (void)QtConcurrent::run([self, id]() {
        auto r = McpManager::instance().start_server(id);
        QMetaObject::invokeMethod(
            qApp,
            [self, r, id]() {
                if (!self)
                    return;
                if (r.is_err())
                    self->show_status(tr("Start failed: ") + QString::fromStdString(r.error()), true);
                else
                    self->show_status(tr("Server started"), false);
                self->load_servers();
            },
            Qt::QueuedConnection);
    });
}

void McpServersSection::on_stop_server() {
    if (selected_server_id_.isEmpty())
        return;
    McpManager::instance().stop_server(selected_server_id_);
    show_status(tr("Server stopped"), false);
    load_servers();
}

void McpServersSection::on_tab_changed(int idx) {
    tab_stack_->setCurrentIndex(idx);
    if (idx == 1)
        load_tools();

    // Drive the two tab buttons directly. The previous version walked every
    // QPushButton in the subtree and checked the first two checkable ones,
    // which silently breaks the moment any other checkable button is added.
    if (servers_tab_btn_)
        servers_tab_btn_->setChecked(idx == 0);
    if (tools_tab_btn_)
        tools_tab_btn_->setChecked(idx == 1);
}

void McpServersSection::show_status(const QString& msg, bool error) {
    status_lbl_->setText(msg);
    status_lbl_->setStyleSheet(error ? "color:" + QString(ui::colors::NEGATIVE()) + ";"
                                     : "color:" + QString(ui::colors::POSITIVE()) + ";");
    status_lbl_->show();
    QTimer::singleShot(4000, status_lbl_, &QLabel::hide);
}

// ============================================================================
// Retranslation
// ============================================================================

void McpServersSection::changeEvent(QEvent* event) {
    if (event->type() == QEvent::LanguageChange)
        retranslateUi();
    QWidget::changeEvent(event);
}

void McpServersSection::retranslateUi() {
    // Title bar.
    if (title_lbl_)
        title_lbl_->setText(tr("MCP SERVERS"));
    if (tools_badge_)
        tools_badge_->setText(tr("%1 internal tools active").arg(McpService::instance().tool_count()));

    // Tab buttons.
    if (servers_tab_btn_)
        servers_tab_btn_->setText(tr("Installed Servers"));
    if (tools_tab_btn_)
        tools_tab_btn_->setText(tr("Tools"));

    // Servers tab chrome.
    if (server_list_lbl_)
        server_list_lbl_->setText(tr("External Servers"));
    if (add_btn_)
        add_btn_->setText(tr("+ Add"));
    if (remove_btn_)
        remove_btn_->setText(tr("Remove"));
    if (start_btn_)
        start_btn_->setText(tr("▶  Start"));
    if (stop_btn_)
        stop_btn_->setText(tr("■  Stop"));

    // Tools tab chrome.
    if (tools_info_lbl_)
        tools_info_lbl_->setText(
            tr("All registered MCP tools — both internal (built-in) and external (from connected servers)."));
    if (tools_table_)
        tools_table_->setHorizontalHeaderLabels({tr("Tool Name"), tr("Server"), tr("Category"), tr("Description")});

    // Detail panel default placeholder — only re-apply when nothing is selected
    // (otherwise we'd clobber the live per-server detail HTML).
    if (detail_lbl_ && selected_server_id_.isEmpty() && server_list_ && server_list_->count() == 0)
        detail_lbl_->setText(tr("No external servers configured.\nClick '+ Add' to add one."));
}

} // namespace fincept::screens