#include "screens/polymarket/PolymarketBrowsePanel.h"

#include "screens/polymarket/PolymarketMarketCard.h"
#include "ui/theme/Theme.h"

#include <QHBoxLayout>
#include <QVBoxLayout>

namespace fincept::screens::polymarket {

using namespace fincept::ui;
using namespace fincept::services::prediction;

PolymarketBrowsePanel::PolymarketBrowsePanel(QWidget* parent) : QWidget(parent) {
    setObjectName("polyBrowsePanel");

    model_ = new PolymarketMarketCardModel(this);
    delegate_ = new PolymarketMarketCardDelegate(this);

    auto* vl = new QVBoxLayout(this);
    vl->setContentsMargins(0, 0, 0, 0);
    vl->setSpacing(0);

    // ── Header bar ───────────────────────────────────────────────────────
    auto* header_bar = new QWidget(this);
    header_bar->setFixedHeight(30);
    header_bar->setStyleSheet(
        QString("background: %1; border-bottom: 1px solid %2;").arg(colors::BG_RAISED(), colors::BORDER_DIM()));
    auto* hbl = new QHBoxLayout(header_bar);
    hbl->setContentsMargins(12, 0, 8, 0);
    hbl->setSpacing(6);

    header_ = new QLabel(tr("MARKETS"));
    header_->setStyleSheet(QString("color: %1; font-size: 9px; font-weight: 700; letter-spacing: 0.8px; "
                                   "background: transparent;")
                               .arg(colors::TEXT_SECONDARY()));
    hbl->addWidget(header_);
    hbl->addStretch(1);
    vl->addWidget(header_bar);

    // ── List view ─────────────────────────────────────────────────────────
    list_view_ = new QListView;
    list_view_->setModel(model_);
    list_view_->setItemDelegate(delegate_);
    list_view_->setVerticalScrollMode(QAbstractItemView::ScrollPerPixel);
    list_view_->setSelectionMode(QAbstractItemView::SingleSelection);
    list_view_->setHorizontalScrollBarPolicy(Qt::ScrollBarAlwaysOff);
    list_view_->setStyleSheet(QString("QListView {"
                                      "  background: %1;"
                                      "  border: none;"
                                      "  outline: none;"
                                      "}"
                                      "QListView::item { border: none; }"
                                      "QScrollBar:vertical {"
                                      "  background: %2;"
                                      "  width: 4px;"
                                      "  border: none;"
                                      "}"
                                      "QScrollBar::handle:vertical {"
                                      "  background: %3;"
                                      "  min-height: 20px;"
                                      "}"
                                      "QScrollBar::add-line:vertical, QScrollBar::sub-line:vertical { height: 0; }")
                                  .arg(colors::BG_BASE(), colors::BG_SURFACE(), colors::BORDER_BRIGHT()));
    list_view_->setAccessibleName(tr("Market list"));
    connect(list_view_, &QListView::clicked, this, &PolymarketBrowsePanel::on_item_clicked);
    // Keyboard: Enter/Return on the highlighted card opens it, matching the
    // click path. Without this the list was mouse-only.
    connect(list_view_, &QListView::activated, this, &PolymarketBrowsePanel::on_item_clicked);
    vl->addWidget(list_view_, 1);

    // ── Pagination bar ────────────────────────────────────────────────────
    auto* page_bar = new QWidget(this);
    page_bar->setFixedHeight(32);
    page_bar->setStyleSheet(
        QString("background: %1; border-top: 1px solid %2;").arg(colors::BG_RAISED(), colors::BORDER_DIM()));

    auto* phl = new QHBoxLayout(page_bar);
    phl->setContentsMargins(8, 0, 8, 0);
    phl->setSpacing(4);

    const QString nav_btn_css = QString("QPushButton {"
                                        "  background: transparent;"
                                        "  color: %1;"
                                        "  border: 1px solid %2;"
                                        "  padding: 3px 12px;"
                                        "  font-size: 9px;"
                                        "  font-weight: 700;"
                                        "}"
                                        "QPushButton:hover { color: %3; border-color: %4; }"
                                        "QPushButton:disabled { color: %5; border-color: %2; }")
                                    .arg(colors::TEXT_SECONDARY(), colors::BORDER_DIM(), colors::TEXT_PRIMARY(),
                                         colors::BORDER_BRIGHT(), colors::TEXT_DIM());

    prev_btn_ = new QPushButton("◀");
    prev_btn_->setStyleSheet(nav_btn_css);
    prev_btn_->setFixedSize(30, 22);
    prev_btn_->setCursor(Qt::PointingHandCursor);
    prev_btn_->setToolTip(tr("Previous page"));
    prev_btn_->setAccessibleName(tr("Previous page"));
    connect(prev_btn_, &QPushButton::clicked, this, &PolymarketBrowsePanel::on_prev);

    page_label_ = new QLabel("1 / 1");
    page_label_->setStyleSheet(
        QString("color: %1; font-size: 9px; background: transparent; min-width: 40px;").arg(colors::TEXT_SECONDARY()));
    page_label_->setAlignment(Qt::AlignCenter);

    next_btn_ = new QPushButton("▶");
    next_btn_->setStyleSheet(nav_btn_css);
    next_btn_->setFixedSize(30, 22);
    next_btn_->setCursor(Qt::PointingHandCursor);
    next_btn_->setToolTip(tr("Next page"));
    next_btn_->setAccessibleName(tr("Next page"));
    connect(next_btn_, &QPushButton::clicked, this, &PolymarketBrowsePanel::on_next);

    phl->addWidget(prev_btn_);
    phl->addStretch(1);
    phl->addWidget(page_label_);
    phl->addStretch(1);
    phl->addWidget(next_btn_);
    vl->addWidget(page_bar);
}

void PolymarketBrowsePanel::set_markets(const QVector<PredictionMarket>& markets) {
    events_mode_ = false;
    current_page_ = 0;
    model_->set_markets(markets);
    header_->setText(tr("MARKETS  %1").arg(markets.size()));
    update_page();
}

void PolymarketBrowsePanel::set_events(const QVector<PredictionEvent>& events) {
    events_mode_ = true;
    current_page_ = 0;
    model_->set_events(events);
    header_->setText(tr("EVENTS  %1").arg(events.size()));
    update_page();
}

void PolymarketBrowsePanel::set_loading(bool loading) {
    if (loading) {
        header_->setText(tr("LOADING..."));
    } else {
        const int total = model_->rowCount();
        header_->setText(events_mode_ ? tr("EVENTS  %1").arg(total) : tr("MARKETS  %1").arg(total));
    }
}

void PolymarketBrowsePanel::clear() {
    events_mode_ = false;
    model_->set_markets({});
    header_->setText(tr("MARKETS"));
    current_page_ = 0;
    update_page();
}

void PolymarketBrowsePanel::set_presentation(const ExchangePresentation& p) {
    if (model_)
        model_->set_presentation(p);
}

void PolymarketBrowsePanel::update_market_row(const PredictionMarket& market) {
    if (model_)
        model_->update_market(market);
}

void PolymarketBrowsePanel::on_item_clicked(const QModelIndex& index) {
    if (!index.isValid())
        return;
    int row = index.row();

    const auto* mkt = model_->market_at(row);
    if (mkt) {
        emit market_selected(*mkt);
        return;
    }

    const auto* evt = model_->event_at(row);
    if (evt) {
        emit event_selected(*evt);
    }
}

void PolymarketBrowsePanel::on_prev() {
    if (current_page_ > 0) {
        --current_page_;
        update_page();
    }
}

void PolymarketBrowsePanel::on_next() {
    int total = model_->rowCount();
    int pages = qMax(1, (total + PAGE_SIZE - 1) / PAGE_SIZE);
    if (current_page_ + 1 < pages) {
        ++current_page_;
        update_page();
    }
}

void PolymarketBrowsePanel::update_page() {
    int total = model_->rowCount();
    int pages = qMax(1, (total + PAGE_SIZE - 1) / PAGE_SIZE);
    if (current_page_ >= pages)
        current_page_ = pages - 1;
    page_label_->setText(QString("%1 / %2").arg(current_page_ + 1).arg(pages));
    prev_btn_->setEnabled(current_page_ > 0);
    next_btn_->setEnabled(current_page_ + 1 < pages);
    // The ◀ / ▶ buttons previously only relabelled themselves — the list view
    // never moved, so paging was a no-op control. Scroll the view to the first
    // row of the page so the buttons actually navigate.
    if (list_view_ && total > 0) {
        const int row = qBound(0, current_page_ * PAGE_SIZE, total - 1);
        const auto idx = model_->index(row, 0);
        if (idx.isValid())
            list_view_->scrollTo(idx, QAbstractItemView::PositionAtTop);
    }
}

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

void PolymarketBrowsePanel::retranslateUi() {
    // Re-derive the header caption (mode word + live count) in the new
    // language. set_loading(false) reuses the current mode + model count.
    if (header_)
        set_loading(false);
    // Pagination arrows + "n / m" page label are symbols/numbers; nav nothing.
}

} // namespace fincept::screens::polymarket