// src/screens/geopolitics/HDXDataPanel.cpp
#include "screens/geopolitics/HDXDataPanel.h"

#include "services/geopolitics/GeopoliticsService.h"
#include "ui/theme/Theme.h"

#include <QDesktopServices>
#include <QHBoxLayout>
#include <QHeaderView>
#include <QScrollArea>
#include <QUrl>

namespace fincept::screens {

using namespace fincept::services::geo;

// Helper: get cyan accent RGB string for rgba() usage
static QString cyan_rgb() {
    QColor c(ui::colors::CYAN());
    return QString("%1,%2,%3").arg(c.red()).arg(c.green()).arg(c.blue());
}

HDXDataPanel::HDXDataPanel(QWidget* parent) : QWidget(parent) {
    build_ui();
    connect_service();
}

void HDXDataPanel::connect_service() {
    auto& svc = GeopoliticsService::instance();
    connect(&svc, &GeopoliticsService::hdx_results_loaded, this, &HDXDataPanel::on_hdx_results);
    // Without this the panel hangs on "Loading HDX data…" forever whenever the
    // fetch fails (and re-fires the failing request on every tab switch).
    connect(&svc, &GeopoliticsService::error_occurred, this, &HDXDataPanel::on_error);
}

void HDXDataPanel::on_error(const QString& context, const QString& message) {
    // GeopoliticsService::error_occurred is a shared channel — an events or
    // categories failure used to blank this table and replace it with an "HDX
    // failed" message that had nothing to do with HDX. Only react to our own
    // contexts.
    static const QStringList kHdxContexts = {QStringLiteral("conflicts"), QStringLiteral("humanitarian"),
                                             QStringLiteral("search"), QStringLiteral("topic"),
                                             QStringLiteral("country")};
    if (!kHdxContexts.contains(context) && !context.startsWith(QStringLiteral("hdx")))
        return;

    // Stop the perpetual spinner and surface the failure in its place.
    if (datasets_table_)
        datasets_table_->setRowCount(0);
    if (dataset_count_)
        dataset_count_->setText(QStringLiteral("0"));
    if (loading_label_) {
        loading_label_->setText(tr("Failed to load HDX data (%1):\n%2\n\nAdjust the query and search again.")
                                    .arg(context, message));
        loading_label_->show();
    }
    if (datasets_table_)
        datasets_table_->setVisible(false);
}

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

    // Header with view tabs
    auto* header = new QWidget(this);
    header->setFixedHeight(48);
    header->setStyleSheet(
        QString("background:%1; border-bottom:1px solid %2;").arg(ui::colors::BG_RAISED(), ui::colors::BORDER_DIM()));
    auto* hhl = new QHBoxLayout(header);
    hhl->setContentsMargins(16, 0, 16, 0);
    hhl->setSpacing(8);

    title_lbl_ = new QLabel(tr("HDX HUMANITARIAN DATA"), header);
    title_lbl_->setStyleSheet(QString("color:%1; font-size:%2px; font-weight:700; font-family:%3; letter-spacing:1px;")
                                  .arg(ui::colors::CYAN())
                                  .arg(ui::fonts::TINY)
                                  .arg(ui::fonts::DATA_FAMILY()));
    hhl->addWidget(title_lbl_);

    auto* div = new QWidget(header);
    div->setFixedSize(1, 20);
    div->setStyleSheet(QString("background:%1;").arg(ui::colors::BORDER_DIM()));
    hhl->addWidget(div);

    auto rgb = cyan_rgb();
    const QStringList views = {tr("Conflicts"), tr("Humanitarian"), tr("Explorer"), tr("Datasets")};
    view_labels_ = views;
    for (int i = 0; i < views.size(); ++i) {
        auto* btn = new QPushButton(views[i].toUpper(), header);
        btn->setCursor(Qt::PointingHandCursor);
        btn->setStyleSheet(QString("QPushButton { color:%1; font-size:%2px; font-family:%3;"
                                   "padding:4px 12px; border:none; background:transparent;"
                                   "font-weight:400; }"
                                   "QPushButton:hover { color:%4; background:rgba(%5,0.04); }")
                               .arg(ui::colors::TEXT_TERTIARY())
                               .arg(ui::fonts::TINY)
                               .arg(ui::fonts::DATA_FAMILY)
                               .arg(ui::colors::CYAN())
                               .arg(rgb));
        connect(btn, &QPushButton::clicked, this, [this, i]() { on_view_changed(i); });
        hhl->addWidget(btn);
        view_buttons_.append(btn);
    }

    hhl->addStretch();

    search_edit_ = new QLineEdit(header);
    search_edit_->setPlaceholderText(tr("Search HDX datasets..."));
    search_edit_->setFixedWidth(240);
    search_edit_->setStyleSheet(QString("QLineEdit { background:%1; color:%2; border:1px solid %3;"
                                        "font-family:%4; font-size:%5px; padding:4px 8px; }"
                                        "QLineEdit:focus { border-color:%6; }")
                                    .arg(ui::colors::BG_RAISED(), ui::colors::TEXT_PRIMARY(), ui::colors::BORDER_MED())
                                    .arg(ui::fonts::DATA_FAMILY)
                                    .arg(ui::fonts::SMALL)
                                    .arg(ui::colors::CYAN()));
    connect(search_edit_, &QLineEdit::returnPressed, this, [this]() {
        auto q = search_edit_->text().trimmed();
        if (!q.isEmpty()) {
            show_loading(true);
            GeopoliticsService::instance().search_hdx_advanced(q);
        }
    });
    hhl->addWidget(search_edit_);

    dataset_count_ = new QLabel(tr("0 datasets"), header);
    dataset_count_->setFixedHeight(22);
    dataset_count_->setStyleSheet(QString("color:%1; font-size:%2px; font-family:%3; padding:2px 6px;"
                                          "background:rgba(%4,0.08); border:1px solid rgba(%4,0.25); font-weight:700;")
                                      .arg(ui::colors::CYAN())
                                      .arg(ui::fonts::TINY)
                                      .arg(ui::fonts::DATA_FAMILY())
                                      .arg(rgb));
    hhl->addWidget(dataset_count_);

    root->addWidget(header);

    // Datasets table
    datasets_table_ = new QTableWidget(this);
    datasets_table_->setColumnCount(5);
    datasets_table_->setHorizontalHeaderLabels(
        {tr("Title"), tr("Organization"), tr("Date"), tr("Resources"), tr("Tags")});
    datasets_table_->setEditTriggers(QAbstractItemView::NoEditTriggers);
    datasets_table_->setSelectionBehavior(QAbstractItemView::SelectRows);
    datasets_table_->setAlternatingRowColors(true);
    datasets_table_->verticalHeader()->setVisible(false);
    datasets_table_->setSortingEnabled(true);

    datasets_table_->horizontalHeader()->setSectionResizeMode(0, QHeaderView::Stretch);
    datasets_table_->horizontalHeader()->setSectionResizeMode(1, QHeaderView::ResizeToContents);
    datasets_table_->horizontalHeader()->setSectionResizeMode(2, QHeaderView::ResizeToContents);
    datasets_table_->horizontalHeader()->setSectionResizeMode(3, QHeaderView::ResizeToContents);
    datasets_table_->horizontalHeader()->setSectionResizeMode(4, QHeaderView::ResizeToContents);

    datasets_table_->verticalHeader()->setDefaultSectionSize(26);

    datasets_table_->setStyleSheet(
        QString("QTableWidget { background:%1; color:%2; gridline-color:%3;"
                "font-family:%4; font-size:%5px; border:none; }"
                "QTableWidget::item { padding:3px 8px; }"
                "QTableWidget::item:selected { background:rgba(%6,0.15); }"
                "QHeaderView::section { background:%7; color:%8; font-weight:700;"
                "padding:5px 8px; border:1px solid %3; font-family:%4; font-size:%5px; }"
                "QTableWidget::item:alternate { background:%9; }")
            .arg(ui::colors::BG_SURFACE(), ui::colors::TEXT_PRIMARY(), ui::colors::BORDER_DIM())
            .arg(ui::fonts::DATA_FAMILY)
            .arg(ui::fonts::SMALL)
            .arg(rgb)
            .arg(ui::colors::BG_RAISED())
            .arg(ui::colors::TEXT_SECONDARY())
            .arg(ui::colors::ROW_ALT()));

    datasets_table_->setAccessibleName(tr("HDX datasets"));
    datasets_table_->setAccessibleDescription(
        tr("Humanitarian Data Exchange datasets. Press Enter on a row to open it on data.humdata.org."));
    // Open the dataset's HDX page. Every CKAN dataset is addressable by its
    // name/id, so a row is actionable rather than a dead end.
    connect(datasets_table_, &QTableWidget::cellActivated, this, [this](int row, int) {
        if (row < 0)
            return;
        auto* it = datasets_table_->item(row, 0);
        if (!it)
            return;
        const QString url = it->data(Qt::UserRole).toString();
        if (!url.isEmpty())
            QDesktopServices::openUrl(QUrl(url));
    });

    // Loading overlay
    loading_label_ = new QLabel(tr("Loading HDX data..."), this);
    loading_label_->setAlignment(Qt::AlignCenter);
    loading_label_->setStyleSheet(QString("color:%1; font-size:%2px; font-family:%3; background:%4;")
                                      .arg(ui::colors::CYAN())
                                      .arg(ui::fonts::DATA)
                                      .arg(ui::fonts::DATA_FAMILY)
                                      .arg(ui::colors::BG_SURFACE()));
    loading_label_->hide();
    root->addWidget(loading_label_, 1);
    root->addWidget(datasets_table_, 1);

    // Explorer filter bar
    explorer_bar_ = new QWidget(this);
    explorer_bar_->setFixedHeight(44);
    explorer_bar_->setStyleSheet(
        QString("background:%1; border-top:1px solid %2;").arg(ui::colors::BG_RAISED(), ui::colors::BORDER_DIM()));
    auto* ehl = new QHBoxLayout(explorer_bar_);
    ehl->setContentsMargins(16, 0, 16, 0);
    ehl->setSpacing(8);

    auto combo_style = QString("QComboBox { background:%1; color:%2; border:1px solid %3;"
                               "font-family:%4; font-size:%5px; padding:4px 6px; }")
                           .arg(ui::colors::BG_RAISED(), ui::colors::TEXT_PRIMARY(), ui::colors::BORDER_MED())
                           .arg(ui::fonts::DATA_FAMILY)
                           .arg(ui::fonts::SMALL);

    auto bar_label_style = QString("color:%1; font-size:%2px; font-family:%3; font-weight:700; letter-spacing:1px;")
                               .arg(ui::colors::TEXT_TERTIARY())
                               .arg(ui::fonts::TINY)
                               .arg(ui::fonts::DATA_FAMILY);

    country_lbl_ = new QLabel(tr("COUNTRY:"), explorer_bar_);
    country_lbl_->setStyleSheet(bar_label_style);
    ehl->addWidget(country_lbl_);
    country_combo_ = new QComboBox(explorer_bar_);
    country_combo_->setStyleSheet(combo_style);
    country_combo_->setEditable(true);
    country_combo_->setPlaceholderText(tr("Select country"));
    for (const auto& r : critical_regions())
        country_combo_->addItem(r);
    ehl->addWidget(country_combo_);

    topic_lbl_ = new QLabel(tr("TOPIC:"), explorer_bar_);
    topic_lbl_->setStyleSheet(bar_label_style);
    ehl->addWidget(topic_lbl_);
    topic_combo_ = new QComboBox(explorer_bar_);
    topic_combo_->setStyleSheet(combo_style);
    // Topic values are search query keys passed to the HDX service — not UI labels.
    topic_combo_->addItems(
        {"conflict", "humanitarian", "displacement", "food security", "health", "education", "refugees"});
    ehl->addWidget(topic_combo_);

    explore_btn_ = new QPushButton(tr("SEARCH"), explorer_bar_);
    explore_btn_->setCursor(Qt::PointingHandCursor);
    {
        QColor cy(ui::colors::CYAN());
        explore_btn_->setStyleSheet(QString("QPushButton { background:%1; color:%2; font-family:%3;"
                                            "font-size:%4px; font-weight:700; border:none; padding:6px 16px; }"
                                            "QPushButton:hover { background:%5; }")
                                        .arg(ui::colors::CYAN())
                                        .arg(ui::colors::BG_BASE())
                                        .arg(ui::fonts::DATA_FAMILY())
                                        .arg(ui::fonts::SMALL)
                                        .arg(cy.darker(120).name()));
    }
    connect(explore_btn_, &QPushButton::clicked, this, [this]() {
        auto country = country_combo_->currentText().trimmed();
        show_loading(true);
        if (!country.isEmpty()) {
            GeopoliticsService::instance().search_hdx_by_country(country);
        } else {
            auto topic = topic_combo_->currentText().trimmed();
            if (!topic.isEmpty())
                GeopoliticsService::instance().search_hdx_by_topic(topic);
            else
                show_loading(false);
        }
    });
    ehl->addWidget(explore_btn_);
    ehl->addStretch();

    root->addWidget(explorer_bar_);

    // Source + licence attribution. HDX redistribution terms require the
    // source and the per-dataset licence to travel with the data; the panel
    // previously showed dataset rows with neither.
    attribution_lbl_ = new QLabel(this);
    attribution_lbl_->setTextFormat(Qt::RichText);
    attribution_lbl_->setOpenExternalLinks(true);
    attribution_lbl_->setWordWrap(true);
    attribution_lbl_->setText(tr("Source: <a href=\"https://data.humdata.org\">Humanitarian Data Exchange (HDX)</a>, "
                                 "OCHA. Each dataset carries its own licence and attribution — open the dataset page "
                                 "before redistributing or citing it."));
    attribution_lbl_->setStyleSheet(QString("color:%1; font-size:%2px; font-family:%3; padding:4px 16px;"
                                            "background:%4; border-top:1px solid %5;")
                                        .arg(ui::colors::TEXT_TERTIARY())
                                        .arg(ui::fonts::TINY)
                                        .arg(ui::fonts::DATA_FAMILY())
                                        .arg(ui::colors::BG_SURFACE())
                                        .arg(ui::colors::BORDER_DIM()));
    root->addWidget(attribution_lbl_);

    on_view_changed(0);
}

void HDXDataPanel::on_view_changed(int index) {
    active_view_ = index;
    auto rgb = cyan_rgb();
    for (int i = 0; i < view_buttons_.size(); ++i) {
        const bool active = (i == index);
        if (active) {
            view_buttons_[i]->setStyleSheet(
                QString("QPushButton { color:%1; font-size:%2px; font-family:%3;"
                        "padding:4px 12px;"
                        "border-bottom:2px solid %1; border-top:none; border-left:none; border-right:none;"
                        "background:rgba(%4,0.06); font-weight:700; }"
                        "QPushButton:hover { background:rgba(%4,0.10); }")
                    .arg(ui::colors::CYAN())
                    .arg(ui::fonts::TINY)
                    .arg(ui::fonts::DATA_FAMILY)
                    .arg(rgb));
        } else {
            view_buttons_[i]->setStyleSheet(QString("QPushButton { color:%1; font-size:%2px; font-family:%3;"
                                                    "padding:4px 12px; border:none; background:transparent;"
                                                    "font-weight:400; }"
                                                    "QPushButton:hover { color:%4; background:rgba(%5,0.04); }")
                                                .arg(ui::colors::TEXT_TERTIARY())
                                                .arg(ui::fonts::TINY)
                                                .arg(ui::fonts::DATA_FAMILY)
                                                .arg(ui::colors::CYAN())
                                                .arg(rgb));
        }
    }

    if (explorer_bar_)
        explorer_bar_->setVisible(index == 2);

    auto& svc = GeopoliticsService::instance();
    switch (index) {
        case 0:
            if (!cache_conflicts_.isEmpty())
                populate_table(cache_conflicts_);
            else {
                show_loading(true);
                svc.search_hdx_conflicts();
            }
            break;
        case 1:
            if (!cache_humanitarian_.isEmpty())
                populate_table(cache_humanitarian_);
            else {
                show_loading(true);
                svc.search_hdx_humanitarian();
            }
            break;
        case 2:
            break;
        case 3:
            if (!cache_datasets_.isEmpty())
                populate_table(cache_datasets_);
            else {
                show_loading(true);
                svc.search_hdx_advanced("humanitarian crisis conflict displacement");
            }
            break;
    }
}

void HDXDataPanel::show_loading(bool on) {
    loading_label_->setVisible(on);
    datasets_table_->setVisible(!on);
}

void HDXDataPanel::on_hdx_results(const QString& context, QVector<HDXDataset> datasets) {
    if (context == "conflicts")
        cache_conflicts_ = datasets;
    else if (context == "humanitarian")
        cache_humanitarian_ = datasets;
    else if (context == "search" || context == "topic" || context == "country")
        cache_datasets_ = datasets;

    bool relevant = (active_view_ == 0 && context == "conflicts") || (active_view_ == 1 && context == "humanitarian") ||
                    (active_view_ == 2 && (context == "country" || context == "topic")) ||
                    (active_view_ == 3 && context == "search");
    if (relevant)
        populate_table(datasets);
}

void HDXDataPanel::populate_table(const QVector<HDXDataset>& datasets) {
    show_loading(false);
    datasets_table_->setSortingEnabled(false);
    datasets_table_->setRowCount(datasets.size());

    for (int i = 0; i < datasets.size(); ++i) {
        const auto& d = datasets[i];
        auto* title_item = new QTableWidgetItem(d.title);
        // Per-dataset licence + link. HDX carries licence metadata on the CKAN
        // record; surface whatever the payload has so the user can see the
        // terms without leaving the terminal, and stash the dataset URL for
        // the row-activation handler.
        const QString licence = d.raw.value(QStringLiteral("license_title")).toString();
        const QString name = d.raw.value(QStringLiteral("name")).toString();
        const QString url = !name.isEmpty() ? QStringLiteral("https://data.humdata.org/dataset/") + name
                            : !d.id.isEmpty() ? QStringLiteral("https://data.humdata.org/dataset/") + d.id
                                              : QString();
        title_item->setData(Qt::UserRole, url);
        QString tip = d.notes;
        if (!licence.isEmpty())
            tip += (tip.isEmpty() ? QString() : QStringLiteral("\n\n")) + tr("Licence: %1").arg(licence);
        if (!url.isEmpty())
            tip += (tip.isEmpty() ? QString() : QStringLiteral("\n")) + url;
        title_item->setToolTip(tip);
        datasets_table_->setItem(i, 0, title_item);

        auto* org_item = new QTableWidgetItem(d.organization);
        if (!licence.isEmpty())
            org_item->setToolTip(tr("Licence: %1").arg(licence));
        datasets_table_->setItem(i, 1, org_item);
        datasets_table_->setItem(i, 2, new QTableWidgetItem(d.date));

        auto* res_item = new QTableWidgetItem(QString::number(d.num_resources));
        res_item->setTextAlignment(Qt::AlignCenter);
        datasets_table_->setItem(i, 3, res_item);

        datasets_table_->setItem(i, 4, new QTableWidgetItem(d.tags.join(", ")));
    }

    datasets_table_->setSortingEnabled(true);
    dataset_count_->setText(tr("%1 datasets").arg(datasets.size()));

    // Empty result is a state, not a silent blank grid.
    if (datasets.isEmpty() && loading_label_) {
        loading_label_->setText(tr("No HDX datasets matched this query.\nTry a broader term or a different country."));
        loading_label_->show();
        datasets_table_->setVisible(false);
    }
}

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

void HDXDataPanel::retranslateUi() {
    if (title_lbl_)
        title_lbl_->setText(tr("HDX HUMANITARIAN DATA"));
    if (search_edit_)
        search_edit_->setPlaceholderText(tr("Search HDX datasets..."));
    if (loading_label_)
        loading_label_->setText(tr("Loading HDX data..."));

    // View-tab buttons — re-apply the fixed labels (upper-cased) in order.
    const QStringList views = {tr("Conflicts"), tr("Humanitarian"), tr("Explorer"), tr("Datasets")};
    view_labels_ = views;
    for (int i = 0; i < view_buttons_.size() && i < views.size(); ++i)
        if (view_buttons_[i])
            view_buttons_[i]->setText(views[i].toUpper());

    // Explorer filter bar
    if (country_lbl_)
        country_lbl_->setText(tr("COUNTRY:"));
    if (topic_lbl_)
        topic_lbl_->setText(tr("TOPIC:"));
    if (country_combo_)
        country_combo_->setPlaceholderText(tr("Select country"));
    if (explore_btn_)
        explore_btn_->setText(tr("SEARCH"));

    // Table headers
    if (datasets_table_)
        datasets_table_->setHorizontalHeaderLabels(
            {tr("Title"), tr("Organization"), tr("Date"), tr("Resources"), tr("Tags")});

    if (attribution_lbl_)
        attribution_lbl_->setText(
            tr("Source: <a href=\"https://data.humdata.org\">Humanitarian Data Exchange (HDX)</a>, "
               "OCHA. Each dataset carries its own licence and attribution — open the dataset page "
               "before redistributing or citing it."));

    // dataset_count_ reflects the last populate_table() and refreshes on next load.
}

} // namespace fincept::screens