#include "channellist.h"
#include "channeldelegate.h"
#include "../db/db_manager.h"
#include <QVBoxLayout>
#include <QHBoxLayout>
#include <QLabel>
#include <QPushButton>
#include <QPainter>
#include <QPixmap>
#include <QMouseEvent>

extern "C" {
#include "../../lib/debug_config.h"
}

/* QListView that prevents deselection, handles invite plus-button clicks */
class ChannelListView : public QListView {
    Q_OBJECT
public:
    using QListView::QListView;

signals:
    void inviteClicked(const QString& channelId);

protected:
    void mousePressEvent(QMouseEvent* e) override {
        QModelIndex idx = indexAt(e->pos());
        if (!idx.isValid()) return;
        QRect plusRect = ChannelDelegate::inviteButtonRect(visualRect(idx));
        if (plusRect.contains(e->pos())) {
            emit inviteClicked(idx.data(ChannelChannelIdRole).toString());
            return;
        }
        QListView::mousePressEvent(e);
    }
    void mouseMoveEvent(QMouseEvent* e) override {
        int prevRow = m_hoveredInviteRow;
        m_hoveredInviteRow = -1;
        QModelIndex idx = indexAt(e->pos());
        if (idx.isValid()) {
            QRect plusRect = ChannelDelegate::inviteButtonRect(visualRect(idx));
            if (plusRect.contains(e->pos()))
                m_hoveredInviteRow = idx.row();
        }
        if (m_hoveredInviteRow != prevRow) {
            model()->setData(model()->index(prevRow, 0), 0, ChannelInviteBtnHoveredRole);
            model()->setData(model()->index(m_hoveredInviteRow, 0), 1, ChannelInviteBtnHoveredRole);
        }
        setCursor(m_hoveredInviteRow >= 0 ? Qt::PointingHandCursor : Qt::ArrowCursor);
        QListView::mouseMoveEvent(e);
    }
    QItemSelectionModel::SelectionFlags selectionCommand(const QModelIndex& idx, const QEvent* e) const override {
        if (idx.isValid())
            return QItemSelectionModel::ClearAndSelect;
        return QItemSelectionModel::NoUpdate;
    }
    void selectionChanged(const QItemSelection& sel, const QItemSelection& desel) override {
        QListView::selectionChanged(sel, desel);
        if (selectionModel() && !selectionModel()->hasSelection() && currentIndex().isValid()
            && currentIndex().row() < model()->rowCount())
            selectionModel()->select(currentIndex(), QItemSelectionModel::ClearAndSelect);
    }

private:
    int m_hoveredInviteRow = -1;
};

static QIcon makeChannelIcon(const QColor &color, const QString &letter) {
    QPixmap pix(32, 32);
    pix.fill(Qt::transparent);
    QPainter p(&pix);
    p.setRenderHint(QPainter::Antialiasing);
    p.setBrush(color);
    p.setPen(Qt::NoPen);
    p.drawRoundedRect(0, 0, 32, 32, 8, 8);
    p.setPen(Qt::white);
    QFont f = p.font();
    f.setBold(true);
    f.setPointSize(14);
    p.setFont(f);
    p.drawText(QRect(0, 0, 32, 32), Qt::AlignCenter, letter);
    p.end();
    return QIcon(pix);
}

ChannelList::ChannelList(DbManager* db, QWidget *parent)
    : QWidget(parent)
    , m_listView(new ChannelListView(this))
    , m_model(new QStandardItemModel(this))
    , m_db(db)
{
    auto *layout = new QVBoxLayout(this);
    layout->setContentsMargins(0, 0, 0, 0);
    layout->setSpacing(0);

    auto *header = new QLabel("Channels", this);
    header->setAlignment(Qt::AlignCenter);
    header->setStyleSheet("font-weight: bold; padding: 8px; background: palette(window);");
    layout->addWidget(header);

    m_listView->setModel(m_model);
    m_listView->setItemDelegate(new ChannelDelegate(this));
    m_listView->setEditTriggers(QAbstractItemView::NoEditTriggers);
    m_listView->setSelectionMode(QAbstractItemView::SingleSelection);
    m_listView->setHorizontalScrollBarPolicy(Qt::ScrollBarAlwaysOff);
    m_listView->setVerticalScrollMode(QAbstractItemView::ScrollPerPixel);
    m_listView->setMouseTracking(true);
    layout->addWidget(m_listView);

    auto *footer = new QWidget(this);
    auto *fl = new QHBoxLayout(footer);
    fl->setContentsMargins(6, 4, 6, 4);
    fl->setSpacing(6);

    auto *gearBtn = new QPushButton(QString::fromUtf8("\xE2\x9A\x99"), footer);
    gearBtn->setFixedSize(28, 28);
    gearBtn->setToolTip(QString::fromUtf8("Настройки"));
    gearBtn->setStyleSheet(
        "QPushButton { border: none; font-size: 18px; background: transparent; color: gray; }"
        "QPushButton:hover { color: palette(text); }");
    fl->addWidget(gearBtn);

    connect(gearBtn, &QPushButton::clicked, this, [this] { emit settingsRequested(); });

    fl->addStretch();

    auto *createBtn = new QPushButton("GRP", footer);
    createBtn->setFixedSize(36, 28);
    createBtn->setToolTip(QString::fromUtf8("Создать группу"));
    createBtn->setStyleSheet(
        "QPushButton { border: 1.5px solid #27AE60; border-radius: 6px;"
        " font-size: 11px; font-weight: bold; color: #27AE60; background: transparent; }"
        "QPushButton:hover { background: #27AE60; color: white; }");
    connect(createBtn, &QPushButton::clicked, this, [this] { emit createGroupRequested(); });
    fl->addWidget(createBtn);

    auto *plusBtn = new QPushButton("+", footer);
    plusBtn->setFixedSize(28, 28);
    plusBtn->setToolTip(QString::fromUtf8("Присоединиться"));
    plusBtn->setStyleSheet(
        "QPushButton { border: 1.5px solid #3390EC; border-radius: 14px;"
        " font-size: 18px; font-weight: bold; color: #3390EC; background: transparent; }"
        "QPushButton:hover { background: #3390EC; color: white; }");
    connect(plusBtn, &QPushButton::clicked, this, [this] { emit joinRequested(); });
    fl->addWidget(plusBtn);

    layout->addWidget(footer);

    connect(m_listView->selectionModel(), &QItemSelectionModel::currentChanged,
            this, [this](const QModelIndex &current, const QModelIndex &) {
                if (current.isValid()) {
                    QString cid = current.data(ChannelChannelIdRole).toString();
                    emit channelSelected(cid);
                }
            });
    connect(static_cast<ChannelListView*>(m_listView), &ChannelListView::inviteClicked,
            this, &ChannelList::inviteRequested);
}

void ChannelList::loadChannels() {
    QString selectedCid;
    if (m_listView->currentIndex().isValid())
        selectedCid = m_listView->currentIndex().data(ChannelChannelIdRole).toString();

    auto* sel = m_listView->selectionModel();
    sel->blockSignals(true);
    m_model->clear();
    if (m_db && m_db->isOpen()) {
        int sortMode = m_db->getUiStateInt("channel_sort", 0);
        auto channels = m_db->getChannels(sortMode == 1 ? ChannelSortMode::Recent : ChannelSortMode::Alphabetical);
        static const QColor colors[] = {
            QColor(74,144,226), QColor(126,211,33), QColor(245,166,35),
            QColor(208,2,27),   QColor(144,19,254), QColor(0,184,148)
        };
        int ci = 0;

        for (const auto& ch : channels) {
            auto letter = ch.name.mid(0, 1).toUpper();
            if (letter.isEmpty()) letter = "#";
            auto *item = new QStandardItem();
            item->setData(ch.name,        ChannelNameRole);
            item->setData(ch.channelId,   ChannelChannelIdRole);
            item->setData(m_db->getChannelLastMessage(ch.channelId), ChannelLastMessageRole);
            item->setData(ch.unreadCount, ChannelUnreadCountRole);
            item->setData(ch.lastMsgAt,   ChannelLastMsgAtRole);
            item->setData(makeChannelIcon(colors[ci % 6], letter), ChannelIconRole);
            m_model->appendRow(item);
            DEBUG_INFO(DEBUG_CATEGORY_DEBUG, "ChannelList::loadChannels row=%d cid='%s' name='%s' unread=%d lastMsgAt=%lld sort=%d",
                       m_model->rowCount()-1, qPrintable(ch.channelId), qPrintable(ch.name), ch.unreadCount,
                       (long long)ch.lastMsgAt, sortMode);
            ci++;
        }
    }
    sel->blockSignals(false);

    if (!selectedCid.isEmpty()) {
        selectChannel(selectedCid);
    } else if (m_model->rowCount() > 0) {
        QModelIndex idx = m_model->index(0, 0);
        sel->select(idx, QItemSelectionModel::ClearAndSelect);
        sel->setCurrentIndex(idx, QItemSelectionModel::NoUpdate);
    }
}

void ChannelList::selectChannel(const QString& channelId) {
    for (int row = 0; row < m_model->rowCount(); row++) {
        if (m_model->item(row)->data(ChannelChannelIdRole).toString() == channelId) {
            QModelIndex idx = m_model->index(row, 0);
            m_listView->selectionModel()->select(idx, QItemSelectionModel::ClearAndSelect);
            m_listView->selectionModel()->setCurrentIndex(idx, QItemSelectionModel::NoUpdate);
            return;
        }
    }
}

void ChannelList::setChannelPeersOnline(const QString& channelId, int count) {
    int found = 0;
    DEBUG_INFO(DEBUG_CATEGORY_DEBUG, "ChannelList::setChannelPeersOnline search='%s' online=%d rows=%d",
               qPrintable(channelId), count, m_model->rowCount());
    for (int row = 0; row < m_model->rowCount(); row++) {
        QStandardItem* item = m_model->item(row);
        if (item) {
            QString itemCid = item->data(ChannelChannelIdRole).toString();
            int match = (itemCid == channelId) ? 1 : 0;
            DEBUG_INFO(DEBUG_CATEGORY_DEBUG, "  row=%d cid='%s' match=%d", row, qPrintable(itemCid), match);
            if (match) {
                item->setData(count, ChannelPeersOnlineRole);
                item->setData(m_autoConnectActive ? 1 : 0, ChannelAutoConnectActiveRole);
                DEBUG_INFO(DEBUG_CATEGORY_DEBUG, "  SET online=%d", count);
                found = 1;
                break;
            }
        }
    }
    if (!found)
        DEBUG_INFO(DEBUG_CATEGORY_DEBUG, "  NOT FOUND in model");
}

void ChannelList::setAutoConnectActive(bool active) {
    m_autoConnectActive = active;
    for (int row = 0; row < m_model->rowCount(); row++) {
        QStandardItem* item = m_model->item(row);
        if (item) item->setData(active ? 1 : 0, ChannelAutoConnectActiveRole);
    }
}

void ChannelList::setChannelUnreadCount(const QString& channelId, int count) {
    for (int row = 0; row < m_model->rowCount(); row++) {
        QStandardItem* item = m_model->item(row);
        if (item && item->data(ChannelChannelIdRole).toString() == channelId) {
            int old = item->data(ChannelUnreadCountRole).toInt();
            DEBUG_DEBUG(DEBUG_CATEGORY_DEBUG, "ChannelList::setChannelUnreadCount ch=%s %d->%d",
                       qPrintable(channelId), old, count);
            item->setData(count, ChannelUnreadCountRole);
            emit m_model->dataChanged(m_model->index(row, 0), m_model->index(row, 0));
            return;
        }
    }
    DEBUG_DEBUG(DEBUG_CATEGORY_DEBUG, "ChannelList::setChannelUnreadCount ch=%s not found", qPrintable(channelId));
}

int ChannelList::getChannelUnreadCount(const QString& channelId) const {
    for (int row = 0; row < m_model->rowCount(); row++) {
        QStandardItem* item = m_model->item(row);
        if (item && item->data(ChannelChannelIdRole).toString() == channelId)
            return item->data(ChannelUnreadCountRole).toInt();
    }
    return 0;
}

#include "channellist.moc"