#include <QCoreApplication>
#include "channellist.h"
#include "channeldelegate.h"
#include "avatars/groupavatarmanager.h"
#include "../db/db_manager.h"
#include <QVBoxLayout>
#include <QHBoxLayout>
#include <QLabel>
#include <QPushButton>
#include <QPainter>
#include <QPainterPath>
#include <QPixmap>
#include <QMouseEvent>
#include <QMenu>
#include <QStyle>
#include <QDropEvent>
#include <QMimeData>
#include <QUrl>

extern "C" {
#include "../../lib/debug_config.h"
#include "../../lib/mem.h"
#include "../transport/gui_bridge.h"
#include "dm/dm_core.h"
}

/* Секундное среднее CPU: фиксированный градиент, заполнение по проценту. */
class CpuLoadIndicator : public QWidget {
public:
    explicit CpuLoadIndicator(QWidget* parent) : QWidget(parent) {
        setObjectName(QStringLiteral("cpuLoadIndicator"));
        setFixedSize(60, 24);
        setAccessibleName(QStringLiteral("CPU"));
    }
    void setValue(int percent) {
        percent = qBound(0, percent, 100);
        if (m_percent == percent) return;
        m_percent = percent; update();
    }
protected:
    void paintEvent(QPaintEvent*) override {
        QPainter painter(this); painter.setRenderHint(QPainter::Antialiasing);
        QPainterPath path; path.addRoundedRect(QRectF(rect()), 5, 5);
        painter.setClipPath(path);
        painter.fillRect(rect(), QColor("#E4E9E6"));
        QLinearGradient gradient(0, 0, width(), 0);
        gradient.setColorAt(0, QColor("#66BB6A"));
        gradient.setColorAt(0.5, QColor("#FFCA28"));
        gradient.setColorAt(1, QColor("#EF5350"));
        painter.fillRect(QRectF(0, 0, width() * m_percent / 100.0, height()), gradient);
        painter.setPen(QColor("#172019"));
        QFont f = font(); f.setBold(true); painter.setFont(f);
        painter.drawText(rect(), Qt::AlignCenter, QString::number(m_percent) + '%');
    }
private:
    int m_percent = 0;
};

/* Пустое место и заголовки секций не сбрасывают выбор канала. */
class ChannelListView : public QListView {
public:
    using QListView::QListView;

protected:
    void mousePressEvent(QMouseEvent* e) override {
        QModelIndex idx = indexAt(e->pos());
        if (!idx.isValid()) return;
        if (idx.data(ChannelIsSectionRole).toBool()) return;
        QListView::mousePressEvent(e);
    }
    QItemSelectionModel::SelectionFlags selectionCommand(const QModelIndex& idx, const QEvent* e) const override {
        if (idx.isValid() && idx.data(ChannelIsSectionRole).toBool())
            return QItemSelectionModel::NoUpdate;
        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);
    }

};

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)
{
    if (auto* avatars = GroupAvatarManager::instance()) connect(avatars, &GroupAvatarManager::changed, this,
        [this, avatars](const QString& channel) {
            const QImage image = avatars->currentImage(channel); if (image.isNull()) return;
            QPixmap pixmap(64, 64); pixmap.fill(Qt::transparent); QPainter painter(&pixmap);
            painter.setRenderHint(QPainter::Antialiasing); QPainterPath path; path.addEllipse(QRectF(0, 0, 64, 64));
            painter.setClipPath(path); painter.drawImage(QRect(0, 0, 64, 64), image); painter.end();
            for (int row = 0; row < m_model->rowCount(); row++) if (m_model->item(row)->data(ChannelChannelIdRole).toString() == channel)
                m_model->item(row)->setData(QIcon(pixmap), ChannelIconRole);
        });
    m_dmPresenceTimer = new QTimer(this);
    m_dmPresenceTimer->setSingleShot(true);
    m_dmPresenceTimer->setInterval(50);
    connect(m_dmPresenceTimer, &QTimer::timeout, this, [this]() {
        auto* inst = gui_bridge_get_inst();
        if (!inst || !m_db) { clearDmPresence(); return; }
        for (const auto& dm : m_db->getDmConversations()) {
            auto* req = (struct dm_messages_req*)u_calloc(1, sizeof(struct dm_messages_req));
            if (!req) { DEBUG_ERROR(DEBUG_CATEGORY_CALL, "PM presence: allocation failed"); return; }
            req->inst = inst;
            snprintf(req->conv_id, sizeof(req->conv_id), "%s", dm.convId.toUtf8().constData());
            gui_bridge_post_uasync_fn(dm_call_route_trampoline, req);
        }
    });
    auto *layout = new QVBoxLayout(this);
    layout->setContentsMargins(0, 0, 0, 0);
    layout->setSpacing(0);

    auto *header = new QLabel(QCoreApplication::translate("ChatGui", "Channels"), this);
    header->setAlignment(Qt::AlignCenter);
    header->setStyleSheet("font-weight: bold; padding: 8px; background: palette(window);");
    auto* headerRow = new QHBoxLayout;
    headerRow->setContentsMargins(0, 0, 8, 0);
    headerRow->addWidget(header, 1);
    m_cpuLoad = new CpuLoadIndicator(this);
    headerRow->addWidget(m_cpuLoad);
    layout->addLayout(headerRow);

    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);
    m_footer = footer; m_footer->setObjectName("channelFooter");
    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(QCoreApplication::translate("ChatGui", "Settings"));
    gearBtn->setStyleSheet(
        "QPushButton { border: none; font-size: 18px; background: transparent; color: #666; }"
        "QPushButton:hover { color: #3390EC; background: rgba(51,144,236,20); border-radius: 14px; }");
    fl->addWidget(gearBtn);

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

    auto *monitorBtn = new QPushButton(QString::fromUtf8("\xF0\x9F\x94\x8D"), footer); /* 🔍 */
    monitorBtn->setFixedSize(28, 28);
    monitorBtn->setToolTip(QCoreApplication::translate("ChatGui", "Connection Monitor"));
    monitorBtn->setStyleSheet(
        "QPushButton { border: none; font-size: 16px; background: transparent; color: #666; }"
        "QPushButton:hover { color: #3390EC; background: rgba(51,144,236,20); border-radius: 14px; }");
    fl->addWidget(monitorBtn);
    connect(monitorBtn, &QPushButton::clicked, this, [this] { emit connMonitorRequested(); });

    fl->addStretch();

    auto* versionLabel = new QLabel(QStringLiteral("v%1").arg(QCoreApplication::applicationVersion()), footer);
    versionLabel->setStyleSheet("font-size: 10px; color: palette(mid);");
    fl->addWidget(versionLabel);

    auto *createBtn = new QPushButton(QCoreApplication::translate("ChatGui", "GRP"), footer);
    createBtn->setFixedSize(36, 28);
    createBtn->setToolTip(QCoreApplication::translate("ChatGui", "Create group"));
    createBtn->setStyleSheet(
        "QPushButton { border: none; border-radius: 6px; font-size: 11px; font-weight: bold;"
        " color: white; background: #27AE60; }"
        "QPushButton:hover { background: #219A52; }");
    connect(createBtn, &QPushButton::clicked, this, [this] { emit createGroupRequested(); });
    fl->addWidget(createBtn);

    auto *plusBtn = new QPushButton("+", footer);
    plusBtn->setFixedSize(28, 28);
    plusBtn->setToolTip(QCoreApplication::translate("ChatGui", "Join"));
    plusBtn->setStyleSheet(
        "QPushButton { border: none; border-radius: 14px; font-size: 18px; font-weight: bold;"
        " color: white; background: #3390EC; }"
        "QPushButton:hover { background: #2B7EC8; }");
    connect(plusBtn, &QPushButton::clicked, this, [this] { emit joinRequested(); });
    fl->addWidget(plusBtn);

    layout->addWidget(footer);
    auto targets = footer->findChildren<QWidget*>(); targets.append(footer);
    for (auto* target : targets) { target->setAcceptDrops(true); target->installEventFilter(this); }
    m_dropHint = new QLabel(footer); m_dropHint->setObjectName("ownFilesDropHint");
    m_dropHint->setAttribute(Qt::WA_TransparentForMouseEvents); m_dropHint->setAlignment(Qt::AlignCenter);
    m_dropHint->setStyleSheet("QLabel { border: 2px dashed palette(highlight); background: palette(window); color: palette(text); }");
    m_dropHint->hide();

    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);
                }
            });
    m_listView->setContextMenuPolicy(Qt::CustomContextMenu);
    connect(m_listView, &QWidget::customContextMenuRequested, this, [this](const QPoint& point) {
        auto index = m_listView->indexAt(point);
        QString channel = index.data(ChannelChannelIdRole).toString();
        if (!index.isValid() || channel.isEmpty() || channel.startsWith(QStringLiteral("dm:"))) return;
        QMenu menu(this);
        auto* files = menu.addAction(QCoreApplication::translate("ChatGui", "Group files"));
        if (menu.exec(m_listView->viewport()->mapToGlobal(point)) == files) emit filesRequested(channel);
    });
}

bool ChannelList::eventFilter(QObject* target, QEvent* event) {
    if (event->type() == QEvent::DragLeave) { m_dropHint->hide(); return true; }
    if (event->type() != QEvent::DragEnter && event->type() != QEvent::DragMove && event->type() != QEvent::Drop)
        return QWidget::eventFilter(target, event);
    auto* drop = static_cast<QDropEvent*>(event);
    QString channel = m_listView->currentIndex().data(ChannelChannelIdRole).toString();
    QString reason;
    if (!channel.toULongLong()) reason = QCoreApplication::translate("ChatGui", "Select a group to upload files");
    else if (!m_db || !m_db->myNodeId() || !gui_bridge_is_uasync_ready())
        reason = QCoreApplication::translate("ChatGui", "Upload unavailable");
    else if (!drop->mimeData()->hasUrls() || drop->mimeData()->urls().isEmpty() || !(drop->possibleActions() & Qt::CopyAction))
        reason = QCoreApplication::translate("ChatGui", "Drop local files to copy");
    QStringList paths;
    if (reason.isEmpty()) for (const auto& url : drop->mimeData()->urls()) {
        if (!url.isLocalFile() || url.toLocalFile().isEmpty()) {
            reason = QCoreApplication::translate("ChatGui", "Only local files can be uploaded"); break;
        }
        paths.append(url.toLocalFile());
    }
    if (event->type() == QEvent::Drop) m_dropHint->hide();
    else {
        m_dropHint->setGeometry(m_footer->rect());
        m_dropHint->setText(reason.isEmpty() ? QCoreApplication::translate("ChatGui", "Copy to my files") : reason);
        m_dropHint->show(); m_dropHint->raise();
    }
    if (!reason.isEmpty()) {
        if (event->type() != QEvent::DragMove)
            DEBUG_WARN(DEBUG_CATEGORY_MEDIA, "file drop: rejected channel=%s reason=%s", qPrintable(channel), qPrintable(reason));
        drop->ignore();
        // После отклонённого DragEnter Qt не гарантирует DragLeave.
        m_dropHint->hide(); return true;
    }
    drop->setDropAction(Qt::CopyAction); drop->accept();
    if (event->type() == QEvent::Drop) {
        DEBUG_INFO(DEBUG_CATEGORY_MEDIA, "file drop: accepted channel=%s files=%d", qPrintable(channel), int(paths.size()));
        QTimer::singleShot(0, this, [this, channel, paths] { emit ownFilesDropped(channel, paths); });
    }
    return true;
}

void ChannelList::refreshDmPresence() {
    if (!m_dmPresenceTimer->isActive()) m_dmPresenceTimer->start();
}

void ChannelList::clearDmPresence() {
    m_dmPresenceTimer->stop();
    m_dmOnline.clear();
    for (int i = 0; i < m_model->rowCount(); i++) {
        auto* item = m_model->item(i);
        if (item->data(ChannelChannelIdRole).toString().startsWith(QStringLiteral("dm:")))
            item->setData(false, ChannelDmOnlineRole);
    }
}

void ChannelList::onDmCallRoute(const uint8_t* data, int len) {
    if (!data || len < 17 || len != 17 + data[0]) {
        DEBUG_WARN(DEBUG_CATEGORY_CALL, "PM presence snapshot: invalid size=%d", len); return;
    }
    QString conv = QString::fromUtf8((const char*)data + 1, data[0]);
    quint64 peer = 0, group = 0;
    memcpy(&peer, data + 1 + data[0], 8); memcpy(&group, data + 9 + data[0], 8);
    bool online = peer && group;
    if (m_dmOnline.value(conv) != online)
        DEBUG_INFO(DEBUG_CATEGORY_CALL, "PM presence: conv=%s online=%d", conv.toUtf8().constData(), online);
    m_dmOnline.insert(conv, online);
    for (int i = 0; i < m_model->rowCount(); i++) {
        auto* item = m_model->item(i);
        if (item->data(ChannelChannelIdRole).toString() == QStringLiteral("dm:") + conv)
            item->setData(online, ChannelDmOnlineRole);
    }
}

void ChannelList::setCpuLoad(int percent) { m_cpuLoad->setValue(percent); }

void ChannelList::loadChannels() {
    refreshDmPresence();
    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);
            if (auto* avatars = GroupAvatarManager::instance()) {
                const QImage image = avatars->image(ch.channelId, ch.avatarVersion, ch.avatarHash);
                if (!image.isNull()) {
                    QPixmap pixmap(64, 64); pixmap.fill(Qt::transparent); QPainter painter(&pixmap);
                    painter.setRenderHint(QPainter::Antialiasing); QPainterPath clip; clip.addEllipse(QRectF(0, 0, 64, 64));
                    painter.setClipPath(clip); painter.drawImage(QRect(0, 0, 64, 64), image); painter.end();
                    item->setData(QIcon(pixmap), ChannelIconRole);
                }
            }
            m_model->appendRow(item);
            DEBUG_DEBUG(DEBUG_CATEGORY_CHAT, "ChannelList::loadChannels row=%d cid='%s' name='%s' unread=%d lastMsgAt=%lld",
                       m_model->rowCount()-1, qPrintable(ch.channelId), qPrintable(ch.name), ch.unreadCount,
                       (long long)ch.lastMsgAt);
            ci++;
        }

        /* ── секция «Личные» (DM-беседы) ── */
        auto dms = m_db->getDmConversations();
        if (!dms.isEmpty()) {
            auto *section = new QStandardItem();
            section->setData(QCoreApplication::translate("ChatGui", "Direct messages"), ChannelNameRole);
            section->setData(true, ChannelIsSectionRole);
            section->setFlags(Qt::NoItemFlags);
            m_model->appendRow(section);

            static const QColor dmColor(0x8E, 0x44, 0xAD);
            for (const auto& dm : dms) {
                QString name = dm.peerName;
                if (name.isEmpty()) name = QString("0x%1").arg(dm.peerNodeId, 4, 16, QChar('0')).toUpper();
                auto letter = name.mid(0, 1).toUpper();
                if (letter.isEmpty()) letter = "@";
                auto *item = new QStandardItem();
                item->setData(name, ChannelNameRole);
                item->setData(QStringLiteral("dm:") + dm.convId, ChannelChannelIdRole);
                item->setData(m_dmOnline.value(dm.convId), ChannelDmOnlineRole);
                item->setData(QString(), ChannelLastMessageRole);
                item->setData(0, ChannelUnreadCountRole);
                item->setData(dm.lastTs, ChannelLastMsgAtRole);
                item->setData(makeChannelIcon(dmColor, letter), ChannelIconRole);
                m_model->appendRow(item);
                DEBUG_DEBUG(DEBUG_CATEGORY_DM, "ChannelList::loadChannels dm row=%d conv='%s' peer='%s'",
                           m_model->rowCount()-1, qPrintable(dm.convId), qPrintable(name));
            }
        }
    }
    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;
    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;
            if (match) {
                item->setData(count, ChannelPeersOnlineRole);
                item->setData(m_autoConnectActive ? 1 : 0, ChannelAutoConnectActiveRole);
                found = 1;
                break;
            }
        }
    }
    if (!found)
        DEBUG_DEBUG(DEBUG_CATEGORY_CHAT, "ChannelList: channel=%s not found in model", qPrintable(channelId));
}

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_CHAT, "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_CHAT, "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;
}