#include "channeldelegate.h"
#include <QPainter>
#include <QApplication>

ChannelDelegate::ChannelDelegate(QObject *parent)
    : QStyledItemDelegate(parent) {}

QRect ChannelDelegate::inviteButtonRect(const QRect &itemRect) {
    const int margin = 6;
    return QRect(itemRect.right() - margin - InviteBtnSize,
                 itemRect.top() + margin,
                 InviteBtnSize, InviteBtnSize);
}

QRect ChannelDelegate::inviteByLinkButtonRect(const QRect &itemRect) {
    const int margin = 6;
    return QRect(itemRect.right() - margin - InviteBtnSize * 2 - InviteBtnGap,
                 itemRect.top() + margin,
                 InviteBtnSize, InviteBtnSize);
}

QRect ChannelDelegate::settingsButtonRect(const QRect &itemRect) {
    const int margin = 6;
    return QRect(itemRect.right() - margin - InviteBtnSize * 3 - InviteBtnGap * 2,
                 itemRect.top() + margin,
                 InviteBtnSize, InviteBtnSize);
}

void ChannelDelegate::paint(QPainter *painter, const QStyleOptionViewItem &option,
                            const QModelIndex &index) const {
    painter->save();

    /* ── заголовок секции (например, «Личные») ── */
    if (index.data(ChannelIsSectionRole).toBool()) {
        painter->fillRect(option.rect, option.palette.window());
        painter->setPen(option.palette.mid().color());
        QFont f = option.font;
        f.setBold(true);
        painter->setFont(f);
        QRect tr = option.rect.adjusted(12, 0, -8, 0);
        painter->drawText(tr, Qt::AlignLeft | Qt::AlignVCenter,
                          index.data(ChannelNameRole).toString());
        painter->restore();
        return;
    }

    const int barWidth = 4;
    const int margin = 8;
    const int iconSize = 32;

    int peersOnline = index.data(ChannelPeersOnlineRole).toInt();
    int autoActive  = index.data(ChannelAutoConnectActiveRole).toInt();

    /* ── background ── */
    if (option.state & QStyle::State_Selected) {
        painter->fillRect(option.rect, option.palette.highlight());
    } else if (option.state & QStyle::State_MouseOver) {
        painter->fillRect(option.rect, option.palette.light());
    } else {
        painter->fillRect(option.rect, option.palette.base());
    }

    /* ── vertical status bar (left edge, over background) ── */
    QColor barColor = Qt::transparent;
    if (peersOnline > 0)                      barColor = QColor("#4CAF50");
    else if (autoActive && peersOnline == 0)  barColor = QColor("#FFC107");
    if (barColor.alpha() > 0) {
        QRect barRect(option.rect.left(), option.rect.top(), barWidth, option.rect.height());
        painter->fillRect(barRect, barColor);
    }

    QRect iconRect(option.rect.left() + margin + barWidth,
                   option.rect.top() + (option.rect.height() - iconSize) / 2,
                   iconSize, iconSize);

    QIcon icon = qvariant_cast<QIcon>(index.data(ChannelIconRole));
    if (!icon.isNull()) {
        icon.paint(painter, iconRect);
    }

    /* ── online count badge (top-left of avatar, above it) ── */
    if (peersOnline > 0) {
        int badgeSize = 16;
        QRect badgeRect(iconRect.left() - 4, iconRect.top() - 6, badgeSize, badgeSize);
        painter->setRenderHint(QPainter::Antialiasing);
        painter->setBrush(QColor("#4CAF50"));
        painter->setPen(QPen(Qt::white, 1.5));
        painter->drawEllipse(badgeRect);
        QFont badgeFont = option.font;
        badgeFont.setBold(true);
        badgeFont.setPixelSize(10);
        painter->setFont(badgeFont);
        painter->setPen(Qt::white);
        QString num = QString::number(peersOnline);
        if (peersOnline > 9) num = "9+";
        painter->drawText(badgeRect, Qt::AlignCenter, num);
    }

    QRect textRect(iconRect.right() + margin, option.rect.top() + margin,
                   option.rect.right() - iconRect.right() - 2 * margin,
                   option.rect.height() - 2 * margin);

    QString name = index.data(ChannelNameRole).toString();
    QFont nameFont = option.font;
    nameFont.setBold(true);
    nameFont.setPointSize(nameFont.pointSize() + 1);
    painter->setFont(nameFont);

    QColor textColor = (option.state & QStyle::State_Selected)
                       ? option.palette.highlightedText().color()
                       : option.palette.text().color();
    painter->setPen(textColor);

    QRect nameRect = textRect;
    nameRect.setHeight(QFontMetrics(nameFont).height());
    nameRect.setRight(nameRect.right() - InviteBtnSize * 3 - InviteBtnGap * 2 - 4);
    painter->drawText(nameRect, Qt::AlignLeft | Qt::AlignTop,
                      painter->fontMetrics().elidedText(name, Qt::ElideRight, nameRect.width()));

    QString lastMsg = index.data(ChannelLastMessageRole).toString();
    if (!lastMsg.isEmpty()) {
        QFont msgFont = option.font;
        msgFont.setPointSize(msgFont.pointSize() - 1);
        QColor nickColor(0x33, 0x90, 0xEC);
        QColor msgColor  = (option.state & QStyle::State_Selected)
                           ? option.palette.highlightedText().color().darker(120)
                           : QColor(128, 128, 128);
        if (option.state & QStyle::State_Selected) nickColor = nickColor.lighter(140);

        QRect msgRect(textRect.left(), nameRect.bottom() + 4,
                      textRect.width(),
                      option.rect.bottom() - nameRect.bottom() - margin);
        QFontMetrics msgFm(msgFont);

        int colon = lastMsg.indexOf(QString::fromUtf8(": "));
        if (colon >= 0) {
            QString nick = lastMsg.left(colon + 1);
            QString body = lastMsg.mid(colon + 2);

            painter->setFont(msgFont);
            painter->setPen(nickColor);
            QRect nickRect = msgRect;
            nickRect.setWidth(msgFm.horizontalAdvance(nick));
            painter->drawText(nickRect, Qt::AlignLeft | Qt::AlignTop, nick);

            painter->setPen(msgColor);
            QRect bodyRect(msgRect.left() + nickRect.width(), msgRect.top(),
                           msgRect.width() - nickRect.width(), msgRect.height());
            QString elidedBody = msgFm.elidedText(body, Qt::ElideRight, bodyRect.width());
            painter->drawText(bodyRect, Qt::AlignLeft | Qt::AlignTop | Qt::TextWordWrap, elidedBody);
        } else {
            painter->setFont(msgFont);
            painter->setPen(msgColor);
            QString elided = msgFm.elidedText(lastMsg, Qt::ElideRight, msgRect.width());
            painter->drawText(msgRect, Qt::AlignLeft | Qt::AlignTop | Qt::TextWordWrap, elided);
        }
    }

    /* ── unread count badge (right of channel name) ── */
    int unread = index.data(ChannelUnreadCountRole).toInt();
    if (unread > 0) {
        QString unreadText = unread > 99 ? QStringLiteral("99+") : QString::number(unread);
        QFont badgeFont = option.font;
        badgeFont.setBold(true);
        badgeFont.setPixelSize(11);
        QFontMetrics badgeFm(badgeFont);
        int textW = badgeFm.horizontalAdvance(unreadText) + 8;
        int badgeH = 18;
        if (textW < badgeH) textW = badgeH;
        QRect badgeRect(textRect.right() - textW, nameRect.top(),
                        textW, badgeH);
        painter->setRenderHint(QPainter::Antialiasing);
        painter->setBrush(QColor("#E53935"));
        painter->setPen(Qt::NoPen);
        painter->drawRoundedRect(badgeRect, badgeH / 2, badgeH / 2);
        painter->setFont(badgeFont);
        painter->setPen(Qt::white);
        painter->drawText(badgeRect, Qt::AlignCenter, unreadText);
    }

    /* ── invite plus button (top-right) ── */
    QRect plusRect = inviteButtonRect(option.rect);
    bool plusHovered = index.data(ChannelInviteBtnHoveredRole).toInt() != 0;
    painter->setRenderHint(QPainter::Antialiasing);
    QColor plusFill = plusHovered ? QColor(0x4A, 0xA4, 0xF0) : QColor(0x33, 0x90, 0xEC);
    painter->setBrush(plusFill);
    painter->setPen(Qt::NoPen);
    painter->drawEllipse(plusRect);
    painter->setPen(QPen(Qt::white, 2));
    painter->drawLine(plusRect.center().x(), plusRect.top() + 5,
                      plusRect.center().x(), plusRect.bottom() - 5);
    painter->drawLine(plusRect.left() + 5, plusRect.center().y(),
                      plusRect.right() - 5, plusRect.center().y());

    /* ── invite-by-link button (left of plus, orange square with arrow) ── */
    QRect invRect = inviteByLinkButtonRect(option.rect);
    bool invHovered = index.data(ChannelInviteByLinkBtnHoveredRole).toInt() != 0;
    painter->setRenderHint(QPainter::Antialiasing);
    QColor invFill = invHovered ? QColor(0xF0, 0x90, 0x30) : QColor(0xE6, 0x7E, 0x22);
    painter->setBrush(invFill);
    painter->setPen(Qt::NoPen);
    painter->drawRoundedRect(invRect, 3, 3);
    painter->setPen(QPen(Qt::white, 1.5));
    /* arrow: ← */
    int cx = invRect.center().x(), cy = invRect.center().y();
    int dx = 3;
    painter->drawLine(cx + dx, cy - 3, cx - dx, cy);
    painter->drawLine(cx + dx, cy + 3, cx - dx, cy);
    painter->drawLine(cx + dx + 1, cy, cx + dx + 1, cy - 3 + 1);
    painter->drawLine(cx + dx + 1, cy, cx + dx + 1, cy + 3 - 1);

    /* ── settings gear (left of invite-by-link button) ── */
    QRect gearRect = settingsButtonRect(option.rect);
    bool gearHovered = index.data(ChannelSettingsBtnHoveredRole).toInt() != 0;
    QColor gearColor = gearHovered ? QColor("#3390EC") : QColor("#555");
    painter->setPen(QPen(gearColor, 2));
    painter->setBrush(Qt::NoBrush);
    int gr = 5;
    painter->drawEllipse(gearRect.center(), gr, gr);
    painter->drawEllipse(gearRect.center(), gr / 2, gr / 2);
    int gcx = gearRect.center().x(), gcy = gearRect.center().y();
    painter->drawLine(gcx, gcy - gr,      gcx, gcy - gr + 1);
    painter->drawLine(gcx, gcy + gr,      gcx, gcy + gr - 1);
    painter->drawLine(gcx - gr, gcy,      gcx - gr + 1, gcy);
    painter->drawLine(gcx + gr, gcy,      gcx + gr - 1, gcy);
    painter->drawLine(gcx - 3, gcy - 4,   gcx - 3, gcy - 5);
    painter->drawLine(gcx + 3, gcy + 4,   gcx + 3, gcy + 5);
    painter->drawLine(gcx - 4, gcy - 3,   gcx - 5, gcy - 3);
    painter->drawLine(gcx + 4, gcy + 3,   gcx + 5, gcy + 3);

    painter->restore();
}

QSize ChannelDelegate::sizeHint(const QStyleOptionViewItem &option,
                                const QModelIndex &index) const {
    Q_UNUSED(option);
    Q_UNUSED(index);
    return QSize(200, 56);
}