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

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 QListView(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->setContextMenuPolicy(Qt::CustomContextMenu);
    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->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->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->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(m_listView, &QListView::customContextMenuRequested,
            this, &ChannelList::onContextMenu);
}

void ChannelList::loadChannels() {
    QModelIndex curIdx = m_listView->currentIndex();
    QString selectedCid;
    int selectedRow = -1;
    if (curIdx.isValid()) {
        selectedCid = curIdx.data(ChannelChannelIdRole).toString();
        selectedRow = curIdx.row();
    }

    m_model->clear();
    if (!m_db || !m_db->isOpen()) return;

    auto channels = m_db->getChannels();
    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(QString(),      ChannelLastMessageRole);
        item->setData(makeChannelIcon(colors[ci % 6], letter), ChannelIconRole);
        m_model->appendRow(item);
        ci++;
    }

    if (!selectedCid.isEmpty())
        selectChannel(selectedCid);
    if (!m_listView->currentIndex().isValid()) {
        int fallbackRow = (selectedRow >= 0) ? selectedRow : 0;
        if (fallbackRow >= m_model->rowCount())
            fallbackRow = m_model->rowCount() - 1;
        if (fallbackRow >= 0)
            m_listView->setCurrentIndex(m_model->index(fallbackRow, 0));
    }
}

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

void ChannelList::onContextMenu(const QPoint& pos) {
    QModelIndex index = m_listView->indexAt(pos);
    if (!index.isValid()) return;
    QString cid = index.data(ChannelChannelIdRole).toString();
    QMenu menu(this);
    QAction *inviteAction = menu.addAction("Пригласить");
    if (menu.exec(m_listView->viewport()->mapToGlobal(pos)) == inviteAction)
        emit inviteRequested(cid);
}