#include "PicDateItem.h"
#include <QDebug>
#include <QRegExp>
#include <QPainter>
#include <QElapsedTimer>
#include "LogInfo.h"
#include "ItemCommon.h"

// 生成可能的最长时间字符串供尺寸计算使用（基于像素宽度）
static QString generateMaxDateTimeString(const DateItemModel &model, const QFont &font)
{
    if (model.datetimePattern.isEmpty())
        return QString();

    QString s = model.datetimePattern;

    QFontMetrics fm(font);

    auto longestFromList = [&fm] (const QStringList &lst, const QString &fallback) {
        int bestW = -1;
        QString best;
        for (const auto &v : lst) {
            int w = fm.horizontalAdvance(v);
            if (w > bestW) { bestW = w; best = v; }
        }
        return best.isEmpty() ? fallback : best;
    };

    int i = s.indexOf("yyyy");
    if (i != -1) {
        QString repl;
        if (!model.yearsMap.isEmpty()) {
            for (auto v : model.yearsMap.values()) if (v.length() > repl.length()) repl = v;
        } else {
            repl = QString::number(QDate::currentDate().year());
        }
        s.replace(i, 4, repl);
    }

    i = s.indexOf("YY");
    if (i != -1) {
        // 以像素宽度为准，'88' 通常足够宽
        s.replace(i, 2, QString("88"));
    }

    i = s.indexOf("MM");
    if (i != -1) {
        s.replace(i, 2, longestFromList(model.monthsMap, QString("88")));
    }

    i = s.indexOf("dd");
    if (i != -1) {
        s.replace(i, 2, longestFromList(model.daysMap, QString("88")));
    }

    i = s.indexOf("HH");
    if (i != -1) {
        s.replace(i, 2, longestFromList(model.hoursMap, QString("88")));
    }

    QRegExp minutePattern("mm");
    if (s.contains(minutePattern)) s.replace(minutePattern, QString("88"));

    QRegExp secondPattern("ss");
    if (s.contains(secondPattern)) s.replace(secondPattern, QString("88"));

    i = s.indexOf("w");
    if (i != -1) {
        s.replace(i, 1, longestFromList(model.weeksMap, QString("888")));
    }

    QRegExp weekNumberPattern("c");
    if (s.contains(weekNumberPattern)) s.replace(weekNumberPattern, QString("88"));

    return s;
}

PicDateItem::PicDateItem(QGraphicsItem *parent, QGraphicsScene *scene, const SourceType type)
    :PicTextItem(parent, scene, type)
{
    m_timer.setInterval(20);
    connect(&m_timer, &QTimer::timeout, [this](){
        updateDatetimeStr();
    });
    
    // m_timer.start();
}

void PicDateItem::setModel(DateItemModel model)
{
    m_model = std::move(model);

    // 计时：测量生成最长字符串和字体度量两段耗时
    QElapsedTimer t1;
    t1.start();
    m_maxDateTimeStr = generateMaxDateTimeString(m_model, font());
    qint64 genUs = t1.nsecsElapsed() / 1000; // microseconds

    QElapsedTimer t2;
    t2.start();
    if (m_maxDateTimeStr.isEmpty()) {
        m_maxSize = QSize();
    } else {
        QFontMetrics fm(font());
        int w = fm.horizontalAdvance(m_maxDateTimeStr);
        int h = fm.height();
        m_maxSize = QSize(w, h);
    }
    qint64 fmUs = t2.nsecsElapsed() / 1000; // microseconds

    qDebug() << "PicDateItem::setModel timing(us): generate=" << genUs << ", fm=" << fmUs << ", total=" << (genUs + fmUs);

    m_currDateTimeStr = ItemUtils::generateTxtFromDateItemModel(m_model, QDateTime::currentDateTime());
    applyModify();
}

const DateItemModel& PicDateItem::model() const
{
    return m_model;
}

bool PicDateItem::updateDatetimeStr()
{
    if (m_model.datetimePattern.isEmpty())
        return false;

    if(m_currDateTimeStr.isEmpty()) {
        m_currDateTimeStr = ItemUtils::generateTxtFromDateItemModel(m_model, QDateTime::currentDateTime());
        applyModify();
        return true;
    }
    
    auto now = QDateTime::currentDateTime();
    auto str = ItemUtils::generateTxtFromDateItemModel(m_model, now);
    if(str == m_currDateTimeStr) {
        return false;
    }

    m_currDateTimeStr = str;
    applyModify();
    return true;
}

void PicDateItem::setCustomAttrs(const QXmlStreamAttributes &attrs)
{
    // 结构类似这样
    // weeksMap = "MON<br>TUR<br>WED<br>TUE<br>THU<br>FRI<br>SAT<br>SUN"
    // yearsMap = "2023<subbr>2023年<br>2024<subbr>2024年<br>2025<subbr>2025年"

    auto m = DateItemModel();
    DateItemModel::loadFromXml(m, attrs);
    setModel(std::move(m));
}

void PicDateItem::saveCustomAttrs(QXmlStreamAttributes &attrs)
{
    DateItemModel::saveToXml(m_model, attrs);
}

QImage PicDateItem::itemImage()
{
    if(m_model.datetimePattern.isEmpty())
        return QImage();

    auto currImg = strToImage(m_currDateTimeStr);

    if (m_maxSize.isEmpty())
        return currImg;

    int width = qMax(currImg.width(), m_maxSize.width());
    int height = currImg.height();

    QImage img(width, height, QImage::Format_ARGB32);
    img.fill(QColor(0,0,0,0).rgba());

    QPainter painter(&img);
    int y = (height - currImg.height()) / 2;
    painter.drawImage(0, y, currImg);
    painter.end();

    return img;
}

QRectF PicDateItem::boundingRect() const
{
    return PicTextItem::boundingRect();

    // // 优先使用已经应用变换后的 m_itemImage（与 PicTextItem 保持一致）
    // if (!m_itemImage.isNull()) {
    //     return QRectF(0, 0, m_itemImage.width(), m_itemImage.height());
    // }

    // // 否则基于缓存的最大像素尺寸和粗体倍数估算
    // int w = m_maxSize.width();
    // int h = m_maxSize.height();
    // if (w <= 0 || h <= 0)
    //     return QGraphicsTextItem::boundingRect();

    // qreal bw = qreal(w) * qMax(1, m_boldMultiple);
    // return QRectF(0, 0, bw, qreal(h));
}