#include "messageshowarea.h"

#include "mainwidget.h"
#include "userinfowidget.h"
#include <qtimer.h>

MessageShowArea::MessageShowArea() {
    //初始化基本属性
    this->setSizePolicy(QSizePolicy::Expanding, QSizePolicy::Expanding);
    this->setWidgetResizable(true);

    //设置滚动条样式
    this->verticalScrollBar()->setStyleSheet("QScrollBar:vertical { width: 2px; background-color: rgb(240, 240, 240); }");
    this->horizontalScrollBar()->setStyleSheet("QScrollBar:horizontal { height: 0; }");
    this->setStyleSheet("QScrollArea { border: none; }");

    //创建container这样的widget，作为包含内部元素的容器
    container = new QWidget();
    this->setWidget(container);

    //给container添加界面布局管理器
    QVBoxLayout* layout = new QVBoxLayout();
    layout->setSpacing(0);
    layout->setContentsMargins(0, 0, 0, 0);
    container->setLayout(layout);

    // 添加测试数据
#if TEST_UI

    //测试长消息
    model::UserInfo userInfo;
    userInfo.nickname = "???";
    userInfo.userId = "4862";
    userInfo.phone = "00000000000";
    userInfo.description = "A test description.";
    const QString s = R"(The starry sky is just a few years ago. And the past may no longer exist,The only thing that remains is light years away, it's just an ethereal phantom.)";

    userInfo.avatar = QIcon(":/resource/image/defaultAvatar.png");
    Message message = Message::makeMessage(model::TEXT_TYPE, "", userInfo, s.toUtf8(), "");
    this->addMessage(false, message);

    bool k = true;
    for(int i = 0; i < 8; i++) {
        model::UserInfo userInfo;
        userInfo.userId = QString::number(i);
        userInfo.phone = "12345678900";
        userInfo.description = "A test description.";
        userInfo.nickname = "xyz" + QString::number(i);
        userInfo.avatar = QIcon(":/resource/image/defaultAvatar.png");
        Message message = Message::makeMessage(model::TEXT_TYPE, "", userInfo, (QString("this is a test message...") + QString::number(i)).toUtf8(), "");
        k = !k;
        this->addMessage(k, message);
    }
#endif

}

void MessageShowArea::addFrontMessage(bool isLeft, const Message &message)
{
    MessageItem* messageItem = MessageItem::makeMessageItem(isLeft, message);
    QVBoxLayout* layout = dynamic_cast<QVBoxLayout*>(container->layout());
    layout->insertWidget(0, messageItem);
}

void MessageShowArea::addMessage(bool isLeft, const Message &message)
{
    MessageItem* messageItem = MessageItem::makeMessageItem(isLeft, message);
    container->layout()->addWidget(messageItem);
}

void MessageShowArea::clear()
{
    QLayout* layout = container->layout();
    //要遍历布局管理器，删除里面的元素
    for(int i = layout->count() - 1; i >= 0; i--) {
        QLayoutItem* item = layout->takeAt(i);
        if(item != nullptr && item->widget() != nullptr) {
            delete item->widget();
        }
    }
}

void MessageShowArea::scrollToEnd()
{
    //拿到滚动区域的滚动条
    //获取到滚动条的最大值并设置
    //为了使滚动到正确的位置，即能够在界面绘制好后进行滚动设置
    //这里选择给滚动条加个延时
    QTimer* timer = new QTimer();
    connect(timer, &QTimer::timeout, this, [=]() {
        //获取到垂直滚动条的最大值
        int maxValue = this->verticalScrollBar()->maximum();
        //设置滚动条滚动的位置
        this->verticalScrollBar()->setValue(maxValue);

        timer->stop();
        timer->deleteLater();
        });
    timer->start(500);
}

////////////////////////////////////////////
/// 表示一个消息元素
////////////////////////////////////////////
MessageItem::MessageItem(bool isLeft)
    :isLeft(isLeft)
{

}

MessageItem *MessageItem::makeMessageItem(bool isLeft, const Message &message)
{
    //创建对象和布局管理器
    MessageItem* messageItem = new MessageItem(isLeft);
    QGridLayout* layout = new QGridLayout();
    layout->setSpacing(10);
    layout->setContentsMargins(30, 10, 40, 0);

    //这个message最低不能低于100
    messageItem->setMinimumHeight(100);
    messageItem->setLayout(layout);

    //创建头像
    QPushButton* avatarBtn = new QPushButton();
    avatarBtn->setFixedSize(40, 40);
    avatarBtn->setIconSize(QSize(40, 40));
    avatarBtn->setIcon(message.sender.avatar);
    avatarBtn->setStyleSheet("QPushButton { border: none; }");
    if(isLeft) {
        layout->addWidget(avatarBtn, 0, 0, 2, 1, Qt::AlignCenter | Qt::AlignLeft);
    } else {
        layout->addWidget(avatarBtn, 0, 1, 2, 1, Qt::AlignCenter | Qt::AlignRight);
    }

    //创建名字和时间
    QLabel* nameLabel = new QLabel();
    nameLabel->setText(message.sender.nickname + "  " + message.time);
    nameLabel->setAlignment(Qt::AlignBottom);
    nameLabel->setStyleSheet("QLabel { font-size: 12px; color: rgb(178, 178, 178); }");
    if(isLeft) {
        layout->addWidget(nameLabel, 0, 1);
    } else {
        layout->addWidget(nameLabel, 0, 0, Qt::AlignRight);
    }

    //创建消息体
    QWidget* contentWidget = nullptr;
    switch(message.messageType) {
    case model::TEXT_TYPE:
        contentWidget = makeTextMessageItem(isLeft, message.content);
        break;
    case model::IMAGE_TYPE:
        contentWidget = makeImageMessageItem();
        break;
    case model::FILE_TYPE:
        contentWidget = makeFileMessageItem();
        break;
    case model::SPEECH_TYPE:
        contentWidget = makeSpeechMessageItem();
        break;
    default:
        LOG() << "error messageType: " << message.messageType;
    }
    if(isLeft) {
        layout->addWidget(contentWidget, 1, 1);
    } else {
        layout->addWidget(contentWidget, 1, 0);
    }

    //连接信号槽，处理用户点击头像的操作
    connect(avatarBtn, &QPushButton::clicked, messageItem, [=]() {
        MainWidget* mainWidget = MainWidget::getInstance();
        UserInfoWidget* userInfoWidget = new UserInfoWidget(message.sender, mainWidget);
        userInfoWidget->setStyleSheet("QDialog { background-color: rgb(245, 245, 245); }");
        userInfoWidget->exec();
        });

    return messageItem;
}

QWidget *MessageItem::makeTextMessageItem(bool isLeft, const QString &text)
{
    MessageContentLabel* messageContentLabel = new MessageContentLabel(text, isLeft);
    return messageContentLabel;
}

QWidget *MessageItem::makeImageMessageItem()
{
    return nullptr;
}

QWidget *MessageItem::makeFileMessageItem()
{
    return nullptr;
}

QWidget *MessageItem::makeSpeechMessageItem()
{
    return nullptr;
}



////////////////////////////////////////////
/// 创建类表示“文本消息”正文部分
////////////////////////////////////////////
MessageContentLabel::MessageContentLabel(const QString &text, bool isLeft)
    :isLeft(isLeft)
{
    this->setSizePolicy(QSizePolicy::Expanding, QSizePolicy::Expanding);

    QFont font;
    font.setFamily("微软雅黑");
    font.setPixelSize(16);

    this->label = new QLabel(this);
    this->label->setText(text);
    this->label->setFont(font);
    this->label->setAlignment(Qt::AlignCenter | Qt::AlignLeft);
    this->label->setWordWrap(true);
    this->label->setStyleSheet("QLabel { padding: 0 10px; line-height: 1.2; background-color: transparent; }");
}

//这个函数会在该控件被显示时，自动的调用到
void MessageContentLabel::paintEvent(QPaintEvent *event)
{
    (void) event;

    //获取到父元素的宽度
    QObject* object = this->parent();
    if(!object->isWidgetType()) {
        //说明当前的对象不是QWidget，则不需要进行任何后续的绘制操作
        return;
    }
    QWidget* parent = dynamic_cast<QWidget*>(object);
    int width = parent->width() * 0.6;

    //计算当前文本，如果单行防止放置需要多宽
    QFontMetrics metrics(this->label->font());
    int totalWidth = metrics.horizontalAdvance(this->label->text());

    //计算出此处的行数是多少
    int rows = (totalWidth / (width - 40)) + 1;
    if(rows == 1) {
        //若此时得到的行数只有一行
        width = totalWidth + 40;
    }

    //根据行数来确定高度
    //行数 × 行高（字体高度的 1.2 倍） + 上下内边距（各 10px）
    int height = rows * (this->label->font().pixelSize() * 1.2 ) + 20;

    //绘制圆角矩形和箭头
    QPainter painter(this);
    QPainterPath path;
    //设置抗锯齿
    painter.setRenderHint(QPainter::Antialiasing);
    if(isLeft) {
        painter.setPen(QPen(QColor(255, 255, 255)));
        painter.setBrush(QColor(255, 255, 255)); //白色填充

        //绘制圆角矩形
        painter.drawRoundedRect(10, 0, width, height, 10 ,10);
        //绘制箭头
        path.moveTo(10, 15);
        path.lineTo(0, 20);
        path.lineTo(10, 25);
        path.closeSubpath(); //绘制的线形成闭合的多边形，才能进行使用Brush填充颜色
        painter.drawPath(path);//设置好，调用画笔进行绘制操作

        this->label->setGeometry(10, 0, width, height);
    } else {
        painter.setPen(QPen(QColor(137, 217, 97)));
        painter.setBrush(QColor(137, 217, 97));

        //圆角矩形左侧边的横坐标位置
        int leftPos = this->width() - width - 10; //10 用来容纳箭头的宽度
        //圆角矩形右侧边的横坐标位置
        int rightPos = this->width() - 10;

        //绘制圆角矩形
        painter.drawRoundedRect(leftPos, 0, width, height, 10, 10);
        //绘制箭头
        path.moveTo(rightPos, 15);
        path.lineTo(rightPos + 10, 20);
        path.lineTo(rightPos, 25);
        path.closeSubpath(); //绘制的线形成闭合的多边形，才能进行使用Brush填充颜色
        painter.drawPath(path);//设置好，调用画笔进行绘制操作

        this->label->setGeometry(leftPos, 0, width, height);
    }

    //重新设置父元素的高度，保证父元素足够的高，能够容纳下上述绘制消息的显示区域
    //注意高度要涵盖之前的名字和时间的label的高度，以及留一点的冗余的空间
    parent->setFixedHeight(height + 50);
}