//
// Created by Krad on 2021/12/16.
//

#include "RollingMessageWidget.h"

#include <QLabel>
#include <QThread>
#include <QDebug>
#include <QShowEvent>

namespace {
    const int WAIT_TIMES = 60;
    const int LABEL_MARGIN_TOP = 2;
    const int LABEL_MARGIN_LEFT = 5;
    const int LABEL_FONT_WIDTH = 16;
    const int MOVING_STEP = 2;
}

RollingMessageWidget::RollingMessageWidget(QWidget *parent)
: QWidget(parent)
, mCurrentLabel(new QLabel(this))
, mNextLabel(new QLabel(this))
{
    this->setFixedHeight(36);
    this->setSizePolicy(QSizePolicy::Expanding,QSizePolicy::Preferred);
}

RollingMessageWidget::~RollingMessageWidget() {
    if (mTimerId >= 0) killTimer(mTimerId);
}

void RollingMessageWidget::timerEvent(QTimerEvent *e) {
    if (!this->isVisible()) return;
    //滚动
    if (mRolling) {
        //end rolling, reset next
        if (mRolledDistance == TOTAL_ROLL_DISTANCE){
            mWaitStep = 0;
            mRolling = false;
            QPoint p3 = {TOTAL_ROLL_DISTANCE + LABEL_MARGIN_LEFT, LABEL_MARGIN_TOP};
            mCurrentLabel->move(p3);
            std::swap(mCurrentLabel, mNextLabel);
            return;
        }
        //rolling
        mRolledDistance += 2;
        QPoint p1 = {TOTAL_ROLL_DISTANCE + LABEL_MARGIN_LEFT - mRolledDistance, LABEL_MARGIN_TOP};
        mNextLabel->move(p1);
        if (p1.x() - mCurrentLabel->geometry().x() <= mCurrentLabel->width() + 20)
        {
            QPoint p2 = {mCurrentLabel->geometry().x() - MOVING_STEP, LABEL_MARGIN_TOP};
            mCurrentLabel->move(p2);
        }
        return ;
    }
    else{

        //有等待的高优先级消息时，不停顿
        if (mWaitStep == WAIT_TIMES || (mWaitPriorityCount > 0 && mWaitStep == WAIT_TIMES / 3)){
            mLocker.lock();
            mNextLabel->setText(getNextMessage());
            mNextLabel->setFixedWidth(mNextLabel->text().length() * LABEL_FONT_WIDTH);
            mLocker.unlock();
        } else{
            mWaitStep++;
        }
    }
}

void RollingMessageWidget::setMessageList(const QStringList &message) {
    //empty, don't set
    if (message.isEmpty()) return;
    mMessages.clear();
    // set default label
    mCurrentLabel->setText(message[0]);
    mMessages.push_back({0, message[0], 0});
    //add list
    if (message.length()>0)
    {
        for (int k = 1; k < message.length(); ++k) {
            mMessages.push_front({k, message[k], -1});
        }
    }

}

void RollingMessageWidget::updateMessagePriority(int innerIndex, int priority) {
    //lock thread
    mLocker.lock();
    //高优先级，需要插入
    if (priority > 0)
    {
        int idx = -1, insertIdx = -1;
        for (int i = 0; i < mMessages.length(); ++i) {
            if (mMessages[i].innerId == innerIndex)
            {
                mMessages[i].priority = priority;
                idx = i;
            }
            else if (insertIdx < 0 && mMessages[i].priority < 1)
            {
                insertIdx = i;
            }
            if (idx>=0 && insertIdx >= 0) break;
        }
        insertIdx = insertIdx == -1 ? 0 : insertIdx;
        //move
        if(insertIdx < idx)mMessages.move(idx, insertIdx);
        mWaitPriorityCount++;
    }
    // 低优先级，更新状态即可
    else{
        for (WarnMessage & message : mMessages) {
            if (message.innerId == innerIndex) {
                message.priority = -1;
                break;
            }
        }
    }
    mLocker.unlock();
}

QString RollingMessageWidget::getNextMessage() {

    QString ret = "No message";
    int retryCount = 0;
    bool priorityFlag = false;
    while (retryCount < mMessages.length()){
        mMessages.move(0, mMessages.length() - 1);
        retryCount++;
        if(mMessages.last().priority >= 0)
        {
            priorityFlag = mMessages.last().priority > 0;
            ret = mMessages.last().msg;
            mMessages.last().priority = 0;
            break;
        }
    }
    if (priorityFlag && mWaitPriorityCount > 0) mWaitPriorityCount--;
    mRolledDistance = 0;
    mRolling = true;
    mWaitStep = 0;
    return ret;
}

void RollingMessageWidget::showEvent(QShowEvent *event) {
    QWidget::showEvent(event);
    if (!mInitFlag)
    {
        TOTAL_ROLL_DISTANCE = this->width();
        QPoint p1 = {LABEL_MARGIN_LEFT,LABEL_MARGIN_TOP};
        mCurrentLabel->setFixedHeight(30);
        mCurrentLabel->show();
        mCurrentLabel->move(p1);
        mCurrentLabel->setText(tr("Message of warn!"));
        mCurrentLabel->setFixedWidth(mCurrentLabel->text().length() * LABEL_FONT_WIDTH);
        QPoint p2 = {TOTAL_ROLL_DISTANCE + LABEL_MARGIN_LEFT, LABEL_MARGIN_TOP};
        mNextLabel->setFixedHeight(30);
        mNextLabel->show();
        mNextLabel->move(p2);
        mNextLabel->setText(tr("Message2 of warn!"));
        mNextLabel->setFixedWidth(mNextLabel->text().length() * LABEL_FONT_WIDTH);
        mTimerId = startTimer(40);
        mInitFlag = true;
    }
}