#include "elescroll.h"
#include "playwin.h"
#include <QOpenGLWidget>
#include <QPainter>
#include <QPaintEvent>

EleScroll::EleScroll(QWidget *parent, QString dirPre, const JValue &json, int w, int h) : QWidget{parent}, w(w), h(h) {
    img.load(dirPre + json["id"].toString());
    auto effStr = json["effect"].toString();
    if(effStr.isEmpty() || effStr=="no") return;

    auto scrollSpeed = json["scrollSpeed"].toDouble();
    if(scrollSpeed==0) {
        auto scrollDur = json["effectSpeed"].toDouble();
        if(scrollDur==0) return;
        scrollSpeed = 1000 / scrollDur;
    }
    interval = step = 1;
    if(scrollSpeed > 60) step = (int) round(scrollSpeed/60);
    else if(scrollSpeed < 60) interval = (int) round(60/scrollSpeed);
    int idx = effStr.lastIndexOf(' ');
    if(idx > -1) {
        effect = effStr.at(idx+1).toLatin1();
        if(effect=='l') end = -(img.width()-step);
        else if(effect=='r') end = img.width()-step;
        else if(effect=='t') end = -(img.height()-step);
        else if(effect=='b') end = img.height()-step;
    }
}
EleScroll::EleScroll(QWidget *parent, QString imgPath, char effect, double scrollSpeed) : QWidget{parent}, effect(effect) {
    img.load(imgPath);
    if(effect==0) return;
    if(scrollSpeed==0) return;
    interval = step = 1;
    if(scrollSpeed > 60) step = (int) round(scrollSpeed/60);
    else if(scrollSpeed < 60) interval = (int) round(60/scrollSpeed);
    if(effect=='l') end = -(img.width()-step);
    else if(effect=='r') end = img.width()-step;
    else if(effect=='t') end = -(img.height()-step);
    else if(effect=='b') end = img.height()-step;
}

void EleScroll::paintEvent(QPaintEvent *e) {
    if(img.isNull()) return;
    auto rect = e->rect();
    QPainter painter(this);
    painter.setRenderHints(QPainter::Antialiasing|QPainter::SmoothPixmapTransform);
    if(effect=='l') {
        int x = cur;
        do {
            if(x > rect.left()-img.width() && x < rect.right()+1) painter.drawPixmap(x, 0, img);
            x += img.width();
        } while(x < rect.right()+1);
    } else if(effect=='r') {
        int x = cur + w;
        bool con1;
        do {
            x -= img.width();
            con1 = x > rect.left()-img.width();
            if(con1 && x < rect.right()+1) painter.drawPixmap(x, 0, img);
        } while(con1);
    } else if(effect=='t') {
        int y = cur;
        do {
            if(y > rect.top()-img.height() && y < rect.bottom()+1) painter.drawPixmap(0, y, img);
            y += img.height();
        } while(y < rect.bottom()+1);
    } else if(effect=='b') {
        int y = cur + h;
        bool con1;
        do {
            y -= img.height();
            con1 = y > rect.top()-img.height();
            if(con1 && y < rect.bottom()+1) painter.drawPixmap(0, y, img);
        } while(con1);
    } else painter.drawPixmap(0, 0, img);
    if(freshCnt==0 && effect!=0 && interval!=0) connect(PlayWin::self->gl, &QOpenGLWidget::frameSwapped, this, &EleScroll::doFrame, Qt::UniqueConnection);
}

void EleScroll::doFrame() {
    if(! isVisible()) {
        freshCnt = cur = 0;
        disconnect(PlayWin::self->gl, &QOpenGLWidget::frameSwapped, this, &EleScroll::doFrame);
        return;
    }
    if(freshCnt < interval) freshCnt++;
    else {
        freshCnt = 1;
        if(effect=='t' || effect=='l') {
            if(cur <= end) cur -= end;
            else cur -= step;
        } else if(effect=='b' || effect=='r') {
            if(cur >= end) cur -= end;
            else cur += step;
        }
        update();
    }
}