/* -*- Mode: C; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*-
 *
 * Copyright (C) 2019 Tianjin KYLIN Information Technology Co., Ltd.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA.
 *
 */
#include "switchbutton.h"

#include <QDebug>
#define THEME_QT_SCHEMA "org.ukui.style"
#define THEME_GTK_SCHEMA "org.mate.interface"
#define TIMER_INTERVAL 5 //每隔5ms动画移动一次
#define MOVING_STEPS 40  //动画总共移动40次

SwitchButton::SwitchButton(QWidget *parent, bool useDisableStyle) :
    QWidget(parent)
{
//    this->resize(QSize(52, 24));
    this->setFixedSize(QSize(50, 24));

    checked = false;
    hover = false;
    disabled = false;
    isMoving = false;
    isAnimation = true;
    m_useDisableStyle = useDisableStyle;

    space = 4;
    rectRadius = height()/2;

    mStep = width()/MOVING_STEPS;//也就是40次动画就可以走完，每次时间间隔是固定的5ms
    mStartX = 0;
    mEndX= 0;

    mTimer = new QTimer(this);
    mTimer->setInterval(TIMER_INTERVAL);//动画更新时间
    connect(mTimer, SIGNAL(timeout()), this, SLOT(updatevalue()));
    if(QGSettings::isSchemaInstalled(THEME_GTK_SCHEMA) && QGSettings::isSchemaInstalled(THEME_QT_SCHEMA)) {
        QByteArray qtThemeID(THEME_QT_SCHEMA);
        QByteArray gtkThemeID(THEME_GTK_SCHEMA);

        m_gtkThemeSetting = new QGSettings(gtkThemeID,QByteArray(),this);
        m_qtThemeSetting = new QGSettings(qtThemeID,QByteArray(),this);

        QString style = m_qtThemeSetting->get("styleName").toString();
        changeColor(style);

        connect(m_qtThemeSetting,&QGSettings::changed, [this] (const QString &key) {
            QString style = m_qtThemeSetting->get("styleName").toString();
            if (key == "styleName") {
               changeColor(style);
            }
        });
    }
}

SwitchButton::~SwitchButton()
{
}

void SwitchButton::paintEvent(QPaintEvent *){

    QPainter painter(this);
    //启用反锯齿
    painter.setRenderHint(QPainter::Antialiasing, true);
    painter.setCompositionMode(QPainter::CompositionMode_Source);
    drawBg(&painter);
    if(!isAnimation)//动画如果禁用，则圆形滑块isMoving始终为false
        isMoving =false;
    if(isMoving)
        animation(&painter);
    drawSlider(&painter);
    painter.end();
}

void SwitchButton::changeColor(const QString &themes) {
    if (hover) {
        return ;//在鼠标下，禁止切换颜色鼠标离开时切换颜色
    }
    if (themes == "ukui-dark" || themes == "ukui-black") {
        bgColorOff = QColor(OFF_BG_DARK_COLOR);
        bgColorOn = QColor(ON_BG_DARK_COLOR);
        rectColorEnabled = QColor(ENABLE_RECT_DARK_COLOR);
        rectColorDisabled = QColor(DISABLE_RECT_DARK_COLOR);
        sliderColorDisabled = QColor(DISABLE_RECT_DARK_COLOR);
        sliderColorEnabled = QColor(ENABLE_RECT_DARK_COLOR);
        bgHoverOnColor = QColor(ON_HOVER_BG_DARK_COLOR);
        bgHoverOffColor = QColor(OFF_HOVER_BG_DARK_COLOR);
        bgColorDisabled = QColor(DISABLE_DARK_COLOR);
    } else {
        bgColorOff = QColor(OFF_BG_LIGHT_COLOR);
        bgColorOn = QColor(ON_BG_LIGHT_COLOR);
        rectColorEnabled = QColor(ENABLE_RECT_LIGHT_COLOR);
        rectColorDisabled = QColor(DISABLE_RECT_LIGHT_COLOR);
        sliderColorDisabled = QColor(DISABLE_RECT_LIGHT_COLOR);
        sliderColorEnabled = QColor(ENABLE_RECT_LIGHT_COLOR);
        bgHoverOnColor = QColor(ON_HOVER_BG_LIGHT_COLOR);
        bgHoverOffColor = QColor(OFF_HOVER_BG_LIGHT_COLOR);
        bgColorDisabled = QColor(DISABLE_LIGHT_COLOR);
    }
}

//动画绘制
void SwitchButton::animation(QPainter *painter){
    painter->save();
    int h = height();
    int w = width();
    painter->setPen(Qt::NoPen);
    //颜色设置
    if(checked){
        //开关在左侧时
        painter->setBrush(bgColorOn);
        rect.setRect(0,0,h+mStartX,h);
    }else{
        painter->setBrush(bgColorOff);
        rect.setRect(mStartX,0,w-mStartX,h);
    }
    painter->drawRoundedRect(rect,rectRadius,rectRadius);

    painter->restore();
}

//绘制背景
void SwitchButton::drawBg(QPainter *painter){
    int w = width();
    int h = height();
    painter->save();
    painter->setPen(Qt::NoPen);
    if (disabled && m_useDisableStyle) {
        painter->setPen(Qt::NoPen);
        painter->setBrush(bgColorDisabled);
    } else {
        if(checked){
            if(isMoving){
                painter->setBrush(bgColorOff);
                rect.setRect(mStartX,0,w-mStartX,h);
            }else {
                painter->setBrush(bgColorOn);
                rect.setRect(0, 0, w, h);
            }
        }else{
            if(isMoving){
                painter->setBrush(bgColorOn);
                rect.setRect(0,0,mStartX+h,h);
            }
            else {
                painter->setBrush(bgColorOff);
                rect.setRect(0, 0, w, h);
            }
        }
    }
    //半径为高度的一半
    painter->drawRoundedRect(rect,rectRadius,rectRadius);

    painter->restore();
}

//绘制滑块，也就是圆形按钮
void SwitchButton::drawSlider(QPainter *painter){
    painter->save();
    painter->setPen(Qt::NoPen);

    if (!disabled || !m_useDisableStyle){
        painter->setBrush(sliderColorEnabled);
    }
    else
        painter->setBrush(sliderColorDisabled);
    if (disabled) {
        if (!checked){
            QRect smallRect(8, height() / 2 - 2, 10 , 4);
            painter->drawRoundedRect(smallRect,3,3);
        }else{
            QRect smallRect(width() - 8 * 2, height() / 2 - 2, 10 , 4);
            painter->drawRoundedRect(smallRect,3,3);
        }
    }
            
    QRect rect(0, 0, width(), height());
    int sliderWidth = rect.height() - space * 2;
    QRect sliderRect(mStartX + space, space, sliderWidth, sliderWidth);
    painter->drawEllipse(sliderRect);

    painter->restore();
}

void SwitchButton::mousePressEvent(QMouseEvent *){
    qDebug()<<isMoving<<checked<<disabled;
    if (isMoving) {
        return ;
    }
    if(disabled){
        mEndX = 0;
        Q_EMIT disabledClick();
        return ;
    }else{
        checked = !checked;
        Q_EMIT checkedChanged(checked);

        mStep = width() / MOVING_STEPS;

        if (checked){
            //circle out
    //        endX = width() - height() + space;
            //circle in
            mEndX = width() - height();
        }
        else {
            mEndX = 0;
        }
        mTimer->start();
        isMoving = true;
    }
}

void SwitchButton::resizeEvent(QResizeEvent *){
    //每次开始的x坐标都是跳过圆角，从直线的地方开始计算
    mStep = width() / MOVING_STEPS;

    if (checked){
        //circle out
//        startX = width() - height() + space;
        //circle in
        mStartX = width() - height();
    }
    else
        mStartX = 0;

    rectRadius = height()/2;
    update();
}
void SwitchButton::enterEvent(QEvent *event) {
    bgColorOn = bgHoverOnColor;
    bgColorOff = bgHoverOffColor;

    hover = true;
    update();
    return QWidget::enterEvent(event);
}

void SwitchButton::leaveEvent(QEvent *event) {
    hover = false;

    QString style = m_qtThemeSetting->get("styleName").toString();
    changeColor(style);

    update();
    return QWidget::leaveEvent(event);
}

//根据事件向左还是向右移动
void SwitchButton::updatevalue(){
    if (checked)
        if (mStartX < mEndX-mStep){
            mStartX = mStartX + mStep;
        }
        else{
            mStartX = mEndX;
            mTimer->stop();
            isMoving = false;
        }
    else{
        if (mStartX > mEndX+mStep){
            mStartX = mStartX - mStep;
        }
        else{
            mStartX = mEndX;
            mTimer->stop();
            isMoving = false;
        }
    }
    update();
}

void SwitchButton::setChecked(bool checked){
    if (this->checked != checked){
        this->checked = checked;
        Q_EMIT checkedChanged(checked);
        update();
    }

    mStep = width() / MOVING_STEPS;

    if (checked){
        //circle out
//        endX = width() - height() + space;
        //circle in
        mEndX = width() - height();
    }
    else{
        mEndX = 0;
    }
    mTimer->start();
    isMoving = true;
}

bool SwitchButton::isChecked(){
    return this->checked;
}

void SwitchButton::setDisabledFlag(bool value)
{
    disabled = value;
    update();
}

bool SwitchButton::getDisabledFlag()
{
    return disabled;
}

void SwitchButton::setAnimation(bool on){
    isAnimation = on;
}