#include "calculatordialog.h"
#include "ui_calculatordialog.h"

#include <QScriptEngine>
#include <QRegExp>
#include <QDebug>

// 构造函数
CalculatorDialog::CalculatorDialog(QWidget *parent) :
    QDialog(parent),
    _ui(new Ui::CalculatorDialog)
{
    _ui->setupUi(this);
    // 设置显示框为无边框样式
    _ui->LineEdt_Top->setStyleSheet("QLineEdit{border-width:0;border-style:outset}");
    _ui->LineEdt_Down->setStyleSheet("QLineEdit{border-width:0;border-style:outset}");

    // 添加按钮的快捷键
    _ui->ButtonNum_0->setShortcut(Qt::Key_0);
    _ui->ButtonNum_1->setShortcut(Qt::Key_1);
    _ui->ButtonNum_2->setShortcut(Qt::Key_2);
    _ui->ButtonNum_3->setShortcut(Qt::Key_3);
    _ui->ButtonNum_4->setShortcut(Qt::Key_4);
    _ui->ButtonNum_5->setShortcut(Qt::Key_5);
    _ui->ButtonNum_6->setShortcut(Qt::Key_6);
    _ui->ButtonNum_7->setShortcut(Qt::Key_7);
    _ui->ButtonNum_8->setShortcut(Qt::Key_8);
    _ui->ButtonNum_9->setShortcut(Qt::Key_9);
    _ui->ButtonEqual->setShortcut(Qt::Key_Enter); // 小键盘的回车
    _ui->ButtonPlus->setShortcut(Qt::Key_Plus);
    _ui->ButtonMinus->setShortcut(Qt::Key_Minus);
    _ui->ButtonTimes->setShortcut(Qt::Key_Asterisk);
    _ui->ButtonDivision->setShortcut(Qt::Key_Slash);
    _ui->ButtonDot->setShortcut(Qt::Key_Period);
    _ui->ButtonClear->setShortcut(Qt::Key_Space);
    _ui->ButtonPercent->setShortcut(Qt::Key_Percent);
     _ui->ButtonDel->setShortcut(Qt::Key_Backspace);

    display();
}

CalculatorDialog::~CalculatorDialog()
{
    delete _ui;
}

void CalculatorDialog::display( bool iCompute /*= false*/ )
{
    QString strUp,strDown;
    if( !iCompute )
    {
        strDown = _strCurInput;
    }
    else
    {
        strUp = _strCurInput;
        strDown =_strResult;

        // 将运算结果作为当前输入
        _strCurInput = _strResult;

        // 计算并显示之后，将结果和公式内容清空
        _strResult.clear();
        _strEquation.clear();
    }

    // 如果字符串长度超过控件宽度，会自动换行，导致后面的输入看不到
    _ui->LineEdt_Top->setText(strUp);
    _ui->LineEdt_Down->setText(strDown);
}


void CalculatorDialog::on_ButtonNum_0_clicked()
{
    if( _strCurInput == "0" )
        return;

    _strCurInput += "0";
    display();
}

void CalculatorDialog::on_ButtonNum_1_clicked()
{
    if( _strCurInput == "0" )
        _strCurInput.clear();
    _strCurInput += "1";

    display();
}

void CalculatorDialog::on_ButtonNum_2_clicked()
{
    if(_strCurInput == "0" )
        _strCurInput.clear();

    _strCurInput += "2";

    display();
}

void CalculatorDialog::on_ButtonNum_3_clicked()
{
    if(_strCurInput == "0" )
        _strCurInput.clear();
    _strCurInput += "3";

    display();
}

void CalculatorDialog::on_ButtonNum_4_clicked()
{
    if(_strCurInput == "0" )
        _strCurInput.clear();
    _strCurInput += "4";

    display();
}

void CalculatorDialog::on_ButtonNum_5_clicked()
{
    if(_strCurInput == "0" )
        _strCurInput.clear();
    _strCurInput += "5";

    display();
}

void CalculatorDialog::on_ButtonNum_6_clicked()
{
    if(_strCurInput == "0" )
        _strCurInput.clear();
    _strCurInput += "6";

    display();
}

void CalculatorDialog::on_ButtonNum_7_clicked()
{
    if(_strCurInput == "0" )
        _strCurInput.clear();
    _strCurInput += "7";

    display();
}

void CalculatorDialog::on_ButtonNum_8_clicked()
{
    if(_strCurInput == "0" )
        _strCurInput.clear();
    _strCurInput += "8";

    display();
}

void CalculatorDialog::on_ButtonNum_9_clicked()
{
    if(_strCurInput == "0" )
        _strCurInput.clear();
    _strCurInput += "9";

    display();
}


void CalculatorDialog::on_ButtonPlus_clicked()
{
    if( _strCurInput.isEmpty() || _strCurInput.endsWith('+') || _strCurInput.endsWith('-') ||
            _strCurInput.endsWith("×") || _strCurInput.endsWith("÷") )
    {
        return;
    }

    _strCurInput += "+";
    display();
}

void CalculatorDialog::on_ButtonMinus_clicked()
{
    if( _strCurInput.isEmpty() || _strCurInput.endsWith('+') || _strCurInput.endsWith('-') ||
            _strCurInput.endsWith("×") || _strCurInput.endsWith("÷") )
    {
        return;
    }
    _strCurInput += "-";
    display();
}

void CalculatorDialog::on_ButtonTimes_clicked()
{
    if( _strCurInput.isEmpty() || _strCurInput.endsWith('+') || _strCurInput.endsWith('-') ||
            _strCurInput.endsWith("×") || _strCurInput.endsWith("÷") )
    {
        return;
    }
    _strCurInput += "×";
    display();
}

void CalculatorDialog::on_ButtonDivision_clicked()
{
    if( _strCurInput.isEmpty() || _strCurInput.endsWith('+') || _strCurInput.endsWith('-') ||
            _strCurInput.endsWith("×") || _strCurInput.endsWith("÷") )
    {
        return;
    }

    _strCurInput += "÷";

    display();
}

void CalculatorDialog::on_ButtonDot_clicked()
{
    QString strLastNum = _strCurInput;

    strLastNum.replace("×","*");
    strLastNum.replace("÷","/");
    // 最近的数字中如果有小数点，则不能继续添加点
    int lastOperSign = strLastNum.lastIndexOf( QRegExp("[+-*/]") );
    if( -1 != lastOperSign )
    {
        strLastNum = strLastNum.right(strLastNum.length()-lastOperSign);
    }

    if( strLastNum.contains('.') )
        return;

    _strCurInput += ".";
    display();
}


void CalculatorDialog::on_ButtonEqual_clicked()
{
    if( _strCurInput.isEmpty() || _strCurInput.endsWith('+') || _strCurInput.endsWith('-') ||
            _strCurInput.endsWith("×") || _strCurInput.endsWith("÷") )
    {
        return;
    }

    // 以.结束时，补个零
    if( _strCurInput.endsWith('.') )
        _strCurInput += '0';

    _strEquation = _strCurInput;
    _strCurInput = _strCurInput + "=";

    _strEquation.replace("×","*");
    _strEquation.replace("÷","/");

    QScriptEngine scriptEng;
    QScriptValue scriptVal = scriptEng.evaluate(_strEquation);
    if( scriptEng.hasUncaughtException() )
    {
        qDebug() << "The equation is: " << _strEquation;
        qDebug() << scriptVal.toString();
        _strResult = "Error";
    }
    else
        _strResult = scriptVal.toString();

    display(true);
}

void CalculatorDialog::on_ButtonClear_clicked()
{
    _strCurInput = "0";
    _strResult.clear();
    display();
}

void CalculatorDialog::on_ButtonDel_clicked()
{
    _strCurInput.remove( _strCurInput.length()-1, 1 );
    if( _strCurInput.length() == 0 )
        _strCurInput = "0";
    display();
}

void CalculatorDialog::on_ButtonPercent_clicked()
{
    if( _strCurInput == "0" )
        return;
    bool isNum = false;
    double curVal = _strCurInput.toDouble(&isNum);
    if( !isNum )
        return;

    _strCurInput += "%";

    curVal /= 100.;
    _strResult = QString::number(curVal);

    display(true);
}

void CalculatorDialog::keyPressEvent(QKeyEvent *ev)
{
    if( !ev )
        return;
    qDebug() << "keyboard input idenfiter number : " << ev->key();
    switch( ev->key() )
    {
    case Qt::Key_Return: // 主键盘上的回车
    case Qt::Key_Equal:  // 主键盘上的等号
    {
        on_ButtonEqual_clicked();
    }
        break;
    default:
        break;
    }
}