/*
* Copyright (c) 2012-2015 Christian Surlykke, Petr Vanek
*
* This file is part of qt-lightdm-greeter 
* It is distributed under the LGPL 2.1 or later license.
* Please refer to the LICENSE file for a copy of the license.
*/
#include <QRect>
#include <QApplication>
#include <QDesktopWidget>
#include <QPalette>
#include <QString>
#include <QtDebug>
#include <QTextEdit>
#include <QStyleFactory>
#include <QSvgWidget>
#include <QSvgRenderer>
#include <QAbstractTextDocumentLayout>

#include "mainwindow.h"
#include "loginform.h"
#include "settings.h"

static const Settings _settings;

MainWindow::MainWindow(bool primary, int screen, const QRect &screenRect, QWidget *parent) :
    QWidget(parent),
    m_ScreenRect(screenRect),
    m_Primary(primary),
    m_messages(nullptr)
{
    setObjectName(QString("MainWindow_%1").arg(screen));
    
    setGeometry(screenRect);

    setBackground();

    // TODO: Check if testMode == false and greeter == NULL, if so display big error message
    // instead of exiting/crashing

    // display login dialog only in the main screen

    int spaceY = screenRect.height() / 2;
    
    if (showLoginForm()) {
        m_LoginForm = new LoginForm(this);
        spaceY -= m_LoginForm->height() / 2;

        int maxX = screenRect.width() - m_LoginForm->width();
        int maxY = screenRect.height() - m_LoginForm->height();
        int defaultX = 50*maxX/100;
        int defaultY = 50*maxY/100;
        int offsetX = getOffset(_settings.offsetX(), maxX, defaultX);
        int offsetY = getOffset(_settings.offsetY(), maxY, defaultY);
        
        m_LoginForm->move(offsetX, offsetY);
        m_LoginForm->show();

        // This hack ensures that the primary screen will have focus
        // if there are more screens (move the mouse cursor in the center
        // of primary screen - not in the center of all X area). It
        // won't affect single-screen environments.
        int centerX = screenRect.width()/2 + screenRect.x();
        int centerY = screenRect.height()/2 + screenRect.y();
        QCursor::setPos(centerX, centerY);
    }

    // Banner
    if (!_settings.bannerImagePath().isEmpty()) {
        qWarning() << "Have banner " << _settings.bannerImagePath();
        QSvgWidget *banner = new QSvgWidget(_settings.bannerImagePath(), this);
        qWarning() << banner->sizeHint();
        if (banner->renderer()->isValid()) {
            int bw, bh;
            QSize sh = banner->sizeHint();
            if (sh.height() < spaceY) {
                banner->setFixedSize(sh);
                bw = sh.width();
                bh = sh.height();
            } else {
                int bh = spaceY - 20;
                int bw = sh.width() * bh / sh.height();
                banner->setFixedSize(bw, bh);
            }
            banner->move((screenRect.width() - bw) / 2, (spaceY - bh) / 2);
        }
    }
    int ls = (spaceY > 500 ? 500 : spaceY);
    if (ls > screenRect.height() / 5) ls = screenRect.height() / 5;
    if (ls > screenRect.width() / 5) ls = screenRect.width() / 5;
    QRect logoRect(QPoint(0, screenRect.height() - ls), QSize(ls, ls));
    QSize logoSize = createLogo(logoRect);
    if (showLoginForm()) {
        QRect lwSize(QPoint(logoSize.width(), screenRect.height() * 3/4), QPoint(screenRect.width(), screenRect.height()));
        lwSize.adjust(10, 10, -10, -10);
        createLogWindow(lwSize);
    }
}

MainWindow::~MainWindow()
{
}

QSize MainWindow::createLogo(const QRect &max)
{
    QString path = _settings.bottomLeftLogoPath();
    if (path.isEmpty())
        return QSize(0, 0);
    QSvgWidget *img = new QSvgWidget(path, this);
    if (!img->renderer()->isValid())
        return QSize(0, 0);
    QSize sh = img->sizeHint();
    int w = sh.width(), h = sh.height();
    // This requires that the given rect is square
    if (w > h) {
        if (w != max.width()) {
            h = h * max.width() / w;
            w = max.width();
        }
    } else {
        if (h != max.height()) {
            w = w * max.height() / h;
            h = max.height();
        }
    }
    QSize size(w, h);
    QRect c(max);
    c.adjust(0, max.height() - h, -(max.width() - w), 0);
    c.adjust(10, 10, -10, -10);
    img->setGeometry(c);
    return size;
}

void MainWindow::createLogWindow(const QRect& geom)
{
    QString path = _settings.logMessageFile();
    if (path.isEmpty())
        return;
    QFile f(path);
    if (f.size() == 0 || !f.open(QFile::ReadOnly))
        return;
    m_messages = new QTextEdit(this);
    m_messages->setGeometry(geom);
    int ps = geom.height() / 20;
    if (ps > 20) ps = 20;
    m_messages->setFontPointSize(ps);
    QTextStream stream(&f);
    const QColor black(Qt::black);
    while (!stream.atEnd()) {
        bool ok = false;
        QString line(stream.readLine());
        int i = line.indexOf(' ');
        if (i > 0) {
            QString scol(line.left(i));
            uint col = scol.toUInt(&ok, 16);
            if (ok) {
                m_messages->setTextColor(QColor(QRgb(col)));
                line = line.mid(i + 1);
            }
        }
        if (!ok) {
            m_messages->setTextColor(black);
        }
        m_messages->append(line);
    }
    m_messages->setReadOnly(true);
    m_messages->setStyleSheet("border:none; background:rgba(255,255,255,.33); border-radius:5px");
}

bool MainWindow::showLoginForm()
{
    return m_Primary;
}

void MainWindow::setFocus(Qt::FocusReason reason)
{
    if (m_LoginForm) {
        m_LoginForm->setFocus(reason);
    }
    else  {
        QWidget::setFocus(reason);
    }
}

int MainWindow::getOffset(QString settingsOffset, int maxVal, int defaultVal)
{

    int offset = defaultVal > maxVal ? maxVal : defaultVal;

    if (! settingsOffset.isEmpty())  {
        if (QRegExp("^\\d+px$", Qt::CaseInsensitive).exactMatch(settingsOffset))  {
            offset = settingsOffset.left(settingsOffset.size() - 2).toInt();
            if (offset > maxVal) offset = maxVal;
        }
        else if (QRegExp("^\\d+%$", Qt::CaseInsensitive).exactMatch(settingsOffset)) {
            int offsetPct = settingsOffset.left(settingsOffset.size() -1).toInt();
            if (offsetPct > 100) offsetPct = 100;
            offset = (maxVal * offsetPct)/100;
        }
        else {
            qWarning() << "Could not understand" << settingsOffset
                       << "- must be of form <positivenumber>px or <positivenumber>%, e.g. 35px or 25%" ;
        }
    }

    return offset;
}

void MainWindow::setBackground()
{
    Qt::AspectRatioMode arMode = Qt::KeepAspectRatioByExpanding;
    QString bgPath = _settings.backgrundImagePath();
    if (bgPath.length() != 0) {
        m_background = QImage(bgPath);
        if (m_background.isNull()) {
            qWarning() << "Not able to read" << bgPath << "as image";
        }
             
    }

    if (m_background.isNull()) {
        arMode = Qt::IgnoreAspectRatio;
        QStringList cols = _settings.gradientColors();
        qWarning() << "Got list: " << cols;
        if (cols.length() == 4 || cols.length() == 2) {
            bool ok = true;
            uint a, b, c, d;
            if (ok) a = cols.at(0).toUInt(&ok, 16) | 0xff000000;
            if (ok) b = cols.at(1).toUInt(&ok, 16) | 0xff000000;
            if (cols.length() == 4) {
                if (ok) c = cols.at(2).toUInt(&ok, 16) | 0xff000000;
                if (ok) d = cols.at(3).toUInt(&ok, 16) | 0xff000000;
            } else {
                c = b;
            }
            qWarning() << a << b << c << d;
            if (ok) {
                m_background = QImage(cols.length() / 2, 2, QImage::Format_RGB32);
                m_background.setPixel(0, 0, a);
                m_background.setPixel(0, 1, c);
                if (cols.length() == 4) {
                    m_background.setPixel(1, 0, b);
                    m_background.setPixel(1, 1, d);
                }
            }
        }
    }
    if (m_background.isNull()) {
        // Hard-coded default: Gradient
        m_background = QImage(2, 2, QImage::Format_RGB32);
        m_background.setPixel(0, 0, 0xffffffff);
        m_background.setPixel(1, 0, 0xffffffff);
        m_background.setPixel(0, 1, 0xff888687);
        m_background.setPixel(1, 1, 0xfff9a72b);
    }
    
    QPalette palette;
    if (m_background.isNull()) {
        palette.setColor(QPalette::Background, Qt::black);
    }
    else {
        m_background = m_background.scaled(m_ScreenRect.width(), m_ScreenRect.height(), Qt::KeepAspectRatioByExpanding, Qt::SmoothTransformation);
        int xoff = (m_background.width() -  m_ScreenRect.width()) / 2;
        int yoff = (m_background.height() - m_ScreenRect.height()) / 2;
    	if (xoff != 0 || yoff != 0) {
    		m_background = m_background.copy(xoff, yoff, m_background.width(), m_background.height());
    	}
        QBrush brush(m_background);
        palette.setBrush(this->backgroundRole(), brush);
    }
    this->setPalette(palette);
}