// Copyright (C) 2017 The Qt Company Ltd.
// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR GPL-3.0-only

#include "calendar.h"

#include <QComboBox>
#include <QGridLayout>
#include <QGroupBox>
#include <QCalendarWidget>
#include <QLabel>
#include <QDateEdit>
#include <QCheckBox>
#include <QTextCharFormat>

CalendarWidget::CalendarWidget()
{
    createPreviewGroupBox();
    createGeneralOptionsGroupBox();
    createDatesGroupBox();
    createTextFormatsGroupBox();

    QGridLayout *layout = new QGridLayout;
    layout->addWidget(previewGroupBox, 0, 0);
    layout->addWidget(generalOptionsGroupBox, 0, 1);
    layout->addWidget(datesGroupBox, 1, 0);
    layout->addWidget(textFormatsGroupBox, 1, 1);
    layout->setSizeConstraint(QLayout::SetFixedSize);
    setLayout(layout);

    previewLayout->setRowMinimumHeight(0, calendar->sizeHint().height());
    previewLayout->setColumnMinimumWidth(0, calendar->sizeHint().width());

    setWindowTitle(tr("Calendar Widget"));
}

void CalendarWidget::localeChanged(QLocale locale)
{
    calendar->setLocale(locale);
    firstDayCombo->setCurrentIndex(locale.firstDayOfWeek()-1);
    updateWeekendDays();
}

void CalendarWidget::firstDayChanged(int index)
{
    calendar->setFirstDayOfWeek(Qt::DayOfWeek(
                                firstDayCombo->itemData(index).toInt()));
}

void CalendarWidget::selectionModeChanged(int index)
{
    calendar->setSelectionMode(QCalendarWidget::SelectionMode(
                               selectionModeCombo->itemData(index).toInt()));
}

void CalendarWidget::horizontalHeaderChanged(int index)
{
    calendar->setHorizontalHeaderFormat(QCalendarWidget::HorizontalHeaderFormat(
        horizontalHeaderCombo->itemData(index).toInt()));
}

void CalendarWidget::verticalHeaderChanged(int index)
{
    calendar->setVerticalHeaderFormat(QCalendarWidget::VerticalHeaderFormat(
        verticalHeaderCombo->itemData(index).toInt()));
}

void CalendarWidget::selectedDateChanged()
{
    currentDateEdit->setDate(calendar->selectedDate());
}

void CalendarWidget::minimumDateChanged(QDate date)
{
    calendar->setMinimumDate(date);
    maximumDateEdit->setDate(calendar->maximumDate());
}

void CalendarWidget::maximumDateChanged(QDate date)
{
    calendar->setMaximumDate(date);
    minimumDateEdit->setDate(calendar->minimumDate());
}

bool CalendarWidget::isWeekendDay(Qt::DayOfWeek day) {
    QList<Qt::DayOfWeek> week = calendar->locale().weekdays();
    return !week.contains(day);
}

void CalendarWidget::updateWeekendDays() {
    QTextCharFormat weekFormat, weekendFormat;
    weekFormat.setForeground(qvariant_cast<QColor>(
        weekdayColorCombo->itemData(weekdayColorCombo->currentIndex())));
    weekendFormat.setForeground(qvariant_cast<QColor>(
        weekendColorCombo->itemData(weekendColorCombo->currentIndex())));

    calendar->setWeekdayTextFormat(Qt::Monday, isWeekendDay(Qt::Monday) ? weekendFormat : weekFormat);
    calendar->setWeekdayTextFormat(Qt::Tuesday, isWeekendDay(Qt::Tuesday) ? weekendFormat : weekFormat);
    calendar->setWeekdayTextFormat(Qt::Wednesday, isWeekendDay(Qt::Wednesday) ? weekendFormat : weekFormat);
    calendar->setWeekdayTextFormat(Qt::Thursday, isWeekendDay(Qt::Thursday) ? weekendFormat : weekFormat);
    calendar->setWeekdayTextFormat(Qt::Friday, isWeekendDay(Qt::Friday) ? weekendFormat : weekFormat);
    calendar->setWeekdayTextFormat(Qt::Saturday, isWeekendDay(Qt::Saturday) ? weekendFormat : weekFormat);
    calendar->setWeekdayTextFormat(Qt::Sunday, isWeekendDay(Qt::Sunday) ? weekendFormat : weekFormat);
}

void CalendarWidget::weekdayFormatChanged()
{
    updateWeekendDays();
}

void CalendarWidget::weekendFormatChanged()
{
    updateWeekendDays();
}

void CalendarWidget::reformatHeaders()
{
    QString text = headerTextFormatCombo->currentText();
    QTextCharFormat format;

    if (text == tr("Bold")) {
        format.setFontWeight(QFont::Bold);
    } else if (text == tr("Italic")) {
        format.setFontItalic(true);
    } else if (text == tr("Green")) {
        format.setForeground(Qt::green);
    }
    calendar->setHeaderTextFormat(format);
}

void CalendarWidget::reformatCalendarPage()
{
    if (firstFridayCheckBox->isChecked()) {
        QDate firstFriday(calendar->yearShown(), calendar->monthShown(), 1);
        while (firstFriday.dayOfWeek() != Qt::Friday)
            firstFriday = firstFriday.addDays(1);
        QTextCharFormat firstFridayFormat;
        firstFridayFormat.setForeground(Qt::blue);
        calendar->setDateTextFormat(firstFriday, firstFridayFormat);
    }

    //May First in Red takes precedence
    if (mayFirstCheckBox->isChecked()) {
        const QDate mayFirst(calendar->yearShown(), 5, 1);
        QTextCharFormat mayFirstFormat;
        mayFirstFormat.setForeground(Qt::red);
        calendar->setDateTextFormat(mayFirst, mayFirstFormat);
    }
}

void CalendarWidget::createPreviewGroupBox()
{
    previewGroupBox = new QGroupBox(tr("Preview"));

    calendar = new QCalendarWidget;
    calendar->setMinimumDate(QDate(1900, 1, 1));
    calendar->setMaximumDate(QDate(3000, 1, 1));
    calendar->setGridVisible(true);

    connect(calendar, SIGNAL(currentPageChanged(int,int)),
            this, SLOT(reformatCalendarPage()));

    previewLayout = new QGridLayout;
    previewLayout->addWidget(calendar, 0, 0, Qt::AlignCenter);
    previewGroupBox->setLayout(previewLayout);
}

void CalendarWidget::createGeneralOptionsGroupBox()
{
    generalOptionsGroupBox = new QGroupBox(tr("General Options"));

    firstDayCombo = new QComboBox;
    firstDayCombo->addItem(tr("Monday"), Qt::Monday);
    firstDayCombo->addItem(tr("Tuesday"), Qt::Tuesday);
    firstDayCombo->addItem(tr("Wednesday"), Qt::Wednesday);
    firstDayCombo->addItem(tr("Thursday"), Qt::Thursday);
    firstDayCombo->addItem(tr("Friday"), Qt::Friday);
    firstDayCombo->addItem(tr("Saturday"), Qt::Saturday);
    firstDayCombo->addItem(tr("Sunday"), Qt::Sunday);

    firstDayLabel = new QLabel(tr("Wee&k starts on:"));
    firstDayLabel->setBuddy(firstDayCombo);

    selectionModeCombo = new QComboBox;
    selectionModeCombo->addItem(tr("Single selection"),
                                QCalendarWidget::SingleSelection);
    selectionModeCombo->addItem(tr("None"), QCalendarWidget::NoSelection);

    selectionModeLabel = new QLabel(tr("&Selection mode:"));
    selectionModeLabel->setBuddy(selectionModeCombo);

    gridCheckBox = new QCheckBox(tr("&Grid"));
    gridCheckBox->setChecked(calendar->isGridVisible());

    navigationCheckBox = new QCheckBox(tr("&Navigation bar"));
    navigationCheckBox->setChecked(true);

    horizontalHeaderCombo = new QComboBox;
    horizontalHeaderCombo->addItem(tr("Single letter day names"),
                                   QCalendarWidget::SingleLetterDayNames);
    horizontalHeaderCombo->addItem(tr("Short day names"),
                                   QCalendarWidget::ShortDayNames);
    horizontalHeaderCombo->addItem(tr("None"),
                                   QCalendarWidget::NoHorizontalHeader);
    horizontalHeaderCombo->setCurrentIndex(1);

    horizontalHeaderLabel = new QLabel(tr("&Horizontal header:"));
    horizontalHeaderLabel->setBuddy(horizontalHeaderCombo);

    verticalHeaderCombo = new QComboBox;
    verticalHeaderCombo->addItem(tr("ISO week numbers"),
                                 QCalendarWidget::ISOWeekNumbers);
    verticalHeaderCombo->addItem(tr("None"), QCalendarWidget::NoVerticalHeader);

    verticalHeaderLabel = new QLabel(tr("&Vertical header:"));
    verticalHeaderLabel->setBuddy(verticalHeaderCombo);

    connect(firstDayCombo, SIGNAL(currentIndexChanged(int)),
            this, SLOT(firstDayChanged(int)));
    connect(selectionModeCombo, SIGNAL(currentIndexChanged(int)),
            this, SLOT(selectionModeChanged(int)));
    connect(gridCheckBox, SIGNAL(toggled(bool)),
            calendar, SLOT(setGridVisible(bool)));
    connect(navigationCheckBox, SIGNAL(toggled(bool)),
            calendar, SLOT(setNavigationBarVisible(bool)));
    connect(horizontalHeaderCombo, SIGNAL(currentIndexChanged(int)),
            this, SLOT(horizontalHeaderChanged(int)));
    connect(verticalHeaderCombo, SIGNAL(currentIndexChanged(int)),
            this, SLOT(verticalHeaderChanged(int)));

    QHBoxLayout *checkBoxLayout = new QHBoxLayout;
    checkBoxLayout->addWidget(gridCheckBox);
    checkBoxLayout->addStretch();
    checkBoxLayout->addWidget(navigationCheckBox);

    QGridLayout *outerLayout = new QGridLayout;
    outerLayout->addWidget(firstDayLabel, 0, 0);
    outerLayout->addWidget(firstDayCombo, 0, 1);
    outerLayout->addWidget(selectionModeLabel, 1, 0);
    outerLayout->addWidget(selectionModeCombo, 1, 1);
    outerLayout->addLayout(checkBoxLayout, 2, 0, 1, 2);
    outerLayout->addWidget(horizontalHeaderLabel, 3, 0);
    outerLayout->addWidget(horizontalHeaderCombo, 3, 1);
    outerLayout->addWidget(verticalHeaderLabel, 4, 0);
    outerLayout->addWidget(verticalHeaderCombo, 4, 1);
    generalOptionsGroupBox->setLayout(outerLayout);

    firstDayChanged(firstDayCombo->currentIndex());
    selectionModeChanged(selectionModeCombo->currentIndex());
    horizontalHeaderChanged(horizontalHeaderCombo->currentIndex());
    verticalHeaderChanged(verticalHeaderCombo->currentIndex());
}

void CalendarWidget::createDatesGroupBox()
{
    datesGroupBox = new QGroupBox(tr("Dates"));

    minimumDateEdit = new QDateEdit;
    minimumDateEdit->setDisplayFormat("MMM d yyyy");
    minimumDateEdit->setDateRange(calendar->minimumDate(),
                                  calendar->maximumDate());
    minimumDateEdit->setDate(calendar->minimumDate());

    minimumDateLabel = new QLabel(tr("&Minimum Date:"));
    minimumDateLabel->setBuddy(minimumDateEdit);

    currentDateEdit = new QDateEdit;
    currentDateEdit->setDisplayFormat("MMM d yyyy");
    currentDateEdit->setDate(calendar->selectedDate());
    currentDateEdit->setDateRange(calendar->minimumDate(),
                                  calendar->maximumDate());

    currentDateLabel = new QLabel(tr("&Current Date:"));
    currentDateLabel->setBuddy(currentDateEdit);

    maximumDateEdit = new QDateEdit;
    maximumDateEdit->setDisplayFormat("MMM d yyyy");
    maximumDateEdit->setDateRange(calendar->minimumDate(),
                                  calendar->maximumDate());
    maximumDateEdit->setDate(calendar->maximumDate());

    maximumDateLabel = new QLabel(tr("Ma&ximum Date:"));
    maximumDateLabel->setBuddy(maximumDateEdit);

    connect(currentDateEdit, SIGNAL(dateChanged(QDate)),
            calendar, SLOT(setSelectedDate(QDate)));
    connect(calendar, SIGNAL(selectionChanged()),
            this, SLOT(selectedDateChanged()));
    connect(minimumDateEdit, SIGNAL(dateChanged(QDate)),
            this, SLOT(minimumDateChanged(QDate)));
    connect(maximumDateEdit, SIGNAL(dateChanged(QDate)),
            this, SLOT(maximumDateChanged(QDate)));

    QGridLayout *dateBoxLayout = new QGridLayout;
    dateBoxLayout->addWidget(currentDateLabel, 1, 0);
    dateBoxLayout->addWidget(currentDateEdit, 1, 1);
    dateBoxLayout->addWidget(minimumDateLabel, 0, 0);
    dateBoxLayout->addWidget(minimumDateEdit, 0, 1);
    dateBoxLayout->addWidget(maximumDateLabel, 2, 0);
    dateBoxLayout->addWidget(maximumDateEdit, 2, 1);
    dateBoxLayout->setRowStretch(3, 1);

    datesGroupBox->setLayout(dateBoxLayout);
}

void CalendarWidget::createTextFormatsGroupBox()
{
    textFormatsGroupBox = new QGroupBox(tr("Text Formats"));

    weekdayColorCombo = createColorComboBox();
    weekdayColorCombo->setCurrentIndex(
            weekdayColorCombo->findText(tr("Black")));

    weekdayColorLabel = new QLabel(tr("&Weekday color:"));
    weekdayColorLabel->setBuddy(weekdayColorCombo);

    weekendColorCombo = createColorComboBox();
    weekendColorCombo->setCurrentIndex(
            weekendColorCombo->findText(tr("Red")));

    weekendColorLabel = new QLabel(tr("Week&end color:"));
    weekendColorLabel->setBuddy(weekendColorCombo);

    headerTextFormatCombo = new QComboBox;
    headerTextFormatCombo->addItem(tr("Bold"));
    headerTextFormatCombo->addItem(tr("Italic"));
    headerTextFormatCombo->addItem(tr("Plain"));

    headerTextFormatLabel = new QLabel(tr("&Header text:"));
    headerTextFormatLabel->setBuddy(headerTextFormatCombo);

    firstFridayCheckBox = new QCheckBox(tr("&First Friday in blue"));

    mayFirstCheckBox = new QCheckBox(tr("May &1 in red"));

    connect(weekdayColorCombo, SIGNAL(currentIndexChanged(int)),
            this, SLOT(weekdayFormatChanged()));
    connect(weekendColorCombo, SIGNAL(currentIndexChanged(int)),
            this, SLOT(weekendFormatChanged()));
    connect(headerTextFormatCombo, SIGNAL(currentIndexChanged(QString)),
            this, SLOT(reformatHeaders()));
    connect(firstFridayCheckBox, SIGNAL(toggled(bool)),
            this, SLOT(reformatCalendarPage()));
    connect(mayFirstCheckBox, SIGNAL(toggled(bool)),
            this, SLOT(reformatCalendarPage()));

    QHBoxLayout *checkBoxLayout = new QHBoxLayout;
    checkBoxLayout->addWidget(firstFridayCheckBox);
    checkBoxLayout->addStretch();
    checkBoxLayout->addWidget(mayFirstCheckBox);

    QGridLayout *outerLayout = new QGridLayout;
    outerLayout->addWidget(weekdayColorLabel, 0, 0);
    outerLayout->addWidget(weekdayColorCombo, 0, 1);
    outerLayout->addWidget(weekendColorLabel, 1, 0);
    outerLayout->addWidget(weekendColorCombo, 1, 1);
    outerLayout->addWidget(headerTextFormatLabel, 2, 0);
    outerLayout->addWidget(headerTextFormatCombo, 2, 1);
    outerLayout->addLayout(checkBoxLayout, 3, 0, 1, 2);
    textFormatsGroupBox->setLayout(outerLayout);

    weekdayFormatChanged();
    weekendFormatChanged();
    reformatHeaders();
    reformatCalendarPage();
}

QComboBox *CalendarWidget::createColorComboBox()
{
    QComboBox *comboBox = new QComboBox;
    comboBox->addItem(tr("Red"), QColor(Qt::red));
    comboBox->addItem(tr("Blue"), QColor(Qt::blue));
    comboBox->addItem(tr("Black"), QColor(Qt::black));
    comboBox->addItem(tr("Magenta"), QColor(Qt::magenta));
    return comboBox;
}
