#include <QCoreApplication>
#include <QString>
#include <QFile>
#include <QDir>
#include <QTextStream>
#include <QDebug>


int main(int argc, char *argv[])
{
    QCoreApplication app(argc, argv);

    // prepare the message
    QString message("Hello World!");

    // prepare a file in the users home directory named out.txt
    QFile file(QDir::home().absoluteFilePath("out.txt"));
    // try to open the file in write mode
    if(!file.open(QIODevice::WriteOnly)) {
        qWarning() << "Can not open file with write access";
        return -1;
    }
    // as we handle text we need to use proper text codecs
    QTextStream stream(&file);
    // write message to file via the text stream
    stream << message;

    // do not start the eventloop as this would wait for external IO
    // app.exec();

    // no need to close file, closes automatically when scope ends
    return 0;
}

cmake_minimum_required(VERSION 3.14)

project(projectname VERSION 0.1 LANGUAGES CXX)

set(CMAKE_INCLUDE_CURRENT_DIR ON)

set(CMAKE_AUTOUIC ON)
set(CMAKE_AUTOMOC ON)
set(CMAKE_AUTORCC ON)

set(CMAKE_CXX_STANDARD 11)
set(CMAKE_CXX_STANDARD_REQUIRED ON)

# QtCreator supports the following variables for Android, which are identical to qmake Android variables.
# Check https://doc.qt.io/qt/deployment-android.html for more information.
# They need to be set before the find_package(...) calls below.

#if(ANDROID)
#    set(ANDROID_PACKAGE_SOURCE_DIR "${CMAKE_CURRENT_SOURCE_DIR}/android")
#    if (ANDROID_ABI STREQUAL "armeabi-v7a")
#        set(ANDROID_EXTRA_LIBS
#            ${CMAKE_CURRENT_SOURCE_DIR}/path/to/libcrypto.so
#            ${CMAKE_CURRENT_SOURCE_DIR}/path/to/libssl.so)
#    endif()
#endif()

find_package(QT NAMES Qt6 Qt5 COMPONENTS Core Quick REQUIRED)
find_package(Qt${QT_VERSION_MAJOR} COMPONENTS Core Quick REQUIRED)

set(PROJECT_SOURCES
        main.cpp
        qml.qrc
)

if(${QT_VERSION_MAJOR} GREATER_EQUAL 6)
    qt_add_executable(projectname
        MANUAL_FINALIZATION
        ${PROJECT_SOURCES}
    )
else()
    if(ANDROID)
        add_library(projectname SHARED
            ${PROJECT_SOURCES}
        )
    else()
        add_executable(projectname
          ${PROJECT_SOURCES}
        )
    endif()
endif()

target_compile_definitions(projectname
  PRIVATE $<$<OR:$<CONFIG:Debug>,$<CONFIG:RelWithDebInfo>>:QT_QML_DEBUG>)
target_link_libraries(projectname
  PRIVATE Qt${QT_VERSION_MAJOR}::Core Qt${QT_VERSION_MAJOR}::Quick)

set_target_properties(projectname PROPERTIES
    MACOSX_BUNDLE_GUI_IDENTIFIER my.example.com
    MACOSX_BUNDLE_BUNDLE_VERSION ${PROJECT_VERSION}
    MACOSX_BUNDLE_SHORT_VERSION_STRING ${PROJECT_VERSION_MAJOR}.${PROJECT_VERSION_MINOR}
)

if(QT_VERSION_MAJOR EQUAL 6)
    qt_import_qml_plugins(projectname)
    qt_finalize_executable(projectname)
endif()

#include <QtCore>
#include <QtGui>
#include <QtWidgets>
#include "mainwindow.h"


int main(int argc, char** argv)
{
    QApplication app(argc, argv);

    MainWindow win;
    win.resize(320, 240);
    win.setVisible(true);

    return app.exec();
}

int main(int argc, char** argv)
{
    QApplication app(argc, argv); // init application

    // create the ui

    return app.exec(); // execute event loop
}

#ifndef MAINWINDOW_H
#define MAINWINDOW_H

#include <QtWidgets>

class MainWindow : public QMainWindow
{
public:
    MainWindow(QWidget* parent=0);
    ~MainWindow();
public slots:
    void storeContent();
private:
    QPushButton *m_button;
};

#endif // MAINWINDOW_H

#include "mainwindow.h"

MainWindow::MainWindow(QWidget *parent)
    : QMainWindow(parent)
{
    m_button = new QPushButton("Store Content", this);

    setCentralWidget(m_button);
    connect(m_button, &QPushButton::clicked, this, &MainWindow::storeContent);
}

MainWindow::~MainWindow()
{

}

void MainWindow::storeContent()
{
    qDebug() << "... store content";
    QString message("Hello World!");
    QFile file(QDir::home().absoluteFilePath("out.txt"));
    if(!file.open(QIODevice::WriteOnly)) {
        qWarning() << "Can not open file with write access";
        return;
    }
    QTextStream stream(&file);
    stream << message;
}

class Person : public QObject
{
    Q_OBJECT // enabled meta object abilities

    // property declarations required for QML
    Q_PROPERTY(QString name READ name WRITE setName NOTIFY nameChanged)
    Q_PROPERTY(Gender gender READ gender WRITE setGender NOTIFY genderChanged)

    // enables enum introspections
    Q_ENUMS(Gender)
    
    // makes the type creatable in QML
    QML_ELEMENT

public:
    // standard Qt constructor with parent for memory management
    Person(QObject *parent = 0);

    enum Gender { Unknown, Male, Female, Other };

    QString name() const;
    Gender gender() const;

public slots: // slots can be connected to signals, or called
    void setName(const QString &);
    void setGender(Gender);

signals: // signals can be emitted
    void nameChanged(const QString &name);
    void genderChanged(Gender gender);

private:
    // data members
    QString m_name;
    Gender m_gender;
};

Person::Person(QObject *parent)
    : QObject(parent)
    , m_gender(Person::Unknown)
{
}

QString Person::name() const
{
    return m_name;
}

void Person::setName(const QString &name)
{
    if (m_name != name) // guard
    {
        m_name = name;
        emit nameChanged(m_name);
    }
}

Person* person = new Person();
person->metaObject()->className(); // "Person"
Person::staticMetaObject.className(); // "Person"

vim CMakeLists.txt
cmake . // generates Makefile
make

mkdir build
cd build
cmake ..

// ensure cmake version is at least 3.16.0
cmake_minimum_required(VERSION 3.16.0)

// defines a project with a version
project(foundation_tests VERSION 1.0.0 LANGUAGES CXX)

// pick the C++ standard to use, in this case C++17
set(CMAKE_CXX_STANDARD 17)
set(CMAKE_CXX_STANDARD_REQUIRED ON)

// tell CMake to run the Qt tools moc, rcc, and uic automatically
set(CMAKE_AUTOMOC ON)
set(CMAKE_AUTORCC ON)
set(CMAKE_AUTOUIC ON)

// configure the Qt 6 modules core and test
find_package(Qt6 COMPONENTS Core REQUIRED)
find_package(Qt6 COMPONENTS Test REQUIRED)

// define an executable built from a source file
add_executable(foundation_tests
    tst_foundation.cpp
)

// tell cmake to link the executable to the Qt 6 core and test modules
target_link_libraries(foundation_tests PRIVATE Qt6::Core Qt6::Test)

// myproject.pro

SOURCES += main.cpp

QT += qml quick
SOURCE += main.cpp

// myproject.pro

QT -= gui

SOURCES += main.cpp

// myproject.pro
TEMPLATE = lib

QT -= gui

HEADERS += utils.h
SOURCES += utils.cpp

my.pro
mylib/mylib.pro
mylib/utils.h
mylib/utils.cpp
myapp/myapp.pro
myapp/main.cpp

// my.pro
TEMPLATE = subdirs

subdirs = mylib \
    myapp

myapp.depends = mylib

unix {
    SOURCES += utils_unix.cpp
} else {
    SOURCES += utils.cpp
}

macx {
    CONFIG -= app_bundle
}

QString data("A,B,C,D"); // create a simple string
// split it into parts
QStringList list = data.split(",");
// create a new string out of the parts
QString out = list.join(",");
// verify both are the same
QVERIFY(data == out);
// change the first character to upper case
QVERIFY(QString("A") == out[0].toUpper());

// create some variables
int v = 10;
int base = 10;
// convert an int to a string
QString a = QString::number(v, base);
// and back using and sets ok to true on success
bool ok(false);
int v2 = a.toInt(&ok, base);
// verify our results
QVERIFY(ok == true);
QVERIFY(v = v2);

// create a name
QString name("Joe");
// get the day of the week as string
QString weekday = QDate::currentDate().toString("dddd");
// format a text using paramters (%1, %2)
QString hello = QString("Hello %1. Today is %2.").arg(name).arg(weekday);
// This worked on Monday. Promise!
if(Qt::Monday == QDate::currentDate().dayOfWeek()) {
    QCOMPARE(QString("Hello Joe. Today is Monday."), hello);
} else {
    QVERIFY(QString("Hello Joe. Today is Monday.") !=  hello);
}

// Create a unicode character using the unicode for smile :-)
QChar smile(0x263A);
// you should see a :-) on you console
qDebug() << smile;
// Use a unicode in a string
QChar smile2 = QString("\u263A").at(0);
QVERIFY(smile == smile2);
// Create 12 smiles in a vector
QVector<QChar> smilies(12);
smilies.fill(smile);
// Can you see the smiles
qDebug() << smilies;

// Create a simple list of ints using the new C++11 initialization
// for this you need to add "CONFIG += c++11" to your pro file.
QList<int> list{1,2};

// append another int
list << 3;

// We are using scopes to avoid variable name clashes

{ // iterate through list using Qt for each
    int sum(0);
    foreach (int v, list) {
        sum += v;
    }
    QVERIFY(sum == 6);
}
{ // iterate through list using C++ 11 range based loop
    int sum = 0;
    for(int v : list) {
        sum+= v;
    }
    QVERIFY(sum == 6);
}

{ // iterate through list using JAVA style iterators
    int sum = 0;
    QListIterator<int> i(list);

    while (i.hasNext()) {
        sum += i.next();
    }
    QVERIFY(sum == 6);
}

{ // iterate through list using STL style iterator
    int sum = 0;
    QList<int>::iterator i;
    for (i = list.begin(); i != list.end(); ++i) {
        sum += *i;
    }
    QVERIFY(sum == 6);
}


// using std::sort with mutable iterator using C++11
// list will be sorted in descending order
std::sort(list.begin(), list.end(), [](int a, int b) { return a > b; });
QVERIFY(list == QList<int>({3,2,1}));


int value = 3;
{ // using std::find with const iterator
    QList<int>::const_iterator result = std::find(list.constBegin(), list.constEnd(), value);
    QVERIFY(*result == value);
}

{ // using std::find using C++ lambda and C++ 11 auto variable
    auto result = std::find_if(list.constBegin(), list.constBegin(), [value](int v) { return v == value; });
    QVERIFY(*result == value);
}

QHash<QString, int> hash({{"b",2},{"c",3},{"a",1}});
qDebug() << hash.keys(); // a,b,c - unordered
qDebug() << hash.values(); // 1,2,3 - unordered but same as order as keys

QVERIFY(hash["a"] == 1);
QVERIFY(hash.value("a") == 1);
QVERIFY(hash.contains("c") == true);

{ // JAVA iterator
    int sum =0;
    QHashIterator<QString, int> i(hash);
    while (i.hasNext()) {
        i.next();
        sum+= i.value();
        qDebug() << i.key() << " = " << i.value();
    }
    QVERIFY(sum == 6);
}

{ // STL iterator
    int sum = 0;
    QHash<QString, int>::const_iterator i = hash.constBegin();
    while (i != hash.constEnd()) {
        sum += i.value();
        qDebug() << i.key() << " = " << i.value();
        i++;
    }
    QVERIFY(sum == 6);
}

hash.insert("d", 4);
QVERIFY(hash.contains("d") == true);
hash.remove("d");
QVERIFY(hash.contains("d") == false);

{ // hash find not successfull
    QHash<QString, int>::const_iterator i = hash.find("e");
    QVERIFY(i == hash.end());
}

{ // hash find successfull
    QHash<QString, int>::const_iterator i = hash.find("c");
    while (i != hash.end()) {
        qDebug() << i.value() << " = " << i.key();
        i++;
    }
}

// QMap
QMap<QString, int> map({{"b",2},{"c",2},{"a",1}});
qDebug() << map.keys(); // a,b,c - ordered ascending

QVERIFY(map["a"] == 1);
QVERIFY(map.value("a") == 1);
QVERIFY(map.contains("c") == true);

// JAVA and STL iterator work same as QHash

QStringList data({"a", "b", "c"});
{ // write binary files
    QFile file("out.bin");
    if(file.open(QIODevice::WriteOnly)) {
        QDataStream stream(&file);
        stream << data;
    }
}
{ // read binary file
    QFile file("out.bin");
    if(file.open(QIODevice::ReadOnly)) {
        QDataStream stream(&file);
        QStringList data2;
        stream >> data2;
        QCOMPARE(data, data2);
    }
}
{ // write text file
    QFile file("out.txt");
    if(file.open(QIODevice::WriteOnly)) {
        QTextStream stream(&file);
        QString sdata = data.join(",");
        stream << sdata;
    }
}
{ // read text file
    QFile file("out.txt");
    if(file.open(QIODevice::ReadOnly)) {
        QTextStream stream(&file);
        QStringList data2;
        QString sdata;
        stream >> sdata;
        data2 = sdata.split(",");
        QCOMPARE(data, data2);
    }
}

ListView {
    // using a integer as model
    model: 5
    delegate: Text { text: 'index: ' + index }
}

ListView {
    // using a JS array as model
    model: ['A', 'B', 'C', 'D', 'E']
    delegate: Text { 'Char['+ index +']: ' + modelData }
}

ListView {
    // using a dynamic QML ListModel as model
    model: ListModel {
        ListElement { char: 'A' }
        ListElement { char: 'B' }
        ListElement { char: 'C' }
        ListElement { char: 'D' }
        ListElement { char: 'E' }
    }
    delegate: Text { 'Char['+ index +']: ' + model.char }
}

#ifndef DATAENTRYMODEL_H
#define DATAENTRYMODEL_H

#include <QtCore>
#include <QtGui>

class DataEntryModel : public QAbstractListModel
{
    Q_OBJECT
public:
    explicit DataEntryModel(QObject *parent = 0);
    ~DataEntryModel();

public: // QAbstractItemModel interface
    virtual int rowCount(const QModelIndex &parent) const;
    virtual QVariant data(const QModelIndex &index, int role) const;
private:
    QList<QString> m_data;
};

#endif // DATAENTRYMODEL_H

#include "dataentrymodel.h"

DataEntryModel::DataEntryModel(QObject *parent)
    : QAbstractListModel(parent)
{
    // initialize our data (QList<QString>) with a list of color names
    m_data = QColor::colorNames();
}

DataEntryModel::~DataEntryModel()
{
}

int DataEntryModel::rowCount(const QModelIndex &parent) const
{
    Q_UNUSED(parent);
    // return our data count
    return m_data.count();
}

QVariant DataEntryModel::data(const QModelIndex &index, int role) const
{
    // the index returns the requested row and column information.
    // we ignore the column and only use the row information
    int row = index.row();

    // boundary check for the row
    if(row < 0 || row >= m_data.count()) {
        return QVariant();
    }

    // A model can return data for different roles.
    // The default role is the display role.
    // it can be accesses in QML with "model.display"
    switch(role) {
        case Qt::DisplayRole:
            // Return the color name for the particular row
            // Qt automatically converts it to the QVariant type
            return m_data.value(row);
    }

    // The view asked for other data, just return an empty QVariant
    return QVariant();
}

#include <QtGui>
#include <QtQml>

#include "dataentrymodel.h"

int main(int argc, char *argv[])
{
    QGuiApplication app(argc, argv);

    // register the type DataEntryModel
    // under the url "org.example" in version 1.0
    // under the name "DataEntryModel"
    qmlRegisterType<DataEntryModel>("org.example", 1, 0, "DataEntryModel");

    QQmlApplicationEngine engine;
    engine.load(QUrl(QStringLiteral("qrc:/main.qml")));

    return app.exec();
}

import org.example 1.0

ListView {
    id: view
    anchors.fill: parent
    model: DataEntryModel {}
    delegate: ListDelegate {
        // use the defined model role "display"
        text: model.display
    }
    highlight: ListHighlight { }
}

#ifndef ROLEENTRYMODEL_H
#define ROLEENTRYMODEL_H

#include <QtCore>
#include <QtGui>

class RoleEntryModel : public QAbstractListModel
{
    Q_OBJECT
public:
    // Define the role names to be used
    enum RoleNames {
        NameRole = Qt::UserRole,
        HueRole = Qt::UserRole+2,
        SaturationRole = Qt::UserRole+3,
        BrightnessRole = Qt::UserRole+4
    };

    explicit RoleEntryModel(QObject *parent = 0);
    ~RoleEntryModel();

    // QAbstractItemModel interface
public:
    virtual int rowCount(const QModelIndex &parent) const override;
    virtual QVariant data(const QModelIndex &index, int role) const override;
protected:
    // return the roles mapping to be used by QML
    virtual QHash<int, QByteArray> roleNames() const override;
private:
    QList<QColor> m_data;
    QHash<int, QByteArray> m_roleNames;
};

#endif // ROLEENTRYMODEL_H

#include "roleentrymodel.h"

RoleEntryModel::RoleEntryModel(QObject *parent)
    : QAbstractListModel(parent)
{
    // Set names to the role name hash container (QHash<int, QByteArray>)
    // model.name, model.hue, model.saturation, model.brightness
    m_roleNames[NameRole] = "name";
    m_roleNames[HueRole] = "hue";
    m_roleNames[SaturationRole] = "saturation";
    m_roleNames[BrightnessRole] = "brightness";

    // Append the color names as QColor to the data list (QList<QColor>)
    for(const QString& name : QColor::colorNames()) {
        m_data.append(QColor(name));
    }

}

RoleEntryModel::~RoleEntryModel()
{
}

int RoleEntryModel::rowCount(const QModelIndex &parent) const
{
    Q_UNUSED(parent);
    return m_data.count();
}

QVariant RoleEntryModel::data(const QModelIndex &index, int role) const
{
    int row = index.row();
    if(row < 0 || row >= m_data.count()) {
        return QVariant();
    }
    const QColor& color = m_data.at(row);
    qDebug() << row << role << color;
    switch(role) {
    case NameRole:
        // return the color name as hex string (model.name)
        return color.name();
    case HueRole:
        // return the hue of the color (model.hue)
        return color.hueF();
    case SaturationRole:
        // return the saturation of the color (model.saturation)
        return color.saturationF();
    case BrightnessRole:
        // return the brightness of the color (model.brightness)
        return color.lightnessF();
    }
    return QVariant();
}

QHash<int, QByteArray> RoleEntryModel::roleNames() const
{
    return m_roleNames;
}

ListView {
    id: view
    anchors.fill: parent
    model: RoleEntryModel {}
    focus: true
    delegate: ListDelegate {
        text: 'hsv(' +
              Number(model.hue).toFixed(2) + ',' +
              Number(model.saturation).toFixed() + ',' +
              Number(model.brightness).toFixed() + ')'
        color: model.name
    }
    highlight: ListHighlight { }
}

// inserts a color at the index (0 at begining, count-1 at end)
Q_INVOKABLE void insert(int index, const QString& colorValue);
// uses insert to insert a color at the end
Q_INVOKABLE void append(const QString& colorValue);
// removes a color from the index
Q_INVOKABLE void remove(int index);
// clear the whole model (e.g. reset)
Q_INVOKABLE void clear();

// gives the size of the model
Q_PROPERTY(int count READ count NOTIFY countChanged)
// gets a color at the index
Q_INVOKABLE QColor get(int index);

void DynamicEntryModel::insert(int index, const QString &colorValue)
{
    if(index < 0 || index > m_data.count()) {
        return;
    }
    QColor color(colorValue);
    if(!color.isValid()) {
        return;
    }
    // view protocol (begin => manipulate => end]
    emit beginInsertRows(QModelIndex(), index, index);
    m_data.insert(index, color);
    emit endInsertRows();
    // update our count property
    emit countChanged(m_data.count());
}

void DynamicEntryModel::append(const QString &colorValue)
{
    insert(count(), colorValue);
}

void DynamicEntryModel::remove(int index)
{
    if(index < 0 || index >= m_data.count()) {
        return;
    }
    emit beginRemoveRows(QModelIndex(), index, index);
    m_data.removeAt(index);
    emit endRemoveRows();
    // do not forget to update our count property
    emit countChanged(m_data.count());
}

QColor DynamicEntryModel::get(int index)
{
    if(index < 0 || index >= m_data.count()) {
        return QColor();
    }
    return m_data.at(index);
}

import QtQuick
import QtQuick.Window
import QtQuick.Controls
import QtQuick.Layouts

// our module
import org.example 1.0

Window {
    visible: true
    width: 480
    height: 480

    Background { // a dark background
        id: background
    }

    // our dyanmic model
    DynamicEntryModel {
        id: dynamic
        onCountChanged: {
            // we print out count and the last entry when count is changing
            print('new count: ' + dynamic.count)
            print('last entry: ' + dynamic.get(dynamic.count - 1))
        }
    }

    ColumnLayout {
        anchors.fill: parent
        anchors.margins: 8
        ScrollView {
            Layout.fillHeight: true
            Layout.fillWidth: true
            ListView {
                id: view
                // set our dynamic model to the views model property
                model: dynamic
                delegate: ListDelegate {
                    required property var model
                    width: ListView.view.width
                    // construct a string based on the models proeprties
                    text: 'hsv(' +
                          Number(model.hue).toFixed(2) + ',' +
                          Number(model.saturation).toFixed() + ',' +
                          Number(model.brightness).toFixed() + ')'
                    // sets the font color of our custom delegates
                    color: model.name

                    onClicked: {
                        // make this delegate the current item
                        view.currentIndex = model.index
                        view.focus = true
                    }
                    onRemove: {
                        // remove the current entry from the model
                        dynamic.remove(model.index)
                    }
                }
                highlight: ListHighlight { }
                // some fun with transitions :-)
                add: Transition {
                    // applied when entry is added
                    NumberAnimation {
                        properties: "x"; from: -view.width;
                        duration: 250; easing.type: Easing.InCirc
                    }
                    NumberAnimation { properties: "y"; from: view.height;
                        duration: 250; easing.type: Easing.InCirc
                    }
                }
                remove: Transition {
                    // applied when entry is removed
                    NumberAnimation {
                        properties: "x"; to: view.width;
                        duration: 250; easing.type: Easing.InBounce
                    }
                }
                displaced: Transition {
                    // applied when entry is moved
                    // (e.g because another element was removed)
                    SequentialAnimation {
                        // wait until remove has finished
                        PauseAnimation { duration: 250 }
                        NumberAnimation { properties: "y"; duration: 75
                        }
                    }
                }
            }
        }
        TextEntry {
            id: textEntry
            onAppend: function (color) {
                // called when the user presses return on the text field
                // or clicks the add button
                dynamic.append(color)
            }

            onUp: {
                // called when the user presses up while the text field is focused
                view.decrementCurrentIndex()
            }
            onDown: {
                // same for down
                view.incrementCurrentIndex()
            }
        }
    }
}