/*
 * bigintmandelwidget.cpp
 *
 * This file is covered by the LICENSE file in the root of this project.
 */

#include <QFileDialog>
#include <QLayout>
#include <QMouseEvent>
#include <QPainter>
#include <QPushButton>
#include <QtConcurrent/QtConcurrent>

#include "bigintmandelwidget.h"
#include "mandellabel.h"
#include "menubar.h"
#include "settingswidget.h"

BigintMandelWidget::BigintMandelWidget(QWidget *parent)
:   QWidget(parent),
    fw(new QFutureWatcher<MandelResultCell>(this)),
    settings(128, QSize(502, 334)),
    menu_bar(new MenuBar(this)),
    scroll_area(new QScrollArea(this)),
    mandel_label(new MandelLabel(this)),
    status_bar(new QStatusBar(this)),
    settings_widget(new SettingsWidget(this))
{
    scroll_area->setWidget(mandel_label);
    connect(
        settings_widget,
        &QDialog::accepted,
        this,
        &BigintMandelWidget::settings_widget_accepted
    );
    connect(
        fw,
        &QFutureWatcher<MandelResultCell>::resultReadyAt,
        this,
        &BigintMandelWidget::finished_cell
    );
    connect(
        fw,
        &QFutureWatcher<MandelResultCell>::finished,
        this,
        &BigintMandelWidget::finished
    );
    setLayout(new QVBoxLayout());
    layout()->addWidget(menu_bar);
    layout()->addWidget(scroll_area);
    status_bar->setSizeGripEnabled(false);
    layout()->addWidget(status_bar);
    mandel_label->resize(settings.get_params().get_size());
    start();
}

BigintMandelWidget::~BigintMandelWidget() {
    stop();
}

void BigintMandelWidget::finished_cell(int num) {
    QSize size = settings.get_params().get_size();
    int y = num / size.width() + 1;
    mandel_label->set_draw_progress(y < size.height() - 1 ? y + 1 : -1);
    settings.finished_cell(num, fw->resultAt(num));
    update();
}

void BigintMandelWidget::finished() {
    mandel_label->set_draw_progress(-1);
    update();
}

void BigintMandelWidget::update_status_bar() {
    QTextStream ss;
    static int prev_num_threads = -1;
    int num_threads;
    if (fw->isFinished())
        num_threads = -1;
    else
        num_threads = QThreadPool::globalInstance()->activeThreadCount();
    if (num_threads == prev_num_threads)
        return;
    ss.setString(new QString());
    if (num_threads != -1)
        ss << "Calculating with " << num_threads << " threads ...";
    else if (settings.get_zoom_factor() == -1)
        ss << "Choose a zoom factor from the \"Zoom\" menu.";
    else
        ss << "Click the rendering to zoom.";
    status_bar->showMessage(*ss.string());
    prev_num_threads = num_threads;
}

void BigintMandelWidget::start() {
    stop();
    fw->setFuture(
        QtConcurrent::mapped(
            settings.get_cells(),
            [](const MandelCell &cell){ return cell.iterate(); }
        )
    );
    settings.set_zoom_factor(-1);
    update();
}

void BigintMandelWidget::stop() {
    fw->cancel();
    fw->waitForFinished();
}

void BigintMandelWidget::mousePressEvent(QMouseEvent *event) {
    QSize size(settings.get_params().get_size());
    QPoint pos(event->pos());
    QWidget *w;
    int zoom_factor = settings.get_zoom_factor();
    for (w = mandel_label; w != this; w = w->parentWidget())
        pos = w->mapFromParent(pos);
    if (event->button() != Qt::MouseButton::LeftButton
            || !fw->isFinished()
            || pos.x() < 0
            || pos.x() >= size.width()
            || pos.y() < 0
            || pos.y() >= size.height()
            || zoom_factor == -1)
        return;
    settings.zoom(get_ideal_size(), zoom_factor, pos);
    start();
}

static inline QString get_save_file_name(
    QWidget *parent = nullptr,
    const QString &caption = QString(),
    const QString &dir = QString(),
    const QString &filter_title = QString(),
    const QStringList &ext_list = QStringList{},
    const QString default_ext = QString()
) {
    QTextStream ss(new QString());
    QStringList::const_iterator ext_list_iter;
    QString file_name;
    ss << filter_title << " (" << ext_list.join(" ") << ")";
    file_name = QFileDialog::getSaveFileName(
        parent, caption, dir, *ss.string()
    );
    if (file_name.isEmpty())
        return file_name;
    ss.string()->clear();
    ss << file_name;
    for (
        ext_list_iter = ext_list.constBegin();
        ext_list_iter != ext_list.constEnd();
        ext_list_iter++
    )
        if (file_name.endsWith(*ext_list_iter))
            break;
    if (ext_list_iter == ext_list.constEnd())
        ss << default_ext;
    return *ss.string();
}

void BigintMandelWidget::export_img() {
    QString file_name = get_save_file_name(
        this,
        "Save image",
        "",
        "Images",
        QStringList{".png", ".xpm", ".jpg"},
        ".png"
    );
    if (!file_name.isEmpty())
        settings.save_img(file_name);
}

void BigintMandelWidget::exec_settings_widget() {
    settings_widget->update_params(settings.get_params());
    settings_widget->exec();
}

void BigintMandelWidget::reset() {
    settings.reset(128, get_ideal_size());
    start();
}

void BigintMandelWidget::settings_widget_accepted() {
    if (settings_widget->is_clear_image_checked()) {
        settings.set_params(settings_widget->get_params());
        settings.clear();
    } else {
        quint64 max_iter = settings_widget->get_max_iter();
        if (max_iter <= settings.get_max_iter())
            return;
        settings.set_max_iter(max_iter);
    }
    start();
}

void BigintMandelWidget::load_data() {
    QFile file;
    QJsonObject json;
    QByteArray qba;
    QString file_name = QFileDialog::getOpenFileName(
        this, "Load Data", "", "BigintMandel Data (*.json *.json.qcompress)"
    );
    if (file_name.isEmpty())
        return;
    file.setFileName(file_name);
    if (!file.open(QIODevice::ReadOnly)) {
        qWarning("Couldn't open save file.");
        return;
    }
    qba = file.readAll();
    file.close();
    if (file_name.endsWith(".qcompress"))
        qba = qUncompress(qba);
    settings.from_json(QJsonDocument::fromJson(qba).object());
    update();
}

void BigintMandelWidget::save_data() {
    QFile file;
    QByteArray qba;
    QString file_name = get_save_file_name(
        this,
        "Save data",
        "",
        "Bigintmandel Data",
        QStringList{".json", ".json.qcompress"},
        ".json.qcompress"
    );
    if (file_name.isEmpty())
        return;
    qba = QJsonDocument(settings.to_json()).toJson();
    if (file_name.endsWith(".qcompress"))
        qba = qCompress(qba, 9);
    file.setFileName(file_name);
    if (!file.open(QIODevice::WriteOnly)) {
        qWarning("Couldn't open save file.");
        return;
    }
    file.write(qba);
    file.close();
}

void BigintMandelWidget::update() {
    update_status_bar();
    QWidget::update();
}

void BigintMandelWidget::resize_to_window() {
    QSize size = get_ideal_size();
    if (size == settings.get_params().get_size())
        return;
    settings.set_size(size);
    settings.clear();
    start();
}