/*
 * Squawk messenger. 
 * Copyright (C) 2019  Yury Gubich <blue@macaw.me>
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

#include "conversation.h"
#include "ui_conversation.h"

#include <QDebug>
#include <QClipboard>
#include <QScrollBar>
#include <QTimer>
#include <QFileDialog>
#include <QMimeDatabase>
#include <QAbstractTextDocumentLayout>
#include <QApplication>
#include <QTemporaryFile>
#include <QDir>
#include <QMenu>
#include <QBitmap>

#include <unistd.h>
#include <algorithm>

#include "shared/icons.h"
#include "shared/utils.h"
#include "shared/pathcheck.h"
#include "shared/defines.h"

constexpr QSize avatarSize(50, 50);

Conversation::Conversation(bool muc, Models::Account* acc, Models::Element* el, const QString pJid, const QString pRes, QWidget* parent):
    QWidget(parent),
    isMuc(muc),
    account(acc),
    element(el),
    palJid(pJid),
    activePalResource(pRes),
    m_ui(new Ui::Conversation()),
    ker(),
    thread(),
    statusIcon(0),
    statusLabel(0),
    filesLayout(0),
    overlay(new QWidget()),
    filesToAttach(),
    feed(new FeedView()),
    delegate(new MessageDelegate(this)),
    manualSliderChange(false),
    tsb(QApplication::style()->styleHint(QStyle::SH_ScrollBar_Transient) == 1),
    pasteImageAction(new QAction(tr("Paste Image"), this)),
    shadow(10, 1, Qt::black, this),
    contextMenu(new QMenu()),
    currentAction(CurrentAction::none),
    currentMessageId()
{
    createUI();
    createFeed();
    subscribeEvents();
    initializeOverlay();
}

Conversation::~Conversation() {
    delete contextMenu;
    
    element->feed->decrementObservers();
    delete m_ui;
}

void Conversation::createFeed() {
    feed->setItemDelegate(delegate);
    feed->setFrameShape(QFrame::NoFrame);
    feed->setContextMenuPolicy(Qt::CustomContextMenu);
    feed->setModel(element->feed);
    element->feed->incrementObservers();
    m_ui->widget->layout()->addWidget(feed);

    connect(element->feed, &Models::MessageFeed::newMessage, this, &Conversation::onFeedMessage);
    connect(feed, &FeedView::resized, this, &Conversation::positionShadow);
    connect(feed, &FeedView::customContextMenuRequested, this, &Conversation::onFeedContext);
}

void Conversation::createUI() {
    m_ui->setupUi(this);
    statusIcon = m_ui->statusIcon;
    statusLabel = m_ui->statusLabel;

    filesLayout = new FlowLayout(m_ui->filesPanel, 0);
    m_ui->filesPanel->setLayout(filesLayout);

    m_ui->currentActionBadge->setVisible(false);
    m_ui->encryptionButton->setVisible(false);

    shadow.setFrames(true, false, true, false);
}

void Conversation::subscribeEvents() {
    connect(account, &Models::Account::childChanged, this, &Conversation::onAccountChanged);
    connect(&ker, &KeyEnterReceiver::enterPressed, this, qOverload<>(&Conversation::initiateMessageSending));
    connect(&ker, &KeyEnterReceiver::imagePasted, this, &Conversation::onImagePasted);
    connect(m_ui->sendButton, &QPushButton::clicked, this, qOverload<>(&Conversation::initiateMessageSending));
    connect(m_ui->attachButton, &QPushButton::clicked, this, &Conversation::onAttach);
    connect(m_ui->clearButton, &QPushButton::clicked, this, &Conversation::clear);
    connect(m_ui->messageEditor->document()->documentLayout(), &QAbstractTextDocumentLayout::documentSizeChanged,
            this, &Conversation::onTextEditDocSizeChanged);
    connect(m_ui->encryptionButton, &QPushButton::clicked, this, &Conversation::onEncryptionButtonClicked);

    m_ui->messageEditor->installEventFilter(&ker);

    connect(m_ui->messageEditor, &QTextEdit::customContextMenuRequested, this, &Conversation::onMessageEditorContext);
    connect(pasteImageAction, &QAction::triggered, this, &Conversation::onImagePasted);

    connect(m_ui->currentActionBadge, &Badge::closeClicked, this, &Conversation::clear);
}

void Conversation::onAccountChanged(Models::Item* item, int row, int col) {
    SHARED_UNUSED(row);
    if (item == account) {
        if (col == 2 && account->getState() == Shared::ConnectionState::connected) {        //to request the history when we're back online after reconnect
            //if (!requestingHistory) {
                //requestingHistory = true;
                //line->showBusyIndicator();
                //emit requestArchive("");
                //scroll = down;
            //}
        }
    }
}

void Conversation::initializeOverlay() {
    QGridLayout* gr = static_cast<QGridLayout*>(layout());
    QLabel* progressLabel = new QLabel(tr("Drop files here to attach them to your message"));
    gr->addWidget(overlay, 0, 0, 2, 1);
    QVBoxLayout* nl = new QVBoxLayout();
    QGraphicsOpacityEffect* opacity = new QGraphicsOpacityEffect();
    opacity->setOpacity(0.8);
    overlay->setLayout(nl);
    overlay->setBackgroundRole(QPalette::Base);
    overlay->setAutoFillBackground(true);
    overlay->setGraphicsEffect(opacity);
    progressLabel->setAlignment(Qt::AlignCenter);
    QFont pf = progressLabel->font();
    pf.setBold(true);
    pf.setPointSize(26);
    progressLabel->setWordWrap(true);
    progressLabel->setFont(pf);
    nl->addStretch();
    nl->addWidget(progressLabel);
    nl->addStretch();
    overlay->hide();
}

void Conversation::setName(const QString& name) {
    m_ui->nameLabel->setText(name);
    setWindowTitle(name);
}

QString Conversation::getAccount() const {
    return account->getName();
}

QString Conversation::getJid() const {
    return palJid;
}

KeyEnterReceiver::KeyEnterReceiver(QObject* parent): QObject(parent), ownEvent(false) {}

bool KeyEnterReceiver::eventFilter(QObject* obj, QEvent* event) {
    QEvent::Type type = event->type();
    if (type == QEvent::KeyPress) {
        QKeyEvent* key = static_cast<QKeyEvent*>(event);
        int k = key->key();
        if (k == Qt::Key_Enter || k == Qt::Key_Return) {
            Qt::KeyboardModifiers mod = key->modifiers();
            if (mod & Qt::ControlModifier) {
                mod = mod & ~Qt::ControlModifier;
                QKeyEvent* nEvent = new QKeyEvent(event->type(), k, mod, key->text(), key->isAutoRepeat(), key->count());
                QCoreApplication::postEvent(obj, nEvent);
                ownEvent = true;
                return true;
            } else {
                if (ownEvent) {
                    ownEvent = false;
                } else {
                    emit enterPressed();
                    return true;
                }
            }
        }
        if (k == Qt::Key_V && key->modifiers() & Qt::CTRL) {
            if (Conversation::checkClipboardImage()) {
                emit imagePasted();
                return true;
            }
        }
    }
    return QObject::eventFilter(obj, event);
}

bool Conversation::checkClipboardImage() {
    return !QApplication::clipboard()->image().isNull();
}

QString Conversation::getPalResource() const {
    return activePalResource;
}

void Conversation::setPalResource(const QString& res) {
    activePalResource = res;
}

void Conversation::initiateMessageSending() {
    QString body(m_ui->messageEditor->toPlainText());
    
    if (body.size() > 0) {
        Shared::Message msg = createMessage();
        msg.setBody(body);
        initiateMessageSending(msg);
    }
    if (filesToAttach.size() > 0) {
        for (const Badge* badge : filesToAttach) {
            Shared::Message msg = createMessage();
            msg.setAttachPath(badge->id);
            element->feed->registerUpload(msg.getId());
            initiateMessageSending(msg);
        }
    }
    clear();
}

void Conversation::initiateMessageSending(const Shared::Message& msg) {
    if (currentAction == CurrentAction::edit) {
        emit replaceMessage(currentMessageId, msg);
        currentAction = CurrentAction::none;
    } else {
        emit sendMessage(msg);
    }
}

void Conversation::onImagePasted() {
    QImage image = QApplication::clipboard()->image();
    if (image.isNull())
        return;

    QTemporaryFile *tempFile = new QTemporaryFile(QDir::tempPath() + QStringLiteral("/squawk_img_attach_XXXXXX.png"), QApplication::instance());
    tempFile->open();
    image.save(tempFile, "PNG");
    tempFile->close();
    qDebug() << "image on paste temp file: " << tempFile->fileName();
    addAttachedFile(tempFile->fileName());

    // The file, if successfully uploaded, will be copied to Download folder.
    // On application closing, this temporary file will be automatically removed by Qt.
    // See Core::NetworkAccess::onUploadFinished.
}

void Conversation::onAttach() {
    QFileDialog* d = new QFileDialog(this, tr("Chose a file to send"));
    d->setFileMode(QFileDialog::ExistingFile);
    
    connect(d, &QFileDialog::accepted, this, &Conversation::onFileSelected);
    connect(d, &QFileDialog::rejected, d, &QFileDialog::deleteLater);
    
    d->show();
}

void Conversation::onFileSelected() {
    QFileDialog* d = static_cast<QFileDialog*>(sender());
    for (const QString& path : d->selectedFiles())
        addAttachedFile(path);
    
    d->deleteLater();
}

void Conversation::setStatus(const QString& status) {
    statusLabel->setText(Shared::processMessageBody(status));
}

Models::Roster::ElId Conversation::getId() const {
    return {getAccount(), getJid()};
}

void Conversation::addAttachedFile(const QString& path) {
    std::vector<Badge*>::const_iterator itr = std::find_if(
        filesToAttach.begin(),
        filesToAttach.end(),
        [&path] (const Badge* badge) {return badge->id == path;}
    );
    if (itr != filesToAttach.end())
        return;

    QMimeDatabase db;
    QMimeType type = db.mimeTypeForFile(path);
    QFileInfo info(path);

    QIcon fileIcon = QIcon::fromTheme(type.iconName());
    if (fileIcon.isNull())
        fileIcon.addFile(QString::fromUtf8(":/images/fallback/dark/big/mail-attachment.svg"), QSize(), QIcon::Normal, QIcon::Off);

    Badge* badge = new Badge(path, info.fileName(), fileIcon);
    filesToAttach.push_back(badge);
    
    connect(badge, &Badge::closeClicked, this, &Conversation::onBadgeClose);
    filesLayout->addWidget(badge);
    if (filesLayout->count() == 1)
        filesLayout->setContentsMargins(3, 3, 3, 3);
}

void Conversation::removeAttachedFile(const QString& id) {
    std::vector<Badge*>::const_iterator itr = std::find_if(
        filesToAttach.begin(),
        filesToAttach.end(),
        [&id] (const Badge* badge) {return badge->id == id;}
    );
    if (itr != filesToAttach.end()) {
        Badge* badge = *itr;
        filesToAttach.erase(itr);
        if (filesLayout->count() == 1)
            filesLayout->setContentsMargins(0, 0, 0, 0);

        badge->deleteLater();
    }
}

void Conversation::onBadgeClose() {
    Badge* badge = static_cast<Badge*>(sender());
    removeAttachedFile(badge->id);
}

void Conversation::clearAttachedFiles() {
    for (Badge* badge : filesToAttach)
        badge->deleteLater();

    filesToAttach.clear();
    filesLayout->setContentsMargins(0, 0, 0, 0);
}

void Conversation::clear() {
    currentMessageId.clear();
    currentAction = CurrentAction::none;
    m_ui->currentActionBadge->setVisible(false);
    clearAttachedFiles();
    m_ui->messageEditor->clear();
}

void Conversation::onEncryptionButtonClicked() {}

void Conversation::setAvatar(const QString& path) {
    QPixmap pixmap;
    if (path.size() == 0)
        pixmap = Shared::icon("user", true).pixmap(avatarSize);
    else
        pixmap = QPixmap(path).scaled(avatarSize, Qt::KeepAspectRatio, Qt::SmoothTransformation);

    QPixmap result(avatarSize);
    result.fill(Qt::transparent);
    QPainter painter(&result);
    painter.setRenderHint(QPainter::Antialiasing);
    painter.setRenderHint(QPainter::SmoothPixmapTransform);
    QPainterPath maskPath;
    maskPath.addEllipse(0, 0, avatarSize.width(), avatarSize.height());
    painter.setClipPath(maskPath);
    painter.drawPixmap(0, 0, pixmap);

    m_ui->avatar->setPixmap(result);
}

void Conversation::onTextEditDocSizeChanged(const QSizeF& size) {
    m_ui->messageEditor->setMaximumHeight(int(size.height()));
}

void Conversation::setFeedFrames(bool top, bool right, bool bottom, bool left) {
    shadow.setFrames(top, right, bottom, left);
}

void Conversation::dragEnterEvent(QDragEnterEvent* event) {
    bool accept = false;
    if (event->mimeData()->hasUrls()) {
        QList<QUrl> list = event->mimeData()->urls();
        for (const QUrl& url : list) {
            if (url.isLocalFile()) {
                QFileInfo info(url.toLocalFile());
                if (info.isReadable() && info.isFile()) {
                    accept = true;
                    break;
                }
            }
        }
    }
    if (accept) {
        event->acceptProposedAction();
        overlay->show();
    }
}

void Conversation::dragLeaveEvent(QDragLeaveEvent* event) {
    SHARED_UNUSED(event);
    overlay->hide();
}

void Conversation::dropEvent(QDropEvent* event) {
    bool accept = false;
    if (event->mimeData()->hasUrls()) {
        QList<QUrl> list = event->mimeData()->urls();
        for (const QUrl& url : list) {
            if (url.isLocalFile()) {
                QFileInfo info(url.toLocalFile());
                if (info.isReadable() && info.isFile()) {
                    addAttachedFile(info.canonicalFilePath());
                    accept = true;
                }
            }
        }
    }
    if (accept)
        event->acceptProposedAction();

    overlay->hide();
}

Shared::Message Conversation::createMessage() const {
    Shared::Message msg;
    msg.setOutgoing(true);
    msg.generateRandomId();
    msg.setCurrentTime();
    msg.setState(Shared::Message::State::pending);
    return msg;
}

void Conversation::onFeedMessage(const Shared::Message& msg) {
    this->onMessage(msg);
}

void Conversation::onMessage(const Shared::Message& msg) {
    if (!msg.getForwarded()) {
        QApplication::alert(this);
        if (window()->windowState().testFlag(Qt::WindowMinimized))
            emit notifyableMessage(getAccount(), msg);

    }
}

void Conversation::positionShadow() {
    int w = width();
    int h = feed->height();
    
    shadow.resize(w, h);
    shadow.move(feed->pos());
    shadow.raise();
}

void Conversation::onFeedContext(const QPoint& pos) {
    QModelIndex index = feed->indexAt(pos);
    if (index.isValid()) {
        Shared::Message* item = static_cast<Shared::Message*>(index.internalPointer());
        
        contextMenu->clear();
        QString id = item->getId();
        bool showMenu = false;
        if (item->getState() == Shared::Message::State::error) {
            showMenu = true;
            QAction* resend = contextMenu->addAction(Shared::icon("view-refresh"), tr("Try sending again")); 
            connect(resend, &QAction::triggered, [this, id]() {
                element->feed->registerUpload(id);
                emit resendMessage(id);
            });
        }

        QString selected = feed->getSelectedText();
        if (selected.size() > 0) {
            showMenu = true;
            QAction* copy = contextMenu->addAction(Shared::icon("edit-copy"), tr("Copy selected"));
            connect(copy, &QAction::triggered, [selected] () {
                QClipboard* cb = QApplication::clipboard();
                cb->setText(selected);
            });
        }

        QString body = item->getBody();
        if (body.size() > 0) {
            showMenu = true;
            QAction* copy = contextMenu->addAction(Shared::icon("edit-copy"), tr("Copy message"));
            connect(copy, &QAction::triggered, [body] () {
                QClipboard* cb = QApplication::clipboard();
                cb->setText(body);
            });
        }
        
        QString path = Shared::resolvePath(item->getAttachPath());
        if (!path.isEmpty()) {
            showMenu = true;
            QAction* open = contextMenu->addAction(Shared::icon("document-preview"), tr("Open")); 
            connect(open, &QAction::triggered, [path]() {
                QDesktopServices::openUrl(QUrl::fromLocalFile(path));
            });
            
            QAction* show = contextMenu->addAction(Shared::icon("folder"), tr("Show in folder")); 
            connect(show, &QAction::triggered, [path]() {
                Shared::Global::highlightInFileManager(path);
            });
        }

        bool hasAttach = !item->getAttachPath().isEmpty() || !item->getOutOfBandUrl().isEmpty();
        //the only mandatory condition - is for the message to be outgoing, the rest is just a good intention on the server
        if (item->getOutgoing() && !hasAttach  && index.row() < 100 && item->getTime().daysTo(QDateTime::currentDateTimeUtc()) < 20) {
            showMenu = true;
            QAction* edit = contextMenu->addAction(Shared::icon("edit-rename"), tr("Edit"));
            connect(edit, &QAction::triggered, this, std::bind(&Conversation::onMessageEditRequested, this, id));
        }
        
        if (showMenu)
            contextMenu->popup(feed->viewport()->mapToGlobal(pos));
    }
}

void Conversation::onMessageEditorContext(const QPoint& pos) {
    pasteImageAction->setEnabled(Conversation::checkClipboardImage());

    QMenu *editorMenu = m_ui->messageEditor->createStandardContextMenu();
    editorMenu->addSeparator();
    editorMenu->addAction(pasteImageAction);

    editorMenu->exec(this->m_ui->messageEditor->mapToGlobal(pos));
}

void Conversation::onMessageEditRequested(const QString& id) {
    clear();

    try {
        Shared::Message msg = element->feed->getMessage(id);

        currentMessageId = id;
        m_ui->currentActionBadge->setVisible(true);
        m_ui->currentActionBadge->setText(tr("Editing message..."));
        currentAction = CurrentAction::edit;
        m_ui->messageEditor->setText(msg.getBody());
        QString path = msg.getAttachPath();
        if (path.size() > 0)
            addAttachedFile(path);

    } catch (const Models::MessageFeed::NotFound& e) {
        qDebug() << "The message requested to be edited was not found" << e.getMessage().c_str();
        qDebug() << "Ignoring";
    }
}

void Conversation::showEvent(QShowEvent* event) {
    QWidget::showEvent(event);

    emit shown();
    m_ui->messageEditor->setFocus();
}