#include "vutils.h"
#include <QFile>
#include <QDir>
#include <QDebug>
#include <QRegExp>
#include <QClipboard>
#include <QApplication>
#include <QMimeData>
#include <QJsonObject>
#include <QJsonDocument>
#include <QDateTime>
#include <QFileInfo>
#include <QImageReader>
#include <QKeyEvent>
#include <QScreen>
#include <cmath>
#include <QLocale>
#include <QPushButton>
#include <QElapsedTimer>
#include <QValidator>
#include <QRegExpValidator>
#include <QRegExp>

#include "vfile.h"
#include "vnote.h"

extern VConfigManager vconfig;

QVector<QPair<QString, QString>> VUtils::s_availableLanguages;

const QString VUtils::c_imageLinkRegExp = QString("\\!\\[([^\\]]*)\\]\\(([^\\)\"]+)\\s*(\"(\\\\.|[^\"\\)])*\")?\\s*\\)");

const QString VUtils::c_fileNameRegExp = QString("[^\\\\/:\\*\\?\"<>\\|]*");

const QString VUtils::c_fencedCodeBlockStartRegExp = QString("^(\\s*)```([^`\\s]*)\\s*[^`]*$");

const QString VUtils::c_fencedCodeBlockEndRegExp = QString("^(\\s*)```$");

VUtils::VUtils()
{
}

void VUtils::initAvailableLanguage()
{
    if (!s_availableLanguages.isEmpty()) {
        return;
    }

    s_availableLanguages.append(QPair<QString, QString>("en_US", "English (US)"));
    s_availableLanguages.append(QPair<QString, QString>("zh_CN", "Chinese"));
}

QString VUtils::readFileFromDisk(const QString &filePath)
{
    QFile file(filePath);
    if (!file.open(QIODevice::ReadOnly | QIODevice::Text)) {
        qWarning() << "fail to read file" << filePath;
        return QString();
    }
    QString fileText(file.readAll());
    file.close();
    qDebug() << "read file content:" << filePath;
    return fileText;
}

bool VUtils::writeFileToDisk(const QString &filePath, const QString &text)
{
    QFile file(filePath);
    if (!file.open(QIODevice::WriteOnly | QIODevice::Text)) {
        qWarning() << "fail to open file" << filePath << "to write";
        return false;
    }
    QTextStream stream(&file);
    stream << text;
    file.close();
    qDebug() << "write file content:" << filePath;
    return true;
}

QRgb VUtils::QRgbFromString(const QString &str)
{
    Q_ASSERT(str.length() == 6);
    QString rStr = str.left(2);
    QString gStr = str.mid(2, 2);
    QString bStr = str.right(2);

    bool ok, ret = true;
    int red = rStr.toInt(&ok, 16);
    ret = ret && ok;
    int green = gStr.toInt(&ok, 16);
    ret = ret && ok;
    int blue = bStr.toInt(&ok, 16);
    ret = ret && ok;

    if (ret) {
        return qRgb(red, green, blue);
    }
    qWarning() << "fail to construct QRgb from string" << str;
    return QRgb();
}

QString VUtils::generateImageFileName(const QString &path, const QString &title,
                                      const QString &format)
{
    Q_ASSERT(!title.isEmpty());
    QRegExp regExp("\\W");
    QString baseName(title.toLower());

    // Remove non-character chars.
    baseName.remove(regExp);

    // Constrain the length of the name.
    baseName.truncate(10);

    baseName.prepend('_');

    // Add current time and random number to make the name be most likely unique
    baseName = baseName + '_' + QString::number(QDateTime::currentDateTime().toTime_t());
    baseName = baseName + '_' + QString::number(qrand());

    QString imageName = baseName + "." + format.toLower();
    QString filePath = QDir(path).filePath(imageName);
    int index = 1;

    while (QFileInfo::exists(filePath)) {
        imageName = QString("%1_%2.%3").arg(baseName).arg(index++)
                                       .arg(format.toLower());
        filePath = QDir(path).filePath(imageName);
    }

    return imageName;
}

void VUtils::processStyle(QString &style, const QVector<QPair<QString, QString> > &varMap)
{
    // Process style
    for (int i = 0; i < varMap.size(); ++i) {
        const QPair<QString, QString> &map = varMap[i];
        style.replace("@" + map.first, map.second);
    }
}

QString VUtils::fileNameFromPath(const QString &p_path)
{
    if (p_path.isEmpty()) {
        return p_path;
    }

    return QFileInfo(QDir::cleanPath(p_path)).fileName();
}

QString VUtils::basePathFromPath(const QString &p_path)
{
    if (p_path.isEmpty()) {
        return p_path;
    }

    return QFileInfo(QDir::cleanPath(p_path)).path();
}

QVector<ImageLink> VUtils::fetchImagesFromMarkdownFile(VFile *p_file,
                                                       ImageLink::ImageLinkType p_type)
{
    V_ASSERT(p_file->getDocType() == DocType::Markdown);
    QVector<ImageLink> images;

    bool isOpened = p_file->isOpened();
    if (!isOpened && !p_file->open()) {
        return images;
    }

    const QString &text = p_file->getContent();
    if (text.isEmpty()) {
        if (!isOpened) {
            p_file->close();
        }

        return images;
    }

    QRegExp regExp(c_imageLinkRegExp);
    QString basePath = p_file->retriveBasePath();
    int pos = 0;
    while (pos < text.size() && (pos = regExp.indexIn(text, pos)) != -1) {
        QString imageUrl = regExp.capturedTexts()[2].trimmed();

        ImageLink link;
        QFileInfo info(basePath, imageUrl);
        if (info.exists()) {
            if (info.isNativePath()) {
                // Local file.
                link.m_path = QDir::cleanPath(info.absoluteFilePath());

                if (QDir::isRelativePath(imageUrl)) {
                    link.m_type = p_file->isInternalImageFolder(VUtils::basePathFromPath(link.m_path)) ?
                                  ImageLink::LocalRelativeInternal : ImageLink::LocalRelativeExternal;
                } else {
                    link.m_type = ImageLink::LocalAbsolute;
                }
            } else {
                link.m_type = ImageLink::Resource;
                link.m_path = imageUrl;
            }
        } else {
            QUrl url(imageUrl);
            link.m_path = url.toString();
            link.m_type = ImageLink::Remote;
        }

        if (link.m_type & p_type) {
            images.push_back(link);
            qDebug() << "fetch one image:" << link.m_type << link.m_path;
        }

        pos += regExp.matchedLength();
    }

    if (!isOpened) {
        p_file->close();
    }

    return images;
}

bool VUtils::makePath(const QString &p_path)
{
    if (p_path.isEmpty()) {
        return true;
    }

    bool ret = true;
    QDir dir;
    if (dir.mkpath(p_path)) {
        qDebug() << "make path" << p_path;
    } else {
        qWarning() << "fail to make path" << p_path;
        ret = false;
    }

    return ret;
}

ClipboardOpType VUtils::opTypeInClipboard()
{
    QClipboard *clipboard = QApplication::clipboard();
    const QMimeData *mimeData = clipboard->mimeData();

    if (mimeData->hasText()) {
        QString text = mimeData->text();
        QJsonObject clip = QJsonDocument::fromJson(text.toLocal8Bit()).object();
        if (clip.contains("operation")) {
            return (ClipboardOpType)clip["operation"].toInt();
        }
    }
    return ClipboardOpType::Invalid;
}

bool VUtils::copyFile(const QString &p_srcFilePath, const QString &p_destFilePath, bool p_isCut)
{
    QString srcPath = QDir::cleanPath(p_srcFilePath);
    QString destPath = QDir::cleanPath(p_destFilePath);

    if (srcPath == destPath) {
        return true;
    }

    if (p_isCut) {
        QFile file(srcPath);
        if (!file.rename(destPath)) {
            qWarning() << "fail to copy file" << srcPath << destPath;
            return false;
        }
    } else {
        if (!QFile::copy(srcPath, destPath)) {
            qWarning() << "fail to copy file" << srcPath << destPath;
            return false;
        }
    }
    return true;
}

// Copy @p_srcDirPath to be @p_destDirPath.
bool VUtils::copyDirectory(const QString &p_srcDirPath, const QString &p_destDirPath, bool p_isCut)
{
    QString srcPath = QDir::cleanPath(p_srcDirPath);
    QString destPath = QDir::cleanPath(p_destDirPath);
    if (srcPath == destPath) {
        return true;
    }

    // Make a directory
    QDir parentDir(VUtils::basePathFromPath(p_destDirPath));
    QString dirName = VUtils::fileNameFromPath(p_destDirPath);
    if (!parentDir.mkdir(dirName)) {
        qWarning() << QString("fail to create target directory %1: already exists").arg(p_destDirPath);
        return false;
    }

    // Handle sub-dirs recursively and copy files.
    QDir srcDir(p_srcDirPath);
    QDir destDir(p_destDirPath);
    Q_ASSERT(srcDir.exists() && destDir.exists());
    QFileInfoList nodes = srcDir.entryInfoList(QDir::Dirs | QDir::Files | QDir::Hidden
                                               | QDir::NoSymLinks | QDir::NoDotAndDotDot);
    for (int i = 0; i < nodes.size(); ++i) {
        const QFileInfo &fileInfo = nodes.at(i);
        QString name = fileInfo.fileName();
        if (fileInfo.isDir()) {
            if (!copyDirectory(srcDir.filePath(name), destDir.filePath(name), p_isCut)) {
                return false;
            }
        } else {
            Q_ASSERT(fileInfo.isFile());
            if (!copyFile(srcDir.filePath(name), destDir.filePath(name), p_isCut)) {
                return false;
            }
        }
    }

    // Delete the src dir if p_isCut
    if (p_isCut) {
        if (!srcDir.removeRecursively()) {
            qWarning() << "fail to remove directory" << p_srcDirPath;
            return false;
        }
    }
    return true;
}

int VUtils::showMessage(QMessageBox::Icon p_icon, const QString &p_title, const QString &p_text, const QString &p_infoText,
                        QMessageBox::StandardButtons p_buttons, QMessageBox::StandardButton p_defaultBtn, QWidget *p_parent,
                        MessageBoxType p_type)
{
    QMessageBox msgBox(p_icon, p_title, p_text, p_buttons, p_parent);
    msgBox.setInformativeText(p_infoText);
    msgBox.setDefaultButton(p_defaultBtn);

    if (p_type == MessageBoxType::Danger) {
        QPushButton *okBtn = dynamic_cast<QPushButton *>(msgBox.button(QMessageBox::Ok));
        if (okBtn) {
            okBtn->setStyleSheet(vconfig.c_dangerBtnStyle);
        }
    }
    return msgBox.exec();
}

QString VUtils::generateCopiedFileName(const QString &p_dirPath, const QString &p_fileName)
{
    QString suffix;
    QString base = p_fileName;
    int dotIdx = p_fileName.lastIndexOf('.');
    if (dotIdx != -1) {
        // .md
        suffix = p_fileName.right(p_fileName.size() - dotIdx);
        base = p_fileName.left(dotIdx);
    }
    QDir dir(p_dirPath);
    QString name = p_fileName;
    QString filePath = dir.filePath(name);
    int index = 0;
    while (QFile(filePath).exists()) {
        QString seq;
        if (index > 0) {
            seq = QString::number(index);
        }
        index++;
        name = QString("%1_copy%2%3").arg(base).arg(seq).arg(suffix);
        filePath = dir.filePath(name);
    }
    return name;
}

QString VUtils::generateCopiedDirName(const QString &p_parentDirPath, const QString &p_dirName)
{
    QDir dir(p_parentDirPath);
    QString name = p_dirName;
    QString dirPath = dir.filePath(name);
    int index = 0;
    while (QDir(dirPath).exists()) {
        QString seq;
        if (index > 0) {
            seq = QString::number(index);
        }
        index++;
        name = QString("%1_copy%2").arg(p_dirName).arg(seq);
        dirPath = dir.filePath(name);
    }
    return name;
}

const QVector<QPair<QString, QString>>& VUtils::getAvailableLanguages()
{
    if (s_availableLanguages.isEmpty()) {
        initAvailableLanguage();
    }

    return s_availableLanguages;
}

bool VUtils::isValidLanguage(const QString &p_lang)
{
    for (auto const &lang : getAvailableLanguages()) {
        if (lang.first == p_lang) {
            return true;
        }
    }

    return false;
}

bool VUtils::isImageURL(const QUrl &p_url)
{
    QString urlStr;
    if (p_url.isLocalFile()) {
        urlStr = p_url.toLocalFile();
    } else {
        urlStr = p_url.toString();
    }
    return isImageURLText(urlStr);
}

bool VUtils::isImageURLText(const QString &p_url)
{
    QFileInfo info(p_url);
    return QImageReader::supportedImageFormats().contains(info.suffix().toLower().toLatin1());
}

qreal VUtils::calculateScaleFactor()
{
    // const qreal refHeight = 1152;
    // const qreal refWidth = 2048;
    const qreal refDpi = 96;

    qreal dpi = QGuiApplication::primaryScreen()->logicalDotsPerInch();
    qreal factor = dpi / refDpi;
    return factor < 1 ? 1 : factor;
}

bool VUtils::realEqual(qreal p_a, qreal p_b)
{
    return std::abs(p_a - p_b) < 1e-8;
}

QChar VUtils::keyToChar(int p_key)
{
    if (p_key >= Qt::Key_A && p_key <= Qt::Key_Z) {
        return QChar('a' + p_key - Qt::Key_A);
    }
    return QChar();
}

QString VUtils::getLocale()
{
    QString locale = vconfig.getLanguage();
    if (locale == "System" || !isValidLanguage(locale)) {
        locale = QLocale::system().name();
    }
    return locale;
}

void VUtils::sleepWait(int p_milliseconds)
{
    if (p_milliseconds <= 0) {
        return;
    }

    QElapsedTimer t;
    t.start();
    while (t.elapsed() < p_milliseconds) {
        QCoreApplication::processEvents();
    }
}

DocType VUtils::docTypeFromName(const QString &p_name)
{
    static QMap<int, QVector<QString>> suffixes;

    if (suffixes.isEmpty()) {
        QVector<QString> md;
        md << "md" << "markdown" << "mkd";
        suffixes[(int)DocType::Markdown] = md;

        QVector<QString> list;
        list << "ls" << "list";
        suffixes[(int)DocType::List] = list;

        QVector<QString> container;
        container << "co" << "container" << "con";
        suffixes[(int)DocType::Container] = container;
    }

    QString suf = QFileInfo(p_name).suffix().toLower();
    for (auto it = suffixes.begin(); it != suffixes.end(); ++it) {
        if (it.value().contains(suf)) {
            return DocType(it.key());
        }
    }

    return DocType::Html;
}

QString VUtils::generateHtmlTemplate(MarkdownConverterType p_conType, bool p_exportPdf)
{
    QString jsFile, extraFile;
    switch (p_conType) {
    case MarkdownConverterType::Marked:
        jsFile = "qrc" + VNote::c_markedJsFile;
        extraFile = "<script src=\"qrc" + VNote::c_markedExtraFile + "\"></script>\n";
        break;

    case MarkdownConverterType::Hoedown:
        jsFile = "qrc" + VNote::c_hoedownJsFile;
        // Use Marked to highlight code blocks.
        extraFile = "<script src=\"qrc" + VNote::c_markedExtraFile + "\"></script>\n";
        break;

    case MarkdownConverterType::MarkdownIt:
        jsFile = "qrc" + VNote::c_markdownitJsFile;
        extraFile = "<script src=\"qrc" + VNote::c_markdownitExtraFile + "\"></script>\n" +
                    "<script src=\"qrc" + VNote::c_markdownitAnchorExtraFile + "\"></script>\n" +
                    "<script src=\"qrc" + VNote::c_markdownitTaskListExtraFile + "\"></script>\n" +
                    "<script src=\"qrc" + VNote::c_markdownitSubExtraFile + "\"></script>\n" +
                    "<script src=\"qrc" + VNote::c_markdownitSupExtraFile + "\"></script>\n" +
                    "<script src=\"qrc" + VNote::c_markdownitFootnoteExtraFile + "\"></script>\n";
        break;

    case MarkdownConverterType::Showdown:
        jsFile = "qrc" + VNote::c_showdownJsFile;
        extraFile = "<script src=\"qrc" + VNote::c_showdownExtraFile + "\"></script>\n" +
                    "<script src=\"qrc" + VNote::c_showdownAnchorExtraFile + "\"></script>\n";

        break;

    default:
        Q_ASSERT(false);
    }

    if (vconfig.getEnableMermaid()) {
        extraFile += "<link rel=\"stylesheet\" type=\"text/css\" href=\"qrc" + VNote::c_mermaidCssFile + "\"/>\n" +
                     "<script src=\"qrc" + VNote::c_mermaidApiJsFile + "\"></script>\n" +
                     "<script>var VEnableMermaid = true;</script>\n";
    }

    if (vconfig.getEnableFlowchart()) {
        extraFile += "<script src=\"qrc" + VNote::c_raphaelJsFile + "\"></script>\n" +
                     "<script src=\"qrc" + VNote::c_flowchartJsFile + "\"></script>\n" +
                     "<script>var VEnableFlowchart = true;</script>\n";
    }

    if (vconfig.getEnableMathjax()) {
        extraFile += "<script type=\"text/x-mathjax-config\">"
                     "MathJax.Hub.Config({\n"
                     "                    tex2jax: {inlineMath: [['$','$'], ['\\\\(','\\\\)']]},\n"
                     "                    showProcessingMessages: false,\n"
                     "                    messageStyle: \"none\"});\n"
                     "</script>\n"
                     "<script type=\"text/javascript\" async src=\"" + VNote::c_mathjaxJsFile + "\"></script>\n" +
                     "<script>var VEnableMathjax = true;</script>\n";
    }

    if (vconfig.getEnableImageCaption()) {
        extraFile += "<script>var VEnableImageCaption = true;</script>\n";
    }

    QString htmlTemplate;
    if (p_exportPdf) {
        htmlTemplate = VNote::s_markdownTemplatePDF;
    } else {
        htmlTemplate = VNote::s_markdownTemplate;
    }

    htmlTemplate.replace(c_htmlJSHolder, jsFile);
    if (!extraFile.isEmpty()) {
        htmlTemplate.replace(c_htmlExtraHolder, extraFile);
    }

    return htmlTemplate;
}

QString VUtils::getFileNameWithSequence(const QString &p_directory,
                                        const QString &p_baseFileName)
{
    QDir dir(p_directory);
    if (!dir.exists() || !dir.exists(p_baseFileName)) {
        return p_baseFileName;
    }

    // Append a sequence.
    QFileInfo fi(p_baseFileName);
    QString baseName = fi.baseName();
    QString suffix = fi.completeSuffix();
    int seq = 1;
    QString fileName;
    do {
        fileName = QString("%1_%2").arg(baseName).arg(QString::number(seq++), 3, '0');
        if (!suffix.isEmpty()) {
            fileName = fileName + "." + suffix;
        }
    } while (dir.exists(fileName));

    return fileName;
}

bool VUtils::checkPathLegal(const QString &p_path)
{
    // Ensure every part of the p_path is a valid file name until we come to
    // an existing parent directory.
    if (p_path.isEmpty()) {
        return false;
    }

    if (QFileInfo::exists(p_path)) {
#if defined(Q_OS_WIN)
            // On Windows, "/" and ":" will also make exists() return true.
            if (p_path.startsWith('/') || p_path == ":") {
                return false;
            }
#endif

        return true;
    }

    bool ret = false;
    int pos;
    QString basePath = basePathFromPath(p_path);
    QString fileName = fileNameFromPath(p_path);
    QValidator *validator = new QRegExpValidator(QRegExp(c_fileNameRegExp));
    while (!fileName.isEmpty()) {
        QValidator::State validFile = validator->validate(fileName, pos);
        if (validFile != QValidator::Acceptable) {
            break;
        }

        if (QFileInfo::exists(basePath)) {
            ret = true;

#if defined(Q_OS_WIN)
            // On Windows, "/" and ":" will also make exists() return true.
            if (basePath.startsWith('/') || basePath == ":") {
                ret = false;
            }
#endif

            break;
        }

        fileName = fileNameFromPath(basePath);
        basePath = basePathFromPath(basePath);
    }

    delete validator;
    return ret;
}

bool VUtils::equalPath(const QString &p_patha, const QString &p_pathb)
{
    QString a = QDir::cleanPath(p_patha);
    QString b = QDir::cleanPath(p_pathb);

#if defined(Q_OS_WIN)
    a = a.toLower();
    b = b.toLower();
#endif

    return a == b;
}