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/*!
\class QxtCsvModel
\inmodule QxtCore
\brief The QxtCsvModel class provides a QAbstractTableModel for CSV Files
 */



#include "qxtcsvmodel.h"
#include <QFile>
#include <QTextStream>
#include <QDebug>

class QxtCsvModelPrivate : public QxtPrivate<QxtCsvModel>
{
public:
    QxtCsvModelPrivate() : csvData(), header(), maxColumn(0), quoteMode(QxtCsvModel::DefaultQuoteMode)
    {}
    QXT_DECLARE_PUBLIC(QxtCsvModel)

    QList<QStringList> csvData;
    QStringList header;
    int maxColumn;
    QxtCsvModel::QuoteMode quoteMode;
};

/*!
  Creates an empty QxtCsvModel with parent \a parent.
  */
QxtCsvModel::QxtCsvModel(QObject *parent) : QAbstractTableModel(parent)
{
    QXT_INIT_PRIVATE(QxtCsvModel);
}

/*!
  Creates a QxtCsvModel with the parent \a parent and content loaded from \a file.

  See \a setSource for information on the \a withHeader and \a separator properties, or
  if you need control over the quoting method or codec used to parse the file.

  \sa setSource
  */
QxtCsvModel::QxtCsvModel(QIODevice *file, QObject *parent, bool withHeader, QChar separator) : QAbstractTableModel(parent)
{
    QXT_INIT_PRIVATE(QxtCsvModel);
    setSource(file, withHeader, separator);
}

/*!
  \overload 

  Creates a QxtCsvModel with the parent \a parent and content loaded from \a file.

  See \a setSource for information on the \a withHeader and \a separator properties, or
  if you need control over the quoting method or codec used to parse the file.

  \sa setSource
  */
QxtCsvModel::QxtCsvModel(const QString filename, QObject *parent, bool withHeader, QChar separator) : QAbstractTableModel(parent)
{
    QXT_INIT_PRIVATE(QxtCsvModel);
    QFile src(filename);
    setSource(&src, withHeader, separator);
}

QxtCsvModel::~QxtCsvModel()
{}

/*!
    \reimp
 */
int QxtCsvModel::rowCount(const QModelIndex& parent) const
{
    if (parent.row() != -1 && parent.column() != -1) return 0;
    return qxt_d().csvData.count();
}

/*!
    \reimp
 */
int QxtCsvModel::columnCount(const QModelIndex& parent) const
{
    if (parent.row() != -1 && parent.column() != -1) return 0;
    return qxt_d().maxColumn;
}

/*!
    \reimp
 */
QVariant QxtCsvModel::data(const QModelIndex& index, int role) const
{
    if(index.parent() != QModelIndex()) return QVariant();
    if(role == Qt::DisplayRole || role == Qt::EditRole || role == Qt::UserRole) {
        if(index.row() < 0 || index.column() < 0 || index.row() >= rowCount())
            return QVariant();
        const QStringList& row = qxt_d().csvData[index.row()];
        if(index.column() >= row.length())
            return QVariant();
        return row[index.column()];
    }
    return QVariant();
}

/*!
    \reimp
 */
QVariant QxtCsvModel::headerData(int section, Qt::Orientation orientation, int role) const
{
    if(section < qxt_d().header.count() && orientation == Qt::Horizontal && (role == Qt::DisplayRole || role == Qt::EditRole || role == Qt::UserRole))
        return qxt_d().header[section];
    else
        return QAbstractTableModel::headerData(section, orientation, role);
}

/*!
  \overload

  Reads in a CSV file from the provided \a file using \a codec.
  */
void QxtCsvModel::setSource(const QString filename, bool withHeader, QChar separator, QTextCodec* codec)
{
    QFile src(filename);
    setSource(&src, withHeader, separator, codec);
}

/*!
  Reads in a CSV file from the provided \a file using \a codec.

  The value of \a separator will be used to delimit fields, subject to the specified \a quoteMode.
  If \a withHeader is set to true, the first line of the file will be used to populate the model's
  horizontal header.
  
  \sa quoteMode
  */
void QxtCsvModel::setSource(QIODevice *file, bool withHeader, QChar separator, QTextCodec* codec)
{
    QxtCsvModelPrivate* d_ptr = &qxt_d();
    bool headerSet = !withHeader;
    if(!file->isOpen())
        file->open(QIODevice::ReadOnly);
    if(withHeader)
        d_ptr->maxColumn = 0;
    else
        d_ptr->maxColumn = d_ptr->header.size();
    d_ptr->csvData.clear();
    QStringList row;
    QString field;
    QChar quote;
    QChar ch, buffer(0);
    bool readCR = false;
    QTextStream stream(file);
    if(codec) {
        stream.setCodec(codec);
    } else {
        stream.setAutoDetectUnicode(true);
    }
    while(!stream.atEnd()) {
        if(buffer != QChar(0)) {
            ch = buffer; 
            buffer = QChar(0);
        } else {
            stream >> ch;
        }
        if(ch == '\n' && readCR) 
            continue;
        else if(ch == '\r')
            readCR = true;
        else
            readCR = false;
        if(ch != separator && (ch.category() == QChar::Separator_Line || ch.category() == QChar::Separator_Paragraph || ch.category() == QChar::Other_Control)) {
            row << field;
            field.clear();
            if(!row.isEmpty()) {
                if(!headerSet) {
                    d_ptr->header = row;
                    headerSet = true;
                } else {
                    d_ptr->csvData.append(row);
                }
                if(row.length() > d_ptr->maxColumn) {
                    d_ptr->maxColumn = row.length();
                }
            }
            row.clear();
        } else if((d_ptr->quoteMode & DoubleQuote && ch == '"') || (d_ptr->quoteMode & SingleQuote && ch == '\'')) {
            quote = ch;
            do {
                stream >> ch;
                if(ch == '\\' && d_ptr->quoteMode & BackslashEscape) {
                    stream >> ch;
                } else if(ch == quote) {
                    if(d_ptr->quoteMode & TwoQuoteEscape) {
                        stream >> buffer;
                        if(buffer == quote) {
                            buffer = QChar(0);
                            field.append(ch);
                            continue;
                        }
                    }
                    break;
                }
                field.append(ch);
            } while(!stream.atEnd());
        } else if(ch == separator) {
            row << field;
            field.clear();
        } else {
            field.append(ch);
        }
    }
    if(!field.isEmpty()) 
        row << field;
    if(!row.isEmpty()) {
        if(!headerSet)
            d_ptr->header = row;
        else
            d_ptr->csvData.append(row);
    }
    file->close();
}

/*!
  Sets the horizontal headers of the model to the values provided in \a data.
 */
void QxtCsvModel::setHeaderData(const QStringList& data)
{
    qxt_d().header = data;
    emit headerDataChanged(Qt::Horizontal, 0, data.count());
}

/*!
  \reimp
  */
bool QxtCsvModel::setHeaderData(int section, Qt::Orientation orientation, const QVariant& value, int role)
{
    if(orientation != Qt::Horizontal) return false;                   // We don't support the vertical header
    if(role != Qt::DisplayRole && role != Qt::EditRole) return false; // We don't support any other roles
    if(section < 0) return false;                                     // Bogus input
    while(section > qxt_d().header.size()) {
        qxt_d().header << QString();
    }
    qxt_d().header[section] = value.toString();
    emit headerDataChanged(Qt::Horizontal, section, section);
    return true;
}

/*!
    \reimp
 */
bool QxtCsvModel::setData(const QModelIndex& index, const QVariant& data, int role)
{
    if (index.parent() != QModelIndex()) return false;

    if(role == Qt::DisplayRole || role == Qt::EditRole || role == Qt::UserRole) {
        if(index.row() >= rowCount() || index.column() >= columnCount() || index.row() < 0 || index.column() < 0) return false;
        QStringList& row = qxt_d().csvData[index.row()];
        while(row.length() <= index.column())
            row << QString();
        row[index.column()] = data.toString();
        emit dataChanged(index, index);
        return true;
    }
    return false;
}

/*!
    \reimp
 */
bool QxtCsvModel::insertRow(int row, const QModelIndex& parent)
{
    return insertRows(row, 1, parent);
}

/*!
    \reimp
 */
bool QxtCsvModel::insertRows(int row, int count, const QModelIndex& parent)
{
    if (parent != QModelIndex() || row < 0) return false;
    emit beginInsertRows(parent, row, row + count);
    QxtCsvModelPrivate& d_ptr = qxt_d();
    if(row >= rowCount()) {
        for(int i = 0; i < count; i++) d_ptr.csvData << QStringList();
    } else {
        for(int i = 0; i < count; i++) d_ptr.csvData.insert(row, QStringList());
    }
    emit endInsertRows();
    return true;
}

/*!
    \reimp
 */
bool QxtCsvModel::removeRow(int row, const QModelIndex& parent)
{
    return removeRows(row, 1, parent);
}

/*!
    \reimp
 */
bool QxtCsvModel::removeRows(int row, int count, const QModelIndex& parent)
{
    if (parent != QModelIndex() || row < 0) return false;
    if (row >= rowCount()) return false;
    if (row + count >= rowCount()) count = rowCount() - row;
    emit beginRemoveRows(parent, row, row + count);
    QxtCsvModelPrivate& d_ptr = qxt_d();
    for (int i = 0;i < count;i++)
        d_ptr.csvData.removeAt(row);
    emit endRemoveRows();
    return true;
}

/*!
    \reimp
 */
bool QxtCsvModel::insertColumn(int col, const QModelIndex& parent)
{
    return insertColumns(col, 1, parent);
}

/*!
    \reimp
 */
bool QxtCsvModel::insertColumns(int col, int count, const QModelIndex& parent)
{
    if (parent != QModelIndex() || col < 0) return false;
    beginInsertColumns(parent, col, col + count - 1);
    QxtCsvModelPrivate& d_ptr = qxt_d();
    for(int i = 0; i < rowCount(); i++) {
        QStringList& row = d_ptr.csvData[i];
        while(col >= row.length()) row.append(QString());
        for(int j = 0; j < count; j++) {
            row.insert(col, QString());
        }
    }
    for(int i = 0; i < count ;i++)
        d_ptr.header.insert(col, QString());
    d_ptr.maxColumn += count;
    endInsertColumns();
    return true;
}

/*!
    \reimp
 */
bool QxtCsvModel::removeColumn(int col, const QModelIndex& parent)
{
    return removeColumns(col, 1, parent);
}

/*!
    \reimp
 */
bool QxtCsvModel::removeColumns(int col, int count, const QModelIndex& parent)
{
    if (parent != QModelIndex() || col < 0) return false;
    if (col >= columnCount()) return false;
    if (col + count >= columnCount()) count = columnCount() - col;
    emit beginRemoveColumns(parent, col, col + count);
    QxtCsvModelPrivate& d_ptr = qxt_d();
    QString before, after;
    for(int i = 0; i < rowCount(); i++) {
        for(int j = 0; j < count; j++) {
            d_ptr.csvData[i].removeAt(col);
        }
    }
    for(int i = 0; i < count; i++)
        d_ptr.header.removeAt(col);
    emit endRemoveColumns();
    return true;
}

static QString qxt_addCsvQuotes(QxtCsvModel::QuoteMode mode, QString field)
{
    bool addDoubleQuotes = ((mode & QxtCsvModel::DoubleQuote) && field.contains('"'));
    bool addSingleQuotes = ((mode & QxtCsvModel::SingleQuote) && field.contains('\''));
    bool quoteField = (mode & QxtCsvModel::AlwaysQuoteOutput) || addDoubleQuotes || addSingleQuotes;
    if(quoteField && !addDoubleQuotes && !addSingleQuotes) {
        if(mode & QxtCsvModel::DoubleQuote)
            addDoubleQuotes = true;
        else if(mode & QxtCsvModel::SingleQuote)
            addSingleQuotes = true;
    } 
    if(mode & QxtCsvModel::BackslashEscape) {
        if(addDoubleQuotes) 
            return '"' + field.replace("\\", "\\\\").replace("\"", "\\\"") + '"';
        if(addSingleQuotes)
            return '\'' + field.replace("\\", "\\\\").replace("'", "\\'") + '\'';
    } else {
        if(addDoubleQuotes) 
            return '"' + field.replace("\"", "\"\"") + '"';
        if(addSingleQuotes)
            return '\'' + field.replace("'", "''") + '\'';
    }
    return field;
}

/*!
  Outputs the content of the model as a CSV file to the device \a dest using \a codec.

  Fields in the output file will be separated by \a separator. Set \a withHeader to true
  to output a row of headers at the top of the file.
 */ 
void QxtCsvModel::toCSV(QIODevice* dest, bool withHeader, QChar separator, QTextCodec* codec) const
{
    const QxtCsvModelPrivate& d_ptr = qxt_d();
    int row, col, rows, cols;
    rows = rowCount();
    cols = columnCount();
    QString data;
    if(!dest->isOpen()) dest->open(QIODevice::WriteOnly | QIODevice::Truncate);
    QTextStream stream(dest);
    if(codec) stream.setCodec(codec);
    if(withHeader) {
        data = "";
        for(col = 0; col < cols; ++col) {
            if(col > 0) data += separator;
            data += qxt_addCsvQuotes(d_ptr.quoteMode, d_ptr.header.at(col)); 
        }
        stream << data << endl;
    }
    for(row = 0; row < rows; ++row)
    {
        const QStringList& rowData = d_ptr.csvData[row];
        data = "";
        for(col = 0; col < cols; ++col) {
            if(col > 0) data += separator;
            if(col < rowData.length())
                data += qxt_addCsvQuotes(d_ptr.quoteMode, rowData.at(col)); 
            else
                data += qxt_addCsvQuotes(d_ptr.quoteMode, QString());; 
        }
        stream << data << endl;
    }
    stream << flush;
    dest->close();
}

/*!
  \overload

  Outputs the content of the model as a CSV file to the file specified by \a filename using \a codec.

  Fields in the output file will be separated by \a separator. Set \a withHeader to true
  to output a row of headers at the top of the file.
 */ 
void QxtCsvModel::toCSV(const QString filename, bool withHeader, QChar separator, QTextCodec* codec) const
{
    QFile dest(filename);
    toCSV(&dest, withHeader, separator, codec);
}

/*!
    \reimp
 */
Qt::ItemFlags QxtCsvModel::flags(const QModelIndex& index) const
{
    return Qt::ItemIsEditable | QAbstractTableModel::flags(index);
}

/*!
 * Returns the current quoting mode.
 * \sa setQuoteMode
 */
QxtCsvModel::QuoteMode QxtCsvModel::quoteMode() const
{
    return qxt_d().quoteMode;
}

/*!
 * Sets the current quoting mode. The default quoting mode is BothQuotes | BackslashEscape.
 *
 * The quoting mode determines what kinds of quoting is used for reading and writing CSV files.
 * \sa quoteMode
 * \sa QuoteOption
 */
void QxtCsvModel::setQuoteMode(QuoteMode mode)
{
    qxt_d().quoteMode = mode;
}

/*!
  Sets the content of the cell at row \a row and column \a column to \a value.
  
  \sa text
  */
void QxtCsvModel::setText(int row, int column, const QString& value)
{
    setData(index(row, column), value);
}

/*!
  Fetches the content of the cell at row \a row and column \a column.
  
  \sa setText
  */
QString QxtCsvModel::text(int row, int column) const
{
    return data(index(row, column)).toString();
}

/*!
  Sets the content of the header for column \a column to \a value.
  
  \sa headerText
  */
void QxtCsvModel::setHeaderText(int column, const QString& value)
{
    setHeaderData(column, Qt::Horizontal, value);
}

/*!
  Fetches the content of the cell at row \a row and column \a column.
  
  \sa setText
  */
QString QxtCsvModel::headerText(int column) const
{
    return headerData(column, Qt::Horizontal).toString();
}