/*
 * Copyright (C) 2009, 2010 Nicolas Bonnefon and other contributors
 *
 * This file is part of glogg.
 *
 * glogg 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.
 *
 * glogg 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 glogg.  If not, see <http://www.gnu.org/licenses/>.
 */

#ifndef ABSTRACTLOGDATA_H
#define ABSTRACTLOGDATA_H

#include <QObject>
#include <QString>
#include <QStringList>

// Base class representing a set of data.
// It can be either a full set or a filtered set.
class AbstractLogData : public QObject {
  Q_OBJECT

  public:
    AbstractLogData();
    // Permit each child to have its destructor
    virtual ~AbstractLogData() {};

    // Returns the line passed as a QString
    QString getLineString( qint64 line ) const;
    // Returns the line passed as a QString, with tabs expanded
    QString getExpandedLineString( qint64 line ) const;
    // Returns a set of lines as a QStringList
    QStringList getLines( qint64 first_line, int number ) const;
    // Returns a set of lines with tabs expanded
    QStringList getExpandedLines( qint64 first_line, int number ) const;
    // Returns the total number of lines
    qint64 getNbLine() const;
    // Returns the visible length of the longest line
    // Tabs are expanded
    int getMaxLength() const;
    // Returns the visible length of the passed line
    // Tabs are expanded
    int getLineLength( qint64 line ) const;

    // Set the view to use the passed encoding for display
    void setDisplayEncoding( const char* encoding_name );
    // Configure how the view shall interpret newline characters
    // this should be non zero for encodings where \n is encoded
    // in multiple bytes (e.g. UTF-16)
    void setMultibyteEncodingOffsets( int before_cr, int after_cr );

    // Length of a tab stop
    static const int tabStop = 8;

  protected:
    // Internal function called to get a given line
    virtual QString doGetLineString( qint64 line ) const = 0;
    // Internal function called to get a given line
    virtual QString doGetExpandedLineString( qint64 line ) const = 0;
    // Internal function called to get a set of lines
    virtual QStringList doGetLines( qint64 first_line, int number ) const = 0;
    // Internal function called to get a set of expanded lines
    virtual QStringList doGetExpandedLines( qint64 first_line, int number ) const = 0;
    // Internal function called to get the number of lines
    virtual qint64 doGetNbLine() const = 0;
    // Internal function called to get the maximum length
    virtual int doGetMaxLength() const = 0;
    // Internal function called to get the line length
    virtual int doGetLineLength( qint64 line ) const = 0;
    // Internal function called to set the encoding
    virtual void doSetDisplayEncoding( const char* encoding ) = 0;
    // Internal function called to set the newline offsets
    virtual void doSetMultibyteEncodingOffsets( int before_cr, int after_cr ) = 0;

    static inline QString untabify( const QString& line ) {
        QString untabified_line;
        int total_spaces = 0;

        for ( int j = 0; j < line.length(); j++ ) {
            if ( line[j] == '\t' ) {
                int spaces = tabStop - ( ( j + total_spaces ) % tabStop );
                // LOG(logDEBUG4) << "Replacing tab at char " << j << " (" << spaces << " spaces)";
                QString blanks( spaces, QChar(' ') );
                untabified_line.append( blanks );
                total_spaces += spaces - 1;
            }
            else {
                untabified_line.append( line[j] );
            }
        }

        return untabified_line;
    }

    static inline QString untabify( const char* line ) {
        QString untabified_line;
        int total_spaces = 0;

        for ( const char* i = line; *i != '\0'; i++ ) {
            if ( *i == '\t' ) {
                int spaces = tabStop - ( ( (i - line) + total_spaces ) % tabStop );
                // LOG(logDEBUG4) << "Replacing tab at char " << j << " (" << spaces << " spaces)";
                QString blanks( spaces, QChar(' ') );
                untabified_line.append( blanks );
                total_spaces += spaces - 1;
            }
            else {
                untabified_line.append( *i );
            }
        }

        return untabified_line;
    }
};

#endif