/**
 * @file FileFinder/Engine/ifilefinder.h
 * @brief Interface for the file finder engine
 * @author Enar Vaikene
 *
 * Copyright (c) 2011-2019 Enar Vaikene
 *
 * This file is part of the eVaf C++ cross-platform application development framework.
 *
 * This file can be used under the terms of the GNU General Public License
 * version 3.0 as published by the Free Software Foundation and appearing in
 * the file LICENSE included in the packaging of this file. Please review the
 * the following information to ensure the GNU General Public License version
 * 3.0 requirements will be met: http://www.gnu.org/copyleft/gpl.html.
 *
 * Alternatively, this file may be used in accordance with the Commercial License
 * Agreement provided with the Software.
 */

#ifndef __FILEFINDER_ENGINE_IFILEFINDER_H
#  define __FILEFINDER_ENGINE_IFILEFINDER_H

#include <QObject>
#include <QString>

namespace eVaf {
namespace FileFinder {

/**
 * File filter defining patterns for file names and contents.
 *
 * File name patterns are wildcards (QRegExp::WildcardUnix). Multiple patterns can be separated by comma like,
 * for example, "*.cpp,*.h". To include a comma in the pattern, escape it with '\'.
 *
 * Content patterns are regular expressions (QRegExp::RegExp).
 * 
 * A file matches the filter if:
 * @li file name matches the includeNames pattern or the includeNames pattern is empty;
 * @li and; file name does not match the excludeNames pattern or the excludeNames pattern is empty;
 * @li and; file content matches the includeContent pattern or the includeContent pattern is empty;
 * @li and; file content does not match the excludeContent pattern or the excludeContent patytern is empty.
 */
struct Filter
{
    Filter()
    {}

    Filter(QString const & in, QString const & en, QString const & ic, QString const & ec)
        : includeNames(in)
        , excludeNames(en)
        , includeContent(ic)
        , excludeContent(ec)
    {}

    /// QRegExp expression specifying file names that are included in the search result
    QString includeNames;

    /// QRegExp expression specifying file names that are excluded from the search result
    QString excludeNames;

    /// QRegExp expression specifying file content that is included in the search result
    QString includeContent;

    /// QRegExp expression specifying file content that is excluded from the search result
    QString excludeContent;
};

/**
 * File finder interface.
 *
 * The iFileFinder interface is used to search for files using name and content filters.
 */
class iFileFinder : public QObject
{
    Q_OBJECT

public:

    /// Interface constructor
    iFileFinder() : QObject() {}

    /// Empty virtual destructor
    virtual ~iFileFinder() {}

    /**
     * Starts a file search in the directory dir using filter.
     * @param dir Directory where to search
     * @param recursive If True, searches also in sub-directories
     * @param filter File name and content filter
     *
     * The search() function searches for files matching the given filter. The search is started
     * in the directory dir and continues recursively into sub-directories if the recursive flag
     * is set to true.
     *
     * The function is non-blocking and returns immediately. Results of the search are reported
     * with found() signals and the finished() signal indicates that the search is either finished
     * or canceled.
     *
     * If a new search is started before the current search is finished, then the current search is canceled.
     */
    virtual void search(QString const & dir, bool recursive, Filter const & filter) = 0;

    /**
     * Cancels an ongoing search.
     */
    virtual void cancel() = 0;

    /**
     * Indicates that a search is ongoing
     */
    virtual bool busy() const = 0;


signals:

    /**
     * Signal emitted for every file found during the search.
     * @param fileName name of the file with a path relative to the search directory
     * @param dir Search directory
     */
    void found(QString const & fileName, QString const & dir);

    /**
     * Signal emitted when the search is finished
     * @param canceled True if the search was canceled instead of finished
     */
    void finished(bool canceled);

};


} // namespace eVaf::FileFinder
} // namespace eVaf

Q_DECLARE_INTERFACE(eVaf::FileFinder::iFileFinder, "eVaf.FileFinder.iFileFinder/1.0")

#endif // ifilefinder.h