/*=============================================================================

  Library: CTK

  Copyright (c) University College London

  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  You may obtain a copy of the License at

    http://www.apache.org/licenses/LICENSE-2.0

  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.

=============================================================================*/

#ifndef __ctkCmdLineModuleDefaultPathBuilder_h
#define __ctkCmdLineModuleDefaultPathBuilder_h

#include "ctkCommandLineModulesCoreExport.h"
#include <QStringList>
#include <QScopedPointer>

struct ctkCmdLineModuleDefaultPathBuilderPrivate;

/**
 * \class ctkCmdLineModuleDefaultPathBuilder
 * \brief Builds up a list of directory paths to search for command
 * line modules.
 * \ingroup CommandLineModulesCore
 * \author m.clarkson@ucl.ac.uk
 *
 * Implements the following basic strategy, depending on which boolean
 * flags are on: By default they are all off, as directory scanning is
 * often time consuming.
 *
 * <pre>
 * 1. CTK_MODULE_LOAD_PATH environment variable
 * 2. Home directory
 * 3. Home directory / cli-modules
 * 4. Current working directory
 * 5. Current working directory / cli-modules
 * 6. Application directory
 * 7. Application directory / cli-modules
 * </pre>
 */
class CTK_CMDLINEMODULECORE_EXPORT ctkCmdLineModuleDefaultPathBuilder
{

public:

  ctkCmdLineModuleDefaultPathBuilder();
  ~ctkCmdLineModuleDefaultPathBuilder();

  /**
   * @brief Instruct the builder to include the users
   * home directory and sub-folder cli-modules.
   */
  virtual void setLoadFromHomeDir(bool doLoad);

  /**
   * @brief Instruct the builder to include the current
   * running directory and sub-folder cli-modules.
   */
  virtual void setLoadFromCurrentDir(bool doLoad);

  /**
   * @brief Instruct the builder to include the application
   * installation directory and sub-folder cli-modules.
   */
  virtual void setLoadFromApplicationDir(bool doLoad);

  /**
   * @brief Instruct the builder to include the path denoted
   * by the environment variable CTK_MODULE_LOAD_PATH.
   */
  virtual void setLoadFromCtkModuleLoadPath(bool doLoad);

  /**
   * @brief Builds the list of paths to search and returns them
   * as QStringList
   * @return a QStringList of directory path names
   */
  virtual QStringList build() const;

private:

  QScopedPointer<ctkCmdLineModuleDefaultPathBuilderPrivate> d;
  Q_DISABLE_COPY(ctkCmdLineModuleDefaultPathBuilder)
};

#endif