/***************************************************************************
 *   Copyright (c) Ian Rees                    (ian.rees@gmail.com) 2015   *
 *                                                                         *
 *   This file is part of the FreeCAD CAx development system.              *
 *                                                                         *
 *   This library is free software; you can redistribute it and/or         *
 *   modify it under the terms of the GNU Library General Public           *
 *   License as published by the Free Software Foundation; either          *
 *   version 2 of the License, or (at your option) any later version.      *
 *                                                                         *
 *   This library  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 Library General Public License for more details.                  *
 *                                                                         *
 *   You should have received a copy of the GNU Library General Public     *
 *   License along with this library; see the file COPYING.LIB. If not,    *
 *   write to the Free Software Foundation, Inc., 59 Temple Place,         *
 *   Suite 330, Boston, MA  02111-1307, USA                                *
 *                                                                         *
 ***************************************************************************/


#ifndef BASE_ENUMERATION_H
#define BASE_ENUMERATION_H

#include <string>
#include <vector>

//#include <App/PropertyStandard.h>

namespace App
{
    class PropertyEnumeration;

    /// A bidirectional string-integer mapping
    /*!
     * This is mainly intended for two purposes: working around the difficulty
     * in C++ of sharing enumerations between different source files,
     * namespaces, etc. and as the data type stored by App::PropertyEnumeration
     *
     * Internally, Enumeration maintains
     *  -# Either a const pointer to an array of C-style strings, or a vector
     *  of C++ std::strings
     *  -# An integer index into that array/vector representing the string
     *  representing the instance's value.
     *
     * If built with FC_DEBUG defined, some boundaries of passed in pointers
     * will be checked.  Otherwise, the caller has the responsibility of
     * checking the limits of given indices.
     *
     * \todo Implement lazy copy
     */
    class AppExport Enumeration
    {
        friend class App::PropertyEnumeration;
        public:
            /// Constructs an empty Enumeration object
            Enumeration();

            /// Standard copy constructor
            Enumeration(const Enumeration& other);

            /// Constructs an Enumeration with a single element
            Enumeration(const char *valStr);

            /// Constructs an Enumeration using val within list
            Enumeration(const char **list, const char *valStr);

            /// Standard destructor
            ~Enumeration();

            /** Sets the enumeration string list
             * The list is a NULL terminated array of pointers to const
             * char* strings.
             * \code
             * const char enums[] = {"Black","White","Other",NULL}
             * \endcode
             *
             * If Enumeration was already valid, will attempt to preserve
             * the string-representation value of the Enumeration
             *
             * Enumeration does not take ownership of the passed object
             */
            void setEnums(const char **plEnums);

            /// Set all enum values as vector of strings
            /*!
             * This method causes the Enumeration to dynamically allocate
             * it's own array of C Strings, which will be deleted by the
             * destructor or subsequent calls to setEnums().  So, it is
             * important to make sure the Enumeration stays in scope as
             * long as values returned by getCStr are in use.
             *
             * If Enumeration was already valid, will attempt to preserve
             * the string-representation value of the Enumeration
             */
            void setEnums(const std::vector<std::string> &values);

            /// Set the enum using a C string
            void setValue(const char *value);

            /// Overload of setValue(const char *value)
            void setValue(const std::string &value) {setValue(value.c_str());}

            /// Set the enum using a long
            /*!
             * if checkRange is set to true, throws Base::ValueError when
             * values are set out of range
             *
             * Checks for boundaries via assert()
             */
            void setValue(long value, bool checkRange = false);

            /// Checks if the property is set to a certain string value
            bool isValue(const char *value) const;

            /// Checks if a string is included in the enumeration
            bool contains(const char *value) const;

            /// Return the value as C string
            /*!
             * Returns NULL if the enumeration is invalid.
             */
            const char * getCStr(void) const;

            /// Return value as integer
            /*!
             * Returns -1 if the Enumeration isn't valid
             */
            int getInt(void) const;

            /// get all possible enum values as vector of strings
            std::vector<std::string> getEnumVector(void) const;

            /// get pointer to the enum list
            const char ** getEnums(void) const;

            /// Returns true if the instance is in a usable state
            bool isValid(void) const;

            /// Returns the highest usable integer value for this enum
            /*!
             * Returns -1 if the enumeration is not valid according to isValid()
             */
            int maxValue(void) const {return _maxVal;};

            /// Assignment operator
            Enumeration & operator=(const Enumeration &other);

            /// true iff our string representation matches other's
            /*!
             * Returns false if either Enumeration is not valid.
             */
            bool operator==(const Enumeration &other) const;

            /// true iff our string representation matches other
            /*!
             * Returns false if Enumeration is not valid.
             */
            bool operator==(const char *other) const;
        protected:
            /// Returns true if instance was not initialized via static string list
            bool isCustom(void) const {return _ownEnumArray;};

            /// Updates _maxVal
            void findMaxVal(void);

            /// De-allocates memory used in _EnumArray
            /*!
             * Important to not call this unless this Enumeration owns array.
             */
            void tearDown(void);

        private:
            /// Handle to C Strings of possible enumeration values
            const char **_EnumArray;

            /// Whether instance owns _EnumArray
            bool _ownEnumArray;

            /// Integer value of the enumeration
            /*!
             * This serves as an index into _EnumArray to get the string
             * representation.
             */
            int _index;

            /*! Cached result from findMaxVal()
             * Value should either be the maximum allowable integer value for
             * the Enumeration, or -1 if not initialized
             */
            int _maxVal;
    };  // class Enumeration
}   // namespace App

#endif // #ifndef BASE_ENUMERATION_H