/*
 * ----------------------------------------------------------------------
 *  RpUnits.h - Header file for Rappture Units
 *
 *   RpUnits Class Declaration / Definition
 *
 * ======================================================================
 *  AUTHOR:  Derrick Kearney, Purdue University
 *  Copyright (c) 2004-2005  Purdue Research Foundation
 *
 *  See the file "license.terms" for information on usage and
 *  redistribution of this file, and for a DISCLAIMER OF ALL WARRANTIES.
 * ======================================================================
 */
#include <iostream>
#include <string>
#include <list>
#include <sstream>
#include <stdlib.h>
#include <errno.h>
#include <math.h>

#include "RpDict.h"
#include "RpUnitsStd.h"

#ifndef _RpUNITS_H
#define _RpUNITS_H

#define LIST_TEMPLATE RpUnitsListEntry

//define our different types of units
#define RP_TYPE_ENERGY  "energy"
#define RP_TYPE_LENGTH  "length"
#define RP_TYPE_TEMP    "temperature"
#define RP_TYPE_TIME    "time"
#define RP_TYPE_VOLUME  "volume"


// should the define function:
// 1. compare portions of inStr to unit names that have previously 
//    been defined (you must parse in order for this option to work)
#define COMPARE_MASK    1
// 2. create a unit if no unit by the name exists.
#define CREATE_MASK     2
// 3. parse the unit name to try to find previously defined units.
#define PARSE_MASK      4

class RpUnits;

class RpUnitsPreset {
    public:
        RpUnitsPreset () {
            addPresetAll();
        };

        static int addPresetAll();
        static int addPresetEnergy();
        static int addPresetLength();
        static int addPresetTemp();
        static int addPresetTime();
        static int addPresetVolume();
};

// simple class to hold info about a conversion.
// holds where we are converting from
// holds where we are converting to
// hold the pointer to a function to do the forward conversion (from->to)
// hold the pointer to a function to do the backward conversion (to->from)
//
class conversion
{
    public:

        const RpUnits* getFrom()    { return (const RpUnits*) fromPtr; };
        const RpUnits* getTo()      { return (const RpUnits*) toPtr; };

        friend class RpUnits;

        // copy constructor
        conversion ( conversion& other)
            :   fromPtr             (other.fromPtr),
                toPtr               (other.toPtr),
                convForwFxnPtr      (other.convForwFxnPtr),
                convBackFxnPtr      (other.convBackFxnPtr),
                convForwFxnPtrDD    (other.convForwFxnPtrDD),
                convBackFxnPtrDD    (other.convBackFxnPtrDD),
                convForwFxnPtrVoid  (other.convForwFxnPtrVoid),
                convForwData        (other.convForwData),
                convBackFxnPtrVoid  (other.convBackFxnPtrVoid),
                convBackData        (other.convBackData)
            {};

        // copy assignment operator
        conversion& operator= ( conversion& other )
            {
                fromPtr             = other.fromPtr;
                toPtr               = other.toPtr;
                convForwFxnPtr      = other.convForwFxnPtr;
                convBackFxnPtr      = other.convBackFxnPtr;
                convForwFxnPtrDD    = other.convForwFxnPtrDD;
                convBackFxnPtrDD    = other.convBackFxnPtrDD;
                convForwFxnPtrVoid  = other.convForwFxnPtrVoid;
                convForwData        = other.convForwData;
                convBackFxnPtrVoid  = other.convBackFxnPtrVoid;
                convBackData        = other.convBackData;
                return *this;
            }

        // default destructor
        virtual ~conversion ()
        {}

    private:

        const RpUnits* fromPtr;
        const RpUnits* toPtr;
        double (*convForwFxnPtr)(double);
        double (*convBackFxnPtr)(double);
        double (*convForwFxnPtrDD)(double,double);
        double (*convBackFxnPtrDD)(double,double);
        void* (*convForwFxnPtrVoid)(void*, void*);
        void* convForwData;
        void* (*convBackFxnPtrVoid)(void*, void*);
        void* convBackData;

        // constructor
        // private because i only want RpUnits to be able to
        // create a conversion
        conversion (
                const RpUnits* fromPtr,
                const RpUnits* toPtr,
                double (*convForwFxnPtr)(double),
                double (*convBackFxnPtr)(double)
             )
            :   fromPtr             (fromPtr),
                toPtr               (toPtr),
                convForwFxnPtr      (convForwFxnPtr),
                convBackFxnPtr      (convBackFxnPtr),
                convForwFxnPtrDD    (NULL),
                convBackFxnPtrDD    (NULL),
                convForwFxnPtrVoid  (NULL),
                convForwData        (NULL),
                convBackFxnPtrVoid  (NULL),
                convBackData        (NULL)
            {};

        // constructor for 2 argument conversion functions
        conversion (
                const RpUnits* fromPtr,
                const RpUnits* toPtr,
                double (*convForwFxnPtr)(double,double),
                double (*convBackFxnPtr)(double,double)
             )
            :   fromPtr             (fromPtr),
                toPtr               (toPtr),
                convForwFxnPtr      (NULL),
                convBackFxnPtr      (NULL),
                convForwFxnPtrDD    (convForwFxnPtr),
                convBackFxnPtrDD    (convBackFxnPtr),
                convForwFxnPtrVoid  (NULL),
                convForwData        (NULL),
                convBackFxnPtrVoid  (NULL),
                convBackData        (NULL)
            {};

        // constructor for user defined void* returning 1 arg conversion fxns.
        // the 1 arg is a user defined void* object
        conversion (
                const RpUnits* fromPtr,
                const RpUnits* toPtr,
                void* (*convForwFxnPtrVoid)(void*, void*),
                void* convForwData,
                void* (*convBackFxnPtrVoid)(void*, void*),
                void* convBackData
             )
            :   fromPtr             (fromPtr),
                toPtr               (toPtr),
                convForwFxnPtr      (NULL),
                convBackFxnPtr      (NULL),
                convForwFxnPtrDD    (NULL),
                convBackFxnPtrDD    (NULL),
                convForwFxnPtrVoid  (convForwFxnPtrVoid),
                convForwData        (convForwData),
                convBackFxnPtrVoid  (convBackFxnPtrVoid),
                convBackData        (convBackData)
            {};

};

// used by the RpUnits class to create a linked list of the conversions
// associated with the specific unit.
//
// we could templitize this and make a generic linked list
// or could use generic linked list class from book programming with objects
//
class convEntry
{

    public:

        friend class RpUnits;

        virtual ~convEntry()
        {}

    private:

        conversion* conv;
        convEntry*  prev;
        convEntry*  next;

        convEntry (
                conversion* conv,
                convEntry*  prev,
                convEntry*  next
             )
            :   conv    (conv),
                prev    (prev),
                next    (next)
            {};

};

class RpUnitsListEntry
{

    public:

        // constructor
        RpUnitsListEntry (const RpUnits* unit, double exponent)
            : unit     (unit),
              exponent (exponent)
        {};

        // copy constructor
        RpUnitsListEntry (const RpUnitsListEntry& other)
            : unit     (other.unit),
              exponent (other.exponent)
        {};

        // copy assignment operator
        RpUnitsListEntry& operator= (const RpUnitsListEntry& other) {
            unit = other.unit;
            exponent = other.exponent;
            return *this;
        }

        // negate the exponent
        void negateExponent() const;

        // print the name of the object
        std::string name() const;

        // report the basis of the RpUnits object being stored.
        const RpUnits* getBasis() const;

        // return the RpUnits*
        const RpUnits* getUnitsObj() const;

        // return the exponent
        double getExponent() const;

        // destructor
        virtual ~RpUnitsListEntry ()
        {}

    private:

        const RpUnits* unit;
        mutable double exponent;
};

class RpUnits
{
    /*
     * helpful units site
     * http://aurora.regenstrief.org/~gunther/units.html
     * http://www.nodc.noaa.gov/dsdt/ucg/
     * http://www.cellml.org/meeting_minutes/archive/
     *        20010110_meeting_minutes.html
     */

    public:

        // users member fxns
        std::string getUnits() const;
        std::string getUnitsName() const;
        double getExponent() const;
        const RpUnits* getBasis() const;

        // retrieve a units type.
        std::string getType() const;

        // retrieve a list of compatible units.
        std::list<std::string> getCompatible() const;


        // convert from one RpUnits to another if the conversion is defined
        double convert(         const RpUnits* toUnits,
                                double val,
                                int* result=NULL    ) const;
        // convert from one RpUnits to another if the conversion is defined
        void* convert(          const RpUnits* toUnits, 
                                void* val, 
                                int* result=NULL) const;
        // convert from one RpUnits to another if the conversion is defined
        // double convert(std::string, double val);
        // convert from one RpUnits to another if the conversion is defined
        std::string convert (   const RpUnits* toUnits,
                                double val,
                                int showUnits = 0,
                                int* result = NULL  ) const;

        static std::string convert ( std::string val,
                                     std::string toUnits,
                                     int showUnits,
                                     int* result = NULL );

        /*
        static std::string convert ( std::string val,
                                     std::string toUnits,
                                     int showUnits,
                                     int* result = NULL );
        */

        // turn the current unit to the metric system
        // this should only be used for units that are part of the
        // metric system. doesnt deal with exponents, just prefixes
        double makeBasis(double value, int* result = NULL) const;
        const RpUnits & makeBasis(double* value, int* result = NULL) const;

        static int makeMetric(const RpUnits * basis);

        // find a RpUnits object that should exist in RpUnitsTable
        // returns 0 on success (object was found)
        // returns !0 on failure (object not found)
        static const RpUnits* find(std::string key);

        // user calls define to add a RpUnits object or to add a relation rule
        //
        // add RpUnits Object
        static RpUnits * define(const std::string units,
                                const RpUnits* basis=NULL,
                                const std::string type=""   );

        // add relation rule

        static RpUnits * define(const RpUnits* from,
                                const RpUnits* to,
                                double (*convForwFxnPtr)(double),
                                double (*convBackFxnPtr)(double));

        static RpUnits * define(const RpUnits* from,
                                const RpUnits* to,
                                double (*convForwFxnPtr)(double,double),
                                double (*convBackFxnPtr)(double,double));

        static RpUnits * define(const RpUnits* from,
                                const RpUnits* to,
                                void* (*convForwFxnPtr)(void*, void*),
                                void* convForwData,
                                void* (*convBackFxnPtr)(void*, void*),
                                void* convBackData);


        // populate the dictionary with a set of units specified by group
        // if group equals......................then load................
        //      "all"                       load all available units
        //      "energy"                    load units related to energy
        //      "length"                    load units related to length
        //      "temp"                      load units related to temperature
        //      "time"                      load units related to time
        //      "volume"                    load units related to volume
        //  (no other groups have been created)

        static int addPresets (const std::string group);

        // undefining a relation rule is probably not needed
        // int undefine(); // delete a relation

        // why are these functions friends...
        // probably need to find a better way to let RpUnits
        // use the RpDict and RpDictEntry fxns
        friend class RpDict<std::string,RpUnits*>;
        friend class RpDictEntry<std::string,RpUnits*>;

        friend int insert(std::string key,RpUnits* val);


        // copy constructor
        RpUnits (RpUnits &other)
            : units    (other.units),
              exponent (other.exponent),
              basis    (other.basis),
              type     (other.type),
              convList (NULL)
        {
            convEntry* q = NULL;
            convEntry* curr = NULL;

            dict = other.dict;

            if (other.convList) {
                q = other.convList;
                convList = new convEntry (q->conv,NULL,NULL);
                curr = convList;
                while (q->next) {
                    q = q->next;
                    curr->next = new convEntry (q->conv,curr,NULL);
                    curr = curr->next;
                }
            }
        }

        // copy assignment operator
        RpUnits& operator= (const RpUnits& other) {

            convEntry* q = NULL;
            convEntry* curr = NULL;

            if ( this != &other ) {
                delete convList;
            }

            dict = other.dict;
            units = other.units;
            exponent = other.exponent;
            basis = other.basis;
            type = other.type;

            if (other.convList) {
                q = other.convList;
                convList = new convEntry (q->conv,NULL,NULL);
                curr = convList;
                while (q->next) {
                    q = q->next;
                    curr->next = new convEntry (q->conv,curr,NULL);
                    curr = curr->next;
                }
            }

            return *this;
        }

        // default destructor
        //
        ~RpUnits ()
        {
            // go to the type list and remove a variable by this name


            // clean up dynamic memory

            convEntry* p = convList;
            convEntry* tmp = p;

            while (p != NULL) {
                tmp = p;
                p = p->next;
                delete tmp;
            }
        }

    private:

        // i hope to replace these vars with a small class representing a
        // of a linked list of units. that way we can handle complex units.
        // this will also require that we move the getUnits, getExponent, 
        // and getBasis, makeBasis functionality into the smaller class,
        // that represents each part of the units. we should keep getUnits,
        // getBasis, and makeBasis in this class, but modify them to go
        // through the linked list of units and combine the units back into
        // what the caller expects to see.
        // ie. cm2/Vms (mobility), will be split into the objects cm2, V, ms
        // when getUnits is called, the user should see cm2/Vms again.
        // for basis, possibly let the user choose a basis, and for makeBasis
        // move through the linked list, only converting the metric elements.
        //

        std::string units;
        double exponent;
        const RpUnits* basis;
        std::string type;

        // linked list of units this RpUnit can convert to
        // its mutable because the connectConversion function takes in a
        // const RpUnits* and attempts to change the convList variable
        // within the RpUnits Object
        mutable convEntry* convList;


        // dictionary to store the units.
        static RpDict<std::string,RpUnits*>* dict;

        // create a units element
        // class takes in three pieces of info
        // 1) string describing the units
        // 2) double describing the exponent
        // 3) pointer to RpUnits object describing the basis 
        //      of the units (the fundamental unit)
        //

        RpUnits (
                    const std::string& units,
                    double& exponent,
                    const RpUnits* basis,
                    const std::string type
                )
            :   units       (units),
                exponent    (exponent),
                basis       (basis),
                type        (type),
                convList    (NULL)
        {};

        // insert new RpUnits object into RpUnitsTable
        // returns 0 on success (object inserted or already exists)
        // returns !0 on failure (object cannot be inserted or dne)
        // int RpUnits::insert(std::string key) const;

        typedef std::list<LIST_TEMPLATE> RpUnitsList;
        typedef RpUnitsList::iterator RpUnitsListIter;

        void newExponent(double newExponent) {exponent = newExponent;};

        static int units2list( const std::string& inUnits,
                               RpUnitsList& outList         );
        static int grabExponent(const std::string& inStr, double* exp);
        static int grabUnitString( const std::string& inStr);
        static const RpUnits* grabUnits (std::string inStr, int* offset);
        static int negateListExponents(RpUnitsList& unitsList);
        static int RpUnits::printList(RpUnitsList& unitsList);

        static int RpUnits::compareListEntryBasis( RpUnitsList& fromList,
                                                   RpUnitsListIter& fromIter,
                                                   RpUnitsListIter& toIter);

        static int RpUnits::compareListEntrySearch( RpUnitsList& fromList,
                                                    RpUnitsListIter& fromIter,
                                                    RpUnitsListIter& toIter);

        void RpUnits::connectConversion(conversion* conv) const;

};

/*--------------------------------------------------------------------------*/
/*--------------------------------------------------------------------------*/

#endif