/** @file add.cpp
 *
 *  Implementation of GiNaC's sums of expressions. */

/*
 *  GiNaC Copyright (C) 1999-2000 Johannes Gutenberg University Mainz, Germany
 *
 *  This program 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 2 of the License, or
 *  (at your option) any later version.
 *
 *  This program 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 this program; if not, write to the Free Software
 *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */

#include <iostream>
#include <stdexcept>

#include "add.h"
#include "mul.h"
#include "archive.h"
#include "debugmsg.h"
#include "utils.h"

#ifndef NO_NAMESPACE_GINAC
namespace GiNaC {
#endif // ndef NO_NAMESPACE_GINAC

GINAC_IMPLEMENT_REGISTERED_CLASS(add, expairseq)

//////////
// default constructor, destructor, copy constructor assignment operator and helpers
//////////

// public

add::add()
{
    debugmsg("add default constructor",LOGLEVEL_CONSTRUCT);
    tinfo_key = TINFO_add;
}

add::~add()
{
    debugmsg("add destructor",LOGLEVEL_DESTRUCT);
    destroy(0);
}

add::add(const add & other)
{
    debugmsg("add copy constructor",LOGLEVEL_CONSTRUCT);
    copy(other);
}

const add & add::operator=(const add & other)
{
    debugmsg("add operator=",LOGLEVEL_ASSIGNMENT);
    if (this != &other) {
        destroy(1);
        copy(other);
    }
    return *this;
}

// protected

void add::copy(const add & other)
{
    inherited::copy(other);
}

void add::destroy(bool call_parent)
{
    if (call_parent) inherited::destroy(call_parent);
}

//////////
// other constructors
//////////

// public

add::add(const ex & lh, const ex & rh)
{
    debugmsg("add constructor from ex,ex",LOGLEVEL_CONSTRUCT);
    tinfo_key = TINFO_add;
    overall_coeff = _ex0();
    construct_from_2_ex(lh,rh);
    GINAC_ASSERT(is_canonical());
}

add::add(const exvector & v)
{
    debugmsg("add constructor from exvector",LOGLEVEL_CONSTRUCT);
    tinfo_key = TINFO_add;
    overall_coeff = _ex0();
    construct_from_exvector(v);
    GINAC_ASSERT(is_canonical());
}

/*
add::add(const epvector & v, bool do_not_canonicalize)
{
    debugmsg("add constructor from epvector,bool",LOGLEVEL_CONSTRUCT);
    tinfo_key = TINFO_add;
    if (do_not_canonicalize) {
        seq=v;
#ifdef EXPAIRSEQ_USE_HASHTAB
        combine_same_terms(); // to build hashtab
#endif // def EXPAIRSEQ_USE_HASHTAB
    } else {
        construct_from_epvector(v);
    }
    GINAC_ASSERT(is_canonical());
}
*/

add::add(const epvector & v)
{
    debugmsg("add constructor from epvector",LOGLEVEL_CONSTRUCT);
    tinfo_key = TINFO_add;
    overall_coeff = _ex0();
    construct_from_epvector(v);
    GINAC_ASSERT(is_canonical());
}

add::add(const epvector & v, const ex & oc)
{
    debugmsg("add constructor from epvector,ex",LOGLEVEL_CONSTRUCT);
    tinfo_key = TINFO_add;
    overall_coeff = oc;
    construct_from_epvector(v);
    GINAC_ASSERT(is_canonical());
}

add::add(epvector * vp, const ex & oc)
{
    debugmsg("add constructor from epvector *,ex",LOGLEVEL_CONSTRUCT);
    tinfo_key = TINFO_add;
    GINAC_ASSERT(vp!=0);
    overall_coeff = oc;
    construct_from_epvector(*vp);
    delete vp;
    GINAC_ASSERT(is_canonical());
}

//////////
// archiving
//////////

/** Construct object from archive_node. */
add::add(const archive_node &n, const lst &sym_lst) : inherited(n, sym_lst)
{
    debugmsg("add constructor from archive_node", LOGLEVEL_CONSTRUCT);
}

/** Unarchive the object. */
ex add::unarchive(const archive_node &n, const lst &sym_lst)
{
    return (new add(n, sym_lst))->setflag(status_flags::dynallocated);
}

/** Archive the object. */
void add::archive(archive_node &n) const
{
    inherited::archive(n);
}

//////////
// functions overriding virtual functions from bases classes
//////////

// public

basic * add::duplicate() const
{
    debugmsg("add duplicate",LOGLEVEL_DUPLICATE);
    return new add(*this);
}

void add::print(ostream & os, unsigned upper_precedence) const
{
    debugmsg("add print",LOGLEVEL_PRINT);
    if (precedence<=upper_precedence) os << "(";
    numeric coeff;
    bool first = true;
    // first print the overall numeric coefficient, if present:
    if (!overall_coeff.is_zero()) {
        os << overall_coeff;
        first = false;
    }
    // then proceed with the remaining factors:
    for (epvector::const_iterator cit=seq.begin(); cit!=seq.end(); ++cit) {
        coeff = ex_to_numeric(cit->coeff);
        if (!first) {
            if (coeff.csgn()==-1) os << '-'; else os << '+';
        } else {
            if (coeff.csgn()==-1) os << '-';
            first = false;
        }
        if (!coeff.is_equal(_num1()) &&
            !coeff.is_equal(_num_1())) {
            if (coeff.is_rational()) {
                if (coeff.is_negative())
                    os << -coeff;
                else
                    os << coeff;
            } else {
                if (coeff.csgn()==-1)
                    (-coeff).print(os, precedence);
                else
                    coeff.print(os, precedence);
            }
            os << '*';
        }
        os << cit->rest;
    }
    if (precedence<=upper_precedence) os << ")";
}

void add::printraw(ostream & os) const
{
    debugmsg("add printraw",LOGLEVEL_PRINT);

    os << "+(";
    for (epvector::const_iterator it=seq.begin(); it!=seq.end(); ++it) {
        os << "(";
        (*it).rest.bp->printraw(os);
        os << ",";
        (*it).coeff.bp->printraw(os);        
        os << "),";
    }
    os << ",hash=" << hashvalue << ",flags=" << flags;
    os << ")";
}

void add::printcsrc(ostream & os, unsigned type, unsigned upper_precedence) const
{
    debugmsg("add print csrc", LOGLEVEL_PRINT);
    if (precedence <= upper_precedence)
        os << "(";

    // Print arguments, separated by "+"
    epvector::const_iterator it = seq.begin();
    epvector::const_iterator itend = seq.end();
    while (it != itend) {

        // If the coefficient is -1, it is replaced by a single minus sign
        if (it->coeff.compare(_num1()) == 0) {
            it->rest.bp->printcsrc(os, type, precedence);
        } else if (it->coeff.compare(_num_1()) == 0) {
            os << "-";
            it->rest.bp->printcsrc(os, type, precedence);
        } else if (ex_to_numeric(it->coeff).numer().compare(_num1()) == 0) {
            it->rest.bp->printcsrc(os, type, precedence);
            os << "/";
            ex_to_numeric(it->coeff).denom().printcsrc(os, type, precedence);
        } else if (ex_to_numeric(it->coeff).numer().compare(_num_1()) == 0) {
            os << "-";
            it->rest.bp->printcsrc(os, type, precedence);
            os << "/";
            ex_to_numeric(it->coeff).denom().printcsrc(os, type, precedence);
        } else {
            it->coeff.bp->printcsrc(os, type, precedence);
            os << "*";
            it->rest.bp->printcsrc(os, type, precedence);
        }

        // Separator is "+", except if the following expression would have a leading minus sign
        it++;
        if (it != itend && !(it->coeff.compare(_num0()) < 0 || (it->coeff.compare(_num1()) == 0 && is_ex_exactly_of_type(it->rest, numeric) && it->rest.compare(_num0()) < 0)))
            os << "+";
    }
    
    if (!overall_coeff.is_equal(_ex0())) {
        if (overall_coeff.info(info_flags::positive)) os << '+';
        overall_coeff.bp->printcsrc(os,type,precedence);
    }
    
    if (precedence <= upper_precedence)
        os << ")";
}

bool add::info(unsigned inf) const
{
    // TODO: optimize
    if (inf==info_flags::polynomial ||
        inf==info_flags::integer_polynomial ||
        inf==info_flags::cinteger_polynomial ||
        inf==info_flags::rational_polynomial ||
        inf==info_flags::crational_polynomial ||
        inf==info_flags::rational_function) {
        for (epvector::const_iterator it=seq.begin(); it!=seq.end(); ++it) {
            if (!(recombine_pair_to_ex(*it).info(inf)))
                return false;
        }
        return overall_coeff.info(inf);
    } else {
        return inherited::info(inf);
    }
}

int add::degree(const symbol & s) const
{
    int deg = INT_MIN;
    if (!overall_coeff.is_equal(_ex0())) {
        deg = 0;
    }
    int cur_deg;
    for (epvector::const_iterator cit=seq.begin(); cit!=seq.end(); ++cit) {
        cur_deg=(*cit).rest.degree(s);
        if (cur_deg>deg) deg=cur_deg;
    }
    return deg;
}

int add::ldegree(const symbol & s) const
{
    int deg = INT_MAX;
    if (!overall_coeff.is_equal(_ex0())) {
        deg = 0;
    }
    int cur_deg;
    for (epvector::const_iterator cit=seq.begin(); cit!=seq.end(); ++cit) {
        cur_deg = (*cit).rest.ldegree(s);
        if (cur_deg<deg) deg=cur_deg;
    }
    return deg;
}

ex add::coeff(const symbol & s, int n) const
{
    epvector coeffseq;
    coeffseq.reserve(seq.size());

    epvector::const_iterator it=seq.begin();
    while (it!=seq.end()) {
        coeffseq.push_back(combine_ex_with_coeff_to_pair((*it).rest.coeff(s,n),
                                                         (*it).coeff));
        ++it;
    }
    if (n==0) {
        return (new add(coeffseq,overall_coeff))->setflag(status_flags::dynallocated);
    }
    return (new add(coeffseq))->setflag(status_flags::dynallocated);
}

ex add::eval(int level) const
{
    // simplifications: +(;c) -> c
    //                  +(x;1) -> x

    debugmsg("add eval",LOGLEVEL_MEMBER_FUNCTION);

    epvector * evaled_seqp=evalchildren(level);
    if (evaled_seqp!=0) {
        // do more evaluation later
        return (new add(evaled_seqp,overall_coeff))->
                   setflag(status_flags::dynallocated);
    }
    
#ifdef DO_GINAC_ASSERT
    for (epvector::const_iterator cit=seq.begin(); cit!=seq.end(); ++cit) {
        GINAC_ASSERT(!is_ex_exactly_of_type((*cit).rest,add));
        if (is_ex_exactly_of_type((*cit).rest,numeric)) {
            dbgprint();
        }
        GINAC_ASSERT(!is_ex_exactly_of_type((*cit).rest,numeric));
    }
#endif // def DO_GINAC_ASSERT
    
    if (flags & status_flags::evaluated) {
        GINAC_ASSERT(seq.size()>0);
        GINAC_ASSERT((seq.size()>1)||!overall_coeff.is_equal(_ex0()));
        return *this;
    }
    
    int seq_size=seq.size();
    if (seq_size==0) {
        // +(;c) -> c
        return overall_coeff;
    } else if ((seq_size==1)&&overall_coeff.is_equal(_ex0())) {
        // +(x;0) -> x
        return recombine_pair_to_ex(*(seq.begin()));
    }
    return this->hold();
}

exvector add::get_indices(void) const
{
    // FIXME: all terms in the sum should have the same indices (compatible
    // tensors) however this is not checked, since there is no function yet
    // which compares indices (idxvector can be unsorted)
    if (seq.size()==0) {
        return exvector();
    }
    return (seq.begin())->rest.get_indices();
}    

ex add::simplify_ncmul(const exvector & v) const
{
    if (seq.size()==0) {
        return inherited::simplify_ncmul(v);
    }
    return (*seq.begin()).rest.simplify_ncmul(v);
}    

// protected

/** Implementation of ex::diff() for a sum. It differentiates each term.
 *  @see ex::diff */
ex add::derivative(const symbol & s) const
{
    // D(a+b+c)=D(a)+D(b)+D(c)
    return (new add(diffchildren(s)))->setflag(status_flags::dynallocated);
}

int add::compare_same_type(const basic & other) const
{
    return inherited::compare_same_type(other);
}

bool add::is_equal_same_type(const basic & other) const
{
    return inherited::is_equal_same_type(other);
}

unsigned add::return_type(void) const
{
    if (seq.size()==0) {
        return return_types::commutative;
    }
    return (*seq.begin()).rest.return_type();
}
   
unsigned add::return_type_tinfo(void) const
{
    if (seq.size()==0) {
        return tinfo_key;
    }
    return (*seq.begin()).rest.return_type_tinfo();
}

ex add::thisexpairseq(const epvector & v, const ex & oc) const
{
    return (new add(v,oc))->setflag(status_flags::dynallocated);
}

ex add::thisexpairseq(epvector * vp, const ex & oc) const
{
    return (new add(vp,oc))->setflag(status_flags::dynallocated);
}

expair add::split_ex_to_pair(const ex & e) const
{
    if (is_ex_exactly_of_type(e,mul)) {
        const mul & mulref=ex_to_mul(e);
        ex numfactor=mulref.overall_coeff;
        // mul * mulcopyp=static_cast<mul *>(mulref.duplicate());
        mul * mulcopyp=new mul(mulref);
        mulcopyp->overall_coeff=_ex1();
        mulcopyp->clearflag(status_flags::evaluated);
        mulcopyp->clearflag(status_flags::hash_calculated);
        return expair(mulcopyp->setflag(status_flags::dynallocated),numfactor);
    }
    return expair(e,_ex1());
}

expair add::combine_ex_with_coeff_to_pair(const ex & e,
                                          const ex & c) const
{
    GINAC_ASSERT(is_ex_exactly_of_type(c,numeric));
    if (is_ex_exactly_of_type(e,mul)) {
        const mul & mulref=ex_to_mul(e);
        ex numfactor=mulref.overall_coeff;
        //mul * mulcopyp=static_cast<mul *>(mulref.duplicate());
        mul * mulcopyp=new mul(mulref);
        mulcopyp->overall_coeff=_ex1();
        mulcopyp->clearflag(status_flags::evaluated);
        mulcopyp->clearflag(status_flags::hash_calculated);
        if (are_ex_trivially_equal(c,_ex1())) {
            return expair(mulcopyp->setflag(status_flags::dynallocated),numfactor);
        } else if (are_ex_trivially_equal(numfactor,_ex1())) {
            return expair(mulcopyp->setflag(status_flags::dynallocated),c);
        }
        return expair(mulcopyp->setflag(status_flags::dynallocated),
                          ex_to_numeric(numfactor).mul_dyn(ex_to_numeric(c)));
    } else if (is_ex_exactly_of_type(e,numeric)) {
        if (are_ex_trivially_equal(c,_ex1())) {
            return expair(e,_ex1());
        }
        return expair(ex_to_numeric(e).mul_dyn(ex_to_numeric(c)),_ex1());
    }
    return expair(e,c);
}
    
expair add::combine_pair_with_coeff_to_pair(const expair & p,
                                            const ex & c) const
{
    GINAC_ASSERT(is_ex_exactly_of_type(p.coeff,numeric));
    GINAC_ASSERT(is_ex_exactly_of_type(c,numeric));

    if (is_ex_exactly_of_type(p.rest,numeric)) {
        GINAC_ASSERT(ex_to_numeric(p.coeff).is_equal(_num1())); // should be normalized
        return expair(ex_to_numeric(p.rest).mul_dyn(ex_to_numeric(c)),_ex1());
    }

    return expair(p.rest,ex_to_numeric(p.coeff).mul_dyn(ex_to_numeric(c)));
}
    
ex add::recombine_pair_to_ex(const expair & p) const
{
    //if (p.coeff.compare(_ex1())==0) {
    //if (are_ex_trivially_equal(p.coeff,_ex1())) {
    if (ex_to_numeric(p.coeff).is_equal(_num1())) {
        return p.rest;
    } else {
        return p.rest*p.coeff;
    }
}

ex add::expand(unsigned options) const
{
    if (flags & status_flags::expanded)
        return *this;
    
    epvector * vp = expandchildren(options);
    if (vp==0) {
        return *this;
    }
    return (new add(vp,overall_coeff))->
        setflag(status_flags::expanded |
                status_flags::dynallocated);
}

//////////
// new virtual functions which can be overridden by derived classes
//////////

// none

//////////
// non-virtual functions in this class
//////////

// none

//////////
// static member variables
//////////

// protected

unsigned add::precedence = 40;

//////////
// global constants
//////////

const add some_add;
const type_info & typeid_add = typeid(some_add);

#ifndef NO_NAMESPACE_GINAC
} // namespace GiNaC
#endif // ndef NO_NAMESPACE_GINAC