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

/*
 *  GiNaC Copyright (C) 1999-2001 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 "matrix.h"
#include "archive.h"
#include "debugmsg.h"
#include "utils.h"

namespace GiNaC {

GINAC_IMPLEMENT_REGISTERED_CLASS(add, expairseq)

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

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

DEFAULT_COPY(add)
DEFAULT_DESTROY(add)

//////////
// 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)
{
	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
//////////

DEFAULT_ARCHIVING(add)

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

// public

void add::print(const print_context & c, unsigned level) const
{
	debugmsg("add print", LOGLEVEL_PRINT);

	if (is_of_type(c, print_tree)) {

		inherited::print(c, level);

	} else if (is_of_type(c, print_csrc)) {

		if (precedence() <= level)
			c.s << "(";
	
		// Print arguments, separated by "+"
		epvector::const_iterator it = seq.begin(), 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->print(c, precedence());
			} else if (it->coeff.compare(_num_1()) == 0) {
				c.s << "-";
				it->rest.bp->print(c, precedence());
			} else if (ex_to_numeric(it->coeff).numer().compare(_num1()) == 0) {
				it->rest.bp->print(c, precedence());
				c.s << "/";
				ex_to_numeric(it->coeff).denom().print(c, precedence());
			} else if (ex_to_numeric(it->coeff).numer().compare(_num_1()) == 0) {
				c.s << "-";
				it->rest.bp->print(c, precedence());
				c.s << "/";
				ex_to_numeric(it->coeff).denom().print(c, precedence());
			} else {
				it->coeff.bp->print(c, precedence());
				c.s << "*";
				it->rest.bp->print(c, 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)))
				c.s << "+";
		}
	
		if (!overall_coeff.is_zero()) {
			if (overall_coeff.info(info_flags::positive))
				c.s << '+';
			overall_coeff.bp->print(c, precedence());
		}
	
		if (precedence() <= level)
			c.s << ")";

	} else {

		if (precedence() <= level) {
			if (is_of_type(c, print_latex))
				c.s << "{(";
			else
				c.s << "(";
		}

		numeric coeff;
		bool first = true;

		// First print the overall numeric coefficient, if present
		if (!overall_coeff.is_zero()) {
			if (!is_of_type(c, print_tree))
				overall_coeff.print(c, 0);
			else
				overall_coeff.print(c, precedence());
			first = false;
		}

		// Then proceed with the remaining factors
		epvector::const_iterator it = seq.begin(), itend = seq.end();
		while (it != itend) {
			coeff = ex_to_numeric(it->coeff);
			if (!first) {
				if (coeff.csgn() == -1) c.s << '-'; else c.s << '+';
			} else {
				if (coeff.csgn() == -1) c.s << '-';
				first = false;
			}
			if (!coeff.is_equal(_num1()) &&
			    !coeff.is_equal(_num_1())) {
				if (coeff.is_rational()) {
					if (coeff.is_negative())
						(-coeff).print(c);
					else
						coeff.print(c);
				} else {
					if (coeff.csgn() == -1)
						(-coeff).print(c, precedence());
					else
						coeff.print(c, precedence());
				}
				if (is_of_type(c, print_latex))
					c.s << ' ';
				else
					c.s << '*';
			}
			it->rest.print(c, precedence());
			it++;
		}

		if (precedence() <= level) {
			if (is_of_type(c, print_latex))
				c.s << ")}";
			else
				c.s << ")";
		}
	}
}

bool add::info(unsigned inf) const
{
	switch (inf) {
		case info_flags::polynomial:
		case info_flags::integer_polynomial:
		case info_flags::cinteger_polynomial:
		case info_flags::rational_polynomial:
		case info_flags::crational_polynomial:
		case info_flags::rational_function: {
			for (epvector::const_iterator i=seq.begin(); i!=seq.end(); ++i) {
				if (!(recombine_pair_to_ex(*i).info(inf)))
					return false;
			}
			return overall_coeff.info(inf);
		}
		case info_flags::algebraic: {
			for (epvector::const_iterator i=seq.begin(); i!=seq.end(); ++i) {
				if ((recombine_pair_to_ex(*i).info(inf)))
					return true;
			}
			return false;
		}
	}
	return inherited::info(inf);
}

int add::degree(const ex & 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 ex & 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 ex & s, int n) const
{
	epvector coeffseq;
	
	epvector::const_iterator it=seq.begin();
	while (it!=seq.end()) {
		ex restcoeff = it->rest.coeff(s,n);
		if (!restcoeff.is_zero())
			coeffseq.push_back(combine_ex_with_coeff_to_pair(restcoeff,it->coeff));
		++it;
	}
	
	return (new add(coeffseq, n==0 ? overall_coeff : default_overall_coeff()))->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_zero());
		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();
}

ex add::evalm(void) const
{
	// Evaluate children first and add up all matrices. Stop if there's one
	// term that is not a matrix.
	epvector *s = new epvector;
	s->reserve(seq.size());

	bool all_matrices = true;
	bool first_term = true;
	matrix sum;

	epvector::const_iterator it = seq.begin(), itend = seq.end();
	while (it != itend) {
		const ex &m = recombine_pair_to_ex(*it).evalm();
		s->push_back(split_ex_to_pair(m));
		if (is_ex_of_type(m, matrix)) {
			if (first_term) {
				sum = ex_to_matrix(m);
				first_term = false;
			} else
				sum = sum.add(ex_to_matrix(m));
		} else
			all_matrices = false;
		it++;
	}

	if (all_matrices)
		return sum + overall_coeff;
	else
		return (new add(s, overall_coeff))->setflag(status_flags::dynallocated);
}

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 = new mul(mulref);
		mulcopyp->overall_coeff = _ex1();
		mulcopyp->clearflag(status_flags::evaluated);
		mulcopyp->clearflag(status_flags::hash_calculated);
		mulcopyp->setflag(status_flags::dynallocated);
		return expair(*mulcopyp,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 = new mul(mulref);
		mulcopyp->overall_coeff = _ex1();
		mulcopyp->clearflag(status_flags::evaluated);
		mulcopyp->clearflag(status_flags::hash_calculated);
		mulcopyp->setflag(status_flags::dynallocated);
		if (are_ex_trivially_equal(c, _ex1()))
			return expair(*mulcopyp, numfactor);
		else if (are_ex_trivially_equal(numfactor, _ex1()))
			return expair(*mulcopyp, c);
		else
			return expair(*mulcopyp, 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 (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) {
		// the terms have not changed, so it is safe to declare this expanded
		setflag(status_flags::expanded);
		return *this;
	}
	
	return (new add(vp,overall_coeff))->setflag(status_flags::expanded | status_flags::dynallocated);
}

} // namespace GiNaC