/*
 *  OpenSCAD (www.openscad.org)
 *  Copyright (C) 2009-2011 Clifford Wolf <clifford@clifford.at> and
 *                          Marius Kintel <marius@kintel.net>
 *
 *  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.
 *
 *  As a special exception, you have permission to link this program
 *  with the CGAL library and distribute executables, as long as you
 *  follow the requirements of the GNU GPL in regard to all of the
 *  software in the executable aside from CGAL.
 *
 *  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 "function.h"
#include "expression.h"
#include "context.h"
#include "dxfdim.h"
#include "builtin.h"
#include "mathc99.h"
#include <time.h>

AbstractFunction::~AbstractFunction()
{
}

Value AbstractFunction::evaluate(const Context*, const QVector<QString>&, const QVector<Value>&) const
{
	return Value();
}

QString AbstractFunction::dump(QString indent, QString name) const
{
	return QString("%1abstract function %2();\n").arg(indent, name);
}

Function::~Function()
{
	for (int i=0; i < argexpr.size(); i++)
		delete argexpr[i];
	delete expr;
}

Value Function::evaluate(const Context *ctx, const QVector<QString> &call_argnames, const QVector<Value> &call_argvalues) const
{
	Context c(ctx);
	c.args(argnames, argexpr, call_argnames, call_argvalues);
	if (expr)
		return expr->evaluate(&c);
	return Value();
}

QString Function::dump(QString indent, QString name) const
{
	QString text = QString("%1function %2(").arg(indent, name);
	for (int i=0; i < argnames.size(); i++) {
		if (i > 0)
			text += QString(", ");
		text += argnames[i];
		if (argexpr[i])
			text += QString(" = ") + argexpr[i]->dump();
	}
	text += QString(") = %1;\n").arg(expr->dump());
	return text;
}

QHash<QString, AbstractFunction*> builtin_functions;

BuiltinFunction::~BuiltinFunction()
{
}

Value BuiltinFunction::evaluate(const Context *ctx, const QVector<QString> &call_argnames, const QVector<Value> &call_argvalues) const
{
	return eval_func(ctx, call_argnames, call_argvalues);
}

QString BuiltinFunction::dump(QString indent, QString name) const
{
	return QString("%1builtin function %2();\n").arg(indent, name);
}

static double deg2rad(double x)
{
	while (x < 0.0)
		x += 360.0;
	while (x >= 360.0)
		x -= 360.0;
	x = x * M_PI * 2.0 / 360.0;
	return x;
}

static double rad2deg(double x)
{
	x = x * 360.0 / (M_PI * 2.0);
	while (x < 0.0)
		x += 360.0;
	while (x >= 360.0)
		x -= 360.0;
	return x;
}

Value builtin_abs(const Context *, const QVector<QString>&, const QVector<Value> &args)
{
	if (args.size() == 1 && args[0].type == Value::NUMBER)
		return Value(fabs(args[0].num));
	return Value();
}

Value builtin_sign(const Context *, const QVector<QString>&, const QVector<Value> &args)
{
	if (args.size() == 1 && args[0].type == Value::NUMBER)
		return Value((args[0].num<0) ? -1.0 : ((args[0].num>0) ? 1.0 : 0.0));
	return Value();
}

double frand() 
{ 
    return rand()/(double(RAND_MAX)+1); 
} 

double frand(double min, double max) 
{ 
    return (min>max) ? frand()*(min-max)+max : frand()*(max-min)+min;  
} 

Value builtin_rands(const Context *, const QVector<QString>&, const QVector<Value> &args)
{
	if (args.size() == 3 &&
			args[0].type == Value::NUMBER && 
			args[1].type == Value::NUMBER && 
			args[2].type == Value::NUMBER)
	{
		srand((unsigned int)time(0));
	}
	else if (args.size() == 4 && 
					 args[0].type == Value::NUMBER && 
					 args[1].type == Value::NUMBER && 
					 args[2].type == Value::NUMBER && 
					 args[3].type == Value::NUMBER)
	{
		srand((unsigned int)args[3].num);
	}
	else
	{
		return Value();
	}
	
	Value v;
	v.type = Value::VECTOR;
	
	for (int i=0; i<args[2].num; i++)
	{	
		Value * r = new Value(frand(args[0].num, args[1].num));
		v.vec.append(r);
	}
	
	return v;
}


Value builtin_min(const Context *, const QVector<QString>&, const QVector<Value> &args)
{
	if (args.size() >= 1 && args[0].type == Value::NUMBER) {
		double val = args[0].num;
		for (int i = 1; i < args.size(); i++)
			if (args[1].type == Value::NUMBER)
				val = fmin(val, args[i].num);
		return Value(val);
	}
	return Value();
}

Value builtin_max(const Context *, const QVector<QString>&, const QVector<Value> &args)
{
	if (args.size() >= 1 && args[0].type == Value::NUMBER) {
		double val = args[0].num;
		for (int i = 1; i < args.size(); i++)
			if (args[1].type == Value::NUMBER)
				val = fmax(val, args[i].num);
		return Value(val);
	}
	return Value();
}

Value builtin_sin(const Context *, const QVector<QString>&, const QVector<Value> &args)
{
	if (args.size() == 1 && args[0].type == Value::NUMBER)
		return Value(sin(deg2rad(args[0].num)));
	return Value();
}

Value builtin_cos(const Context *, const QVector<QString>&, const QVector<Value> &args)
{
	if (args.size() == 1 && args[0].type == Value::NUMBER)
		return Value(cos(deg2rad(args[0].num)));
	return Value();
}

Value builtin_asin(const Context *, const QVector<QString>&, const QVector<Value> &args)
{
	if (args.size() == 1 && args[0].type == Value::NUMBER)
		return Value(rad2deg(asin(args[0].num)));
	return Value();
}

Value builtin_acos(const Context *, const QVector<QString>&, const QVector<Value> &args)
{
	if (args.size() == 1 && args[0].type == Value::NUMBER)
		return Value(rad2deg(acos(args[0].num)));
	return Value();
}

Value builtin_tan(const Context *, const QVector<QString>&, const QVector<Value> &args)
{
	if (args.size() == 1 && args[0].type == Value::NUMBER)
		return Value(tan(deg2rad(args[0].num)));
	return Value();
}

Value builtin_atan(const Context *, const QVector<QString>&, const QVector<Value> &args)
{
	if (args.size() == 1 && args[0].type == Value::NUMBER)
		return Value(rad2deg(atan(args[0].num)));
	return Value();
}

Value builtin_atan2(const Context *, const QVector<QString>&, const QVector<Value> &args)
{
	if (args.size() == 2 && args[0].type == Value::NUMBER && args[1].type == Value::NUMBER)
		return Value(rad2deg(atan2(args[0].num, args[1].num)));
	return Value();
}

Value builtin_pow(const Context *, const QVector<QString>&, const QVector<Value> &args)
{
	if (args.size() == 2 && args[0].type == Value::NUMBER && args[1].type == Value::NUMBER)
		return Value(pow(args[0].num, args[1].num));
	return Value();
}

Value builtin_round(const Context *, const QVector<QString>&, const QVector<Value> &args)
{
	if (args.size() == 1 && args[0].type == Value::NUMBER)
		return Value(round(args[0].num));
	return Value();
}

Value builtin_ceil(const Context *, const QVector<QString>&, const QVector<Value> &args)
{
	if (args.size() == 1 && args[0].type == Value::NUMBER)
		return Value(ceil(args[0].num));
	return Value();
}

Value builtin_floor(const Context *, const QVector<QString>&, const QVector<Value> &args)
{
	if (args.size() == 1 && args[0].type == Value::NUMBER)
		return Value(floor(args[0].num));
	return Value();
}

Value builtin_sqrt(const Context *, const QVector<QString>&, const QVector<Value> &args)
{
	if (args.size() == 1 && args[0].type == Value::NUMBER)
		return Value(sqrt(args[0].num));
	return Value();
}

Value builtin_exp(const Context *, const QVector<QString>&, const QVector<Value> &args)
{
	if (args.size() == 1 && args[0].type == Value::NUMBER)
		return Value(exp(args[0].num));
	return Value();
}

Value builtin_log(const Context *, const QVector<QString>&, const QVector<Value> &args)
{
	if (args.size() == 2 && args[0].type == Value::NUMBER && args[1].type == Value::NUMBER)
		return Value(log(args[1].num) / log(args[0].num));
	if (args.size() == 1 && args[0].type == Value::NUMBER)
		return Value(log(args[0].num) / log(10.0));
	return Value();
}

Value builtin_ln(const Context *, const QVector<QString>&, const QVector<Value> &args)
{
	if (args.size() == 1 && args[0].type == Value::NUMBER)
		return Value(log(args[0].num));
	return Value();
}

Value builtin_str(const Context *, const QVector<QString>&, const QVector<Value> &args)
{
	QString str;
	for (int i = 0; i < args.size(); i++)
	{
		if (args[i].type == Value::STRING)
			str += args[i].text;
		else
			str += args[i].dump();
	}
	return Value(str);
}

Value builtin_lookup(const Context *, const QVector<QString>&, const QVector<Value> &args)
{
	double p, low_p, low_v, high_p, high_v;
	if (args.size() < 2 || !args[0].getnum(p) || args[1].vec.size() < 2 || args[1].vec[0]->vec.size() < 2)
		return Value();
	if (!args[1].vec[0]->getv2(low_p, low_v) || !args[1].vec[0]->getv2(high_p, high_v))
		return Value();
	for (int i = 1; i < args[1].vec.size(); i++) {
		double this_p, this_v;
		if (args[1].vec[i]->getv2(this_p, this_v)) {
			if (this_p <= p && (this_p > low_p || low_p > p)) {
				low_p = this_p;
				low_v = this_v;
			}
			if (this_p >= p && (this_p < high_p || high_p < p)) {
				high_p = this_p;
				high_v = this_v;
			}
		}
	}
	if (p <= low_p)
		return Value(low_v);
	if (p >= high_p)
		return Value(high_v);
	double f = (p-low_p) / (high_p-low_p);
	return Value(high_v * f + low_v * (1-f));
}

void initialize_builtin_functions()
{
	builtin_functions["abs"] = new BuiltinFunction(&builtin_abs);
	builtin_functions["sign"] = new BuiltinFunction(&builtin_sign);
	builtin_functions["rands"] = new BuiltinFunction(&builtin_rands);
	builtin_functions["min"] = new BuiltinFunction(&builtin_min);
	builtin_functions["max"] = new BuiltinFunction(&builtin_max);
	builtin_functions["sin"] = new BuiltinFunction(&builtin_sin);
	builtin_functions["cos"] = new BuiltinFunction(&builtin_cos);
	builtin_functions["asin"] = new BuiltinFunction(&builtin_asin);
	builtin_functions["acos"] = new BuiltinFunction(&builtin_acos);
	builtin_functions["tan"] = new BuiltinFunction(&builtin_tan);
	builtin_functions["atan"] = new BuiltinFunction(&builtin_atan);
	builtin_functions["atan2"] = new BuiltinFunction(&builtin_atan2);
	builtin_functions["round"] = new BuiltinFunction(&builtin_round);
	builtin_functions["ceil"] = new BuiltinFunction(&builtin_ceil);
	builtin_functions["floor"] = new BuiltinFunction(&builtin_floor);
	builtin_functions["pow"] = new BuiltinFunction(&builtin_pow);
	builtin_functions["sqrt"] = new BuiltinFunction(&builtin_sqrt);
	builtin_functions["exp"] = new BuiltinFunction(&builtin_exp);
	builtin_functions["log"] = new BuiltinFunction(&builtin_log);
	builtin_functions["ln"] = new BuiltinFunction(&builtin_ln);
	builtin_functions["str"] = new BuiltinFunction(&builtin_str);
	builtin_functions["lookup"] = new BuiltinFunction(&builtin_lookup);
	initialize_builtin_dxf_dim();
}

void destroy_builtin_functions()
{
	foreach (AbstractFunction *v, builtin_functions)
		delete v;
	builtin_functions.clear();
}