/*
 *  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 "builtin.h"
#include <sstream>
#include <ctime>
#include "mathc99.h"
#include <algorithm>
#include "stl-utils.h"

AbstractFunction::~AbstractFunction()
{
}

Value AbstractFunction::evaluate(const Context*, const std::vector<std::string>&, const std::vector<Value>&) const
{
	return Value();
}

std::string AbstractFunction::dump(const std::string &indent, const std::string &name) const
{
	std::stringstream dump;
	dump << indent << "abstract function " << name << "();\n";
	return dump.str();
}

Function::~Function()
{
	std::for_each(this->argexpr.begin(), this->argexpr.end(), del_fun<Expression>());
	delete expr;
}

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

std::string Function::dump(const std::string &indent, const std::string &name) const
{
	std::stringstream dump;
	dump << indent << "function " << name << "(";
	for (size_t i=0; i < argnames.size(); i++) {
		if (i > 0) dump << ", ";
		dump << argnames[i];
		if (argexpr[i]) dump << " = " << *argexpr[i];
	}
	dump << ") = " << *expr << ";\n";
	return dump.str();
}

BuiltinFunction::~BuiltinFunction()
{
}

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

std::string BuiltinFunction::dump(const std::string &indent, const std::string &name) const
{
	std::stringstream dump;
	dump << indent << "builtin function " << name << "();\n";
	return dump.str();
}

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 std::vector<std::string>&, const std::vector<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 std::vector<std::string>&, const std::vector<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 std::vector<std::string>&, const std::vector<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.push_back(r);
	}
	
	return v;
}


Value builtin_min(const Context *, const std::vector<std::string>&, const std::vector<Value> &args)
{
	if (args.size() >= 1 && args[0].type == Value::NUMBER) {
		double val = args[0].num;
		for (size_t 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 std::vector<std::string>&, const std::vector<Value> &args)
{
	if (args.size() >= 1 && args[0].type == Value::NUMBER) {
		double val = args[0].num;
		for (size_t 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 std::vector<std::string>&, const std::vector<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 std::vector<std::string>&, const std::vector<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 std::vector<std::string>&, const std::vector<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 std::vector<std::string>&, const std::vector<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 std::vector<std::string>&, const std::vector<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 std::vector<std::string>&, const std::vector<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 std::vector<std::string>&, const std::vector<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 std::vector<std::string>&, const std::vector<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 std::vector<std::string>&, const std::vector<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 std::vector<std::string>&, const std::vector<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 std::vector<std::string>&, const std::vector<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 std::vector<std::string>&, const std::vector<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 std::vector<std::string>&, const std::vector<Value> &args)
{
	if (args.size() == 1 && args[0].type == Value::NUMBER)
		return Value(exp(args[0].num));
	return Value();
}

Value builtin_length(const Context *, const std::vector<std::string>&, const std::vector<Value> &args)
{
	if (args.size() == 1){
		if (args[0].type == Value::VECTOR)
			return Value((double) args[0].vec.size());
		if (args[0].type == Value::STRING)
			return Value((double) args[0].text.size());
	}
	return Value();
}

Value builtin_log(const Context *, const std::vector<std::string>&, const std::vector<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 std::vector<std::string>&, const std::vector<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 std::vector<std::string>&, const std::vector<Value> &args)
{
	std::stringstream stream;

	for (size_t i = 0; i < args.size(); i++) {
		stream << args[i].toString();
	}
	return Value(stream.str());
}

Value builtin_lookup(const Context *, const std::vector<std::string>&, const std::vector<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 (size_t 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));
}

#define QUOTE(x__) # x__
#define QUOTED(x__) QUOTE(x__)

Value builtin_version(const Context *, const std::vector<std::string>&, const std::vector<Value> &)
{
	Value val;
	val.type = Value::VECTOR;
	val.append(new Value(double(OPENSCAD_YEAR)));
	val.append(new Value(double(OPENSCAD_MONTH)));
#ifdef OPENSCAD_DAY
	val.append(new Value(double(OPENSCAD_DAY)));
#endif
	return val;
}

Value builtin_version_num(const Context *ctx, const std::vector<std::string>& call_argnames, const std::vector<Value> &args)
{
	Value val = (args.size() == 0) ? builtin_version(ctx, call_argnames, args) : args[0];
	double y, m, d = 0;
	if (!val.getv3(y, m, d)) {
		if (!val.getv2(y, m)) {
			return Value();
		}
	}
	return Value(y * 10000 + m * 100 + d);
}

void register_builtin_functions()
{
	Builtins::init("abs", new BuiltinFunction(&builtin_abs));
	Builtins::init("sign", new BuiltinFunction(&builtin_sign));
	Builtins::init("rands", new BuiltinFunction(&builtin_rands));
	Builtins::init("min", new BuiltinFunction(&builtin_min));
	Builtins::init("max", new BuiltinFunction(&builtin_max));
	Builtins::init("sin", new BuiltinFunction(&builtin_sin));
	Builtins::init("cos", new BuiltinFunction(&builtin_cos));
	Builtins::init("asin", new BuiltinFunction(&builtin_asin));
	Builtins::init("acos", new BuiltinFunction(&builtin_acos));
	Builtins::init("tan", new BuiltinFunction(&builtin_tan));
	Builtins::init("atan", new BuiltinFunction(&builtin_atan));
	Builtins::init("atan2", new BuiltinFunction(&builtin_atan2));
	Builtins::init("round", new BuiltinFunction(&builtin_round));
	Builtins::init("ceil", new BuiltinFunction(&builtin_ceil));
	Builtins::init("floor", new BuiltinFunction(&builtin_floor));
	Builtins::init("pow", new BuiltinFunction(&builtin_pow));
	Builtins::init("sqrt", new BuiltinFunction(&builtin_sqrt));
	Builtins::init("exp", new BuiltinFunction(&builtin_exp));
	Builtins::init("len", new BuiltinFunction(&builtin_length));
	Builtins::init("log", new BuiltinFunction(&builtin_log));
	Builtins::init("ln", new BuiltinFunction(&builtin_ln));
	Builtins::init("str", new BuiltinFunction(&builtin_str));
	Builtins::init("lookup", new BuiltinFunction(&builtin_lookup));
	Builtins::init("version", new BuiltinFunction(&builtin_version));
	Builtins::init("version_num", new BuiltinFunction(&builtin_version_num));
}