/* see copyright notice in squirrel.h */
#include <squirrel.h>
#include <math.h>
#include <stdlib.h>
#include <sqstdmath.h>

#define SINGLE_ARG_FUNC(_funcname) static SQInteger math_##_funcname(HSQUIRRELVM v){ \
	SQFloat f; \
	sq_getfloat(v,2,&f); \
	sq_pushfloat(v,(SQFloat)_funcname(f)); \
	return 1; \
}

#define TWO_ARGS_FUNC(_funcname) static SQInteger math_##_funcname(HSQUIRRELVM v){ \
	SQFloat p1,p2; \
	sq_getfloat(v,2,&p1); \
	sq_getfloat(v,3,&p2); \
	sq_pushfloat(v,(SQFloat)_funcname(p1,p2)); \
	return 1; \
}

static SQInteger math_srand(HSQUIRRELVM v)
{
	SQInteger i;
	if(SQ_FAILED(sq_getinteger(v,2,&i)))
		return sq_throwerror(v,_SC("invalid param"));
	srand((unsigned int)i);
	return 0;
}

static SQInteger math_rand(HSQUIRRELVM v)
{
	sq_pushinteger(v,rand());
	return 1;
}

static SQInteger math_iabs(HSQUIRRELVM v)
{
	SQInteger n;
	sq_getinteger(v,2,&n);
	sq_pushinteger(v,(SQInteger)abs((int)n)); 
	return 1; 
}

static SQInteger math_abs(HSQUIRRELVM v)
{
	if(sq_gettype(v,2) == OT_INTEGER) {
		SQInteger n;
		sq_getinteger(v,2,&n);
		sq_pushinteger(v,(SQInteger)abs((int)n));
	} else {
		SQFloat f;
		sq_getfloat(v,2,&f);
		sq_pushfloat(v,(SQFloat)fabs(f));
	}
	return 1; 
}

static SQInteger math_min(HSQUIRRELVM v)
{
	SQInteger n = sq_gettop(v);
	SQInteger minidx = 2;
	for (SQInteger i=3;i<=n;i++) {
		sq_push(v, minidx);
		sq_push(v, i);
		if (sq_cmp(v) < 0) {
			minidx = i;
		}
	}
	sq_push(v, minidx);
	return 1;
}

static SQInteger math_max(HSQUIRRELVM v)
{
	SQInteger n = sq_gettop(v);
	SQInteger maxidx = 2;
	for (SQInteger i=3;i<=n;i++) {
		sq_push(v, maxidx);
		sq_push(v, i);
		if (sq_cmp(v) > 0) {
			maxidx = i;
		}
	}
	sq_push(v, maxidx);
	return 1;
}

SINGLE_ARG_FUNC(sqrt)
SINGLE_ARG_FUNC(fabs)
SINGLE_ARG_FUNC(sin)
SINGLE_ARG_FUNC(cos)
SINGLE_ARG_FUNC(asin)
SINGLE_ARG_FUNC(acos)
SINGLE_ARG_FUNC(log)
SINGLE_ARG_FUNC(log10)
SINGLE_ARG_FUNC(tan)
SINGLE_ARG_FUNC(atan)
TWO_ARGS_FUNC(atan2)
TWO_ARGS_FUNC(pow)
SINGLE_ARG_FUNC(floor)
SINGLE_ARG_FUNC(ceil)
SINGLE_ARG_FUNC(exp)

#define _DECL_FUNC(name,nparams,tycheck) {_SC(#name),math_##name,nparams,tycheck}
static SQRegFunction mathlib_funcs[] = {
	_DECL_FUNC(sqrt,2,_SC(".n")),
	_DECL_FUNC(sin,2,_SC(".n")),
	_DECL_FUNC(cos,2,_SC(".n")),
	_DECL_FUNC(asin,2,_SC(".n")),
	_DECL_FUNC(acos,2,_SC(".n")),
	_DECL_FUNC(log,2,_SC(".n")),
	_DECL_FUNC(log10,2,_SC(".n")),
	_DECL_FUNC(tan,2,_SC(".n")),
	_DECL_FUNC(atan,2,_SC(".n")),
	_DECL_FUNC(atan2,3,_SC(".nn")),
	_DECL_FUNC(pow,3,_SC(".nn")),
	_DECL_FUNC(floor,2,_SC(".n")),
	_DECL_FUNC(ceil,2,_SC(".n")),
	_DECL_FUNC(exp,2,_SC(".n")),
	_DECL_FUNC(srand,2,_SC(".n")),
	_DECL_FUNC(rand,1,NULL),
	_DECL_FUNC(fabs,2,_SC(".n")),
	_DECL_FUNC(iabs,2,_SC(".n")),
	_DECL_FUNC(abs,2,_SC(".n")),
	_DECL_FUNC(min,-2,NULL),
	_DECL_FUNC(max,-2,NULL),
	{0,0},
};

#ifndef M_PI
#define M_PI (3.14159265358979323846)
#endif

SQRESULT sqstd_register_mathlib(HSQUIRRELVM v)
{
	SQInteger i=0;
	while(mathlib_funcs[i].name!=0)	{
		sq_pushstring(v,mathlib_funcs[i].name,-1);
		sq_newclosure(v,mathlib_funcs[i].f,0);
		sq_setparamscheck(v,mathlib_funcs[i].nparamscheck,mathlib_funcs[i].typemask);
		sq_setnativeclosurename(v,-1,mathlib_funcs[i].name);
		sq_createslot(v,-3);
		i++;
	}
	sq_pushstring(v,_SC("RAND_MAX"),-1);
	sq_pushinteger(v,RAND_MAX);
	sq_createslot(v,-3);
	sq_pushstring(v,_SC("PI"),-1);
	sq_pushfloat(v,(SQFloat)M_PI);
	sq_createslot(v,-3);
	return SQ_OK;
}
