/*
 * Copyright (C) 2020 Weber Yann
 * 
 * This file is part of pyrpn.
 * 
 * pyrpn 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 3 of the License, or
 * any later version.
 * 
 * pyrpn 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 pyrpn.  If not, see <http://www.gnu.org/licenses/>.
 */
#include "rpn_if.h"

rpn_if_t* rpn_if_new(const rpn_if_param_t *params, rpn_value_t *memmap)
{
	rpn_if_t *res;
	size_t i;
	int err;

	res = malloc(sizeof(rpn_if_t));
	if(!res)
	{
		goto error;
	}
	
	//memcpy(&res->params, params, sizeof(rpn_if_param_t));
	res->params = params;

	if(memmap)
	{
		res->self_mem = 0;
		res->mem = memmap;
	}
	else
	{
		res->self_mem = 1;
		res->mem = mmap(NULL, params->mem_sz, PROT_READ|PROT_WRITE, MAP_ANON,
			-1, 0);
		if(res->mem == (void*)-1)
		{
			goto mmap_err;
		}
	}

	res->rpn_res = malloc(sizeof(rpn_value_t) *
		(params->rpn_sz + params->rpn_argc));
	if(!res->rpn_res)
	{
		goto rpn_malloc_err;
	}
	res->rpn_args = &(res->rpn_res[params->rpn_sz]);

	res->rpn = malloc(sizeof(rpn_expr_t*) * params->rpn_sz);
	if(!res->rpn)
	{
		goto rpn_expr_err;
	}
	for(i=0; i<params->rpn_sz; i++)
	{
		if(rpn_expr_init(&(res->rpn[i]), params->rpn_stack_sz,
				params->rpn_argc) < 0)
		{
			goto rpn_init_error;
		}
	}

	return res;

	rpn_init_error:
		err = errno;
		while(i)
		{
			rpn_expr_close(&(res->rpn[i]));
			i--;
		}
	rpn_expr_err:
		err = errno;
		free(res->rpn_res);
	rpn_malloc_err:
		err = errno;
		if(res->self_mem)
		{
			munmap(res->mem, params->mem_sz);
		}
	mmap_err:
		err = errno;
		free(res);
	error:
		err = errno;
		errno = err;
		return NULL;
}

void rpn_if_free(rpn_if_t* rif)
{
	size_t i;
	for(i=0; i<rif->params->rpn_sz; i++)
	{
		rpn_expr_close(&(rif->rpn[i]));
	}
	free(rif->rpn);
	free(rif->rpn_res);
	if(rif->self_mem)
	{
		munmap(rif->mem, rif->params->mem_sz);
	}
	free(rif);
}

size_t rpn_if_step(rpn_if_t *rif, size_t pos)
{
	size_t i;
	size_t newpos;
	rif->params->arg_f(rif, pos, rif->rpn_args);
	/* WRONG ! rif->rpn_args is in rif structure and do not have to be
	   given as argument... */
	for(i=0; i<rif->params->rpn_sz; i++)
	{
		rif->rpn_res[i] = rpn_expr_eval(&(rif->rpn[i]), rif->rpn_args);
	}
	//rif->params->res_f(rif, &newpos, rif->rpn_res);
	/* MEGA WRONG ! rif->rpn_res is in rif structure and do not have to be
	   given as argument... */
	rif->params->res_f(rif, &newpos, NULL);
	return newpos;
}

rpn_expr_t **rpn_if_rpn_get(rpn_if_t *rif)
{
	return &(rif->rpn);
}