/* Syntax analyser
 * by Marek Zelem
 */

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>

#include "language.h"

static int patri_term(tab_t * tab, sym_t term)
{
	int i;
	if ( /* term==END && */ tab->terminal[0] == END)
		return 1;
	for (i = 0; i < 16 && tab->terminal[i] != END; i++) {
		if (tab->terminal[i] == term)
			return 1;
		if (term == END && tab->terminal[i] == TEND)
			return 1;
	}
	return 0;
}

static tab_t *najdi_tab(tab_t * tab, sym_t stav, sym_t term)
{
	while (tab->stav != END) {
		if (tab->stav == stav && patri_term(tab, term))
			return tab;
		tab++;
	}
	return NULL;
}

#define RESIZE_STACK	\
	if( (stack=realloc(stack,sizeof(sym_t)*stacksize))==NULL )\
		return(E|0x0fff)

static sym_t get_want(sym_t * stack, int stacklen)
{
	while (stacklen >= 0) {
		if ((stack[stacklen] & TYP) == T)
			return stack[stacklen];
		if ((stack[stacklen] & TYP) != O)
			return END;
		stacklen--;
	}
	return END;
}

sym_t sa_automat(tab_t * tab, sym_t start,
		 sym_t(*lex) (lex_t *, long, sym_t), void (*out) (lex_t *,
								  sym_t),
		 long d)
{
	lex_t l;
	int i;
	tab_t *t;
	sym_t *stack, want;
	int stacklen, stacksize;
	stack = NULL;
	stacklen = 0;
	stacksize = 100;
	RESIZE_STACK;
	stack[stacklen++] = start;
	lex(&l, d, END);
	if ((l.sym & TYP) == E) {
		free(stack);
		return l.sym;
	}
	while (stacklen > 0) {
		while ((t = najdi_tab(tab, stack[stacklen - 1], l.sym)) ==
		       NULL) {
			lang_error("Unexpected %s", lex2str(&l));
//printf("\nError: Here can't be %s (line %d column %d)\n",lex2str(&l),
//lex_line,lex_char);
			if (l.sym != END)
				lex(&l, d, END);
			else {
				free(stack);
				return E | 0;
			}
		}
		stacklen--;
		i = 0;
		while (t->stack[i] != END)
			i++;
		i--;
		while (i >= 0) {
			stack[stacklen++] = t->stack[i--];
			if (stacklen >= stacksize) {
				stacksize += 100;
				RESIZE_STACK;
			}
		}
		while (stacklen > 0 &&
		       ((stack[stacklen - 1] & TYP) == T
			|| (stack[stacklen - 1] & TYP) == O)
		    ) {
			if ((stack[stacklen - 1] & TYP) == T) {
				if (l.sym != stack[stacklen - 1]) {
					lex_t pl;
					pl.sym = stack[stacklen - 1];
					pl.num = 0;
					lang_error("Missing %s",
						   lex2str(&pl));
//printf("\nError: expected symbol %s ",lex2str(&pl) );
//printf("and come %s on line %d column %d\n",lex2str(&l),lex_line,lex_char);
//                                      free(stack);
//                                      return(E|1);
				} else {
					if (l.sym != END) {
						want =
						    get_want(stack,
							     stacklen - 2);
						lex(&l, d, want);
					}
					if ((l.sym & TYP) == E) {
						free(stack);
						lang_error("Lexical %d",
							   l.sym & ~TYP);
						return l.sym;
					}
				}
			}
			if ((stack[stacklen - 1] & TYP) == O) {
				out(&l, stack[stacklen - 1]);
			}
			stacklen--;
		}
	}
	free(stack);
	return T;
}