%{
/* grecs - Gray's Extensible Configuration System
   Copyright (C) 2007-2021 Sergey Poznyakoff

   Grecs 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 (at your
   option) any later version.

   Grecs 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 Grecs. If not, see <http://www.gnu.org/licenses/>. */

#ifdef HAVE_CONFIG_H
# include <config.h>
#endif
#include <grecs.h>
#include <grecs-gram.h>
#include <stdlib.h>
#include <stdarg.h>
#include <string.h>
#include <errno.h>
  
int yylex(void);
int yyerror(char const *s);

static struct grecs_node *parse_tree;
%}

%define parse.error verbose
%locations

%union {
	char *string;
	grecs_value_t svalue, *pvalue;
	struct grecs_list *list;
	struct grecs_node *node;
	grecs_locus_t locus;
	struct { struct grecs_node *head, *tail; } node_list;
}

%token <string> STRING QSTRING MSTRING IDENT
%type <string> string slist
%type <list> slist0
%type <svalue> value
%type <pvalue> vallist tag
%type <list> values list vlist
%type <node> stmt simple block maybe_stmtlist
%type <node_list> stmtlist

%%

input   : maybe_stmtlist
          {
		  parse_tree = grecs_node_create(grecs_node_root, &@1);
		  parse_tree->v.texttab = grecs_text_table();
		  grecs_node_bind(parse_tree, $1, 1);
	  }
        ;

maybe_stmtlist:
          /* empty */
          {
		  $$ = NULL;
	  }
        | stmtlist
	  {
		  $$ = $1.head;
	  }
        ;

stmtlist: stmt
          {
		  $$.head = $$.tail = $1;
	  } 
        | stmtlist stmt
	  {
		  grecs_node_bind($1.tail, $2, 0);
	  }
        ;

stmt    : simple
        | block
        ;

simple  : IDENT vallist ';'
          {
		  $$ = grecs_node_create_points(grecs_node_stmt,
						@1.beg, @2.end);
		  $$->ident = $1;
		  $$->idloc = @1;
		  $$->v.value = $2;
	  }
        | IDENT ';'
	  {
		  $$ = grecs_node_create(grecs_node_stmt, &@1);
		  $$->ident = $1;
		  $$->idloc = @1;
		  $$->v.value = NULL;
	  }
        ;

block   : IDENT tag '{' stmtlist '}' opt_sc
          {
		  $$ = grecs_node_create_points(grecs_node_block,
						@1.beg, @5.end);
		  $$->ident = $1;
		  $$->idloc = @1;
		  $$->v.value = $2;
		  grecs_node_bind($$, $4.head, 1);
	  }
        ;

tag     : /* empty */
          {
		  $$ = NULL;
	  }
        | vallist
        ;

vallist : vlist
          {
		  size_t n;
		  
		  if ((n = grecs_list_size($1)) == 1) {
			  $$ = grecs_list_index($1, 0);
		  } else {
			  size_t i;
			  struct grecs_list_entry *ep;
		
			  $$ = grecs_malloc(sizeof($$[0]));
			  $$->type = GRECS_TYPE_ARRAY;
			  $$->locus = @1;
			  $$->v.arg.c = n;
			  $$->v.arg.v = grecs_calloc(n,
						     sizeof($$->v.arg.v[0]));
			  for (i = 0, ep = $1->head; ep; i++, ep = ep->next)
				  $$->v.arg.v[i] = ep->data;
		  }
		  $1->free_entry = NULL;
		  grecs_list_free($1);	      
	  }
	;

vlist   : value
          {
		  $$ = grecs_value_list_create();
		  grecs_list_append($$, grecs_value_ptr_from_static(&$1));
	  }
        | vlist value
          {
		  grecs_list_append($1, grecs_value_ptr_from_static(&$2));
	  }
        ;

value   : string
          {
		  $$.type = GRECS_TYPE_STRING;
		  $$.locus = @1;
		  $$.v.string = $1;
	  }
        | list
          {
		  $$.type = GRECS_TYPE_LIST;
		  $$.locus = @1;
		  $$.v.list = $1;
	  }
        | MSTRING
          {
		  $$.type = GRECS_TYPE_STRING;
		  $$.locus = @1;
		  $$.v.string = $1;
	  }	      
        ;        

string  : STRING
        | IDENT
        | slist
        ;

slist   : slist0
          {
		  struct grecs_list_entry *ep;
		  
		  grecs_line_begin();
		  for (ep = $1->head; ep; ep = ep->next) {
			  grecs_line_add(ep->data, strlen(ep->data));
			  free(ep->data);
			  ep->data = NULL;
		  }
		  $$ = grecs_line_finish();
		  grecs_list_free($1);
	  }
        ;

slist0  : QSTRING 
          {
		  $$ = grecs_list_create();
		  grecs_list_append($$, $1);
	  }
        | slist0 QSTRING
          {
		  grecs_list_append($1, $2);
		  $$ = $1;
	  }
        ;

list    : '(' ')'
          {
		  $$ = NULL;
	  }
        | '(' values ')'
          {
		  $$ = $2;
	  }
        | '(' values ',' ')'
          {
		  $$ = $2;
	  }
        ;

values  : value
          {
		  $$ = grecs_value_list_create();
		  grecs_list_append($$, grecs_value_ptr_from_static(&$1));
	  }
        | values ',' value
          {
		  grecs_list_append($1, grecs_value_ptr_from_static(&$3));
		  $$ = $1;
	  }
        ;

opt_sc  : /* empty */
        | ';'
        ;

%%

int
yyerror(char const *s)
{
	grecs_error(&yylloc, 0, "%s", s);
	return 0;
}

struct grecs_node *
grecs_grecs_parser(const char *name, int traceflags)
{
	int rc;
	if (grecs_lex_begin(name, traceflags & GRECS_TRACE_LEX))
		return NULL;
	yydebug = traceflags & GRECS_TRACE_GRAM;
	parse_tree = NULL;
	rc = yyparse();
	if (grecs_error_count)
		rc = 1;
	grecs_lex_end(rc);
	if (rc) {
		grecs_tree_free(parse_tree);
		parse_tree = NULL;
	}
	return parse_tree;
}




    

