%{
#include <stdio.h>
#include <string.h>
#include <stdlib.h>

#ifdef __cplusplus
extern "C" {
#endif

#include "configrc.h"
    
static int open_new_rcsection();
static int close_new_rcsection();
static int close_all_rcsection();

%}

%union {
    struct rc_item_t *rc_item;
    unsigned int expr;
}

%token BEGIN_RC END_RC EQUAL
%token <rc_item> KEYWORD
%token <expr> NUMBER 
%token LSHIFT RSHIFT
%left '-' '+'
%left '*' '/'
%nonassoc UMINUS

%type <expr> expression

%%

rc_sections: rc_section
| rc_sections rc_section

rc_section: begin_rc rc_items end_rc;

begin_rc: BEGIN_RC { printf("Open a new RC section\n");open_new_rcsection(); }
end_rc: END_RC { printf("Close a new RC section\n");close_new_rcsection(); }

rc_items: rc_item
| rc_items rc_item;

rc_item: KEYWORD EQUAL expression {
    printf("Change RC item %s to %d\n", $1->rc_item_name, $3);
    *$1->rc_item_ptr = $3;
}

expression: expression '+' expression {  $$ = $1 + $3; }
| expression '-' expression {  $$ = $1 - $3; }
| expression '*' expression {  $$ = $1 * $3; }
| expression '/' expression {
    if ($3 == 0.0) yyerror("divide by zero");
    else $$ = $1 / $3;
}
| '-' expression %prec UMINUS { $$ = -$2; }
| '(' expression ')' { $$ = $2; }
| NUMBER;

%%

 
#ifdef __cplusplus
}
#endif

struct rc_param_t *rc_params = NULL;
struct rc_param_t *last_rcparam = NULL;

char *config_fn = NULL;
FILE *config_fp = NULL;

int yywrap()
{
    return (1);
}

static int open_new_rcsection()
{
    int rcparam_number = 0;

    /* The first element of rc_params is always there even we don't have config file
     * If config file is set, the first element of rc_params will be reset
     */
    if (last_rcparam != NULL) {
        rcparam_number =  last_rcparam - rc_params + 1;
        rc_params = (struct rc_param_t *)realloc(rc_params, (rcparam_number + 1) * sizeof (struct rc_param_t));
    }
    
    last_rcparam = rc_params + rcparam_number;
    if (rcparam_number >= 1) /* copy field from last rc_param */
        memcpy(last_rcparam, last_rcparam - 1, sizeof(struct rc_param_t));

    last_rcparam->mask = 0;
    
    return 0;
}

static int close_new_rcsection()
{
    int rcparam_number = rc_params - last_rcparam;

    if (rcparam_number >= 2) {
        struct rc_param_t *prior_rcparam = last_rcparam - 1;
        
        /* make last rc param cover more frames if there is gap */
        if (prior_rcparam->frame_end < (last_rcparam->frame_start - 1))
            prior_rcparam->frame_end = last_rcparam->frame_start - 1;
    }
    
    if (last_rcparam->frame_end < last_rcparam->frame_start)
        last_rcparam->frame_end = last_rcparam->frame_start;
    
    return 0;
}