#ifndef SK_STATE_H
#define SK_STATE_H

#include "value.h"

#define SK size_t
#define SK_NO_ID (-1)

struct local
{
    int id;
    size_t addr;
};

struct stack_value
{
    size_t addr;
    struct value* value;
};

struct frame
{
    struct vec stack_values;
    struct vec locals;
    struct vec stack;
    struct fun* fun;
};

struct global
{
    int id;
    size_t addr;
};

struct state
{
    struct vec frames;
    size_t addr;
    int global_id;
    struct vec globals;
    struct vec global_values;
};

typedef SK (*nfun_body)(struct state*, struct vec*);

void stack_value_init(struct stack_value* self,
                size_t addr,
                struct value* new_value);

void stack_value_free(struct stack_value* self);

void frame_init(struct frame* self);
void frame_free(struct frame* self);

void state_init(struct state* self);
void state_free(struct state* self);

SK state_make_ref(struct state* self);
struct value* state_try_deref(struct state* self, size_t ref);

struct frame* state_frame(struct state* self);
void state_push_frame(struct state* self);
void state_pop_frame(struct state* self);

SK state_top(struct state* self);
struct value* state_try_get_value(struct state* self, SK value);
struct local* state_try_get_local_by_id(struct state* self, int id);

SK state_pop(struct state* self);

SK state_push(struct state* self,
              TypeKind type,
              union val val,
              int line);

SK state_push_int(struct state* self, int integer, int line);
SK state_push_bool(struct state* self, bool boolean, int line);
SK state_push_float(struct state* self, double real, int line);
SK state_push_string(struct state* self, char const* str, int line);
SK state_push_fun(struct state* self, struct fun* fun, int line);
SK state_push_ref(struct state* self, size_t ref, int line);

struct local* state_try_get_local(struct state* self, int id);

SK state_local_store(struct state* self,
                     int id);

void state_closure_store(struct state* self,
                         int id);

void state_local_load(struct state* self,
                      int id);

void state_global_load(struct state* self,
                      int id);

void state_closure_load(struct state* self,
                        int id);

TypeKind state_common_num_type(struct state* self, SK lhs, SK rhs);
TypeKind state_type(struct state* self, SK value);
double state_as_real(struct state* self, SK lhs);
int state_line(struct state* self, SK lhs);

SK state_add(struct state* self);
SK state_sub(struct state* self);
SK state_usub(struct state* self);
SK state_mul(struct state* self);
SK state_div(struct state* self);
SK state_mod(struct state* self);
SK state_pow(struct state* self);

SK state_and(struct state* self);
SK state_or(struct state* self);
SK state_not(struct state* self);

SK state_lt(struct state* self);
SK state_gt(struct state* self);
SK state_eq(struct state* self);

int state_add_global(struct state* self,
                     struct value* value);

void state_call(struct state* self, struct fun* fun);
void state_ret(struct state* self);
SK state_add_nfun(struct state* self,
                  nfun_body body,
                  int arity);
#endif