/* spl_vm.h — SIR interpreter */

#ifndef __SPL_VM_H__
#define __SPL_VM_H__

#include "include/core_vec.h"
#include "spl_ir.h"
#include <stdint.h>

#define SPL_STACK_CANARY ((spl_val_t)0xDEADBEEFCAFEBABEull)

typedef struct {
    uintptr_t saved_sp;
    uintptr_t saved_fp;
    uintptr_t saved_ip;
    spl_val_t nargs;
} spl_callframe_t;

typedef VEC(spl_val_t) spl_stack_vec_t;
typedef VEC(spl_callframe_t) spl_frame_vec_t;

typedef struct {
    spl_stack_vec_t stacks;
    spl_frame_vec_t frames;
    uintptr_t gp; // global pointer
    uintptr_t sp; // stack pointer
    uintptr_t fp; // frame pointer
    uintptr_t cp; // call pointer
    uintptr_t ip; // instr pointer
    int exit_code;
    int trace; /* non-zero to print each instruction */
    int debug; /* non-zero to enable canary checks */
    spl_prog_t *prog;
    char error_msg[1024];
    struct {
        uintptr_t max_stack_depth;
        uintptr_t max_call_depth;
    } config;
} spl_vm_t;

/* Initialize VM with default sizes (SPL_DEFAULT_STACK_SIZE /
 * SPL_DEFAULT_CALL_DEPTH) */
void spl_vm_init(spl_vm_t *vm);

/* Initialize VM with custom sizes (pass 0 to use defaults) */
void spl_vm_init_ex(spl_vm_t *vm, int stack_size, int call_depth);

/* Free dynamically allocated memory in VM */
void spl_vm_drop(spl_vm_t *vm);

int spl_vm_load_prog(spl_vm_t *vm, spl_prog_t *prog);
int spl_vm_prepare(spl_vm_t *vm, const char *entry, int argc, const char **argv, const char **envp);

/* Enable/disable instruction-level tracing */
void spl_vm_set_trace(spl_vm_t *vm, int enabled);

/* Enable/disable debug mode (stack canary protection) */
void spl_vm_set_debug(spl_vm_t *vm, int enabled);

int spl_vm_run_once(spl_vm_t *vm);
int spl_vm_run_until(spl_vm_t *vm, size_t step);

void spl_vm_dump_instr(spl_vm_t *vm, spl_val_t ip);
void spl_vm_stackdump(spl_vm_t *vm, spl_val_t sp);
int spl_vm_backtrace(spl_vm_t *vm, spl_val_t fp);

#endif /* __SPL_VM_H__ */