#include "am.h"

#include "env.h"
#include "store.h"

#include <assert.h>
#include <string.h>

void am_init(am_t *am)
{
	memset(am, 0, sizeof(am_t));
	am->sp = am->stack + AM_STACK_SIZE - 1;
	store_init(am);
	env_init(am);
}

void am_push(am_t *am, am_reg_t reg)
{
	assert(am->sp >= am->stack);
	*am->sp-- = am->regs[reg];
}

void am_pop(am_t *am, am_reg_t reg)
{
	assert(am->sp < am->stack + AM_STACK_SIZE - 1);
	am->regs[reg] = *++am->sp;
}

void am_append(am_t *am, am_reg_t list_reg, am_reg_t item_reg)
{
	expr_t *list = am->regs[list_reg];
	while (!list->is_atom)
		list = list->pair.cdr;

	list->is_atom = false;
	list->pair.car = am->regs[item_reg];
	list->pair.cdr = expr_empty_list(am);
}

void am_car(am_t *am, am_reg_t dest, am_reg_t src)
{
	assert(!am->regs[src]->is_atom);
	am->regs[dest] = am->regs[src]->pair.car;
}

void am_cdr(am_t *am, am_reg_t dest, am_reg_t src)
{
	assert(!am->regs[src]->is_atom);
	am->regs[dest] = am->regs[src]->pair.cdr;
}

void am_assign(am_t *am, am_reg_t dest, am_reg_t src)
{
	am->regs[dest] = am->regs[src];
}

void am_call(am_t *am, am_reg_t proc)
{
	assert(am->regs[proc]->is_atom);
	assert(am->regs[proc]->atom.type == ATOM_TYPE_PRIM_PROC);
	assert(am->regs[proc]->atom.prim_proc != NULL);
	am->regs[proc]->atom.prim_proc(am);
}