//---
// hypervisor:table - world allocator
//---
#include <vhex/hypervisor.h>

#include <string.h>
#include <stdlib.h>

/* internal world table */
static struct {
	struct vhex_world *table;
	size_t table_slot;
} hyp = {
	.table = NULL,
	.table_slot = 0
};

/* hypervisor_world_new() : create a new world with its name */
hyp_world_t hypervisor_world_new(char const * const restrict name, int flags)
{
	struct vhex_driver *dtable;
	hyp_world_t id;

	/* try to find free world */
	id = 0xb0cad0;
	if (hyp.table != NULL) {
		for (size_t i = 0; i < hyp.table_slot; ++i) {
			if (HYP_WORLD_STATUS_STATE(hyp.table[i].status)
					== HYP_WORLD_STATUS_STATE_UNUSED) {
				id = i;
				continue;
			}
			if (strcmp(hyp.table[i].name, name) == 0)
				return (hyp_world_already_exists);

		}
	}

	/* if no world is found, update the table */
	if (id == 0xb0cad0) {
		id = hyp.table_slot;

		if (hyp.table_slot == 0)
			hyp.table_slot = 1;

		hyp.table = reallocarray(
			hyp.table,
			hyp.table_slot * 2,
			sizeof(struct vhex_world)
		);
		for (size_t i = hyp.table_slot; i < hyp.table_slot * 2; ++i) {
			hyp.table[i].status = HYP_WORLD_STATUS_STATE_UNUSED;
			hyp.table[i].driver = NULL;
			hyp.table[i].name = NULL;
		}

		hyp.table_slot = hyp.table_slot * 2;
	}

	/* initialize the world */
	hyp.table[id].name = strdup(name);
	hyp.table[id].status = HYP_WORLD_STATUS_SET(
		flags,
		HYP_WORLD_STATUS_STATE_UNINIT
	);
	if (hyp.table[id].driver == NULL) {
		hyp.table[id].driver = malloc(
			vhex_driver_count() * sizeof(*hyp.table[id].driver)
		);
		dtable = vhex_driver_table();
		for (int i = 0; i < vhex_driver_count(); ++i) {
			hyp.table[id].driver[i].context = malloc(
				dtable[i].state_size
			);
		}
	}

	return (id);
}


/* hypervisor_world_find() : find a world using its name */
hyp_world_t hypervisor_world_find(char const * const restrict name)
{
	if (hyp.table != NULL) {
		for (size_t i = 0; i < hyp.table_slot; ++i) {
			if (strcmp(hyp.table[i].name, name) == 0)
				return (i);
		}
	}
	return (hyp_world_not_found);
}

/* hypervisor_world_get() : get a word using its ID */
struct vhex_world *hypervisor_world_get(hyp_world_t id)
{
	if (id < 0 || (size_t)id >= hyp.table_slot)
		return (NULL);
	if (HYP_WORLD_STATUS_STATE(hyp.table[id].status)
			== HYP_WORLD_STATUS_STATE_UNUSED) {
		return (NULL);
	}
	return (&hyp.table[id]);
}


/* hypervisor_world_delete() : remove world */
hyp_world_t hypervisor_world_delete(hyp_world_t id)
{
	if (id < 0 || (size_t)id >= hyp.table_slot)
		return (hyp_world_bad_id);

	if (HYP_WORLD_STATUS_FLAGS(hyp.table[id].status)
					== HYP_WORLD_STATUS_FLAG_UNDELETABLE) {
		return (hyp_world_undeletable);
	}

	hyp.table[id].status = HYP_WORLD_STATUS_STATE_UNUSED;
}