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

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

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

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

	/* try to find free world */
	id = -1;
	for (int i = 0; i < hyp.world.number; ++i) {
		if (hyp.world.table[i].status.USED == 0) {
			id = i;
			continue;
		}
		if (strcmp(hyp.world.table[i].name, name) == 0)
			return (hyp_world_already_exists);
	}

	/* if no world is found, update the table */
	if (id == -1) {
		id = hyp.world.number;

		hyp.world.number += hyp.world.number;
		if (hyp.world.number == 0)
			hyp.world.number = 2;

		hyp.world.table = reallocarray(
			hyp.world.table,
			hyp.world.number,
			sizeof(struct vhex_world)
		);

		for (int i = id; i < hyp.world.number; ++i) {
			hyp.world.table[i].driver = NULL;
			hyp.world.table[i].name = NULL;
			hyp.world.table[id].status.LOCKED = 0;
			hyp.world.table[id].status.ACTIVE = 0;
			hyp.world.table[id].status.INIT   = 0;
			hyp.world.table[id].status.USED   = 0;
		}
	}

	/* initialize the world */
	hyp.world.table[id].name = strdup(name);
	hyp.world.table[id].status.LOCKED = 0;
	hyp.world.table[id].status.ACTIVE = 0;
	hyp.world.table[id].status.INIT   = 0;
	hyp.world.table[id].status.USED   = 1;

	if (hyp.world.table[id].driver == NULL) {
		hyp.world.table[id].driver = calloc(
			vhex_driver_count(),
			sizeof(*hyp.world.table[id].driver)
		);
		dtable = vhex_driver_table();
		for (int i = 0; i < vhex_driver_count(); ++i) {
			hyp.world.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.world.table != NULL) {
		for (int i = 0; i < hyp.world.number; ++i) {
			if (strcmp(hyp.world.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 || id >= hyp.world.number)
		return (NULL);
	if (hyp.world.table[id].status.USED == 0) {
		return (NULL);
	}
	return (&hyp.world.table[id]);
}


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

	if (hyp.world.table[id].status.LOCKED == 1)
		return (hyp_world_undeletable);

	hyp.world.table[id].status.USED = 0;
}