#ifndef ENT_H
#define ENT_H

#include "common.h"
#include "physics.h"

#define ENTITY_INVALID_IDX UINT32_MAX

// typedef enum {
// 	ENT_COMP_TRANSFORM,
// 	ENT_COMP_MODEL,
// 	ENT_COMP_PHYSICS,
// 	ENT_COMP_EDITOR,
// 	ENT_COMP_CNT,
// } EntityComponentType;

typedef struct {
	u64 parent;
	u64 first_child;
	u64 prev, next; // siblings
	/* parent-local */
	Vec3 pos, scale;
	Quaternion rot;
} TransformCmp;

typedef struct {
	char *key;
	Model *mdl;
	bool has, draw;
} ModelCmp;

typedef struct {
	PhysicsBody *bodies;
	PhysicsJoint *joints;
	u32 body_cnt, joint_cnt;

	struct {
		PhysicsBodyRuntime *bodies;
		b3JointId *joints;
	} runtime;

	bool has, debug_draw;
} PhysicsCmp;

typedef struct {
	bool selected; 
} EditorCmp; // transient data for non transient entities ^___^

typedef struct {
	TransformCmp tr;
	ModelCmp mdl;
	PhysicsCmp phys;
	EditorCmp ed;

	u64 pid; // persistent serialized id, not runtime entity id
	char *name;
} Entity;

void		entity_system_init(void);
void		entity_system_exit(void);
void		entity_system_clear(void);
void		entity_system_update(void);
void		entity_system_draw_3d(void);
void		entity_system_set_next_pid(u64);

/* clears all entities of their selected flag */
void		entities_clear_selected(void);

u64		entity_create(bool transient); // transient means no pid
u64		entity_restore(u64 pid);
void		entity_delete(u64 id);
void		entity_clean(Entity*); // clean entity data without removing
Entity		entity_extract_now(u64 id); // removes, returns ownership
bool		entity_valid(u64 id);

Entity*		entity_get(u64 id);
u64		entity_id_at(u32 dense_idx);
u64		entity_id_from_pid(u64 pid);
Entity*		entity_data(void);
u32		entity_count(void);
u64		entity_next_pid(void);

bool		entity_set_parent(u64 id, u64 parent_id);

/* transform component data */
Matrix		entity_world_matrix(u64 id);
/* space identifies the reference entity, 0 means world space. */
Vec3		entity_point_to_world(u64 space, Vec3 point);
bool		entity_point_to_local(u64 space, Vec3 point, Vec3 *out);

Vec3		entity_world_pos(u64 id);
Quaternion	entity_world_rot(u64 id);
void		entity_set_world_pos(Entity*, Vec3);
void		entity_set_world_rot(Entity*, Quaternion);

#endif