#ifndef ENTITY_H
#define ENTITY_H

#include "sheet.h"
#include "mixer.h"

/* ========================== *
 * Entity
 * ========================== */

struct entity_handle {
    u64 idx;
    u64 gen;
};

enum entity_prop {
    ENTITY_PROP_NONE,

    ENTITY_PROP_ANIMATING,
    ENTITY_PROP_PLAYER_CONTROLLED,
    ENTITY_PROP_CAMERA,

    /* Test props */

    ENTITY_PROP_TEST,
    ENTITY_PROP_TEST_FOLLOW_MOUSE,
    ENTITY_PROP_TEST_SOUND_EMITTER,

    ENTITY_PROP_COUNT
};

struct entity {
    b32 valid;
    struct entity_handle handle;
    u64 continuity_gen;
    u64 props[(ENTITY_PROP_COUNT + 63) / 64];

    struct entity *next_free;

    /* Tree */
    struct entity_handle parent;
    struct entity_handle next;
    struct entity_handle prev;
    struct entity_handle first;
    struct entity_handle last;

    /* ====================================================================== */
    /* Translation, rotation, scale in relation to parent entity */

    struct xform rel_xform;
    struct xform world_xform;  /* Calculated post-physics */

    /* ====================================================================== */
    /* Physics */

    struct v2 acceleration;
    struct v2 velocity;

    /* ENTITY_PROP_PLAYER_CONTROLLED */
    f32 player_max_speed;
    f32 player_acceleration;

    /* ====================================================================== */
    /* Sprite */

    struct xform sprite_xform;
    struct string sprite_name;
    struct string sprite_tag_name;
    u32 sprite_tint;

    /* ====================================================================== */
    /* Animation */

    /* ENTITY_PROP_ANIMATING */
    b32 animation_looping;
    f64 animation_start_time;  /* Calculated */

    /* ====================================================================== */
    /* Testing */

    /* ENTITY_PROP_TEST */
    b32 test_initialized;
    struct xform test_start_rel_xform;
    struct xform test_start_sprite_xform;

    /* ENTITY_PROP_TEST_SOUND_EMITTER */
    struct string sound_name;
    struct mixer_desc sound_desc;
    struct mixer_track_handle sound_handle;

    /* ====================================================================== */

    /* ENTITY_PROP_CAMERA */
    b32 camera_active;
    struct entity_handle camera_follow;
    f32 camera_zoom;
};

DECLARE_NIL_STRUCT(struct entity, entity_nil);

/* Prop */

void entity_enable_prop(struct entity *entity, enum entity_prop prop);
void entity_disable_prop(struct entity *entity, enum entity_prop prop);
b32 entity_has_prop(struct entity *entity, enum entity_prop prop);

#endif