#include "ecs_core.h"

// Define component id storage (global symbol used by ecs_id(Position))
ecs_entity_t ecs_id(Position) = 0;

static bool g_ecs_core_inited = false;
static draw_square_fn g_draw_square = 0;

// Simple placeholder render system: iterates Positions
static void RenderSys(ecs_iter_t* it) {
    Position* p = ecs_field(it, Position, 1);
    if (!g_draw_square) return;
    for (int i = 0; i < it->count; i++) {
        g_draw_square(p[i].x, p[i].y, 0.1f, 1.0f, 1.0f, 1.0f, 1.0f);
    }
}

void ecs_core_init(ecs_world_t* world) {
    if (g_ecs_core_inited) return;
    // Register components
    ECS_COMPONENT_DEFINE(world, Position);

    // Systems: run every frame on update for Position
    ECS_SYSTEM(world, RenderSys, EcsOnUpdate, Position);

    g_ecs_core_inited = true;
}

void ecs_spawn_test_entities(ecs_world_t* world) {
    // Two entities with different positions
    ecs_entity_t e1 = ecs_new(world);
    ecs_set(world, e1, Position, { -0.3f, 0.0f });

    ecs_entity_t e2 = ecs_new(world);
    ecs_set(world, e2, Position, { 0.3f, 0.0f });
}

void ecs_core_set_draw_api(draw_square_fn draw_square) {
    g_draw_square = draw_square;
}