// debug_overlay.cpp - Implementación del overlay de debug.

#include "core/system/debug_overlay.hpp"

#include <string>

#include "core/types.hpp"

namespace System {

    namespace {
        // Posición y tamaño del overlay en coordenadas lógicas (1280×720).
        constexpr float OVERLAY_X = 12.0F;
        constexpr float OVERLAY_Y_FPS = 12.0F;
        constexpr float OVERLAY_LINE_HEIGHT = 18.0F;  // separación entre líneas (scale 0.4 → ~16 px alto)
        constexpr float OVERLAY_SCALE = 0.4F;
        constexpr float OVERLAY_SPACING = 2.0F;
        constexpr float OVERLAY_BRIGHTNESS = 1.0F;

        // Cadencia de actualización del valor de FPS mostrado.
        constexpr float FPS_UPDATE_INTERVAL = 0.5F;
    }  // namespace

    DebugOverlay::DebugOverlay(Rendering::Renderer* renderer,
        const Config::RenderingConfig& rendering_cfg)
        : text_(renderer),
          rendering_cfg_(&rendering_cfg) {}

    void DebugOverlay::update(float delta_time) {
        fps_accumulator_ += delta_time;
        fps_frame_count_++;

        if (fps_accumulator_ >= FPS_UPDATE_INTERVAL) {
            fps_display_ = static_cast<int>(fps_frame_count_ / fps_accumulator_);
            fps_frame_count_ = 0;
            fps_accumulator_ = 0.0F;
        }
    }

    void DebugOverlay::draw() const {
        if (!visible_) {
            return;
        }

        const std::string FPS_TEXT = "FPS: " + std::to_string(fps_display_);
        const std::string VSYNC_TEXT = std::string("VSYNC: ") + (rendering_cfg_->vsync == 1 ? "ON" : "OFF");
        const std::string AA_TEXT = std::string("AA: ") + (rendering_cfg_->antialias == 1 ? "ON" : "OFF");

        text_.render(FPS_TEXT,
            Vec2{.x = OVERLAY_X, .y = OVERLAY_Y_FPS},
            OVERLAY_SCALE,
            OVERLAY_SPACING,
            OVERLAY_BRIGHTNESS);
        text_.render(VSYNC_TEXT,
            Vec2{.x = OVERLAY_X, .y = OVERLAY_Y_FPS + OVERLAY_LINE_HEIGHT},
            OVERLAY_SCALE,
            OVERLAY_SPACING,
            OVERLAY_BRIGHTNESS);
        text_.render(AA_TEXT,
            Vec2{.x = OVERLAY_X, .y = OVERLAY_Y_FPS + (2.0F * OVERLAY_LINE_HEIGHT)},
            OVERLAY_SCALE,
            OVERLAY_SPACING,
            OVERLAY_BRIGHTNESS);
    }

}  // namespace System