#pragma once

#include <functional>
#include <memory>
#include <vector>

struct Entity;

/**
 * Shared state for one gameplay scene instance.
 */
struct GameContext {
    /**
     * @brief Pointer to the entity list owned by the active gameplay scene.
     */
    std::vector<std::shared_ptr<Entity>> *entities = nullptr;

    /** @brief World entity (scroll/spawn owner). */
    Entity *worldEntity = nullptr;
    /** @brief Gravity well entity. */
    Entity *wellEntity = nullptr;
    /** @brief Player probe entity. */
    Entity *probeEntity = nullptr;
    /** @brief Stats entity that owns meter + star records. */
    Entity *statsEntity = nullptr;

    /** @brief Shared horizontal world scroll value. */
    float scrollX = 0.0f;

    /** @brief Optional callback invoked when the probe dies. */
    std::function<void()> onPlayerDeath;

    /** @brief Callbacks fired whenever a collectible is picked up. */
    std::vector<std::function<void(Entity &)>> collectiblePickedListeners;

    /** @brief Callbacks fired whenever meter value changes. */
    std::vector<std::function<void(float, float)>> meterChangedListeners;

    /**
     * Registers a collectible pickup listener.
     *
     * @param listener Callback receiving the collected entity.
     */
    void AddCollectiblePickedListener(std::function<void(Entity &)> listener) {
        collectiblePickedListeners.push_back(std::move(listener));
    }

    /**
     * Emits collectible pickup event.
     *
     * @param collectible The collected entity.
     */
    void EmitCollectiblePicked(Entity &collectible) {
        for (auto &listener : collectiblePickedListeners) {
            listener(collectible);
        }
    }

    /**
     * Registers a meter changed listener.
     *
     * @param listener Callback receiving old value then new value.
     */
    void AddMeterChangedListener(std::function<void(float, float)> listener) {
        meterChangedListeners.push_back(std::move(listener));
    }

    /**
     * Emits meter changed event.
     *
     * @param oldValue Meter value before mutation.
     * @param newValue Meter value after mutation.
     */
    void EmitMeterChanged(float oldValue, float newValue) {
        for (auto &listener : meterChangedListeners) {
            listener(oldValue, newValue);
        }
    }
};