#pragma once

#include "fl/vector.h"
#include "fl/singleton.h"
#include "fl/xymap.h"
#include "fl/screenmap.h"
#include "fl/namespace.h"



#ifndef FASTLED_ENGINE_EVENTS_MAX_LISTENERS
#define FASTLED_ENGINE_EVENTS_MAX_LISTENERS 8
#endif

#ifndef FASTLED_HAS_ENGINE_EVENTS
#ifdef __AVR__
#define FASTLED_HAS_ENGINE_EVENTS 0
#else
#define FASTLED_HAS_ENGINE_EVENTS 1
#endif
#endif  // FASTLED_HAS_ENGINE_EVENTS

FASTLED_NAMESPACE_BEGIN
class CLEDController;
FASTLED_NAMESPACE_END

namespace fl {

class EngineEvents {
  public:
    class Listener {
      public:
        // Note that the subclass must call EngineEvents::addListener(this) to
        // start listening. In the subclass destructor, the subclass should call
        // EngineEvents::removeListener(this).
        Listener();
        virtual ~Listener();
        virtual void onBeginFrame() {}
        virtual void onEndShowLeds() {}
        virtual void onEndFrame() {}
        virtual void onStripAdded(CLEDController *strip, uint32_t num_leds) {
            (void)strip;
            (void)num_leds;
        }
        // Called to set the canvas for UI elements for a particular strip.
        virtual void onCanvasUiSet(CLEDController *strip, const ScreenMap& screenmap) {
            (void)strip;
            (void)screenmap;
        }
        virtual void onPlatformPreLoop() {}  
        virtual void onPlatformPreLoop2() {}
    };
    

    static void addListener(Listener *listener, int priority = 0) {
        #if FASTLED_HAS_ENGINE_EVENTS
        EngineEvents::getInstance()->_addListener(listener, priority);
        #else
        (void)listener;
        (void)priority;
        #endif
    }
    
    static void removeListener(Listener *listener) {
        #if FASTLED_HAS_ENGINE_EVENTS
        EngineEvents::getInstance()->_removeListener(listener);
        #else
        (void)listener;
        #endif
    }
    
    static bool hasListener(Listener *listener) {
        #if FASTLED_HAS_ENGINE_EVENTS
        return EngineEvents::getInstance()->_hasListener(listener);
        #else
        (void)listener;
        return false;
        #endif
    }
    
    static void onBeginFrame() {
        #if FASTLED_HAS_ENGINE_EVENTS
        EngineEvents::getInstance()->_onBeginFrame();
        #endif
    }
    
    static void onEndShowLeds() {
        #if FASTLED_HAS_ENGINE_EVENTS
        EngineEvents::getInstance()->_onEndShowLeds();
        #endif
    }
    
    static void onEndFrame() {
        #if FASTLED_HAS_ENGINE_EVENTS
        EngineEvents::getInstance()->_onEndFrame();
        #endif
    }
    
    static void onStripAdded(CLEDController *strip, uint32_t num_leds) {
        #if FASTLED_HAS_ENGINE_EVENTS
        EngineEvents::getInstance()->_onStripAdded(strip, num_leds);
        #else
        (void)strip;
        (void)num_leds;
        #endif
    }


    static void onCanvasUiSet(CLEDController *strip, const ScreenMap& xymap) {
        #if FASTLED_HAS_ENGINE_EVENTS
        EngineEvents::getInstance()->_onCanvasUiSet(strip, xymap);
        #else
        (void)strip;
        (void)xymap;
        #endif
    }

    static void onPlatformPreLoop() {
        #if FASTLED_HAS_ENGINE_EVENTS
        EngineEvents::getInstance()->_onPlatformPreLoop();
        #endif
    }

  private:
    // Safe to add a listeners during a callback.
    void _addListener(Listener *listener, int priority);
    // Safe to remove self during a callback.
    void _removeListener(Listener *listener);
    void _onBeginFrame();
    void _onEndShowLeds();
    void _onEndFrame();
    void _onStripAdded(CLEDController *strip, uint32_t num_leds);
    void _onCanvasUiSet(CLEDController *strip, const ScreenMap& xymap);
    void _onPlatformPreLoop();
    bool _hasListener(Listener *listener);
#if FASTLED_HAS_ENGINE_EVENTS
    struct Pair {
        Listener *listener = nullptr;
        int priority = 0;
        Pair(Listener *listener, int priority) : listener(listener), priority(priority) {}
    };
    typedef fl::FixedVector<Pair, FASTLED_ENGINE_EVENTS_MAX_LISTENERS>
        ListenerList;
    ListenerList mListeners;
#endif

    static EngineEvents *getInstance();

    EngineEvents() = default;
    friend class fl::Singleton<EngineEvents>;
};

} // namespace fl