#pragma once

#include "timeline.h"

#include <SFML/Audio/Music.hpp>
#include <vector>
#include <memory>

class Note;

class ClassicTimeline : public Timeline
{
public:
    explicit ClassicTimeline();
    virtual ~ClassicTimeline();
    virtual void update() override;
    virtual void run(std::vector<Note*>&& notes, const microsec& visibility) override;
    virtual void clear() override;

    virtual microsec currentMusicOffset() const override;
    virtual void drawVisibleNotes() const override;

    void fetchVisibleNotes();
    void findLastVisibleNote(const microsec& music_offset);
    void findFirstVisibleNote();

    Iterator getActiveNote() noexcept;

    bool isExpired(const Iterator& iterator) const;
    inline void expire(Iterator& iterator);

private:
    std::vector<microsec> _input_intervals;
    std::vector<Note*> _timeline;
    microsec _visibility_offset;

    sf::Music _music;

    void updateVisibleSprites(const microsec& music_offset);
    void checkCurrentActiveNote(const microsec& music_offset);
    void checkForNextActiveNote(const microsec& music_offset);
    bool isVisiblyClose(const Iterator& iterator, const microsec& music_offset) const;
    inline bool nothingToDraw() const noexcept;

    /* Difference between top and active note is that
     * top note is the note handling input right now
     * OR it's the closest note from current music offset
     * position, not necessarily active. A note stops being top only
     * after dying or being tapped by player, even if it's already
     * past her perfect offset.
     *
     * Meanwhile active note is the note which is currently handling
     *     player input for grade.
     *
     * An active note is always top note but a top note
     *    is not always active note.
     *                                         */

    Iterator _top_note;
    Iterator _active_note;
    Iterator _last_visible_note;
    Iterator _first_visible_note;
};