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#pragma once

#include "../include/Storage.hpp"
#include "../include/MessageQueue.hpp"
#include "../include/FileAnalyzer.hpp"
#include "../include/AsyncTask.hpp"
#include <SFML/System/Vector2.hpp>
#include <SFML/Graphics/Texture.hpp>
#include <SFML/System/Clock.hpp>
#include <string>
#include <memory>
#include <unordered_map>

namespace QuickMedia {
    enum class LoadingState {
        NOT_LOADED,
        LOADING,
        FINISHED_LOADING,
        APPLIED_TO_TEXTURE
    };

    struct ThumbnailData {
        LoadingState loading_state = LoadingState::NOT_LOADED;
        sf::Texture texture;
        std::unique_ptr<sf::Image> image; // Set in another thread. This should be .reset after loading it into |texture|, to save memory
        size_t counter = 0;
    };

    // This function is async
    bool create_thumbnail(const Path &thumbnail_path, const Path &thumbnail_path_resized, sf::Vector2i resize_target_size, ContentType content_type);

    constexpr int NUM_IMAGE_LOAD_THREADS = 4;

    class AsyncImageLoader {
    public:
        static AsyncImageLoader& get_instance();

        // Never returns nullptr. Instead check the |loading_state| of the thumbnail data to see if it has finished loading.
        // This function should be called every frame for the objects that need to display this thumbnail, otherwise it can be unloaded.
        // set |resize_target_size| to {0, 0} to disable resizing.
        // Note: this method is not thread-safe
        std::shared_ptr<ThumbnailData> get_thumbnail(const std::string &url, bool local, sf::Vector2i resize_target_size);

        // Note: this should only be called once every frame.
        // Note: this method is not thread-safe
        void update();
    private:
        AsyncImageLoader();
        ~AsyncImageLoader();
        AsyncImageLoader(AsyncImageLoader &other) = delete;
        AsyncImageLoader& operator=(AsyncImageLoader &other) = delete;

        struct ThumbnailLoadData {
            Path path;
            Path thumbnail_path;
            bool local;
            std::shared_ptr<ThumbnailData> thumbnail_data;
            sf::Vector2i resize_target_size;
        };

        // set |resize_target_size| to {0, 0} to disable resizing.
        // Note: this method is not thread-safe
        void load_thumbnail(const std::string &url, bool local, sf::Vector2i resize_target_size, std::shared_ptr<ThumbnailData> thumbnail_data);

        // Returns -1 if all threads are busy
        int get_free_load_index() const;
    private:
        bool loading_image[NUM_IMAGE_LOAD_THREADS];
        // TODO: Use curl single-threaded multi-download feature instead
        AsyncTask<void> download_image_thread[NUM_IMAGE_LOAD_THREADS];
        AsyncTask<void> load_image_thread;
        MessageQueue<ThumbnailLoadData> image_load_queue;
        std::unordered_map<std::string, std::shared_ptr<ThumbnailData>> thumbnails;
        size_t counter = 0;
    };
}