#pragma once

#include <memory>
#include <string>
#include <vector>

#include "image_file.h"
#include "key_event.h"
#include "key_help.h"
#include "services/storage_service.h"
#include "ui/canvas.h"

namespace roro {

// A picture from the card, for the Storage App's viewer (issue #45, F1 Q233-Q242): PNG, JPEG, BMP
// and the first picture of a GIF (only JPEG needs a decoder that isn't ours). It is decoded once, straight into the screen's own buffer, and
// left there (App::retainsContent): there is no copy of it in memory. It is decoded again only
// when something else was drawn over it, or when it is zoomed or moved.
//
// The decoding runs on the storage task while the main loop goes on: a photograph takes seconds,
// and the picture appears as it comes. Anything that needs the screen back stops it first.
class ImagePane {
   public:
    explicit ImagePane(StorageService& storage) : storage_(storage) {}

    std::string open(const std::string& path, uint32_t size);  // "" or why it can't be shown
    void close();
    bool onKey(const KeyEvent& e);  // true: the key was the picture's
    void help(std::vector<KeyHelp>& out) const;
    bool update(uint32_t nowMs);    // true: draw again
    void draw(Canvas& c);
    void lost();  // the screen no longer holds it
    void say(const std::string& text);

    struct Job;  // one decoding: shared with the storage task, which may outlive the view of it

   private:
    enum class Phase { Wanted, Decoding, Shown };

    std::string describe() const;
    void start(Canvas& c);
    void cancel();  // returns once the storage task has let go of the screen
    void hideNote(Canvas* c);

    StorageService& storage_;
    std::string path_, problem_, note_;
    uint32_t size_ = 0, noteMs_ = 0, shotAt_ = 0, pushedMs_ = 0;
    files::ImageInfo info_;
    files::ImageFrame frame_;
    Phase phase_ = Phase::Wanted;
    std::shared_ptr<Job> job_;
    Canvas* canvas_ = nullptr;
    bool told_ = false, noteDrawn_ = false;
    std::vector<uint8_t> under_;  // what the note was written over
};

}  // namespace roro