#pragma once

#include <cstdint>

#include <vector>

#include "key_event.h"
#include "key_help.h"

namespace roro {

class Canvas;  // provided by the widget kit

// A foreground, user-facing program (see CONTEXT.md). Exactly one App is on screen at a time.
class App {
   public:
    virtual ~App() = default;

    virtual void onEnter() {}
    virtual void onExit() {}

    // Return true if the key was consumed. An unconsumed Back leaves the App.
    virtual bool onKey(const KeyEvent& event) {
        (void)event;
        return false;
    }

    // True while the App is editing text: the arrow keys then type ; . , / and need Fn to move.
    virtual bool textEntryActive() const { return false; }

    // The keys that work right now, for the help panel (Fn+h): the App's own, in the state it's
    // in. Back, Home and the arrows are added for it. No screen names keys any other way.
    virtual void help(std::vector<KeyHelp>& out) const { (void)out; }
    // What the panel is titled with, when the App's name isn't enough ("Notes: editor").
    virtual const char* helpTitle() const { return nullptr; }

    // Called every main-loop pass while in the foreground (e.g. to refresh live values).
    virtual void update(uint32_t nowMs) { (void)nowMs; }

    virtual void draw(Canvas& canvas) = 0;

    void requestRedraw() { redraw_ = true; }

    bool consumeRedraw() {
        bool r = redraw_;
        redraw_ = false;
        return r;
    }

   private:
    bool redraw_ = false;
};

}  // namespace roro