#ifndef VELOMETER_GUI_H
#define VELOMETER_GUI_H
#include "config.h"
#include <pico/stdlib.h>

enum ButtonInputType {
  BUTTON_SHORT_PRESS,
  BUTTON_LONG_PRESS,
};

enum GUIScreen {
  MAIN_SCREEN,
  MENU_SCREEN,
};

enum DisplayMode {
  DISPLAY_MODE_SPEED,
  DISPLAY_MODE_DISTANCE_FROM_POWER_ON,
  DISPLAY_MODE_TOTAL_DISTANCE,
};

enum MenuOptionType {
  MENU_OPTION_NUMBER,
  MENU_OPTION_ONOFF,
  MENU_OPTION_TEXT,
  MENU_OPTION_LINK,
};

#define TEXT_EDIT_STATIC_BUFFER_SIZE 18
struct TextEditState {
  uint textLength;     // number of characters in input
  uint textByteLength; // number of bytes occupied by characters

  // fixed-size buffers for most cases
  char staticTextBuffer[TEXT_EDIT_STATIC_BUFFER_SIZE];
  uint8_t staticCharWidthBuffer[TEXT_EDIT_STATIC_BUFFER_SIZE];

  // the same thing but in heap for longer input
  bool heapBufferInUse;
  char *heapTextBuffer;
  uint8_t *heapCharWidthBuffer;
  uint heapTextBufferCapacity;
  uint heapCharWidthBufferCapacity;

  // visual edit field properties
  uint cursorPos;           // in characters
  uint cursorPosCharOffset; // for quicker character addressing inside a UTF-8 string
  uint scrollOffset;        // in pixels
};

struct MenuScreenState {
  enum {
    MENU_SCREEN_STATE_CHOOSING_OPTION,
    MENU_SCREEN_STATE_EDITING_OPTION,
  } subState;
  union {
    struct {
      uint chosenOptionIndex;
      short scrollAnimationProgress;
    } choosingOption;
    struct {
      uint optionIndex;
      enum MenuOptionType optionType;
      union {
        uint numberValue;
        bool onOffValue;
        struct TextEditState textEditState;
      };
    } editingOption;
  };
};

struct GUIState {
  uint screen;
  union {
    struct {
      uint displayMode;
      bool displayModeChanged;
    } mainScreen;
    struct MenuScreenState menuScreen;
  } screenState;
  uint8_t drawnTimeHours;
  uint8_t drawnTimeMinutes;
  uint16_t drawnTimeTextWidth;
};

void gui_init();
void on_button_input(short button, enum ButtonInputType type, uint heldButtons);
void update_lcd();

#endif