#ifndef SSD1306_H
#define SSD1306_H

#include <Adafruit_GFX.h>
#include <Wire.h>

#define SCREEN_WIDTH 128
#define SCREEN_HEIGHT 64

#define DISPLAY_I2C_ADDRESS_32 (0x3C)
#define DISPLAY_I2C_ADDRESS_64 (0x3D)
#define DISPLAY_I2C_ADDRESS     DISPLAY_I2C_ADDRESS_32

#define SSD1306_BLACK 0   ///< Draw 'off' pixels
#define SSD1306_WHITE 1   ///< Draw 'on' pixels
#define SSD1306_INVERSE 2 ///< Invert pixels
#define SSD1306_MEMORYMODE 0x20          ///< See datasheet
#define SSD1306_COLUMNADDR 0x21          ///< See datasheet
#define SSD1306_PAGEADDR 0x22            ///< See datasheet
#define SSD1306_SETCONTRAST 0x81         ///< See datasheet 
#define SSD1306_CHARGEPUMP 0x8D          ///< See datasheet
#define SSD1306_SEGREMAP 0xA0            ///< See datasheet
#define SSD1306_DISPLAYALLON_RESUME 0xA4 ///< See datasheet
#define SSD1306_DISPLAYALLON 0xA5        ///< Not currently used
#define SSD1306_NORMALDISPLAY 0xA6       ///< See datasheet
#define SSD1306_INVERTDISPLAY 0xA7       ///< See datasheet
#define SSD1306_SETMULTIPLEX 0xA8        ///< See datasheet
#define SSD1306_DISPLAYOFF 0xAE          ///< See datasheet
#define SSD1306_DISPLAYON 0xAF           ///< See datasheet
#define SSD1306_COMSCANINC 0xC0          ///< Not currently used
#define SSD1306_COMSCANDEC 0xC8          ///< See datasheet
#define SSD1306_SETDISPLAYOFFSET 0xD3    ///< See datasheet
#define SSD1306_SETDISPLAYCLOCKDIV 0xD5  ///< See datasheet
#define SSD1306_SETPRECHARGE 0xD9        ///< See datasheet
#define SSD1306_SETCOMPINS 0xDA          ///< See datasheet
#define SSD1306_SETVCOMDETECT 0xDB       ///< See datasheet

#define SSD1306_SETLOWCOLUMN 0x00  ///< Not currently used
#define SSD1306_SETHIGHCOLUMN 0x10 ///< Not currently used
#define SSD1306_SETSTARTLINE 0x40  ///< See datasheet

#define SSD1306_EXTERNALVCC 0x01  ///< External display voltage source
#define SSD1306_SWITCHCAPVCC 0x02 ///< Gen. display voltage from 3.3V

#define SSD1306_RIGHT_HORIZONTAL_SCROLL 0x26              ///< Init rt scroll
#define SSD1306_LEFT_HORIZONTAL_SCROLL 0x27               ///< Init left scroll
#define SSD1306_VERTICAL_AND_RIGHT_HORIZONTAL_SCROLL 0x29 ///< Init diag scroll
#define SSD1306_VERTICAL_AND_LEFT_HORIZONTAL_SCROLL 0x2A  ///< Init diag scroll
#define SSD1306_DEACTIVATE_SCROLL 0x2E                    ///< Stop scroll
#define SSD1306_ACTIVATE_SCROLL 0x2F                      ///< Start scroll
#define SSD1306_SET_VERTICAL_SCROLL_AREA 0xA3             ///< Set scroll range

#define SSD1306_LCDWIDTH SCREEN_WIDTH ///< DEPRECATED: width w/SSD1306_128_64 defined
#define SSD1306_LCDHEIGHT SCREEN_HEIGHT ///< DEPRECATED: height w/SSD1306_128_64 defined

class SSD1306 : public Adafruit_GFX {
public:
    // Constructor
    //CUI(Adafruit_SSD1306 &display);
    SSD1306();
    void dim(bool dim);
    void setContrast(uint8_t contrast);

protected:
    bool bOK;
    uint8_t buffer[SCREEN_WIDTH * SCREEN_HEIGHT / 8];
    int8_t i2caddr;  ///< I2C address initialized when begin method is called.
    uint8_t contrast; ///< normal contrast setting for this device

    bool begin(uint8_t switchvcc = SSD1306_SWITCHCAPVCC, uint8_t i2caddr = DISPLAY_I2C_ADDRESS);
    inline uint8_t *getBuffer(void) { return buffer; };
    inline void clearDisplayBuffer(void) { memset(buffer, 0, WIDTH * ((HEIGHT + 7) / 8)); };
    void updateScreen();
    void updateRegion(uint8_t pageStart, uint8_t pageEnd, uint8_t colStart , uint8_t colEnd);
    void ssd1306_hscroll(uint8_t dir, uint8_t pageStart, uint8_t pageEnd, uint8_t offset, uint8_t interval);

private:
    int8_t vccstate; ///< VCC selection, set by begin method.
    uint32_t wireClk;    ///< Wire speed for SSD1306 transfers
    uint32_t restoreClk; ///< Wire speed following SSD1306 transfers
    
    virtual void drawPixel(int16_t x, int16_t y, uint16_t color);
    void ssd1306_commandList(const uint8_t *c, uint8_t n);
    void ssd1306_command1(uint8_t c);
};
#endif