#ifndef LCD_SSD1306
#define LCD_SSD1306

//#include "../../io/SoftSPI.h"


/**
 * https://www.displayfuture.com/Display/datasheet/controller/ST7735.pdf
 * https://www.aliexpress.com/item/1-8-inch-TFT-color-screen-module-ST7735-SPI-at-least-4IO-support-C51-STM32-with/32809505663.html?spm=2114.search0302.3.266.14d83b8cQXOxfz&ws_ab_test=searchweb0_0,searchweb201602_0_450_452_532_533_534_10618_535_317_318_319_10059_10696_10084_100031_10083_10547_10304_10546_10843_10887_320_10307_10548_204_448_10065_449_10068_10320_10103_10884_10820,searchweb201603_0,ppcSwitch_0&algo_pvid=7cf0bb24-ac60-4e97-9878-8716f61a79f3&algo_expid=7cf0bb24-ac60-4e97-9878-8716f61a79f3-33
 * https://sites.google.com/site/arduinomega2560projects/microchip-pic/level-3/st7735-1-8-tft (!!!!)
 *
 * display is SPI
 * CLK = clock
 * SDA = mosi
 * RS = data/command
 * RST = reset
 * CS = chip-select
 */

template <typename SPI, int PIN_CS, int PIN_DATA_COMMAND> class ST7735 {

private:

	static constexpr const char* NAME = "ST7735";

	SPI& spi;

public:

	/** ctor */
	ST7735(SPI& spi) : spi(spi) {
		MyGPIO::setOutput(PIN_DATA_COMMAND);
		MyGPIO::setOutput(PIN_CS);
		init();
	}


#define ST7735_NOP     0x00
#define ST7735_SWRESET 0x01
#define ST7735_RDDID   0x04
#define ST7735_RDDST   0x09

#define ST7735_SLPIN   0x10
#define ST7735_SLPOUT  0x11
#define ST7735_PTLON   0x12
#define ST7735_NORON   0x13

#define ST7735_INVOFF  0x20
#define ST7735_INVON   0x21
#define ST7735_DISPOFF 0x28
#define ST7735_DISPON  0x29
#define ST7735_CASET   0x2A
#define ST7735_RASET   0x2B
#define ST7735_RAMWR   0x2C
#define ST7735_RAMRD   0x2E

#define ST7735_PTLAR   0x30
#define ST7735_COLMOD  0x3A
#define ST7735_MADCTL  0x36

#define ST7735_FRMCTR1 0xB1
#define ST7735_FRMCTR2 0xB2
#define ST7735_FRMCTR3 0xB3
#define ST7735_INVCTR  0xB4
#define ST7735_DISSET5 0xB6

#define ST7735_PWCTR1  0xC0
#define ST7735_PWCTR2  0xC1
#define ST7735_PWCTR3  0xC2
#define ST7735_PWCTR4  0xC3
#define ST7735_PWCTR5  0xC4
#define ST7735_VMCTR1  0xC5

#define ST7735_RDID1   0xDA
#define ST7735_RDID2   0xDB
#define ST7735_RDID3   0xDC
#define ST7735_RDID4   0xDD

#define ST7735_PWCTR6  0xFC

#define ST7735_GMCTRP1 0xE0
#define ST7735_GMCTRN1 0xE1


private:

	static constexpr const int V = 128;
	static constexpr const int H = 160;

	inline void waitLong() {
		//vTaskDelay(200 / portTICK_PERIOD_MS);
		for (int i = 0; i < 0x1FFFFF; ++i) {asm("nop");}	// vTaskDelay seems not to block? maybe when display is allocated outside of a function?
	}

	inline void waitShort() {
		//vTaskDelay(20 / portTICK_PERIOD_MS);
		for (int i = 0; i < 0xFFFF; ++i) {asm("nop");}
	}

	void init() {

		debugMod(NAME, "init()");
		
		select();
			sendCommand(ST7735_SWRESET);                         //  1: Software reset, 0 args
		deselect();
				waitLong();
		
		select();
			sendCommand(ST7735_SLPOUT);                          //  2: Out of sleep mode, 0 args
		deselect();
				waitLong();

		select();
		
			sendCommand(ST7735_FRMCTR1);                         //  3: Frame rate ctrl - normal mode) 3 args: 0xb1
				sendData(0x01); sendData(0x2C); sendData(0x2D);   //     Rate = fosc/(1x2+40) * (LINE+2C+2D)
				waitShort();
				
			sendCommand(ST7735_FRMCTR2);                         //  4: Frame rate control - idle mode) 3 args: 0xb2
				sendData(0x01); sendData(0x2C); sendData(0x2D);   //     Rate = fosc/(1x2+40) * (LINE+2C+2D)
				waitShort();
				
			sendCommand(ST7735_FRMCTR3);                         //  5: Frame rate ctrl - partial mode) 6 args: 0xb3
				sendData(0x01); sendData(0x2C); sendData(0x2D);   //     Dot inversion mode
				sendData(0x01); sendData(0x2C); sendData(0x2D);   //     Line inversion mode
				waitShort();
				
			sendCommand(ST7735_INVCTR);                          //  6: Display inversion ctrl) 1 arg) no delay: 0xb4
				sendData(0x07);                                   //     No inversion
				
			sendCommand(ST7735_PWCTR1);                          //  7: Power control) 3 args) no delay: 0xc0
				sendData(0xA2);
				sendData(0x02);                                   //     -4.6V
				sendData(0x84);                                   //     AUTO mode
				
			sendCommand(ST7735_PWCTR2);                          //  8: Power control) 1 arg) no delay: 0xc1
				sendData(0xC5);                                   //     VGH25 = 2.4C VGSEL = -10 VGH = 3 * AVDD
				
			sendCommand(ST7735_PWCTR3);                          //  9: Power control) 2 args) no delay: 0xc2
				sendData(0x0A);                                   //     Opamp current small
				sendData(0x00);                                   //     Boost frequency
				
			sendCommand(ST7735_PWCTR4);                          // 10: Power control) 2 args) no delay:
				sendData(0x8A);                                   //     BCLK/2) Opamp current small & Medium low
				sendData(0x2A);
				
			sendCommand(ST7735_PWCTR5);                          // 11: Power control) 2 args) no delay:
				sendData(0x8A); sendData(0xEE);
				
			sendCommand(ST7735_VMCTR1);                          // 12: Power control) 1 arg) no delay:
				sendData(0x0E);
				
			sendCommand(ST7735_INVOFF);                          // 13: Don't invert display) no args) no delay 0x20
				
			sendCommand(ST7735_MADCTL);                          // 14: Memory access control (directions)) 1 arg:
				sendData(0xC8);                                   //     row addr/col addr); bottom to top refresh
				waitShort();
				
			sendCommand(ST7735_COLMOD);                          // 15: set color mode); 1 arg); no delay:
				sendData(0x05);                                   //     16-bit color

		deselect();
		
		// required??? adjusts colors or something???
		if (1 == 1) {

			select();
				sendCommand(ST7735_GMCTRP1);	//  1: Magical unicorn dust, 16 args, no delay:
					sendData(0x02); sendData(0x1c); sendData(0x07); sendData(0x12);
					sendData(0x37); sendData(0x32); sendData(0x29); sendData(0x2d);
					sendData(0x29); sendData(0x25); sendData(0x2B); sendData(0x39);
					sendData(0x00); sendData(0x01); sendData(0x03); sendData(0x10);

				sendCommand(ST7735_GMCTRN1);	//  2: Sparkles and rainbows, 16 args, no delay:
					sendData(0x03); sendData(0x1d); sendData(0x07); sendData(0x06);
					sendData(0x2E); sendData(0x2C); sendData(0x29); sendData(0x2D);
					sendData(0x2E); sendData(0x2E); sendData(0x37); sendData(0x3F);
					sendData(0x00); sendData(0x00); sendData(0x02); sendData(0x10);
			deselect();
			
		}

		select();
			sendCommand(ST7735_NORON);                           //  3: Normal display on, no args
		deselect();
		waitLong();

		select();
			sendCommand(ST7735_DISPON);                          //  4: Main screen turn on, no args
		deselect();
		waitLong();
		
		debugMod(NAME, "init() done");

	}


	void clean(uint16_t color){

		select();

		uint8_t lo = color & 0xFF;
		uint8_t hi = color >> 8;

		sendCommand(ST7735_CASET); // Column addr set
		sendData(0x00);
		sendData(0);     // XSTART
		sendData(0x00);
		sendData(V-1);     // XEND

		sendCommand(ST7735_RASET); // Row addr set
		sendData(0x00);
		sendData(0);     // YSTART
		sendData(0x00);
		sendData(H-1);     // YEND

		sendCommand(ST7735_RAMWR);

		for(char x=0;x<V;x++){
			for(char y=0;y<H;y++){
				sendData(lo);
				sendData(hi);
			}
		}

		deselect();

	}

public:

	void flush(const uint16_t* data) {

		select();

		sendCommand(ST7735_CASET);	// Column addr set
		sendData(0x00);
		sendData(0);				// XSTART
		sendData(0x00);
		sendData(V-1);				// XEND

		sendCommand(ST7735_RASET);	// Row addr set
		sendData(0x00);
		sendData(0);				// YSTART
		sendData(0x00);
		sendData(H-1);				// YEND

		sendCommand(ST7735_RAMWR);

		modeData();
		/*
		for (int i = 0; i < (V*H); ++i) {
			const uint16_t color = data[i];
			//const uint8_t lo = color & 0xFF;
			//const uint8_t hi = color >> 8;
			//sendData(lo);
			//sendData(hi);
			//spi::writeWord(color);
			spi.writeWord(color);
		}*/
		spi.write((const uint8_t*)data, V*H*sizeof(uint16_t));
		

		deselect();

	}



private:

	void sendData(uint8_t data) {
		modeData();
		spi.writeByte(data);
	}

	void sendCommand(uint8_t cmd) {
		modeCommand();
		spi.writeByte(cmd);
	}

	/** switch D/C line low */
	inline void modeCommand() {
		MyGPIO::clear(PIN_DATA_COMMAND);
	}

	/** switch D/C line high */
	inline void modeData() {
		MyGPIO::set(PIN_DATA_COMMAND);
	}

	/** set CS = low */
	inline void select() {
		MyGPIO::clear(PIN_CS);
	}

	/** set CS = high */
	inline void deselect() {
		MyGPIO::set(PIN_CS);
	}


};


#endif