/*
 * This file is part of the TREZOR project.
 *
 * Copyright (C) 2014 Pavol Rusnak <stick@satoshilabs.com>
 *
 * This library is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Lesser General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with this library.  If not, see <http://www.gnu.org/licenses/>.
 */

#include <libopencm3/stm32/gpio.h>
#include <libopencm3/stm32/spi.h>

#include <string.h>

#include "oled.h"
#include "util.h"

#define OLED_SETCONTRAST		0x81
#define OLED_DISPLAYALLON_RESUME	0xA4
#define OLED_DISPLAYALLON		0xA5
#define OLED_NORMALDISPLAY		0xA6
#define OLED_INVERTDISPLAY		0xA7
#define OLED_DISPLAYOFF			0xAE
#define OLED_DISPLAYON			0xAF
#define OLED_SETDISPLAYOFFSET		0xD3
#define OLED_SETCOMPINS			0xDA
#define OLED_SETVCOMDETECT		0xDB
#define OLED_SETDISPLAYCLOCKDIV		0xD5
#define OLED_SETPRECHARGE		0xD9
#define OLED_SETMULTIPLEX		0xA8
#define OLED_SETLOWCOLUMN		0x00
#define OLED_SETHIGHCOLUMN		0x10
#define OLED_SETSTARTLINE		0x40
#define OLED_MEMORYMODE			0x20
#define OLED_COMSCANINC			0xC0
#define OLED_COMSCANDEC			0xC8
#define OLED_SEGREMAP			0xA0
#define OLED_CHARGEPUMP			0x8D

#define SPI_BASE			SPI1
#define OLED_DC_PORT			GPIOB
#define OLED_DC_PIN			GPIO0	// PB0 | Data/Command
#define OLED_CS_PORT			GPIOA
#define OLED_CS_PIN			GPIO4	// PA4 | SPI Select
#define OLED_RST_PORT			GPIOB
#define OLED_RST_PIN			GPIO1	// PB1 | Reset display

/* TREZOR has a display of size OLED_WIDTH x OLED_HEIGHT (128x64).
 * The contents of this display are buffered in _oledbuffer.  This is
 * an array of OLED_WIDTH * OLED_HEIGHT/8 bytes.  At byte y*OLED_WIDTH + x
 * it stores the column of pixels from (x,8y) to (x,8y+7); the LSB stores
 * the top most pixel.  The pixel (0,0) is the top left corner of the
 * display.
 */

/* Macros to manipulate a single pixel in _oledbuffer:
 * OLED_BUFSET(X,Y) sets pixel X,Y (white)
 * OLED_BUFCLR(X,Y) clears pixel X,Y (black)
 * OLED_BUFTGL(X,Y) toggles pixel X,Y (inverts it)
 */

#define OLED_BUFSET(X,Y)		_oledbuffer[OLED_BUFSIZE - 1 - (X) - ((Y)/8)*OLED_WIDTH] |= (1 << (7 - (Y)%8))
#define OLED_BUFCLR(X,Y)		_oledbuffer[OLED_BUFSIZE - 1 - (X) - ((Y)/8)*OLED_WIDTH] &= ~(1 << (7 - (Y)%8))
#define OLED_BUFTGL(X,Y)		_oledbuffer[OLED_BUFSIZE - 1 - (X) - ((Y)/8)*OLED_WIDTH] ^= (1 << (7 - (Y)%8))

static uint8_t _oledbuffer[OLED_BUFSIZE];
static bool is_debug_mode = 0;

/*
 * Send a block of data via the SPI bus.
 */
inline void SPISend(uint32_t base, uint8_t *data, int len)
{
	int i;
	delay(1);
	for (i = 0; i < len; i++) {
		spi_send(base, data[i]);
	}
	while (!(SPI_SR(base) & SPI_SR_TXE));
	while ((SPI_SR(base) & SPI_SR_BSY));
}

/*
 * Initialize the display.
 */
void oledInit()
{
	static uint8_t s[25] = {
		OLED_DISPLAYOFF,
		OLED_SETDISPLAYCLOCKDIV,
		0x80,
		OLED_SETMULTIPLEX,
		0x3F, // 128x64
		OLED_SETDISPLAYOFFSET,
		0x00,
		OLED_SETSTARTLINE | 0x00,
		OLED_CHARGEPUMP,
		0x14,
		OLED_MEMORYMODE,
		0x00,
		OLED_SEGREMAP | 0x01,
		OLED_COMSCANDEC,
		OLED_SETCOMPINS,
		0x12, // 128x64
		OLED_SETCONTRAST,
		0xCF,
		OLED_SETPRECHARGE,
		0xF1,
		OLED_SETVCOMDETECT,
		0x40,
		OLED_DISPLAYALLON_RESUME,
		OLED_NORMALDISPLAY,
		OLED_DISPLAYON
	};

	gpio_clear(OLED_DC_PORT, OLED_DC_PIN);		// set to CMD
	gpio_set(OLED_CS_PORT, OLED_CS_PIN);		// SPI deselect

	// Reset the LCD
	gpio_set(OLED_RST_PORT, OLED_RST_PIN);
	delay(40);
	gpio_clear(OLED_RST_PORT, OLED_RST_PIN);
	delay(400);
	gpio_set(OLED_RST_PORT, OLED_RST_PIN);

	// init
	gpio_clear(OLED_CS_PORT, OLED_CS_PIN);		// SPI select
	SPISend(SPI_BASE, s, 25);
	gpio_set(OLED_CS_PORT, OLED_CS_PIN);		// SPI deselect

	oledClear();
	oledRefresh();
}

/*
 * Clears the display buffer (sets all pixels to black)
 */
void oledClear()
{
	memset(_oledbuffer, 0, sizeof(_oledbuffer));
}

/*
 * Refresh the display. This copies the buffer to the display to show the
 * contents.  This must be called after every operation to the buffer to
 * make the change visible.  All other operations only change the buffer
 * not the content of the display.
 */
void oledRefresh()
{
	static uint8_t s[3] = {OLED_SETLOWCOLUMN | 0x00, OLED_SETHIGHCOLUMN | 0x00, OLED_SETSTARTLINE | 0x00};

	// draw triangle in upper right corner
	if (is_debug_mode) {
		OLED_BUFTGL(OLED_WIDTH - 5, 0); OLED_BUFTGL(OLED_WIDTH - 4, 0); OLED_BUFTGL(OLED_WIDTH - 3, 0); OLED_BUFTGL(OLED_WIDTH - 2, 0); OLED_BUFTGL(OLED_WIDTH - 1, 0);
		OLED_BUFTGL(OLED_WIDTH - 4, 1); OLED_BUFTGL(OLED_WIDTH - 3, 1); OLED_BUFTGL(OLED_WIDTH - 2, 1); OLED_BUFTGL(OLED_WIDTH - 1, 1); 
		OLED_BUFTGL(OLED_WIDTH - 3, 2); OLED_BUFTGL(OLED_WIDTH - 2, 2); OLED_BUFTGL(OLED_WIDTH - 1, 2);
		OLED_BUFTGL(OLED_WIDTH - 2, 3); OLED_BUFTGL(OLED_WIDTH - 1, 3);
		OLED_BUFTGL(OLED_WIDTH - 1, 4);
	}

	gpio_clear(OLED_CS_PORT, OLED_CS_PIN);		// SPI select
	SPISend(SPI_BASE, s, 3);
	gpio_set(OLED_CS_PORT, OLED_CS_PIN);		// SPI deselect

	gpio_set(OLED_DC_PORT, OLED_DC_PIN);		// set to DATA
	gpio_clear(OLED_CS_PORT, OLED_CS_PIN);		// SPI select
	SPISend(SPI_BASE, _oledbuffer, sizeof(_oledbuffer));
	gpio_set(OLED_CS_PORT, OLED_CS_PIN);		// SPI deselect
	gpio_clear(OLED_DC_PORT, OLED_DC_PIN);		// set to CMD

	// return it back
	if (is_debug_mode) {
		OLED_BUFTGL(OLED_WIDTH - 5, 0); OLED_BUFTGL(OLED_WIDTH - 4, 0); OLED_BUFTGL(OLED_WIDTH - 3, 0); OLED_BUFTGL(OLED_WIDTH - 2, 0); OLED_BUFTGL(OLED_WIDTH - 1, 0);
		OLED_BUFTGL(OLED_WIDTH - 4, 1); OLED_BUFTGL(OLED_WIDTH - 3, 1); OLED_BUFTGL(OLED_WIDTH - 2, 1); OLED_BUFTGL(OLED_WIDTH - 1, 1); 
		OLED_BUFTGL(OLED_WIDTH - 3, 2); OLED_BUFTGL(OLED_WIDTH - 2, 2); OLED_BUFTGL(OLED_WIDTH - 1, 2);
		OLED_BUFTGL(OLED_WIDTH - 2, 3); OLED_BUFTGL(OLED_WIDTH - 1, 3);
		OLED_BUFTGL(OLED_WIDTH - 1, 4);
	}
}

const uint8_t *oledGetBuffer()
{
	return _oledbuffer;
}

void oledSetDebug(bool set)
{
	is_debug_mode = set;
	oledRefresh();
}

void oledSetBuffer(uint8_t *buf)
{
	memcpy(_oledbuffer, buf, sizeof(_oledbuffer));
}

void oledDrawPixel(int x, int y)
{
	if ((x < 0) || (y < 0) || (x >= OLED_WIDTH) || (y >= OLED_HEIGHT)) return;
	OLED_BUFSET(x,y);
}

void oledClearPixel(int x, int y)
{
	if ((x < 0) || (y < 0) || (x >= OLED_WIDTH) || (y >= OLED_HEIGHT)) return;
	OLED_BUFCLR(x,y);
}

void oledDrawChar(int x, int y, char c, int zoom)
{
	int char_width;
	const uint8_t *char_data;

	if ((x >= OLED_WIDTH) || (y >= OLED_HEIGHT)) return;

	char_width = fontCharWidth(c);
	char_data = fontCharData(c);

	int xo, yo;
	for (xo = 0; xo < char_width; xo++) {
		for (yo = 0; yo < FONT_HEIGHT; yo++) {
			if (char_data[xo] & (1 << (FONT_HEIGHT - 1 - yo))) {
				if (zoom <= 1) {
					oledDrawPixel(x + xo, y + yo);
				} else {
					oledBox(x + xo * zoom, y + yo * zoom, x + (xo + 1) * zoom - 1, y + (yo + 1) * zoom - 1, true);
				}
			}
		}
	}
}

char oledConvertChar(const char c) {
	uint8_t a = c;
	if (a < 0x80) return c;
	// UTF-8 handling: https://en.wikipedia.org/wiki/UTF-8#Description
	// bytes 11xxxxxx are first byte of UTF-8 characters
	// bytes 10xxxxxx are successive UTF-8 characters
	if (a >= 0xC0) return '_';
	return 0;
}

int oledStringWidth(const char *text) {
	if (!text) return 0;
	int l = 0;
	char c;
	for (; *text; text++) {
		c = oledConvertChar(*text);
		if (c) {
			l += fontCharWidth(c) + 1;
		}
	}
	return l;
}

void oledDrawString(int x, int y, const char* text)
{
	if (!text) return;
	int size = 1;
	if (*text == 0x01) { // double size
		text++;
		size = 2;
	}
	int l = 0;
	char c;
	for (; *text; text++) {
		c = oledConvertChar(*text);
		if (c) {
			oledDrawChar(x + l, y, c, size);
			l += size * (fontCharWidth(c) + 1);
		}
	}
}

void oledDrawStringCenter(int y, const char* text)
{
	int x = ( OLED_WIDTH - oledStringWidth(text) ) / 2;
	oledDrawString(x, y, text);
}

void oledDrawStringRight(int x, int y, const char* text)
{
	x -= oledStringWidth(text);
	oledDrawString(x, y, text);
}

#define min(X,Y) ((X) < (Y) ? (X) : (Y))

void oledDrawBitmap(int x, int y, const BITMAP *bmp)
{
	int i, j;
	for (i = 0; i < min(bmp->width, OLED_WIDTH - x); i++) {
		for (j = 0; j < min(bmp->height, OLED_HEIGHT - y); j++) {
			if (bmp->data[(i / 8) + j * bmp->width / 8] & (1 << (7 - i % 8))) {
				OLED_BUFSET(x + i, y + j);
			} else {
				OLED_BUFCLR(x + i, y + j);
			}
		}
	}
}

void oledInvert(int x1, int y1, int x2, int y2)
{
	if ((x1 >= OLED_WIDTH) || (y1 >= OLED_HEIGHT) || (x2 >= OLED_WIDTH) || (y2 >= OLED_HEIGHT)) return;
	int x, y;
	for (x = x1; x <= x2; x++) {
		for (y = y1; y <= y2; y++) {
			OLED_BUFTGL(x,y);
		}
	}
}

/*
 * Draw a filled rectangle.
 */
void oledBox(int x1, int y1, int x2, int y2, bool set)
{
	int x, y;
	for (x = x1; x <= x2; x++) {
		for (y = y1; y <= y2; y++) {
			set ? oledDrawPixel(x, y) : oledClearPixel(x, y);
		}
	}
}

void oledHLine(int y) {
	int x;
	for (x = 0; x < OLED_WIDTH; x++) {
		oledDrawPixel(x, y);
	}
}

/*
 * Draw a rectangle frame.
 */
void oledFrame(int x1, int y1, int x2, int y2)
{
	int x, y;
	for (x = x1; x <= x2; x++) {
		oledDrawPixel(x, y1);
		oledDrawPixel(x, y2);
	}
	for (y = y1 + 1; y < y2; y++) {
		oledDrawPixel(x1, y);
		oledDrawPixel(x2, y);
	}
}

/*
 * Animates the display, swiping the current contents out to the left.
 * This clears the display.
 */
void oledSwipeLeft(void)
{
	int i, j, k;
	for (i = 0; i < OLED_WIDTH; i++) {
		for (j = 0; j < OLED_HEIGHT / 8; j++) {
			for (k = OLED_WIDTH-1; k > 0; k--) {
				_oledbuffer[j * OLED_WIDTH + k] = _oledbuffer[j * OLED_WIDTH + k - 1];
			}
			_oledbuffer[j * OLED_WIDTH] = 0;
		}
		oledRefresh();
	}
}

/*
 * Animates the display, swiping the current contents out to the right.
 * This clears the display.
 */
void oledSwipeRight(void)
{
	int i, j, k;
	for (i = 0; i < OLED_WIDTH / 4; i++) {
		for (j = 0; j < OLED_HEIGHT / 8; j++) {
			for (k = 0; k < OLED_WIDTH / 4 - 1; k++) {
				_oledbuffer[k * 4 + 0 + j * OLED_WIDTH] = _oledbuffer[k * 4 + 4 + j * OLED_WIDTH];
				_oledbuffer[k * 4 + 1 + j * OLED_WIDTH] = _oledbuffer[k * 4 + 5 + j * OLED_WIDTH];
				_oledbuffer[k * 4 + 2 + j * OLED_WIDTH] = _oledbuffer[k * 4 + 6 + j * OLED_WIDTH];
				_oledbuffer[k * 4 + 3 + j * OLED_WIDTH] = _oledbuffer[k * 4 + 7 + j * OLED_WIDTH];
			}
			_oledbuffer[j * OLED_WIDTH + OLED_WIDTH - 1] = 0;
			_oledbuffer[j * OLED_WIDTH + OLED_WIDTH - 2] = 0;
			_oledbuffer[j * OLED_WIDTH + OLED_WIDTH - 3] = 0;
			_oledbuffer[j * OLED_WIDTH + OLED_WIDTH - 4] = 0;
		}
		oledRefresh();
	}
}