#include "ch.h"
#include "hal.h"
#include "malloc.h"
#include "string.h"
#include "st7735.h"

#define DELAY 0x80

#define ST7735_Select()   LCD_CS_RES
#define ST7735_Unselect() LCD_CS_SET
#define HAL_Delay(x)      chThdSleepMilliseconds(x)

static void ST7735_Reset(void);

// based on Adafruit ST7735 library for Arduino
static const uint8_t
init_cmds1[] = {          // Init for 7735R, part 1 (red or green tab)
  15,                     // 15 commands in list:
  ST7735_SWRESET, DELAY,  //  1: Software reset, 0 args, w/delay
  150,                    //     150 ms delay
  ST7735_SLPOUT,  DELAY,  //  2: Out of sleep mode, 0 args, w/delay
  255,                    //     500 ms delay
  ST7735_FRMCTR1, 3,      //  3: Frame rate ctrl - normal mode, 3 args:
  0x01, 0x2C, 0x2D,       //     Rate = fosc/(1x2+40) * (LINE+2C+2D)
  ST7735_FRMCTR2, 3,      //  4: Frame rate control - idle mode, 3 args:
  0x01, 0x2C, 0x2D,       //     Rate = fosc/(1x2+40) * (LINE+2C+2D)
  ST7735_FRMCTR3, 6,      //  5: Frame rate ctrl - partial mode, 6 args:
  0x01, 0x2C, 0x2D,       //     Dot inversion mode
  0x01, 0x2C, 0x2D,       //     Line inversion mode
  ST7735_INVCTR, 1,       //  6: Display inversion ctrl, 1 arg, no delay:
  0x07,                   //     No inversion
  ST7735_PWCTR1, 3,       //  7: Power control, 3 args, no delay:
  0xA2,
  0x02,                   //     -4.6V
  0x84,                   //     AUTO mode
  ST7735_PWCTR2, 1,       //  8: Power control, 1 arg, no delay:
  0xC5,                   //     VGH25 = 2.4C VGSEL = -10 VGH = 3 * AVDD
  ST7735_PWCTR3, 2,       //  9: Power control, 2 args, no delay:
  0x0A,                   //     Opamp current small
  0x00,                   //     Boost frequency
  ST7735_PWCTR4, 2,       // 10: Power control, 2 args, no delay:
  0x8A,                   //     BCLK/2, Opamp current small & Medium low
  0x2A,
  ST7735_PWCTR5, 2,       // 11: Power control, 2 args, no delay:
  0x8A, 0xEE,
  ST7735_VMCTR1, 1,       // 12: Power control, 1 arg, no delay:
  0x0E,
  ST7735_INVOFF, 0,       // 13: Don't invert display, no args, no delay
  ST7735_MADCTL, 1,       // 14: Memory access control (directions), 1 arg:
  ST7735_ROTATION,        //     row addr/col addr, bottom to top refresh
  ST7735_COLMOD, 1,       // 15: set color mode, 1 arg, no delay:
  0x05                    //     16-bit color
},

#if (defined(ST7735_IS_128X128) || defined(ST7735_IS_160X128))
init_cmds2[] = {    // Init for 7735R, part 2 (1.44" display)
  2,                //  2 commands in list:
  ST7735_CASET, 4,  //  1: Column addr set, 4 args, no delay:
  0x00, 0x00,       //     XSTART = 0
  0x00, 0x7F,       //     XEND = 127
  ST7735_RASET, 4,  //  2: Row addr set, 4 args, no delay:
  0x00, 0x00,       //     XSTART = 0
  0x00, 0x7F        //     XEND = 127
},
#endif // ST7735_IS_128X128

#ifdef ST7735_IS_160X80
init_cmds2[] = {    // Init for 7735S, part 2 (160x80 display)
  3,                //  3 commands in list:
  ST7735_CASET, 4,  //  1: Column addr set, 4 args, no delay:
  0x00, 0x00,       //     XSTART = 0
  0x00, 0x4F,       //     XEND = 79
  ST7735_RASET, 4,  //  2: Row addr set, 4 args, no delay:
  0x00, 0x00,       //     XSTART = 0
  0x00, 0x9F,       //     XEND = 159
  ST7735_INVON, 0   //  3: Invert colors
},
#endif

init_cmds3[] = {          // Init for 7735R, part 3 (red or green tab)
  4,                      //  4 commands in list:
  ST7735_GMCTRP1, 16,     //  1: Gamma Adjustments (pos. polarity), 16 args, no delay:
  0x02, 0x1c, 0x07, 0x12,
  0x37, 0x32, 0x29, 0x2d,
  0x29, 0x25, 0x2B, 0x39,
  0x00, 0x01, 0x03, 0x10,
  ST7735_GMCTRN1, 16,     //  2: Gamma Adjustments (neg. polarity), 16 args, no delay:
  0x03, 0x1d, 0x07, 0x06,
  0x2E, 0x2C, 0x29, 0x2D,
  0x2E, 0x2E, 0x37, 0x3F,
  0x00, 0x00, 0x02, 0x10,
  ST7735_NORON, DELAY,    //  3: Normal display on, no args, w/delay
  10,                     //     10 ms delay
  ST7735_DISPON, DELAY,   //  4: Main screen turn on, no args w/delay
  100                     //     100 ms delay
};

static void ST7735_Reset(void) {
  //HAL_GPIO_WritePin(ST7735_RES_GPIO_Port, ST7735_RES_Pin, GPIO_PIN_RESET);
  HAL_Delay(5);
  //HAL_GPIO_WritePin(ST7735_RES_GPIO_Port, ST7735_RES_Pin, GPIO_PIN_SET);
}

/**
 * @brief Send command
 * 
 * @param cmd command for display
 */
static void ST7735_WriteCommand(uint8_t cmd) {
  LCD_DC_CMD;
  
  // wite while spi is busy
  while (!(SPI1->SR & SPI_SR_TXE));
  // send data
  SPI1->DR = cmd;
  // wite for data to be transmitted
  while (!(SPI1->SR & SPI_SR_TXE));
  // ... and spi is busy
  while ((SPI1->SR & SPI_SR_BSY));
}

/**
 * @brief Send 8-bit data using DMA
 * 
 * @param buff data to be sended
 * @param buff_size amount of bytes
 */
static void ST7735_WriteData(uint8_t* buff, size_t buff_size) {
  LCD_DC_DATA;
  spiSend(&ST7735_SPI_PORT, buff_size, buff);
}

/**
 * @brief Send 16-bit data trough reg, with end wait.
 * 
 * @param data to send to display
 */
static void ST7735_WriteData16(uint16_t data) {
  LCD_DC_DATA;
  //spiSend(&ST7735_SPI_PORT, buff_size, buff);
  
  // set 16-bit data
  SPI1->CR1 |= SPI_CR1_DFF;
  // wite while spi is busy
  while (!(SPI1->SR & SPI_SR_TXE));
  // send data
  SPI1->DR = data;
  // wite for data too be transmitted
  while (!(SPI1->SR & SPI_SR_TXE));
  // ... and spi is unbusy
  while ((SPI1->SR & SPI_SR_BSY));
  // set 8-bit data
  SPI1->CR1 &= ~(SPI_CR1_DFF);
}

static void ST7735_ExecuteCommandList(const uint8_t *addr) {
  uint8_t numCommands, numArgs;
  uint16_t ms;

  numCommands = *addr ++;
  while (numCommands--) {
    uint8_t cmd = *addr ++;
    ST7735_WriteCommand(cmd);

    numArgs = *addr ++;
    // If high bit set, delay follows args
    ms = numArgs & DELAY;
    numArgs &= ~DELAY;
    if (numArgs) {
      ST7735_WriteData((uint8_t*)addr, numArgs);
      addr += numArgs;
    }

    if (ms) {
      ms = *addr ++;
      if (ms == 255) {
          ms = 500;
      }
      HAL_Delay(ms);
    }
  }
}

static void ST7735_SetAddressWindow(uint8_t x0, uint8_t y0, uint8_t x1, uint8_t y1) {
  // column address set
  ST7735_WriteCommand(ST7735_CASET);
  uint8_t data[] = {0x00, x0 + ST7735_XSTART, 0x00, x1 + ST7735_XSTART};
  ST7735_WriteData(data, sizeof(data));

  // row address set
  ST7735_WriteCommand(ST7735_RASET);
  data[1] = y0 + ST7735_YSTART;
  data[3] = y1 + ST7735_YSTART;
  ST7735_WriteData(data, sizeof(data));

  // write to RAM
  ST7735_WriteCommand(ST7735_RAMWR);
}

void ST7735_Init(void) {
  ST7735_Select();
  ST7735_Reset();
  ST7735_ExecuteCommandList(init_cmds1);
  ST7735_ExecuteCommandList(init_cmds2);
  ST7735_ExecuteCommandList(init_cmds3);
  ST7735_Unselect();
}

/**
 * @brief Draw single pixel
 * 
 * @param x coordinate
 * @param y coordinate
 * @param color pixel colour
 */
void ST7735_DrawPixel(uint16_t x, uint16_t y, uint16_t color) {
  if ((x >= ST7735_WIDTH) || (y >= ST7735_HEIGHT)) {
    return;
  }

  ST7735_Select();
  ST7735_SetAddressWindow(x, y, x+1, y+1);
  ST7735_WriteData16(color);
  ST7735_Unselect();
}

/**
 * @brief Draw fixed width font char.
 * 
 * @param x coordinate,
 * @param y coordinate,
 * @param ch char to draw,
 * @param font fixed width font
 * @param color char color
 * @param bgcolor background color
 */
static void ST7735_WriteChar(uint16_t x, uint16_t y, char ch, FontDef font, uint16_t color, uint16_t bgcolor) {
  uint32_t i, b, j;

  ST7735_SetAddressWindow(x, y, x+font.width-1, y+font.height-1);

  LCD_DC_DATA;
  SPI1->CR1 |= SPI_CR1_DFF;

  uint16_t ih = (ch - 32) * font.height;
  for(i = 0; i < font.height; i++) {
    b = font.data[ih + i];
    for(j = 0; j < font.width; j++) {
      if (b & 0x8000) {
        while (!(SPI1->SR & SPI_SR_TXE));
        SPI1->DR = color;
      } else {
        while (!(SPI1->SR & SPI_SR_TXE));
        SPI1->DR = bgcolor;
      }
      b <<= 1;
    }
  }
  while (!(SPI1->SR & SPI_SR_TXE));
  while ((SPI1->SR & SPI_SR_BSY));
  SPI1->CR1 &= ~(SPI_CR1_DFF);
}

/**
 * @brief 
 * 
 * @param x from ST7735_XSTART to ST7735_WIDTH
 * @param y from ST7735_YSTART to ST7735_HEIGHT
 * @param str string to output
 * @param font 
 * @param color 
 * @param bgcolor 
 */
void ST7735_WriteString(uint16_t x, uint16_t y, const char* str, FontDef font, uint16_t color, uint16_t bgcolor) {
  ST7735_Select();

  char ch = *str;
  while (ch) {
    if (x + font.width >= ST7735_WIDTH) {
      x = 0;
      y += font.height;
      if (y + font.height >= ST7735_HEIGHT) {
        break;
      }

      if (ch == ' ') {
        // skip spaces in the beginning of the new line
        str ++;
        ch = *str;
        continue;
      }
    }
#ifdef USE_UTF8
    if (ch >= 0xC0) {
      switch (ch) {
        case 0xD0: {
          str ++;
          ch = *str;
          if (ch >= 0x90 && ch <= 0xBF) {
            ch += 0x30;
          } else if (ch == 0x84) { // Є
            ch =  0xaa;
          } else if (ch == 0x86) { // І
            ch =  0xb2;
          } else if (ch == 0x87) { // Ї
            ch =  0xaf;
          } else if (ch == 0x81) { // Ё
            ch = 0xA8;
          } else {
            ch =  '.';
          }
          break;
        }
        case 0xD1: {
          str ++;
          ch = *str;
          if (ch >= 0x7E && ch <= 0x8F) {
            ch += 0x70;
          } else if (ch == 0x94) { // є
            ch =  0xba;
          } else if (ch == 0x96) { // і
            ch =  0xb3;
          } else if (ch == 0x97) { // ї
            ch =  0xbf;
          } else if (ch == 0x91) { // ё
            ch = 0xB8;
          } else {
            ch =  '.';
          }
          break;
        }
        case 0xD2: {
          str ++;
          ch = *str;
          if (ch == 0x90) { // Ґ
            ch =  0xa5;
          } else if (ch == 0x91) { // ґ
            ch =  0xb4;
          }
          break;
        }
        case 0xC2: {
          str ++;
          ch = *str;
          if (ch == 0xB0) { // °
            ch = 0xB0;
          }
          break;
        }
      }
    }
#endif /* USE_UTF8 */
    ST7735_WriteChar(x, y, ch, font, color, bgcolor);
    x += font.width;
    str ++;
    ch = *str;
  }

  ST7735_Unselect();
}

/**
 * @brief Draw line or filled rectangle
 * 
 * @param x from ST7735_XSTART to ST7735_WIDTH
 * @param y from ST7735_YSTART to ST7735_HEIGHT
 * @param w from 1 to ST7735_WIDTH
 * @param h from 1 to ST7735_HEIGHT
 * @param color 16-bit RGB565
 */
void ST7735_FillRectangle(uint16_t x, uint16_t y, uint16_t w, uint16_t h, uint16_t color) {
  // clipping
  if ((x >= ST7735_WIDTH) || (y >= ST7735_HEIGHT)) {
      return;
  }
  if ((x + w - 1) >= ST7735_WIDTH) {
      w = ST7735_WIDTH - x;
  }
  if ((y + h - 1) >= ST7735_HEIGHT) {
      h = ST7735_HEIGHT - y;
  }

  ST7735_Select();
  ST7735_SetAddressWindow(x, y, x+w-1, y+h-1);

  for (y = h; y > 0; y--) {
    for (x = w; x > 0; x--) {
      ST7735_WriteData16(color);
    }
  }

  ST7735_Unselect();
}

void ST7735_FillScreen(uint16_t color) {
  ST7735_FillRectangle(0, 0, ST7735_WIDTH, ST7735_HEIGHT, color);
}

void ST7735_DrawImage(uint16_t x, uint16_t y, uint16_t w, uint16_t h, const uint16_t* data) {
  if ((x >= ST7735_WIDTH) || (y >= ST7735_HEIGHT)) {
      return;
  }
  if ((x + w - 1) >= ST7735_WIDTH) {
      return;
  }
  if ((y + h - 1) >= ST7735_HEIGHT) {
      return;
  }

  ST7735_Select();
  ST7735_SetAddressWindow(x, y, x+w-1, y+h-1);
  ST7735_WriteData((uint8_t*)data, sizeof(uint16_t)*w*h);
  ST7735_Unselect();
}

void ST7735_InvertColors(bool invert) {
  ST7735_Select();
  ST7735_WriteCommand(invert ? ST7735_INVON : ST7735_INVOFF);
  ST7735_Unselect();
}

void ST7735_SetGamma(GammaDef gamma) {
  ST7735_Select();
  ST7735_WriteCommand(ST7735_GAMSET);
  ST7735_WriteData((uint8_t *) &gamma, sizeof(gamma));
  ST7735_Unselect();
}