#include "LCD_I2C.h"
#include <unistd.h>

//------------------------------
void send(LCD_I2C*, uint8_t, uint8_t);
void write4bits(LCD_I2C*, uint8_t);
void expanderWrite(LCD_I2C*, uint8_t);
void pulseEnable(LCD_I2C*, uint8_t);

void LCD_delay(unsigned long millisec){ usleep(1000 * millisec); }
void LCD_delayMicro(unsigned long micro){ usleep(micro); }
//------------------------------

void LCD_init(LCD_I2C* lcd_i2c, i2c* i2cbus, uint8_t lcd_addr, uint8_t lcd_cols, uint8_t lcd_rows){
  LCD_initEx(lcd_i2c, i2cbus, lcd_addr, lcd_cols, lcd_rows, LCD_5x8DOTS);
}

void LCD_initEx(LCD_I2C* lcd_i2c, i2c* i2cbus, uint8_t lcd_addr, uint8_t lcd_cols, uint8_t lcd_rows, uint8_t charsize){
  lcd_i2c->_addr = lcd_addr;
  lcd_i2c->_cols = lcd_cols;
  lcd_i2c->_rows = lcd_rows;
  lcd_i2c->_charsize = charsize;
  lcd_i2c->_backlightval = LCD_BACKLIGHT;
  lcd_i2c->_i2cbus = i2cbus;
}

void LCD_begin(LCD_I2C* lcd_i2c){
  lcd_i2c->_displayfunction = LCD_4BITMODE | LCD_1LINE | LCD_5x8DOTS;
  if (lcd_i2c->_rows > 1) lcd_i2c->_displayfunction |= LCD_2LINE;
  if ((lcd_i2c->_charsize != 0) && (lcd_i2c->_rows == 1)) lcd_i2c->_displayfunction |= LCD_5x10DOTS;
  
  LCD_delay(50);
  
  expanderWrite(lcd_i2c, lcd_i2c->_backlightval);
  LCD_delay(1000);
  
  write4bits(lcd_i2c, 0x03 << 4);
  LCD_delayMicro(4500);
  
  write4bits(lcd_i2c, 0x03 << 4);
  LCD_delayMicro(4500);
  
  write4bits(lcd_i2c, 0x03 << 4);
  LCD_delayMicro(150);
  
  write4bits(lcd_i2c, 0x02 << 4);
  
  LCD_command(lcd_i2c, LCD_FUNCTIONSET | lcd_i2c->_displayfunction);
  
  lcd_i2c->_displaycontrol = LCD_DISPLAYON | LCD_CURSOROFF | LCD_BLINKOFF;
  LCD_display(lcd_i2c);
  
  LCD_clear(lcd_i2c);
  
  lcd_i2c->_displaymode = LCD_ENTRYLEFT | LCD_ENTRYSHIFTDECREMENT;
  
  LCD_command(lcd_i2c, LCD_ENTRYMODESET | lcd_i2c->_displaymode);
  
  LCD_home(lcd_i2c);
}

void LCD_clear(LCD_I2C* lcd_i2c){
  LCD_command(lcd_i2c, LCD_CLEARDISPLAY);
  LCD_delayMicro(2000);
}

void LCD_home(LCD_I2C* lcd_i2c){
  LCD_command(lcd_i2c, LCD_RETURNHOME);
  LCD_delayMicro(2000);
}

void LCD_noDisplay(LCD_I2C* lcd_i2c){
  lcd_i2c->_displaycontrol &= ~LCD_DISPLAYON;
	LCD_command(lcd_i2c, LCD_DISPLAYCONTROL | lcd_i2c->_displaycontrol);
}

void LCD_display(LCD_I2C* lcd_i2c){
	lcd_i2c->_displaycontrol |= LCD_DISPLAYON;
	LCD_command(lcd_i2c, LCD_DISPLAYCONTROL | lcd_i2c->_displaycontrol);
}

void LCD_noBlink(LCD_I2C* lcd_i2c){
  lcd_i2c->_displaycontrol &= ~LCD_BLINKON;
  LCD_command(lcd_i2c, LCD_DISPLAYCONTROL | lcd_i2c->_displaycontrol);
}

void LCD_blink(LCD_I2C* lcd_i2c){
  lcd_i2c->_displaycontrol |= LCD_BLINKON;
  LCD_command(lcd_i2c, LCD_DISPLAYCONTROL | lcd_i2c->_displaycontrol);
}

void LCD_noCursor(LCD_I2C* lcd_i2c){
  lcd_i2c->_displaycontrol &= ~LCD_CURSORON;
  LCD_command(lcd_i2c, LCD_DISPLAYCONTROL | lcd_i2c->_displaycontrol);
}

void LCD_cursor(LCD_I2C* lcd_i2c){
  lcd_i2c->_displaycontrol |= LCD_CURSORON;
  LCD_command(lcd_i2c, LCD_DISPLAYCONTROL | lcd_i2c->_displaycontrol);
}

void LCD_scrollDisplayLeft(LCD_I2C* lcd_i2c){ LCD_command(lcd_i2c, LCD_CURSORSHIFT | LCD_DISPLAYMOVE | LCD_MOVELEFT); }

void LCD_scrollDisplayRight(LCD_I2C* lcd_i2c){ LCD_command(lcd_i2c, LCD_CURSORSHIFT | LCD_DISPLAYMOVE | LCD_MOVERIGHT); }

//void LCD_printLeft(LCD_I2C* lcd_i2c){}

//void LCD_printRight(LCD_I2C* lcd_i2c){}

void LCD_leftToRight(LCD_I2C* lcd_i2c){
  lcd_i2c->_displaymode |= LCD_ENTRYLEFT;
  LCD_command(lcd_i2c, LCD_ENTRYMODESET | lcd_i2c->_displaymode);
}

void LCD_rightToLeft(LCD_I2C* lcd_i2c){
  lcd_i2c->_displaymode &= ~LCD_ENTRYLEFT;
  LCD_command(lcd_i2c, LCD_ENTRYMODESET | lcd_i2c->_displaymode);
}

//void LCD_shiftIncrement(LCD_I2C* lcd_i2c){}

//void LCD_shiftDecrement(LCD_I2C* lcd_i2c){}

void LCD_noBacklight(LCD_I2C* lcd_i2c){
  lcd_i2c->_backlightval=LCD_NOBACKLIGHT;
  expanderWrite(lcd_i2c, 0);
}

void LCD_backlight(LCD_I2C* lcd_i2c){
  lcd_i2c->_backlightval=LCD_BACKLIGHT;
  expanderWrite(lcd_i2c, 0);
}

bool LCD_getBacklight(LCD_I2C* lcd_i2c){ return lcd_i2c->_backlightval == LCD_BACKLIGHT; }

void LCD_autoscroll(LCD_I2C* lcd_i2c){
  lcd_i2c->_displaymode |= LCD_ENTRYSHIFTINCREMENT;
  LCD_command(lcd_i2c, LCD_ENTRYMODESET | lcd_i2c->_displaymode);
}

void LCD_noAutoscroll(LCD_I2C* lcd_i2c){
  lcd_i2c->_displaymode &= ~LCD_ENTRYSHIFTINCREMENT;
  LCD_command(lcd_i2c, LCD_ENTRYMODESET | lcd_i2c->_displaymode);
}

void LCD_createChar(LCD_I2C* lcd_i2c, uint8_t location, uint8_t charmap[]){
  location &= 0x7; // we only have 8 locations 0-7
  LCD_command(lcd_i2c, LCD_SETCGRAMADDR | (location << 3));
  for (int i=0; i<8; i++) LCD_write(lcd_i2c, charmap[i]);
}

void LCD_setCursor(LCD_I2C* lcd_i2c, uint8_t col, uint8_t row){
  int row_offsets[] = { 0x00, 0x40, 0x14, 0x54 };
  if (row > lcd_i2c->_rows) row = lcd_i2c->_rows-1;    // we count rows starting w/0
  LCD_command(lcd_i2c, LCD_SETDDRAMADDR | (col + row_offsets[row]));
}

void LCD_command(LCD_I2C* lcd_i2c, uint8_t value){ send(lcd_i2c, value, 0); }

int LCD_write(LCD_I2C* lcd_i2c, uint8_t value){
  send(lcd_i2c, value, Rs);
  return 1;
}

void LCD_blink_on(LCD_I2C* lcd_i2c) { LCD_blink(lcd_i2c); }

void LCD_blink_off(LCD_I2C* lcd_i2c) { LCD_noBlink(lcd_i2c); }

void LCD_cursor_on(LCD_I2C* lcd_i2c) { LCD_cursor(lcd_i2c); }

void LCD_cursor_off(LCD_I2C* lcd_i2c) { LCD_noCursor(lcd_i2c); }

void LCD_setBacklight(LCD_I2C* lcd_i2c, uint8_t new_val){
  if (new_val) LCD_backlight(lcd_i2c);		// turn backlight on
  else LCD_noBacklight(lcd_i2c);		// turn backlight off
}

void LCD_load_custom_character(LCD_I2C* lcd_i2c, uint8_t char_num, uint8_t *rows){ LCD_createChar(lcd_i2c, char_num, rows); }

void LCD_printstr(LCD_I2C* lcd_i2c, const char c[]){ for (size_t i=0; i<strlen(c); i++) LCD_write(lcd_i2c, c[i]); }

//------------------------------
void send(LCD_I2C* lcd_i2c, uint8_t value, uint8_t mode){
  uint8_t highnib = value&0xf0;
  uint8_t lownib = (value<<4)&0xf0;
  write4bits(lcd_i2c, (highnib)|mode);
  write4bits(lcd_i2c, (lownib)|mode);
}

void write4bits(LCD_I2C* lcd_i2c, uint8_t value){
  expanderWrite(lcd_i2c, value);
  pulseEnable(lcd_i2c, value);
}

void expanderWrite(LCD_I2C* lcd_i2c, uint8_t _data){
  i2c_start(lcd_i2c->_i2cbus);
  //address
  {
    uint8_t i2cAddr = lcd_i2c->_addr;
    i2cAddr <<= 1;
    i2cAddr &= -2;
    i2c_writeByte(lcd_i2c->_i2cbus, i2cAddr);
  }
  //data
  i2c_writeByte(lcd_i2c->_i2cbus, (int)(_data) | lcd_i2c->_backlightval);
  i2c_stop(lcd_i2c->_i2cbus);
}
  
void pulseEnable(LCD_I2C* lcd_i2c, uint8_t _data){
  expanderWrite(lcd_i2c, _data | En);
  LCD_delayMicro(1);
  
  expanderWrite(lcd_i2c, _data & ~En);
  LCD_delayMicro(50);
}
//------------------------------