#include <stdio.h>
#include "freertos/FreeRTOS.h"
#include "freertos/task.h"
#include "driver/i2c.h"
#include "rom/ets_sys.h"


#define LCD_20X04   1

#define I2C_ACK_CHECK_EN  1      
#define I2C_ADDRESS_LCD   0x27      
#define I2C_SCL_LCD       18        
#define I2C_SDA_LCD       19        

/* Comandos de la LCD */
#define CLEAR_DISPLAY               0x01
#define RETURN_HOME_UNSHIFT         0x02
#define CURSOR_RIGHT_NO_SHIFT       0x04
#define CURSOR_RIGHT_SHIFT          0x05
#define CURSOR_RIGHT_NO_SHIFT_LEFT  0x06
#define CURSOR_RIGHT_SHIFT_LEFT     0x07
#define DISPLAY_OFF                 0x08
#define DISPLAY_ON_CURSOR_OFF       0x0C
#define DISPLAY_ON_CURSOR_ON_STEADY 0x0E
#define DISPLAY_ON_CURSOR_ON_BLINK  0x0F
#define SHIFT_CURSOR_LEFT           0x10
#define SHIFT_CURSOR_RIGHT          0x14
#define SHIFT_DISPLAY_LEFT          0x18
#define SHIFT_DISPLAY_RIGHT         0x1C
#define SET_4BIT_MODE               0x28
#define RETURN_HOME                 0x80

/* PCF8574 */
#define PCF8574_RS    0
#define PCF8574_RW    1
#define PCF8574_EN    2
#define PCF8574_BL    3

#define LCD_RS_CMD    0
#define LCD_RS_DATA   1

typedef struct {
  uint8_t i2c_address;
  uint8_t i2c_port;
  uint8_t screen_size;
  uint8_t screen_backlight;
} lcd_i2c_device_t;

void sort(uint16_t * weights, uint8_t N) {
  uint8_t iteraciones;

  for (uint8_t i = 0; i < (N-2) ; i++) {

    iteraciones = N - 2 - i;
    printf("%d\n" , weights[iteraciones - i - 1]);

    for (uint8_t index = 0; index <= (iteraciones) ; index ++) {
        if ( weights[index] > weights[index + 1] ) {
          uint16_t temp = weights[index];
          weights[index] = weights[index + 1];
          weights[index + 1] = temp;
        }

    }

  }
}

uint8_t objects_value (uint16_t * weights , uint8_t N, uint16_t w){

  uint32_t sum = 0;
  uint8_t index = 0;

  uint8_t stop = 1;

  while ( stop ) {
    if ((sum + weights[index]) > w) {
      stop--;
    }
    else {
      sum +=weights[index];
      index ++;
    }
  }
  return index;
}

void i2c_init(void);
void lcd_init(lcd_i2c_device_t * lcd);
void lcd_i2c_write_byte(lcd_i2c_device_t * lcd, uint8_t data);
void lcd_i2c_write_command(lcd_i2c_device_t * lcd, uint8_t register_select, uint8_t cmd);
void lcd_set_cursor(lcd_i2c_device_t * lcd, uint8_t column, uint8_t row);
void lcd_i2c_write_custom_char(lcd_i2c_device_t * lcd, uint8_t char_address, const uint8_t * pixels);

void i2c_init(void) 
{
    /* Configure la conexión aquí */
  i2c_config_t i2c_config = {
      .mode = I2C_MODE_MASTER,
      .sda_io_num = I2C_SDA_LCD,
      .sda_pullup_en = GPIO_PULLUP_ENABLE,
      .scl_io_num = I2C_SCL_LCD,
      .scl_pullup_en = GPIO_PULLUP_ENABLE,
      .master.clk_speed = 400000,
  };

  esp_err_t error = i2c_param_config(I2C_NUM_1, &i2c_config);
  if (error != ESP_OK) {
        while(1);
    }
  i2c_driver_install(I2C_NUM_1, I2C_MODE_MASTER, 0, 0, 0);
}

void lcd_init(lcd_i2c_device_t * lcd)
{
  lcd_i2c_write_command(lcd, LCD_RS_CMD, RETURN_HOME_UNSHIFT);
  lcd_i2c_write_command(lcd, LCD_RS_CMD, SET_4BIT_MODE);
  lcd_i2c_write_command(lcd, LCD_RS_CMD, CLEAR_DISPLAY);
  lcd_i2c_write_command(lcd, LCD_RS_CMD, DISPLAY_ON_CURSOR_OFF);
  lcd_i2c_write_command(lcd, LCD_RS_CMD, CURSOR_RIGHT_NO_SHIFT_LEFT);
  vTaskDelay(20 / portTICK_PERIOD_MS);
}

void lcd_i2c_write_byte(lcd_i2c_device_t * lcd, uint8_t data)
{
  i2c_cmd_handle_t cmd_handle = i2c_cmd_link_create();
  i2c_master_start(cmd_handle);
  i2c_master_write_byte(cmd_handle, (lcd->i2c_address << 1) | I2C_MASTER_WRITE, I2C_ACK_CHECK_EN);
  i2c_master_write_byte(cmd_handle, data, 1);
  i2c_master_stop(cmd_handle);
  i2c_master_cmd_begin(lcd->i2c_port, cmd_handle, 100 / portTICK_PERIOD_MS);
  i2c_cmd_link_delete(cmd_handle);
}

void lcd_i2c_write_command(lcd_i2c_device_t * lcd, uint8_t register_select, uint8_t cmd)
{
  uint8_t config = (register_select)? (1 << PCF8574_RS) : 0;
  config |= (lcd->screen_backlight)? (1 << PCF8574_BL) : 0;

  config |= (config & 0x0F) | (0xF0 & cmd);
  config |= (1 << PCF8574_EN);
  lcd_i2c_write_byte(lcd, config);
  ets_delay_us(10);
  config &= ~(1 << PCF8574_EN);
  lcd_i2c_write_byte(lcd, config);
  ets_delay_us(50);

  config = (config & 0x0F) | (cmd << 4);
  config |= (1 << PCF8574_EN);
  lcd_i2c_write_byte(lcd, config);
  ets_delay_us(10);
  config &= ~(1 << PCF8574_EN);
  lcd_i2c_write_byte(lcd, config);
  ets_delay_us(50);

  if (cmd == CLEAR_DISPLAY)
  {
    vTaskDelay(20 / portTICK_PERIOD_MS);
  }
}

void lcd_set_cursor(lcd_i2c_device_t * lcd, uint8_t column, uint8_t row)
{
  switch (row) {
    case 0:
      lcd_i2c_write_command(lcd, LCD_RS_CMD, 0x80 + column);
      break;
    case 1:
      lcd_i2c_write_command(lcd, LCD_RS_CMD, 0xC0 + column);
      break;
    case 2:
      lcd_i2c_write_command(lcd, LCD_RS_CMD, 0x94 + column);
      break;
    case 3:
      lcd_i2c_write_command(lcd, LCD_RS_CMD, 0xD4 + column);
      break;
    default:
      break;
  }
}

void lcd_i2c_write_custom_char(lcd_i2c_device_t * lcd, uint8_t address, const uint8_t * pixels)
{
  lcd_i2c_write_command(lcd, LCD_RS_CMD, 0x40 | (address << 3));

  for (uint8_t i = 0; i < 8; i++)
  {
    lcd_i2c_write_command(lcd, LCD_RS_DATA, pixels[i]);
  }

  lcd_i2c_write_command(lcd, LCD_RS_CMD, RETURN_HOME);
}

void lcd_i2c_print_msg(lcd_i2c_device_t * lcd, char * msg)
{
  uint8_t i = 0;

  while (msg[i] != '\0')
  {
    lcd_i2c_write_command(lcd, LCD_RS_DATA, msg[i++]);
  }
}





#define SMILE        5
#define DROP         2


void app_main()
{

  uint16_t weights[] = {1, 12, 5, 111, 200, 1000, 10};
  uint8_t N = 7;
  uint16_t w = 50;

  sort(weights , N);

  i2c_init();

  lcd_i2c_device_t my_lcd = {
    .i2c_port = I2C_NUM_1,
    .i2c_address = I2C_ADDRESS_LCD,
    .screen_size = LCD_20X04,
    .screen_backlight = 1,
  };

  vTaskDelay(20 / portTICK_PERIOD_MS);
  lcd_init(&my_lcd);

  char message[] = "Max objetos: ";
  char number[] = " ";
  number[0] = objects_value(weights , N, w) + '0';

  lcd_i2c_print_msg(&my_lcd, message);
  lcd_i2c_print_msg(&my_lcd, number);

}