#include <stdio.h>
#include <stdint.h>
#include <string.h>
#include <stdlib.h>
#include "pico/stdlib.h"
#include "hardware/i2c.h"
#include "hardware/adc.h"
#include "ssd1306.h"

// ------------------ DEFINIÇÕES ------------------
#define SDA_PIN 20
#define SCL_PIN 21
#define OLED_ADDR 0x3C
#define LCD_ADDR 0x27

#define JOY_X 27
#define JOY_Y 28

#define LCD_BACKLIGHT 0x08
#define LCD_ENABLE_BIT 0x04

#define LCD_COMMAND 0
#define LCD_CHARACTER 1

#define LCD_CLEARDISPLAY 0x01
#define LCD_RETURNHOME 0x02
#define LCD_ENTRYMODESET 0x04
#define LCD_DISPLAYCONTROL 0x08
#define LCD_FUNCTIONSET 0x20
#define LCD_SETDDRAMADDR 0x80

#define LCD_ENTRYLEFT 0x02
#define LCD_DISPLAYON 0x04
#define LCD_2LINE 0x08

// ------------------ VARIÁVEIS ------------------
ssd1306_t disp;
static int lcd_addr = LCD_ADDR;

// ------------------ FUNÇÕES LCD ------------------
void i2c_write_byte(uint8_t val) {
  i2c_write_blocking(i2c0, lcd_addr, &val, 1, false);
}

void lcd_toggle_enable(uint8_t val) {
  sleep_us(500);
  i2c_write_byte(val | LCD_ENABLE_BIT);
  sleep_us(500);
  i2c_write_byte(val & ~LCD_ENABLE_BIT);
  sleep_us(500);
}

void lcd_send_byte(uint8_t val, int mode) {
  uint8_t high = mode | (val & 0xF0) | LCD_BACKLIGHT;
  uint8_t low  = mode | ((val << 4) & 0xF0) | LCD_BACKLIGHT;
  i2c_write_byte(high);
  lcd_toggle_enable(high);
  i2c_write_byte(low);
  lcd_toggle_enable(low);
}

void lcd_send_cmd(uint8_t cmd) {
  lcd_send_byte(cmd, LCD_COMMAND);
}

void lcd_send_data(uint8_t data) {
  lcd_send_byte(data, LCD_CHARACTER);
}

void lcd_init() {
  sleep_ms(50);
  lcd_send_cmd(0x03);
  lcd_send_cmd(0x03);
  lcd_send_cmd(0x03);
  lcd_send_cmd(0x02);
  lcd_send_cmd(LCD_FUNCTIONSET | LCD_2LINE);
  lcd_send_cmd(LCD_DISPLAYCONTROL | LCD_DISPLAYON);
  lcd_send_cmd(LCD_ENTRYMODESET | LCD_ENTRYLEFT);
  lcd_send_cmd(LCD_CLEARDISPLAY);
  sleep_ms(2);
}

void lcd_clear() {
  lcd_send_cmd(LCD_CLEARDISPLAY);
  sleep_ms(2);
}

void lcd_set_cursor(int line, int pos) {
  int addr = (line == 0 ? 0x80 : 0xC0) + pos;
  lcd_send_cmd(addr);
}

void lcd_string(const char *str) {
  while (*str) {
    lcd_send_data(*str++);
  }
}

// ------------------ CONFIGURAÇÃO ------------------
void setup_I2C() {
  i2c_init(i2c0, 100 * 1000);
  gpio_set_function(SDA_PIN, GPIO_FUNC_I2C);
  gpio_set_function(SCL_PIN, GPIO_FUNC_I2C);
  gpio_pull_up(SDA_PIN);
  gpio_pull_up(SCL_PIN);
}

// ------------------ DESENHO CÍRCULO PREENCHIDO ------------------
void draw_filled_circle(ssd1306_t *disp, int x0, int y0, int r) {
  for (int y = -r; y <= r; y++) {
    for (int x = -r; x <= r; x++) {
      if (x*x + y*y <= r*r) {
        ssd1306_draw_pixel(disp, x0 + x, y0 + y);
      }
    }
  }
}

// ------------------ MAIN ------------------
int main() {
  stdio_init_all();
  setup_I2C();
  adc_init();
  adc_gpio_init(JOY_X);
  adc_gpio_init(JOY_Y);

  lcd_init();

  // OLED
  disp.external_vcc = false;
  ssd1306_init(&disp, 128, 64, OLED_ADDR, i2c0);
  ssd1306_clear(&disp);

  while (true) {
    // Leitura dos eixos analógicos
    adc_select_input(1);
    uint16_t x_raw = adc_read();
    adc_select_input(2);
    uint16_t y_raw = adc_read();

    int16_t x = x_raw - 2048;
    int16_t y = y_raw - 2048;

    char direcao[16] = "Centro";

    if (y > 800 && abs(x) < 600) strcpy(direcao, "Norte");
    else if (y < -800 && abs(x) < 600) strcpy(direcao, "Sul");
    else if (x > 800 && abs(y) < 600) strcpy(direcao, "Oeste");
    else if (x < -800 && abs(y) < 600) strcpy(direcao, "Leste");
    else if (x > 600 && y > 600) strcpy(direcao, "Noroeste");
    else if (x < -600 && y > 600) strcpy(direcao, "Nordeste");
    else if (x > 600 && y < -600) strcpy(direcao, "Sudoeste");
    else if (x < -600 && y < -600) strcpy(direcao, "Sudeste");

    // --- LCD ---
    lcd_clear();
    lcd_set_cursor(0, 0);
    char linha1[17];
    sprintf(linha1, "X:%4d Y:%4d", x_raw, y_raw);
    lcd_string(linha1);
    lcd_set_cursor(1, 0);
    lcd_string(direcao);

    // --- OLED ---
    ssd1306_clear(&disp);

    int cx = 64, cy = 32;   // centro
    int len = 20;           // comprimento da seta
    int thick = 2;          // espessura

    // ponto central (substitui o draw_filled_circle)
    draw_filled_circle(&disp, cx, cy, 3);

    // direção da seta
    int dx = 0, dy = 0;
    if (strcmp(direcao, "Norte") == 0)        { dx = 0;  dy = -len; }
    else if (strcmp(direcao, "Sul") == 0)     { dx = 0;  dy = len; }
    else if (strcmp(direcao, "Leste") == 0)   { dx = len; dy = 0; }
    else if (strcmp(direcao, "Oeste") == 0)   { dx = -len; dy = 0; }
    else if (strcmp(direcao, "Nordeste") == 0){ dx = len; dy = -len; }
    else if (strcmp(direcao, "Noroeste") == 0){ dx = -len; dy = -len; }
    else if (strcmp(direcao, "Sudeste") == 0){ dx =  len; dy =  len; }
    else if (strcmp(direcao, "Sudoeste") == 0){ dx = -len; dy =  len; }

    // seta mais grossa
    for (int i = -thick; i <= thick; i++) {
      ssd1306_draw_line(&disp, cx + i, cy, cx + dx + i, cy + dy);
      ssd1306_draw_line(&disp, cx, cy + i, cx + dx, cy + dy + i);
    }

    // texto grande e centralizado
    ssd1306_draw_string(&disp, 25, 2, 2, direcao);

    ssd1306_show(&disp);
    sleep_ms(200);
  }
}