#include "RTClib.h"
#include <SPI.h>
#include <Wire.h>
#include <Adafruit_GFX.h>
#include <Adafruit_SSD1306.h>

#define OLED_RESET     4
Adafruit_SSD1306 display(128, 64, &Wire, OLED_RESET);

#define C_X 63
#define C_Y 31


RTC_DS1307 rtc;

char daysOfTheWeek[7][12] = {"Sunday", "Monday", "Tuesday", "Wednesday", "Thursday", "Friday", "Saturday"};

void setup () {

  Serial.begin(115200);
  // put your setup code here, to run once:
  display.begin(SSD1306_SWITCHCAPVCC, 0x3c);
  display.display();
  delay(1000);

  display.display();

  if (! rtc.begin()) {
    Serial.println("Couldn't find RTC");
    Serial.flush();
    abort();
  }
}

void setcircle() {
  int t, m, s;
  float theta_r, x, y;

  display.clearDisplay();
  display.drawCircle(C_X, C_Y, 31, SSD1306_WHITE);
  display.drawCircle(C_X, C_Y, 3, SSD1306_WHITE);
  for (int i = 0; i < 12; i++) {
    m = i * 5;
    t = 120 - m * 6;
    theta_r = t * (PI / 180.0);

    x = 63 + 25 * cos(theta_r);  // 計算指針外圍的起始位置，半徑為 28（這裡的 28 是指針的長度）
    y = 31 - 25 * sin(theta_r);
    display.drawLine(x, y, 63 + 31 * cos(theta_r), 31 - 31 * sin(theta_r), SSD1306_WHITE);
    // 繪製指針，起點為 (x, y)，終點為圓邊緣 (63 + 31 * cos(theta_r), 31 - 31 * sin(theta_r))
  }
  for (int i = 0; i < 60; i++) {
    s = i;
    t = 120 - s * 6;
    theta_r = t * (PI / 180.0);

    x = 63 + 28 * cos(theta_r);  // 計算指針外圍的起始位置，半徑為 28（這裡的 28 是指針的長度）
    y = 31 - 28 * sin(theta_r);
    display.drawLine(x, y, 63 + 31 * cos(theta_r), 31 - 31 * sin(theta_r), SSD1306_WHITE);
    // 繪製指針，起點為 (x, y)，終點為圓邊緣 (63 + 31 * cos(theta_r), 31 - 31 * sin(theta_r))
  }
  display.display();
}

float a = 45;
float theta_r, x, y;
int i = 360;
int h = 0, m = 0, s = 0, t;


void loop () {
  DateTime now = rtc.now();

  h = now.hour();
  m = now.minute();
  s = now.second();

  setcircle();
  // put your main code here, to run repeatedly:
  display.setTextSize(1);
  display.setTextColor(SSD1306_WHITE);
  display.setCursor(40, 39);
  display.print(h);
  display.print(":");
  display.print(m);
  display.print(":");
  display.print(s);

  t = 90 - h * 30 - m * 5 / 60.0;

  theta_r = t * (PI / 180.0);
  x = C_X + 10 * cos(theta_r);
  y = C_Y - 10 * sin(theta_r);

  display.drawLine(C_X, C_Y, x, y, SSD1306_WHITE);
  t = 90 - m * 6;
  theta_r = t * (PI / 180.0);
  x = C_X + 18 * cos(theta_r);
  y = C_Y - 18 * sin(theta_r);

  display.drawLine(C_X, C_Y, x, y, SSD1306_WHITE);

  t = 90 - s * 6;
  theta_r = t * (PI / 180.0);
  x = C_X + 25 * cos(theta_r);
  y = C_Y - 25 * sin(theta_r);

  display.drawLine(C_X, C_Y, x, y, SSD1306_WHITE);
  display.display();

  delay(1000);
}