#include <Wire.h>
#include <U8g2lib.h>
#include <RTClib.h>
#include <freertos/FreeRTOS.h>
#include <freertos/task.h>
#include <freertos/queue.h>

// OLED display initialization (SH1107, 128x128)
U8G2_SH1107_128X128_1_HW_I2C u8g2(U8G2_R0);

// RTC initialization
RTC_DS1307 rtc;

// Button pin definition (e.g., GPIO 14)
#define BUTTON_PIN 14

// Queue to communicate time data between tasks
QueueHandle_t timeQueue;

// Structure to hold time data
struct TimeData {
  int hours;
  int minutes;
  int seconds;
};

// Setup function
void setup() {
  // Initialize the Serial for Wokwi's serial monitor
  Serial.begin(115200);

  // Initialize OLED display
  if (!u8g2.begin()) {
    Serial.println("OLED initialization failed!");
    while (1); // Stop further execution if initialization fails
  }
  u8g2.setContrast(255); // Set display contrast

  // Initialize button pin as input
  pinMode(BUTTON_PIN, INPUT_PULLUP);  // Use internal pull-up resistor

  // Initialize RTC module
  if (!rtc.begin()) {
    Serial.println("RTC initialization failed!");
    while (1);
  }

  if (!rtc.isrunning()) {
    Serial.println("RTC is not running, setting the time...");
    rtc.adjust(DateTime(F(__DATE__), F(__TIME__)));
  }

  // Create a queue to hold time data (size of 10, enough to store time information)
  timeQueue = xQueueCreate(10, sizeof(TimeData));

  // Create FreeRTOS tasks
  xTaskCreate(update_time_task, "Update Time Task", 2048, NULL, 1, NULL);
  xTaskCreate(draw_clock_task, "Draw Clock Task", 2048, NULL, 1, NULL);
  xTaskCreate(button_press_task, "Button Press Task", 2048, NULL, 1, NULL);
}

// Function to draw the clock background
void draw_clock_background() {
  int center_x = 64;
  int center_y = 64;

  // Draw circle for the clock
  u8g2.setDrawColor(1);
  u8g2.drawCircle(center_x, center_y, 60, U8G2_DRAW_ALL);

  // Draw tick marks and numbers
  for (int i = 0; i < 12; i++) {
    int xpos = round(center_x + sin(radians(i * 30)) * 54);
    int ypos = round(center_y - cos(radians(i * 30)) * 54);
    u8g2.setFont(u8g2_font_8x13B_mn);
    if (i == 0) u8g2.drawStr(xpos - 5, ypos + 5, "12");
    if (i == 3) u8g2.drawStr(xpos - 5, ypos + 5, "3");
    if (i == 6) u8g2.drawStr(xpos - 5, ypos + 5, "6");
    if (i == 9) u8g2.drawStr(xpos - 5, ypos + 5, "9");
  }
}

// Function to draw clock hands
void draw_clock_hands(int hour, int minute, int second) {
  int center_x = 64;
  int center_y = 64;

  // Draw hour hand
  int hour_angle = (hour % 12) * 30 + (minute / 2);
  int hour_length = 40;
  int hour_x = round(center_x + sin(radians(hour_angle)) * hour_length);
  int hour_y = round(center_y - cos(radians(hour_angle)) * hour_length);
  u8g2.drawLine(center_x, center_y, hour_x, hour_y);

  // Draw minute hand
  int minute_angle = minute * 6;
  int minute_length = 50;
  int minute_x = round(center_x + sin(radians(minute_angle)) * minute_length);
  int minute_y = round(center_y - cos(radians(minute_angle)) * minute_length);
  u8g2.drawLine(center_x, center_y, minute_x, minute_y);

  // Draw second hand
  int second_angle = second * 6;
  int second_length = 60;
  int second_x = round(center_x + sin(radians(second_angle)) * second_length);
  int second_y = round(center_y - cos(radians(second_angle)) * second_length);
  u8g2.drawLine(center_x, center_y, second_x, second_y);
}

// Task to update time from RTC
void update_time_task(void* pvParameters) {
  while (true) {
    // Fetch the current time from RTC
    DateTime now = rtc.now();

    // Create a TimeData struct to send the updated time to the queue
    TimeData currentTime = {now.hour(), now.minute(), now.second()};
    xQueueSend(timeQueue, &currentTime, portMAX_DELAY);

    // Delay for 1 second
    vTaskDelay(1000 / portTICK_PERIOD_MS);
  }
}

// Task to draw the clock on the OLED display
void draw_clock_task(void* pvParameters) {
  while (true) {
    TimeData receivedTime;

    // Wait for time data from the queue
    if (xQueueReceive(timeQueue, &receivedTime, portMAX_DELAY) == pdTRUE) {
      // Draw clock background
      u8g2.firstPage();
      do {
        draw_clock_background();  // Draw background
        draw_clock_hands(receivedTime.hours, receivedTime.minutes, receivedTime.seconds);  // Draw hands
      } while (u8g2.nextPage());  // Continue drawing to the next page
    }

    // Add a small delay before the next iteration
    vTaskDelay(50 / portTICK_PERIOD_MS);
  }
}

// Task to handle button press and print time to console
void button_press_task(void* pvParameters) {
  static unsigned long lastButtonPressTime = 0;
  while (true) {
    // Check for button press
    if (digitalRead(BUTTON_PIN) == LOW) {  // Button is pressed (active low)
      unsigned long currentMillis = millis();
      // Debounce the button press (e.g., wait 200ms)
      if (currentMillis - lastButtonPressTime > 200) {
        // Fetch the current time from RTC
        DateTime now = rtc.now();
        // Send current time to the Wokwi serial monitor
        printf("Current time: %02d:%02d:%02d\n", now.hour(), now.minute(), now.second());
        lastButtonPressTime = currentMillis;
      }
    }
    vTaskDelay(10 / portTICK_PERIOD_MS);  // Delay for a short while to avoid busy-waiting
  }
}

// Main loop (not used as tasks run independently)
void loop() {
  // Nothing is needed here since tasks are handling the work
}