# Rui Santos & Sara Santos - Random Nerd Tutorials
# Complete project details at https://RandomNerdTutorials.com/raspberry-pi-pico-ds3231-rtc-micropython/

from machine import Pin, I2C
import time
import urtc

# Pin setup for SQW pin and LED
CLOCK_INTERRUPT_PIN = 3  # Adjust to your specific GPIO pin for SQW
LED_PIN = 2  # Adjust to your specific GPIO pin for the LED

# Initialize RTC (connected to I2C)
i2c = I2C(0, scl=Pin(5), sda=Pin(4))
rtc = urtc.DS3231(i2c)

# Setup GPIO for SQW and LED
sqw_pin = Pin(CLOCK_INTERRUPT_PIN, Pin.IN, Pin.PULL_UP)
led_pin = Pin(LED_PIN, Pin.OUT)
led_pin.off()

# Add minutes to a datetime tuple and return a new datetime tuple
def add_minutes_to_time(dt, minutes):
    timestamp = time.mktime((dt.year, dt.month, dt.day, dt.hour, dt.minute, dt.second, 0, 0))
    new_timestamp = timestamp + (minutes * 60)
    new_time = time.localtime(new_timestamp)
    return urtc.datetime_tuple(new_time[0], new_time[1], new_time[2], None, new_time[3], new_time[4], new_time[5], 0)

# Print the current time from the RTC
def print_current_time():
    now = rtc.datetime()
    formatted_time = f"{now.year}-{now.month:02}-{now.day:02} {now.hour:02}:{now.minute:02}:{now.second:02}"
    print(f"Current time: {formatted_time}")

# Callback for handling alarm interrupt
def on_alarm(pin):
    print("Alarm triggered! Toggling the LED.")
    led_pin.value(not led_pin.value())  # Toggle the LED

    # Clear the alarm flag and schedule the next alarm
    if rtc.alarm(alarm=0):  # Check if Alarm 0 triggered
        print("Clearing Alarm 0 flag.")
        rtc.alarm(False, alarm=0)  # Clear alarm flag

        # Schedule the alarm to repeat 10 minutes from now
        now = rtc.datetime()
        next_alarm_time = add_minutes_to_time(now, 10)  # Add 10 minutes
        rtc.alarm_time(next_alarm_time, alarm=0)  # Set new alarm
        rtc.interrupt(0)  # Ensure Alarm 0 interrupt is enabled
        print(f"Next alarm set for: {next_alarm_time}")


def setup_alarm():
    # Clear any existing alarms
    rtc.alarm(False, 0)
    rtc.no_interrupt()

    # Get the current time and set the first alarm 1 minute from now
    now = rtc.datetime()
    first_alarm_time = add_minutes_to_time(now, 1)  # Set first alarm for 1 minute from now
    rtc.alarm_time(first_alarm_time, alarm=0)  # Alarm 0

    # Enable the interrupt for Alarm 0
    rtc.interrupt(0)

    print(f"Alarm set for: {first_alarm_time}")

# Attach the interrupt callback
sqw_pin.irq(trigger=Pin.IRQ_FALLING, handler=on_alarm)

try:
    # Sync time to compile time if RTC lost power
    if rtc.lost_power():
        initial_time_tuple = time.localtime()  # tuple (MicroPython)
        initial_time_seconds = time.mktime(initial_time_tuple)  # local time in seconds
        initial_time = urtc.seconds2tuple(initial_time_seconds)  # Convert to tuple compatible with the library
        rtc.datetime(initial_time)  # Sync the RTC

    print("RTC initialized. Setting up the periodic alarm...")
    setup_alarm()

    while True:
        print_current_time()
        time.sleep(5)
except KeyboardInterrupt:
    print("Exiting program.")