from machine import Pin
import dht
import time
last_temp_value=0
wait_time = 2
delta=10
file_name="weather_station.csv"
sensor_active=False
sensor_deactivated = False
press_count=0
last_press_time= 0
debounce_delay = 0.2
double_press_delay= 0.5


def setup():
    global sensor, button, led
    # Set up the DHT sensor
    dht_pin = Pin(15)  # Change to the GPIO pin where your DHT is connected
    sensor = dht.DHT22(dht_pin)  # Use dht.DHT11 for DHT11 sensors
    temperature = get_temperature()
    button=Pin(14,Pin.OUT)
    led=Pin(5, Pin.OUT)

def get_temperature():
    sensor.measure()  # Read the sensor data
    temperature = sensor.temperature()  # Get temperature in Celsius
    return temperature   

def get_delta(last_value, current_value):
    current_Delta=0
    if(last_temp_value!=0):
        current_Delta = (abs(temperature - last_temp_value) / last_temp_value) * 100
    else:
        current_Delta=delta
    return abs(current_Delta)

def format_timestamp():
    t = time.localtime()
    return "{:04d}-{:02d}-{:02d} {:02d}:{:02d}:{:02d}".format(
        t[0], t[1], t[2], t[3], t[4], t[5]
    )
    # t holds year-month-date(space) hour:min: sec

def write_data(event, value):
    global last_temp_value
    # this if block will open file which we created and will add two columns Timestamp 
    with open(file_name, "w") as f: # write mode for "w" we have read mode(r), a for append
        timestamp = format_timestamp()
        if (event=="Start"):
            f.write("Event,Timestamp,Value\n")
            f.write(f"{event},{timestamp},{value},\n")
        else:
            f.write(f"{event},{timestamp},{value},\n")
    
    print(f"Temperature: {value:.1f}°C")
    last_temp_value = value

def push_button(pin):
    global sensor_active, sensor_deactivated, press_count, last_press_time
    current_time = time.ticks_ms() / 1000
    # create two variables debounce_delay and double_press_delay
    if (current_time - last_press_time) < debounce_delay:
        return                                  # to eliminate noise/ function

    if (current_time - last_press_time) < double_press_delay: # in 0.5 sec, two times we press button
        press_count = press_count + 1
    else:
        press_count = 1
    last_press_time = current_time

    if press_count == 1:
        sensor_active = True
        sensor_deactivated = False
        print("DHT22 Activated")
        led.on()
    elif press_count == 2:
        sensor_active = False
        sensor_deactivated = True
        print("DHT22 Deactivated")
        press_count = 0

def blink_led(times):
    for i in range(times):
        led.on()
        time.sleep(0.5)
        led.off()
        time.sleep(0.5)
setup()

# Attach an interrupt to the button to detect a falling edge (button press event) and trigger toggle_sensor function
button.irq(trigger=Pin.IRQ_FALLING, handler=push_button)


while True:
    if sensor_active:
        try:
            temperature = get_temperature()
            if get_delta(last_temp_value, temperature) >= delta:
                write_data("Start", temperature)
                last_temp_value = temperature  # Update the last temperature
        except Exception as error:
            print("Failed to read the sensor", error)
    else:
        if sensor_deactivated:
            blink_led(5)
            sensor_deactivated= False
        led.off()
    time.sleep(2)