import utime
import ujson
import network
import urequests
import machine
from machine import Pin

led = Pin(15, Pin.OUT)
trigger = Pin(2, Pin.OUT)
echo = Pin(3, Pin.IN)

sound = 340 * 100  # m/s * centi = cm/s
threshold = 15  # cm

print("Starting door alarm...")

ssid = "HUAWEI-2EEt-2G"
password = "hxtU2dvx"
server = "https://192.168.100.16:5031"
token = ""

ultra_counter = 0
ultra_threshold = 3
# opened state from previous iteration
previous_opened = False
# TODO: add if open for more than 1 minute, send alert


def connect():
    print("Connecting...")
    wlan = network.WLAN(network.STA_IF)
    wlan.active(False)
    utime.sleep_ms(250)
    wlan.active(True)
    utime.sleep_ms(250)

    wlan.connect(ssid, password)
    utime.sleep_ms(100)

    i = 0
    while not wlan.isconnected():
            print(f"Waiting for connection{(i % 3 + 1) * "."}{3 * " "}", end="\r")
            i += 1
            for _ in range(4):
                led.toggle()
                utime.sleep_ms(250)

            if i % 10 == 0:
                print("Attempting to restart connection...")
                wlan.connect(ssid, password)
                for i in range(10):
                    led.toggle()
                    utime.sleep_ms(50)

    print(f"Connected with IP {wlan.ifconfig()[0]}")
    # update server to default value
    send_req(False)


def send_req(opened: bool):
    print("Updating state...", end="\r")

    data = {"opened": opened}
    raw = ujson.dumps(data)
    try:
        r = urequests.post(f"{server}/write",
                          headers={"Authorization": token, "Content-Type": "application/json"},
                          data=raw)
        print(f"State updated [{r.status_code}]")
    except Exception as e:
        print(f"Error occurred: {e}")


def ultra():
    global ultra_counter, previous_opened

    trigger.low()
    utime.sleep_us(2)
    trigger.high()
    utime.sleep_us(10)
    trigger.low()

    # echo goes high as soon as sound wave is sent
    #   and returns to low once sound gets back
    while echo.value() == 0:
        sent_time = utime.ticks_us()  # us

    while echo.value() == 1:
        received_time = utime.ticks_us()  # us

    delta_time = received_time - sent_time  # us
    distance = delta_time / 1_000_000 * sound / 2
    print(f"distance: {distance} cm")

    if distance < threshold:
        # door closed
        led.low()
        ultra_counter = 0

        # was it closed just now?
        if previous_opened:
            send_req(False)
            previous_opened = False
    else:
        # door opened
        led.high()
        ultra_counter += 1

        # was it opened just now?
        if not previous_opened:
            send_req(True)
            previous_opened = True


connect()

i = 0
# T = 500ms   f = 2 Hz
while True:
    ultra()

    if i == 20:  # every 10 seconds, blink for 100ms
        led.toggle()
        utime.sleep_ms(100)
        led.toggle()
        utime.sleep_ms(400)
        i = 0
    else:
        utime.sleep_ms(500)

    i += 1