import network
import time
import ujson
from machine import Pin
from umqtt.simple import MQTTClient

# =====================================================
# MQTT Parameters
# =====================================================
MQTT_CLIENT_ID = "vent-stepper-subscriber"
MQTT_BROKER = "broker.hivemq.com"
MQTT_TOPIC = "smart/vent/system"

# =====================================================
# Stepper Pins
# =====================================================
STEP_PIN = Pin(14, Pin.OUT)
DIR_PIN = Pin(12, Pin.OUT)

# =====================================================
# WiFi Connection
# =====================================================
print("Connecting to WiFi", end="")
sta_if = network.WLAN(network.STA_IF)
sta_if.active(True)
sta_if.connect("Wokwi-GUEST", "")

while not sta_if.isconnected():
    print(".", end="")
    time.sleep(0.1)

print(" Connected!")

# =====================================================
# MQTT Connection
# =====================================================
print("Connecting to MQTT...", end="")
client = MQTTClient(MQTT_CLIENT_ID, MQTT_BROKER)

# target position
position = 0
target = 0
STEP_DELAY = 800

# =====================================================
# Step Function
# =====================================================
def step(dir):

    DIR_PIN.value(dir)
    STEP_PIN.value(1)
    time.sleep_us(STEP_DELAY)
    STEP_PIN.value(0)
    time.sleep_us(STEP_DELAY)

# 2
# =====================================================
# MQTT Callback
# =====================================================
def on_msg(topic, msg):
    global target
    data= ujson.loads(msg)
    state = data["state"]
    print("msg: ", state)
    if state == "OPEN":
        target = 200
    elif state == "HALF":
        target = 100
    elif state == "CLOSE":
        target = 0

# 1
# =====================================================
# MQTT Setup
# =====================================================
client.set_callback(on_msg)
client.connect()
client.subscribe(MQTT_TOPIC)
print("Connected and subscribed")

# 3
# =====================================================
# Main Loop
# =====================================================
while True:
    client.check_msg()
    if position < target:
        step(1)
        position +=1
    elif position > target:
        step(0)
        position -=1
    time.sleep_ms(1)