from machine import Pin, I2C
from imu import MPU6050
import time
import math
import urequests
import network

# =============================
# BLYNK & WiFi Configuration
# =============================
#BLYNK_AUTH_TOKEN = "Kxd7tjVXDHFFxcl3-U8DS53gC_jC-DXV"
SSID = "Wokwi-GUEST"
PASS = ""

# =============================
# MPU6050 Setup
# =============================
i2c = I2C(1, sda=Pin(21), scl=Pin(22), freq=400000)
mpu = MPU6050(i2c)

# =============================
# PIR Sensors Setup
# =============================
pir_entry = Pin(14, Pin.IN)  # Entrance PIR sensor
pir_exit  = Pin(27, Pin.IN)  # Exit PIR sensor

# =============================
# Parameters
# =============================
VIBRATION_THRESHOLD = 1.5   # g units
WINDOW_SIZE = 5
SCALE_FACTOR = 10
PERSON_THRESHOLD = 20       # Max safe persons on bridge

# =============================
# WiFi Connection
# =============================
def connect_wifi():
    sta_if = network.WLAN(network.STA_IF)
    print('Connecting to network...')
    sta_if.active(True)
    sta_if.connect(SSID, PASS)
    while not sta_if.isconnected():
        time.sleep(0.5)
    print('Network config:', sta_if.ifconfig())

# =============================
# Vibration Calculation
# =============================
def calculate_vibration():
    ax = mpu.accel.x
    ay = mpu.accel.y
    az = mpu.accel.z - 1.0  # remove gravity effect
    return math.sqrt(ax * ax + ay * ay + az * az)

def moving_average(new_value, prev_avg, window_size):
    return (prev_avg * (window_size - 1) + new_value) / window_size

# =============================
# Send Data to Blynk
# =============================
def send_to_blynk(vibration, temperature, person_count):
    try:
        scaled_vibration = vibration * SCALE_FACTOR

        # V1 → vibration
        urequests.get("https://blr1.blynk.cloud/external/api/update?token={}&V1={}".format(BLYNK_AUTH_TOKEN, scaled_vibration))

        # V0 → temperature
        urequests.get("https://blr1.blynk.cloud/external/api/update?token={}&V0={}".format(BLYNK_AUTH_TOKEN, temperature))

        # V2 → number of persons
        urequests.get("https://blr1.blynk.cloud/external/api/update?token={}&V2={}".format(BLYNK_AUTH_TOKEN, person_count))

        print("📡 Sent to Blynk - Vib: {:.2f}, Temp: {:.2f}, Persons: {}".format(
            scaled_vibration, temperature, person_count))
    except Exception as e:
        print("Error sending to Blynk:", e)

# =============================
# MAIN PROGRAM
# =============================
vibration_avg = 0.0
person_count = 0
pir_entry_last = 0
pir_exit_last = 0

connect_wifi()
print("🚨 Bridge Safety Monitoring Started...")

while True:
    try:
        # -------- Vibration ----------
        vibration = calculate_vibration()
        vibration_avg = moving_average(vibration, vibration_avg, WINDOW_SIZE)
        temperature = mpu.temperature

        # -------- People Counting ----------
        entry_state = pir_entry.value()
        exit_state = pir_exit.value()

        # Detect new entry
        if entry_state == 1 and pir_entry_last == 0:
            person_count += 1
            print("🚶 Person ENTERED. Total:", person_count)

        # Detect new exit
        if exit_state == 1 and pir_exit_last == 0:
            if person_count > 0:
                person_count -= 1
            print("🚶 Person LEFT. Total:", person_count)

        pir_entry_last = entry_state
        pir_exit_last = exit_state

        print("-" * 50)
        print("Accel: X={:.3f}, Y={:.3f}, Z={:.3f}".format(mpu.accel.x, mpu.accel.y, mpu.accel.z))
        print("Temperature: {:.2f} °C".format(temperature))
        print("Vibration (avg): {:.3f} g".format(vibration_avg))
        print("Persons on Bridge: {}".format(person_count))

        # -------- Bridge Safety Alerts ----------
        if vibration > VIBRATION_THRESHOLD:
            print("⚠ ALERT: Excessive Vibration on Bridge!")

        if person_count > PERSON_THRESHOLD:
            print("🚨 ALERT: Bridge Overloaded! More than {} persons detected!".format(PERSON_THRESHOLD))

        # -------- Send to Blynk ----------
        send_to_blynk(vibration_avg, temperature, person_count)

    except Exception as e:
        print("Error:", e)

    time.sleep(1)