from machine import Pin, ADC, SoftI2C
from time import sleep
import ssd1306

# === Traffic Light LEDs ===
red_A = Pin(13, Pin.OUT)
green_A = Pin(12, Pin.OUT)
red_B = Pin(14, Pin.OUT)
green_B = Pin(27, Pin.OUT)

# === Potentiometer for Distance Simulation ===
pot = ADC(Pin(34))
pot.atten(ADC.ATTN_11DB)  # Set to full range 0–4095

# === OLED Setup ===
i2c = SoftI2C(scl=Pin(22), sda=Pin(21))  
oled = ssd1306.SSD1306_I2C(128, 64, i2c)

# === Function: Simulate Distance (500m → 0m) ===
def get_distance_from_pot():
    pot_value = pot.read()
    distance = 500 - (pot_value / 4095) * 500
    return distance

# === Function: Update OLED Display ===
def update_oled(distance, message):
    oled.fill(0)
    oled.text("AmbulanceMonitor", 0, 0)
    oled.text("Distance: {} m".format(int(distance)), 0, 20)
    oled.text("Status:", 0, 40)
    oled.text(message, 60, 40)
    oled.show()

# === Function: Traffic Light Logic ===
def update_traffic_lights(near, distance):
    if near:
        print("\n🚨 Ambulance Approaching (<200m)")
        update_oled(distance, "NEAR ")
        red_A.off()
        green_A.on()
        red_B.on()
        green_B.off()
        sleep(60)
        print("⏱️ 1 minute passed. Resetting traffic lights.")
    else:
        print("\n✅ Normal traffic flow")
        update_oled(distance, "NORMALFLOW")

    # Reset to normal state
    red_A.on()
    green_A.off()
    red_B.off()
    green_B.on()

# === Set Initial State ===
red_A.on()
green_A.off()
red_B.off()
green_B.on()

# === Main Loop ===
while True:
    distance = get_distance_from_pot()
    print("📍 Distance to light:", round(distance, 2), "m")

    if distance < 200:
        update_traffic_lights(True, distance)
    else:
        update_traffic_lights(False, distance)

    sleep(5)