import network
import time
from machine import Pin
import machine
from pico_i2c_lcd import I2cLcd
from umqtt_simple import MQTTClient

''' 1.take input from the keypad not the keyboard
    2.wait time should be updating in real time
    3.display entered cond on lcd
    '''

# Wi-Fi credentials
WIFI_SSID = "Wokwi-GUEST"
WIFI_PASSWORD = ""

# Adafruit IO credentials
ADAFRUIT_AIO_USERNAME = "preethi_kannan"
ADAFRUIT_AIO_KEY = "aio_Rqyc95apVwXs8gn0wzAGxVQiDxXV"

# MQTT settings
BROKER = "io.adafruit.com"
FOOD_AVAILABLE_FEED = f"{ADAFRUIT_AIO_USERNAME}/feeds/food"
WAIT_TIME_FEED = f"{ADAFRUIT_AIO_USERNAME}/feeds/queue"
WAIT_TIME_GRAPH = f"{ADAFRUIT_AIO_USERNAME}/feeds/queue"

# HC-SR04 Trigger and Echo Pins
trigger = machine.Pin(5, machine.Pin.OUT)
echo = machine.Pin(18, machine.Pin.IN)

# I2C Pins for LCD
i2c = machine.I2C(0, sda=Pin(0), scl=Pin(1), freq=400000)
lcd = I2cLcd(i2c, 0x27, 2, 16)  # 2x16 LCD display

# Food dictionary
food_dict = {
    "1234": "veg fried rice",
    "5678": "channa masala",
    "1256": "battura"
}

current_food = []  # List of available food items

# Keypad setup (Example: 4x4 keypad matrix)
rows = [Pin(i, Pin.OUT) for i in [13,12,11,10]]  # Adjust pins for your setup
cols = [Pin(i, Pin.IN, Pin.PULL_DOWN) for i in [9,8,7,6]]
key_map = [
    ['1', '2', '3', 'A'],
    ['4', '5', '6', 'B'],
    ['7', '8', '9', 'C'],
    ['*', '0', '#', 'D']
]

# Function to scan keypad
#Activating the row by setting it HIGH means that any button connected 
#to that row can now allow the signal to flow through it when pressed
#basically the pressed button only gets signal to be resigtered as 
#pressed if the row it is in is active at the time.
def read_keypad():
    for row in rows:
        row.value(1)
        for col, col_pin in enumerate(cols):
            if col_pin.value():
                row.value(0)
                return key_map[rows.index(row)][col]
        row.value(0)
    return None


# Wi-Fi connection function
def connect_to_wifi():
    """Connect to Wi-Fi."""
    wlan = network.WLAN(network.STA_IF)
    wlan.active(True)
    wlan.connect(WIFI_SSID, WIFI_PASSWORD)
    print("Connecting to Wi-Fi...")
    while not wlan.isconnected():
        time.sleep(1)
        print("Still connecting...")
    print("Connected to Wi-Fi!")
    print("Network config:", wlan.ifconfig())

# Publish message to MQTT
def mqtt_publish(client, topic, message):
    """Publish a message to an MQTT topic."""
    try:
        client.publish(topic, message)
        print(f"Published to {topic}: {message}")
    except Exception as e:
        print(f"Failed to publish: {e}")

# Process keypad input
def process_keypad_input(client, input_code):
    global current_food
    lcd.clear()
    lcd.putstr(f"Input: {input_code}")
    if input_code.endswith("#"):  # Add food
        item_code = input_code[:-1]
        if item_code in food_dict and food_dict[item_code] not in current_food:
            current_food.append(food_dict[item_code])
            mqtt_publish(client, FOOD_AVAILABLE_FEED, "\n".join(current_food))
    elif input_code.endswith("*"):  # Remove food
        item_code = input_code[:-1]
        if item_code in food_dict and food_dict[item_code] in current_food:
            current_food.remove(food_dict[item_code])
            mqtt_publish(client, FOOD_AVAILABLE_FEED, "\n".join(current_food))


# Measure distance
#manual function to get the distance of objects near the 
#ultrasonic distance sensor.
def measure_distance():
    """Measure the distance using the HC-SR04 sensor."""
    # Trigger the sensor
    trigger.value(0)
    time.sleep_us(2)
    trigger.value(1)
    time.sleep_us(10)
    trigger.value(0)

    # Measure the echo pulse duration
    pulse_time = machine.time_pulse_us(echo, 1, 30000)  # 30ms timeout
    if pulse_time < 0:  # No pulse received
        return -1  # Indicate out of range or sensor error

    # Convert pulse duration to distance in cm
    distance_cm = (pulse_time * 0.0343) / 2  # Divide by 2 for round trip
    return max(0, int(distance_cm))  # Ensure positive distance

# Main Program
connect_to_wifi()

client = MQTTClient("pico", BROKER, user=ADAFRUIT_AIO_USERNAME, password=ADAFRUIT_AIO_KEY)
client.connect()

try:
    lcd.putstr("System Ready!")
    time.sleep(2)
    lcd.clear()
    entered_code = ""
    while True:
        # Measure and publish wait time
        wait_time = measure_distance()
        mqtt_publish(client, WAIT_TIME_FEED, str(wait_time))
        mqtt_publish(client,WAIT_TIME_GRAPH, str(wait_time))
        time.sleep(0.2)
        key = read_keypad()
        if key:
            lcd.clear()
            if key == "#":  # Finalize input
                lcd.putstr(f"Processing {entered_code}")
                process_keypad_input(client, entered_code + "#")
                entered_code = ""
            elif key == "*":  # Remove food
                lcd.putstr(f"Processing {entered_code}")
                process_keypad_input(client, entered_code + "*")
                entered_code = ""
            else:  # Append key
                entered_code += key
                lcd.putstr(f"Code: {entered_code}")
        
        
except KeyboardInterrupt:
    print("Program stopped.")
finally:
    mqtt_publish(client, WAIT_TIME_FEED, str(0))
    mqtt_publish(client, FOOD_AVAILABLE_FEED, "")
    client.disconnect()