from machine import Pin, I2C
import network
import time
from ultrasonic import Ultrasonic  # 自訂模組，用來操作超音波感測器
from umqtt.simple import MQTTClient  # 用來進行 MQTT 通訊
from lcd_api import LcdApi  # LCD 控制 API
from i2c_lcd import I2cLcd  # I2C LCD 類別

# --- WiFi 連線 ---
sta = network.WLAN(network.STA_IF)  # 啟用 WiFi (STA 模式)
sta.active(True)
sta.connect("Wokwi-GUEST", "")  # 連線到 WiFi（Wokwi 無密碼）
while not sta.isconnected():  # 等待 WiFi 成功連線
    time.sleep(0.1)
print("WiFi connected!")  # 成功連線後顯示訊息

# --- LCD 初始化 ---
i2c = I2C(0, scl=Pin(22), sda=Pin(21))  # 設定 I2C 使用的腳位
lcd = I2cLcd(i2c, 0x27, 2, 16)  # 初始化 LCD，2 列 16 字
lcd.clear()
lcd.putstr("Under Detection")  # 初始顯示狀態
time.sleep(1)

# --- 超音波感測器初始化 ---
sensor_left = Ultrasonic(trig_pin=12, echo_pin=13)  # 左側超音波感測器
sensor_right = Ultrasonic(trig_pin=16, echo_pin=17)  # 右側超音波感測器

# --- LED 設定 ---
led_red = Pin(26, Pin.OUT)  # 設定紅色 LED 腳位為輸出
led_red.off()  # 預設關閉紅燈

# --- MQTT 設定 ---
MQTT_BROKER = "mqtt3.thingspeak.com"  # ThingSpeak MQTT 伺服器
MQTT_CLIENT_ID = "MysnAQEPLD0RIiEBNB8MNzY"
MQTT_USER = "MysnAQEPLD0RIiEBNB8MNzY"
MQTT_PASSWORD = "IkTFjR7D6bqxFw/XS6Fme+fq"
MQTT_TOPIC = "channels/2992248/publish"  # 發佈主題（通道）

client = MQTTClient(MQTT_CLIENT_ID, MQTT_BROKER, user=MQTT_USER, password=MQTT_PASSWORD)
client.connect()  # 連接到 MQTT
print("MQTT connected!")  # 成功連線後顯示訊息

# --- 警報狀態變數 ---
alarm_triggered = False  # 判斷目前是否進入警報狀態

# --- 中斷處理函式 ---
def handle_intr(sensor):
    global alarm_triggered
    distance = sensor.distance_cm()  # 讀取超音波感測距離
    print("[Interrupt] Distance: {:.1f} cm".format(distance))  # 顯示測量距離，幫助調試

    if distance < 100:  # 若距離小於 100 公分
        alarm_triggered = True  # 啟動警報狀態
        led_red.on()  # 亮起紅色 LED
        lcd.clear()
        lcd.putstr("Alert!")  # LCD 顯示警報
        payload = "field3=1"  # MQTT 傳送警報為 1（有人）
        client.publish(MQTT_TOPIC, payload)
        print("Alarm ON ")
    else:
        alarm_triggered = False  # 解除警報
        led_red.off()  # 熄滅紅燈
        lcd.clear()
        lcd.putstr("Alarm OFF")  # 恢復正常顯示
        payload = "field3=0"  # MQTT 傳送警報為 0（無人）
        client.publish(MQTT_TOPIC, payload)
        print("Alarm OFF ")

# --- 左右中斷觸發函式 ---
def left_intr(pin):
    handle_intr(sensor_left)

def right_intr(pin):
    handle_intr(sensor_right)

# --- 中斷腳位設定 ---
pir_left = Pin(33, Pin.IN)  # 左側 PIR 感測器輸入腳位
pir_right = Pin(19, Pin.IN)  # 右側 PIR 感測器輸入腳位
pir_left.irq(trigger=Pin.IRQ_RISING, handler=left_intr)  # 偵測上升緣觸發
pir_right.irq(trigger=Pin.IRQ_RISING, handler=right_intr)

# --- 主程式迴圈 ---
while True:
    # 取得左右超音波感測距離
    left = sensor_left.distance_cm()
    right = sensor_right.distance_cm()
    
    # 顯示距離資訊於 Shell
    print("Left: {:.1f} cm".format(left))
    print("Right: {:.1f} cm".format(right))

    # 組成 MQTT 傳送內容（field1: 左距離, field2: 右距離, field3: 警報狀態）
    payload = "field1={:.1f}&field2={:.1f}&field3={}".format(
        left, right, 1 if alarm_triggered else 0)
    client.publish(MQTT_TOPIC, payload)
    print("Published to MQTT:", payload)

    # 若非警報狀態，顯示距離在 LCD 上
    if not alarm_triggered:
        lcd.clear()
        lcd.move_to(0, 0)
        lcd.putstr("Left: {:.1f} cm".format(left))
        lcd.move_to(0, 1)
        lcd.putstr("Right: {:.1f} cm".format(right))

    # 自動清除警報：若左右距離皆大於等於 100 公分
    if alarm_triggered and left >= 100 and right >= 100:
        alarm_triggered = False
        led_red.off()  # 熄滅紅燈
        lcd.clear()
        lcd.putstr("Under Detection")
        client.publish(MQTT_TOPIC, "field3=0")
        print("Alarm auto cleared")

    time.sleep(5)  # 每 5 秒更新一次