code.py

"""
Smart IoT Controller with auto-fallback
- Tries to use MQTT if available
- Falls back to HTTP-only mode if MQTT not available
"""
import os
import time
import wifi
import socketpool
import board
import microcontroller
import digitalio
import rtc
import struct
from adafruit_httpserver.server import HTTPServer
from adafruit_httpserver.request import HTTPRequest
from adafruit_httpserver.response import HTTPResponse
from adafruit_httpserver.methods import HTTPMethod
from adafruit_httpserver.mime_type import MIMEType

# Try to import MQTT support
try:
    import adafruit_minimqtt.adafruit_minimqtt as MQTT
    MQTT_AVAILABLE = True
    print("✓ MQTT library found")
except ImportError:
    MQTT_AVAILABLE = False
    print("⚠ MQTT library not found - running in HTTP-only mode")


# Relay setup
Relay8 = digitalio.DigitalInOut(board.GP14)
Relay8.direction = digitalio.Direction.OUTPUT
relay_state = False  # Track relay state

# --- NTP Time Sync ---
def sync_time_with_ntp(pool, host="time.navy.mi.th"):
    port = 123
    buf = 1024
    address = (host, port)
    
    print(f"🕒 Attempting to sync time with NTP server: {host}")

    # Create NTP Packet
    msg = bytearray(48)
    msg[0] = 0b00100011  # LI, VN, Mode

    try:
        # Create a UDP socket
        client = pool.socket(socketpool.AF_INET, socketpool.SOCK_DGRAM)
        client.settimeout(5)
        
        # Send request
        client.sendto(msg, address)
        
        # Wait for response
        data, address = client.recvfrom(buf)
        client.close()

        # NTP Protocol: time is in bytes 40-43
        t = struct.unpack("!I", data[40:44])[0]
        
        # NTP epoch is 1900, Unix/PC epoch is 1970.
        # Difference is 2208988800 seconds.
        t -= 2208988800
        
        # Add Thailand timezone offset (UTC+7 = 7 hours = 25200 seconds)
        t += 25200
        
        # Set the RTC
        rtc.RTC().datetime = time.localtime(t)
        
        current_time = time.localtime()
        print("✅ Time synced successfully!")
        print(f"📅 Current device time: {current_time.tm_mday}/{current_time.tm_mon}/{current_time.tm_year} {current_time.tm_hour:02}:{current_time.tm_min:02}:{current_time.tm_sec:02}")
        return True

    except OSError as e:
        print(f"❌ NTP connection error: {e}")
        return False
    except Exception as e:
        print(f"❌ An error occurred during NTP sync: {e}")
        return False

# connect to network
print()
print("Connecting to WiFi")


# connect to your SSID
wifi.radio.connect(os.getenv('CIRCUITPY_WIFI_SSID'), os.getenv('CIRCUITPY_WIFI_PASSWORD'))

print("Connected to WiFi")
pool = socketpool.SocketPool(wifi.radio)

# Sync time after connecting to WiFi
sync_time_with_ntp(pool)

server = HTTPServer(pool, "/static")


def Relay_ON():
    global relay_state
    print("🔴 Relay: ON")
    Relay8.value = True
    relay_state = True
    publish_status('on')

def Relay_OFF():
    global relay_state
    print("⚫ Relay: OFF")
    Relay8.value = False
    relay_state = False
    publish_status('off')

def publish_status(state):
    """Publish relay status to MQTT (if available)"""
    if mqtt_client and MQTT_ENABLED:
        try:
            payload = f'{{"state": "{state}", "timestamp": "{time.monotonic()}", "source": "pico"}}'
            mqtt_client.publish(TOPICS['STATUS'], payload)
            print(f"✅ MQTT status published: {state} → {TOPICS['STATUS']}")
        except Exception as e:
            print(f"⚠ MQTT publish error: {e}")
    else:
        print(f"⚠️ MQTT not available for status publish")

def mqtt_message_received(client, topic, message):
    """Callback when MQTT message is received"""
    print(f"📨 MQTT Message received: {topic} = {message}")
    
    if topic == TOPICS['CONTROL']:
        try:
            # ป้องกัน loop: ข้าม message ที่มาจาก backend เอง
            if '"source"' in message and ('"backend"' in message or '"mqtt-control"' in message):
                print("⏭️  Skipping message from backend (loop prevention)")
                return
            
            print(f"📦 Processing command...")
            
            if '"on"' in message or "'on'" in message:
                print("🎯 Command: ON")
                Relay_ON()
            elif '"off"' in message or "'off'" in message:
                print("🎯 Command: OFF")
                Relay_OFF()
            else:
                print(f"⚠️ Unknown command in message")
        except Exception as e:
            print(f"⚠ Error processing MQTT: {e}")

# MQTT Configuration
MQTT_BROKER = os.getenv('MQTT_BROKER', 'broker.hivemq.com')
MQTT_PORT = int(os.getenv('MQTT_PORT', '1883'))
MQTT_USERNAME = os.getenv('MQTT_USERNAME', '')
MQTT_PASSWORD = os.getenv('MQTT_PASSWORD', '')
MQTT_ENABLED = os.getenv('MQTT_ENABLED', 'false').lower() == 'true'

TOPICS = {
    'CONTROL': 'home-iot/relay/control',
    'STATUS': 'home-iot/relay/status',
    'DEVICE': 'home-iot/device/status'
}

mqtt_client = None

# Setup MQTT if enabled and available
if MQTT_ENABLED and MQTT_AVAILABLE:
    try:
        mqtt_client = MQTT.MQTT(
            broker=MQTT_BROKER,
            port=MQTT_PORT,
            socket_pool=pool,
            ssl_context=None
        )
        
        if MQTT_USERNAME and MQTT_PASSWORD:
            mqtt_client.username = MQTT_USERNAME
            mqtt_client.password = MQTT_PASSWORD
        
        mqtt_client.on_message = mqtt_message_received
        
        print(f"Connecting to MQTT broker: {MQTT_BROKER}")
        mqtt_client.connect()
        mqtt_client.subscribe(TOPICS['CONTROL'])
        mqtt_client.publish(TOPICS['DEVICE'], '{"online": true}', retain=True)
        
        print(f"✓ MQTT enabled - subscribed to: {TOPICS['CONTROL']}")
    except Exception as e:
        print(f"⚠ MQTT setup failed: {e}")
        print("→ Falling back to HTTP-only mode")
        mqtt_client = None
        MQTT_ENABLED = False
else:
    print("→ Running in HTTP-only mode")

# API endpoint to get relay status (JSON)
@server.route("/api/relay", method=HTTPMethod.GET)
def get_relay_status(request: HTTPRequest):
    with HTTPResponse(request, content_type=MIMEType.TYPE_JSON) as response:
        response.send('{"state": "' + ('on' if relay_state else 'off') + '", "success": true}')


# API endpoint to control relay (JSON)
@server.route("/api/relay", method=HTTPMethod.POST)
def control_relay(request: HTTPRequest):
    raw_text = request.raw_request.decode("utf8")
    
    # Simple JSON parsing (CircuitPython doesn't have json module built-in)
    if '"state"' in raw_text or "'state'" in raw_text:
        if '"on"' in raw_text or "'on'" in raw_text:
            Relay_ON()
            state = "on"
        elif '"off"' in raw_text or "'off'" in raw_text:
            Relay_OFF()
            state = "off"
        else:
            with HTTPResponse(request, content_type=MIMEType.TYPE_JSON) as response:
                response.send('{"error": "Invalid state", "success": false}')
                return
        
        with HTTPResponse(request, content_type=MIMEType.TYPE_JSON) as response:
            response.send('{"state": "' + state + '", "success": true}')
    else:
        with HTTPResponse(request, content_type=MIMEType.TYPE_JSON) as response:
            response.send('{"error": "Missing state parameter", "success": false}')

print("Starting server..")
# startup the server
try:
    server.start(str(wifi.radio.ipv4_address))
    print("Listening on http://%s" % wifi.radio.ipv4_address)
# if the server fails to begin, restart the pico w
except OSError:
    time.sleep(5)
    print("Restarting..")
    microcontroller.reset()


# Main loop
last_mqtt_check = time.monotonic()
MQTT_CHECK_INTERVAL = 1.0  # Check MQTT every 1 second

while True:
    try:
        # Poll HTTP server
        server.poll()
        
        # Poll MQTT client if enabled
        if mqtt_client and MQTT_ENABLED:
            current_time = time.monotonic()
            if current_time - last_mqtt_check >= MQTT_CHECK_INTERVAL:
                try:
                    mqtt_client.loop()
                    last_mqtt_check = current_time
                except Exception as e:
                    print(f"⚠ MQTT loop error: {e}")
                    # Try to reconnect
                    try:
                        mqtt_client.reconnect()
                    except Exception:
                        pass
        
    except Exception as e:
        print(f"Main loop error: {e}")
        continue