#Imports and such.
import requests, time, smtplib, os
from datetime import datetime, timezone
from email.message import EmailMessage
from dotenv import load_dotenv

load_dotenv()

#Variable declaration.
API_KEY = os.getenv("API_KEY")
NETWORK_ID = os.getenv("NETWORK_ID")
CLIENT_MAC = os.getenv("CLIENT_MAC")

#Passes the API key to the header.
HEADERS = {
    "X-Cisco-Meraki-API-Key": API_KEY
}

#Function to get the clients from the specified network.
def get_clients():

    #Queries the Meraki API using the network ID, and runs a get command to get a response in .JSON format.
    url = f"https://api.meraki.com/api/v1/networks/{NETWORK_ID}/clients"
    response = requests.get(url, headers=HEADERS)

    #Debugging print outs.
    print("Status:", response.status_code)
    print("Response:", response.text)

    #Return the resopnse in .JSON form.
    return response.json()

#Function to send email using SMTP.
def send_email(subject, body, to_email):

    #SMTP credentials.
    from_email = os.getenv("SMTP_EMAIL")
    password = os.getenv("SMTP_PASS")
    smtp_server = os.getenv("SMTP_SERVER")
    smtp_port = os.getenv("SMTP_PORT")

    #Create email object.
    msg = EmailMessage()
    msg["Subject"] = subject
    msg["From"] = from_email
    msg["To"] = to_email
    msg.set_content(body)

    # Connect to specified SMTP server, and then send the email.
    with smtplib.SMTP_SSL(smtp_server, smtp_port) as smtp:
        smtp.login(from_email, password)
        smtp.send_message(msg)

while True:

    #Constantly update the clients, and get the newest data.
    clients = get_clients()

    #Search thruogh the client list for the specified MAC address.
    for client in clients:

        #When it finds the specified MAC address, determine when it was last seen, and also set a variable for the current time.
        if client["mac"] == CLIENT_MAC:
            print("Status: " + client["status"])
            print("IP Address: " + client["ip"])
            last_seen = datetime.fromisoformat(client["lastSeen"].replace("Z", "+00:00"))
            now = datetime.now(timezone.utc)

            #If the client has not been seen for 3 minutes, send an alert email.
            if (now - last_seen).seconds > 180:
                print("Sending email alert...")
                send_email(
                    subject="Meraki Alert",
                    body="Client " + CLIENT_MAC + " is offline!",
                    to_email=os.getenv("SMTP_RECEIVER")
                )

    #Wait a minute before checking again.
    time.sleep(60)