import requests
import time
import json
from datetime import datetime, timedelta
from requests.adapters import HTTPAdapter
from urllib3.util.retry import Retry

# ================= CONFIG =================
BASE_URL = "https://emrtds.nepalpassport.gov.np/iups-api/timeslots/79/{}/false"

START_DATE = datetime(2025, 11, 28)
END_DATE   = datetime(2025, 12, 3)

TELEGRAM_TOKEN = "XXXXXXXXXXXXXXXXXXXXXXXX"
CHAT_ID = "XXXXXXXXXXXXXXX"

CHECK_INTERVAL_MINUTES = 5

HEADERS = {
    "Host": "emrtds.nepalpassport.gov.np",
    "User-Agent": "Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:145.0) Gecko/20100101 Firefox/145.0",
    "Accept": "application/json, text/plain, */*",
    "Accept-Language": "en-US,en;q=0.5",
    "Accept-Encoding": "gzip, deflate, br",
    "Connection": "close",
}

# ================= SETUP SESSIONS =================
# Passport session with retries
session = requests.Session()
session.headers.update(HEADERS)
retries = Retry(
    total=5,
    backoff_factor=0.3,
    status_forcelist=[500, 502, 503, 504]
)
session.mount("https://", HTTPAdapter(max_retries=retries))

# Telegram session (clean, separate headers)
telegram_session = requests.Session()

# ================= GLOBAL CACHE =================
# Stores last known timeslot data per date
last_results = {}

# ================= FUNCTIONS =================
def send_telegram(text):
    try:
        telegram_session.post(
            f"https://api.telegram.org/bot{TELEGRAM_TOKEN}/sendMessage",
            json={"chat_id": CHAT_ID, "text": text},
            timeout=10
        )
    except Exception as e:
        print("Telegram error:", e)


def process_api_response(data, date_str):
    """Detect any change in the timeslot data and send notification."""
    global last_results

    # Convert to stable JSON string for comparison
    current_json = json.dumps(data, sort_keys=True)

    if date_str not in last_results:
        last_results[date_str] = current_json
        print(f"[{date_str}] Initial data stored.")
        return

    if last_results[date_str] != current_json:
        print(f"[{date_str}] 🔔 CHANGE DETECTED!")
        send_telegram(
            f"🔔 Timeslot CHANGE detected for {date_str}\n"
            f"New data:\n{current_json}"
        )
        last_results[date_str] = current_json
    else:
        print(f"[{date_str}] No change.")


def check_date(date_str):
    """Check timeslots for a single date."""
    url = BASE_URL.format(date_str)
    try:
        resp = session.get(url, timeout=10)
        try:
            data = resp.json()
        except json.JSONDecodeError:
            print(f"[{date_str}] Invalid JSON returned.")
            return

        process_api_response(data, date_str)

    except Exception as e:
        print(f"[{date_str}] Request error:", e)


def run_check_once():
    """Loop through all dates in the range and check."""
    current = START_DATE
    while current <= END_DATE:
        ds = current.strftime("%Y-%m-%d")
        print(f"\n=== Checking {ds} ===")
        check_date(ds)
        current += timedelta(days=1)


def main():
    print("🚀 Passport Timeslot Monitor Started")
    while True:
        run_check_once()
        print(f"\nWaiting 10 sec before next check...\n")
        time.sleep(10)


# ================= RUN SCRIPT =================
if __name__ == "__main__":
    main()