import requests
import smtplib
from email.mime.text import MIMEText
from email.mime.multipart import MIMEMultipart
import ccxt

# --- GLOBAL REUSABLE EXCHANGE CONTEXTS (INSTANTIATED ONCE) ---
# Reuses long-lived sockets to completely prevent API network connection rate-limits
UTIL_EXCHANGES = {
    'binance_us': ccxt.binanceus({'enableRateLimit': True}), 
    'bitget': ccxt.bitget({'enableRateLimit': True}),        
    'kraken': ccxt.kraken({'enableRateLimit': True})         
}

def get_live_usdt_dominance():
    """Fetches global USDT Dominance to act as a Macro Kill Switch."""
    try:
        url = "https://api.coingecko.com/api/v3/global"
        response = requests.get(url, timeout=10).json()
        return response['data']['market_cap_percentage']['usdt']
    except Exception as e:
        print(f"Error fetching macro data: {e}")
        return 100.0 

def send_email_alert(sender_email, sender_password, receiver_email, symbol, message):
    """Packages and sends the AI trade signal directly to an email inbox."""
    try:
        msg = MIMEMultipart()
        msg['From'] = sender_email
        msg['To'] = receiver_email
        msg['Subject'] = f"🎯 AI TRADE ALERT: Prime Setup on {symbol}"
        
        msg.attach(MIMEText(message, 'plain'))
        
        server = smtplib.SMTP('smtp.gmail.com', 587)
        server.starttls()
        server.login(sender_email, sender_password)
        server.send_message(msg)
        server.quit()
    except Exception as e:
        print(f"Failed to send email to {receiver_email}: {e}")

def get_global_imbalance(symbol):
    """
    Scans persistent live order books to calculate a normalized global imbalance score.
    Converts native (-1.0 to +1.0) matrix outputs into a standard percentage scale (0.0 to 1.0).
    """
    total_bids_vol = 0
    total_asks_vol = 0
    successful_exchanges = 0
    
    for name, exchange in UTIL_EXCHANGES.items():
        try:
            # Fetch the top 50 orders for depth analysis using optimized global engine
            orderbook = exchange.fetch_order_book(symbol, limit=50)
            
            bids_vol = sum([bid[1] for bid in orderbook['bids']])
            asks_vol = sum([ask[1] for ask in orderbook['asks']])
            
            total_bids_vol += bids_vol
            total_asks_vol += asks_vol
            successful_exchanges += 1
            
        except Exception:
            continue
            
    # Return 0.0 to safely fail-close the trade gate if no exchanges answer the socket call
    if successful_exchanges == 0:
        return 0.0
        
    # Raw Delta Matrix Formula: Outputs between -1.0 and +1.0
    raw_delta_ratio = (total_bids_vol - total_asks_vol) / (total_bids_vol + total_asks_vol + 1e-9)
    
    # Mathematical Normalization: Converts raw ratio smoothly onto a strict 0.0 to 1.0 scale
    # Example: -0.20 becomes 0.40 (40% buy weight) | +0.10 becomes 0.55 (55% buy weight)
    normalized_percentage = (raw_delta_ratio + 1) / 2
    
    return normalized_percentage