import random
import matplotlib.pyplot as plt

# Game parameters
coin_price = 100.0
price_sensitivity = 0.5
volatility = 0.3
price_history = [coin_price]
trade_history = [0]             # User's buy/sell behavior per turn
cumulative_trades = [0]         # Net amount of coins user holds over time

def save_graph():
    plt.clf()
    plt.plot(price_history, label="Coin Price", color='blue')
    plt.plot(trade_history, label="Trade Behavior", color='orange')
    plt.plot(cumulative_trades, label="Net Coins Held", color='green')
    plt.title("Coin Price, Trade Behavior & Net Holdings Over Time")
    plt.xlabel("Turn")
    plt.ylabel("Value")
    plt.legend()
    plt.grid(True)
    plt.savefig("coin_price.png")
    print("📊 Graph saved as 'coin_price.png'")

print("💰 Welcome to Crypto Kids! Type +10 to buy or -10 to sell.")
print("Type 'exit' to stop the game.\n")

while True:
    print(f"\nCurrent Coin Price: {round(coin_price, 2)}")

    user_input = input("Enter buy/sell amount (e.g., +10 or -10): ").strip()
    if user_input.lower() == "exit":
        print("👋 Game Over. Thanks for playing!")
        break

    try:
        trade_amount = int(user_input)
    except ValueError:
        print("⚠️ Please enter a valid number like +10 or -5.")
        continue

    trade_history.append(trade_amount)
    new_total = cumulative_trades[-1] + trade_amount
    cumulative_trades.append(new_total)

    buys = trade_amount if trade_amount > 0 else 0
    sells = -trade_amount if trade_amount < 0 else 0
    net_demand = buys - sells

    price_change_from_demand = net_demand * price_sensitivity
    random_factor = random.uniform(-volatility, volatility) * coin_price
    coin_price += price_change_from_demand + random_factor
    coin_price = max(1, coin_price)

    price_history.append(coin_price)
    save_graph()