import pytest
from src.models.bayesian import BayesianFairValue

def test_bayesian_fair_value_initialization():
    model = BayesianFairValue(prior_prob=0.5, prior_confidence=10.0)
    
    assert model.get_fair_value() == 0.5
    assert model.alpha == 5.0
    assert model.beta == 5.0

def test_bayesian_update():
    model = BayesianFairValue(prior_prob=0.5, prior_confidence=10.0)
    
    # We observe a lot of volume trading at 0.70 implied probability
    model.update(market_implied_prob=0.70, trade_volume=100.0, noise_factor=0.1)
    
    # FV should shift towards 0.70
    fv = model.get_fair_value()
    assert fv > 0.5
    assert fv < 0.70
    
def test_evaluate_opportunity():
    model = BayesianFairValue(prior_prob=0.6, prior_confidence=100.0) # Highly confident at 0.6
    
    # Market asks are way below FV (Underpriced)
    opp_buy = model.evaluate_opportunity(current_ask=0.40, current_bid=0.38)
    assert opp_buy is not None
    assert opp_buy["action"] == "BUY_YES"
    assert opp_buy["edge"] > 0.15 # 0.60 - 0.40 = 0.20ish edge
    
    # Market bids are way above FV (Overpriced)
    opp_sell = model.evaluate_opportunity(current_ask=0.82, current_bid=0.80)
    assert opp_sell is not None
    assert opp_sell["action"] == "SELL_YES"
    assert opp_sell["edge"] > 0.15 # 0.80 - 0.60 = 0.20ish edge