import sys, os
import numpy as np, pandas as pd
from scipy.stats import spearmanr
import random
import warnings; warnings.filterwarnings('ignore')

sys.path.insert(0, os.path.dirname(__file__))
from backtesting.engines.v30_causal_engine import get_data, evaluate_slice, CAP, V30_PARAMS
from backtesting.engines.v36_research_engine import SECTOR_MAP, SECTORS
from backtesting.audits.v53_causal_audit import run_v53_causal

def test_1_1_ic_analysis(dc, vf):
    print("--- Test 1.1: Information Coefficient (IC) Analysis ---")
    mom_long, mom_short = 175, 21
    m_sig = (dc[vf].shift(mom_short) / dc[vf].shift(mom_long)) - 1
    fwd = dc[vf].pct_change(60).shift(-60)
    ic_vals = []
    
    for i in range(mom_long+10, len(dc)-60, 60):
        sig = m_sig.iloc[i].dropna()
        z = pd.Series(index=sig.index, dtype=float)
        for sector in SECTORS:
            stks = [t for t in sig.index if SECTOR_MAP.get(t) == sector]
            if len(stks) > 1:
                mu, sigma = sig[stks].mean(), sig[stks].std()
                z[stks] = (sig[stks] - mu) / (sigma if sigma > 1e-8 else 1e-8)
        common = z.dropna().index.intersection(fwd.iloc[i].dropna().index)
        if len(common) >= 15:
            top = z[common].nlargest(15)
            corr, _ = spearmanr(top.values, fwd.iloc[i][top.index].values)
            if not np.isnan(corr): ic_vals.append(corr)
    
    ic_mean = np.mean(ic_vals)
    ic_std = np.std(ic_vals)
    n = len(ic_vals)
    t_stat = ic_mean / (ic_std / np.sqrt(n))
    
    print(f"Mean IC: {ic_mean:.4f}")
    print(f"Std IC:  {ic_std:.4f}")
    print(f"t-stat:  {t_stat:.2f}")
    if t_stat > 2.0:
        print("Result: PASS (Statistically significant edge)")
    else:
        print("Result: FAIL/WEAK (Check signal power)")
    return t_stat

def test_1_2_regime_ic_decay(dc, spy, vf):
    print("\n--- Test 1.2: Regime-Conditioned IC Decay Analysis ---")
    mom_long, mom_short = 175, 21
    m_sig = (dc[vf].shift(mom_short) / dc[vf].shift(mom_long)) - 1
    fwd = dc[vf].pct_change(60).shift(-60)
    sma = spy.rolling(200).mean()
    
    periods = {
        "Period 1 (2008-2012)": ("2008-01-01", "2012-12-31"),
        "Period 2 (2013-2018)": ("2013-01-01", "2018-12-31"),
        "Period 3 (2019-2025)": ("2019-01-01", "2025-12-31")
    }
    
    # Calculate daily IC for top 15
    ic_series = []
    regimes = []
    dates = []
    
    for i in range(mom_long+10, len(dc)-60, 60):
        sig = m_sig.iloc[i].dropna()
        z = pd.Series(index=sig.index, dtype=float)
        for sector in SECTORS:
            stks = [t for t in sig.index if SECTOR_MAP.get(t) == sector]
            if len(stks) > 1:
                mu, sigma = sig[stks].mean(), sig[stks].std()
                z[stks] = (sig[stks] - mu) / (sigma if sigma > 1e-8 else 1e-8)
        common = z.dropna().index.intersection(fwd.iloc[i].dropna().index)
        if len(common) >= 15:
            top = z[common].nlargest(15)
            corr, _ = spearmanr(top.values, fwd.iloc[i][top.index].values)
            if not np.isnan(corr): 
                dt = dc.index[i]
                ic_series.append(corr)
                dates.append(dt)
                regimes.append("ON" if spy.iloc[i] > sma.iloc[i] else "OFF")
                
    ic_df = pd.DataFrame({'IC': ic_series, 'Regime': regimes}, index=dates)
    
    for name, (start, end) in periods.items():
        mask = (ic_df.index >= start) & (ic_df.index <= end)
        sub = ic_df[mask]['IC']
        if len(sub) > 0:
            t_stat = sub.mean() / (sub.std() / np.sqrt(len(sub)))
            print(f"{name}: t-stat = {t_stat:.2f} (n={len(sub)})")
            
    print("\nBy Regime:")
    for reg in ["ON", "OFF"]:
        sub = ic_df[ic_df['Regime'] == reg]['IC']
        if len(sub) > 0:
            t_stat = sub.mean() / (sub.std() / np.sqrt(len(sub)))
            print(f"Risk-{reg} days: t-stat = {t_stat:.2f} (n={len(sub)})")

def run_variant(dc, spy, vf, daily_ret, mode='random'):
    rebal_days, vol_target, riskoff_haircut = 60, 0.18, 0.50
    sma_lookback, mom_long, mom_short, top_n = 200, 175, 21, 15
    txn_frac = 20 / 10000.0
    
    price_mom = (dc[vf].shift(mom_short) / dc[vf].shift(mom_long)) - 1
    sma = spy.rolling(sma_lookback).mean()
    
    nav, paper_nav = CAP, CAP
    peak_paper_nav, trough_paper_nav = CAP, CAP
    stop_active = False
    
    pick_tks = []
    current_weights = pd.Series(dtype=float)
    port_rets, hist = [], []
    days = 0
    
    for i in range(1, len(dc)):
        if len(port_rets) >= 21:
            w_window = port_rets[-60:] if len(port_rets) >= 60 else port_rets[-21:]
            vs = vol_target / (np.std(w_window)*np.sqrt(252)+1e-8)
        else: vs = 0.5
        
        sp, sm = spy.values[i-1], sma.values[i-1]
        if pd.isna(sm) or sp <= sm: vs *= riskoff_haircut
        vs = float(np.clip(vs, 0.05, 1.0))
        
        day_ret = 0.0
        if pick_tks:
            lr = daily_ret.iloc[i][[t for t in pick_tks if t in daily_ret.columns]].dropna()
            if not lr.empty:
                wt = current_weights.reindex(lr.index).fillna(0)
                if wt.sum() > 0: wt = wt / wt.sum()
                day_ret = (lr * wt).sum() * vs
                
        paper_nav *= (1 + day_ret)
        paper_nav -= paper_nav * txn_frac * 2 / rebal_days * vs
        paper_nav = max(paper_nav, 0.01)
        
        if not stop_active:
            nav *= (1 + day_ret)
            nav -= nav * txn_frac * 2 / rebal_days * vs
            nav = max(nav, 0.01)
            
        port_rets.append(day_ret)
        hist.append(nav)
        
        peak_paper_nav = max(peak_paper_nav, paper_nav)
        paper_dd = (paper_nav / peak_paper_nav) - 1.0
        
        if not stop_active:
            if paper_dd <= -0.15:
                stop_active = True
                trough_paper_nav = paper_nav
                nav -= nav * txn_frac
        else:
            trough_paper_nav = min(trough_paper_nav, paper_nav)
            if paper_nav >= trough_paper_nav * 1.05:
                stop_active = False
                peak_paper_nav = paper_nav
                nav -= nav * txn_frac
                
        days += 1
        if days >= rebal_days:
            days = 0
            avail = price_mom.iloc[i].dropna().index.tolist()
            if not avail: continue
            
            if mode == 'random':
                new_picks = random.sample(avail, min(top_n, len(avail)))
                current_weights = pd.Series(1.0/len(new_picks), index=new_picks)
            elif mode == 'equal':
                # For EW, we could buy everything, but we will pick top N just for EW equivalent or all? 
                # Framework says "Equal-weight all stocks in universe"
                new_picks = avail
                current_weights = pd.Series(1.0/len(new_picks), index=new_picks)
            else:
                new_picks = avail
                
            pick_tks = new_picks
            
    return pd.Series(hist, index=dc.index[1:len(hist)+1])

def test_1_3_null_hypothesis(dc, spy, vf, daily_ret):
    print("\n--- Test 1.3: Null Hypothesis Randomization Test ---")
    
    # Original
    c_orig = run_v53_causal(dc, spy, vf, daily_ret, **V30_PARAMS)
    m_orig = evaluate_slice(c_orig, "2008-01-01", "2025-12-31")
    orig_sharpe = m_orig['sharpe']
    print(f"Original Strategy Sharpe: {orig_sharpe:.4f}")
    
    # Equal Weight
    c_ew = run_variant(dc, spy, vf, daily_ret, mode='equal')
    m_ew = evaluate_slice(c_ew, "2008-01-01", "2025-12-31")
    ew_sharpe = m_ew['sharpe']
    print(f"Equal-Weight Universe Sharpe: {ew_sharpe:.4f}")
    
    # Random (Run 100 iterations as per framework)
    rand_sharpes = []
    print("Running 100 Random iterations...", end="", flush=True)
    for _ in range(100):
        c_rand = run_variant(dc, spy, vf, daily_ret, mode='random')
        m_rand = evaluate_slice(c_rand, "2008-01-01", "2025-12-31")
        rand_sharpes.append(m_rand['sharpe'])
        if _ % 10 == 0: print(".", end="", flush=True)
    print()
    
    rand_median = np.median(rand_sharpes)
    print(f"Random Picks Median Sharpe: {rand_median:.4f}")
    print(f"Random Picks Max Sharpe:    {np.max(rand_sharpes):.4f}")
    
    excess = orig_sharpe - rand_median
    print(f"\nExcess Sharpe vs Random: +{excess:.4f}")
    
    if excess > 0.15:
        print("Result: PASS (Signal adds strong value beyond risk management)")
    elif excess > 0.10:
        print("Result: WEAK PASS (Signal adds marginal value)")
    else:
        print("Result: FAIL (Signal has no edge over random/risk management)")

if __name__ == "__main__":
    print("========================================")
    print(" V53 FRAMEWORK VALIDATION - PHASE 1")
    print("========================================")
    dc, spy, vf, daily_ret = get_data()
    
    test_1_1_ic_analysis(dc, vf)
    test_1_2_regime_ic_decay(dc, spy, vf)
    test_1_3_null_hypothesis(dc, spy, vf, daily_ret)