"""
volume_analysis.py — Volume & order flow with absorption detection,
multi-bar breakout confirmation, and fake breakout identification.

Key fixes vs prior version:
- Absorption detection: high-volume small-body bars at resistance = institutional selling
- Multi-bar breakout confirmation (BREAKOUT_CONFIRMATION_BARS) before firing signal
- ATR buffer on breakout level (price must exceed level by N*ATR, not just 1 tick)
- OBV slope computed over configurable window, normalized vs rolling stddev
- Climax threshold lowered (3.0x) and now triggers a hard absorption check
- Failed retest detection: breakout that closes back below the level = fake
"""

from typing import Dict, Any

import numpy as np
import pandas as pd

from config import (
    VOLUME_MA_PERIOD,
    VOLUME_SPIKE_MULT,
    VOLUME_CLIMAX_MULT,
    VOLUME_WEAK_THRESHOLD,
    BREAKOUT_LOOKBACK,
    BREAKOUT_ATR_BUFFER,
    BREAKOUT_CONFIRMATION_BARS,
    BREAKOUT_RETEST_BARS,
    ABSORPTION_WICK_RATIO,
    ABSORPTION_VOL_MULT,
    ABSORPTION_BODY_RATIO,
    OBV_SLOPE_BARS,
    ATR_PERIOD,
)


def compute_volume_ma(df: pd.DataFrame, period: int = VOLUME_MA_PERIOD) -> pd.Series:
    return df["volume"].rolling(period).mean()


def detect_spikes(df: pd.DataFrame, vol_ma: pd.Series) -> pd.Series:
    return df["volume"] > vol_ma * VOLUME_SPIKE_MULT


def detect_climax(df: pd.DataFrame, vol_ma: pd.Series) -> pd.Series:
    return df["volume"] > vol_ma * VOLUME_CLIMAX_MULT


def detect_absorption(df: pd.DataFrame, vol_ma: pd.Series) -> pd.Series:
    """
    Absorption = high-volume bar with small body and large upper wick,
    occurring near recent highs (institutional supply absorbing retail demand).

    Conditions (all must be true):
    - Volume > ABSORPTION_VOL_MULT * MA
    - Body / range < ABSORPTION_BODY_RATIO (small real body)
    - Upper wick / range > ABSORPTION_WICK_RATIO (large upper wick)
    - Close is in lower half of the bar's range (sellers won the bar)
    """
    bar_range = (df["high"] - df["low"]).replace(0, np.nan)
    body = (df["close"] - df["open"]).abs()
    upper_wick = df["high"] - df[["close", "open"]].max(axis=1)

    body_ratio = body / bar_range
    wick_ratio = upper_wick / bar_range
    close_in_lower_half = df["close"] < (df["low"] + bar_range * 0.5)

    high_volume = df["volume"] > vol_ma * ABSORPTION_VOL_MULT
    small_body = body_ratio < ABSORPTION_BODY_RATIO
    large_wick = wick_ratio > ABSORPTION_WICK_RATIO

    return high_volume & small_body & large_wick & close_in_lower_half


def compute_obv(df: pd.DataFrame) -> pd.Series:
    direction = np.sign(df["close"].diff()).fillna(0)
    return (df["volume"] * direction).cumsum()


def compute_obv_slope(obv: pd.Series, bars: int = OBV_SLOPE_BARS) -> pd.Series:
    """
    OBV slope normalized by rolling stddev of OBV to make it comparable
    across different price scales. Values > 1 = strong upward flow.
    """
    x = np.arange(bars)

    def slope_normalized(window):
        if len(window) < bars:
            return np.nan
        s = np.polyfit(x, window, 1)[0]
        std = np.std(window)
        return s / std if std > 0 else 0.0

    return obv.rolling(bars).apply(slope_normalized, raw=True)


def compute_delta_approx(df: pd.DataFrame) -> pd.Series:
    body = df["close"] - df["open"]
    wick = (df["high"] - df["low"]).replace(0, np.nan)
    buy_ratio = ((body / wick) * 0.5 + 0.5).clip(0.0, 1.0).fillna(0.5)
    return df["volume"] * buy_ratio - df["volume"] * (1 - buy_ratio)


def compute_vwap_deviation(df: pd.DataFrame, period: int = VOLUME_MA_PERIOD) -> pd.Series:
    typical = (df["high"] + df["low"] + df["close"]) / 3
    cum_vp = (typical * df["volume"]).rolling(period).sum()
    cum_vol = df["volume"].rolling(period).sum().replace(0, np.nan)
    vwap = cum_vp / cum_vol
    atr_approx = (df["high"] - df["low"]).rolling(ATR_PERIOD).mean().replace(0, np.nan)
    return (df["close"] - vwap) / atr_approx


def compute_confirmed_breakout(
    df: pd.DataFrame,
    atr_series: pd.Series,
    vol_ma: pd.Series,
    lookback: int = BREAKOUT_LOOKBACK,
    confirm_bars: int = BREAKOUT_CONFIRMATION_BARS,
    atr_buffer: float = BREAKOUT_ATR_BUFFER,
) -> pd.Series:
    """
    Genuine breakout requires ALL of:
    1. Close exceeds prior N-bar high/low by at least atr_buffer * ATR
    2. Close holds above/below that level for confirm_bars consecutive bars
    3. Volume spike on at least one of the confirmation bars
    4. No absorption signal on the breakout bar or confirmation bars

    Returns: +1 confirmed bull breakout, -1 confirmed bear, 0 none
    """
    prior_high = df["high"].rolling(lookback).max().shift(lookback)
    prior_low = df["low"].rolling(lookback).min().shift(lookback)
    spike = detect_spikes(df, vol_ma)
    absorption = detect_absorption(df, vol_ma)

    # Level cleared with buffer
    cleared_up = df["close"] > prior_high + atr_series * atr_buffer
    cleared_dn = df["close"] < prior_low - atr_series * atr_buffer

    # Rolling confirmation: all bars in last confirm_bars cleared the level
    held_up = cleared_up.rolling(confirm_bars).min().fillna(0).astype(bool)
    held_dn = cleared_dn.rolling(confirm_bars).min().fillna(0).astype(bool)

    # Volume spike in confirmation window
    vol_ok = spike.rolling(confirm_bars).max().fillna(0).astype(bool)

    # No absorption in confirmation window
    no_absorption = (~absorption).rolling(confirm_bars).min().fillna(1).astype(bool)

    signal = pd.Series(0, index=df.index)
    signal[held_up & vol_ok & no_absorption] = 1
    signal[held_dn & vol_ok & no_absorption] = -1
    return signal


def detect_failed_breakout(
    df: pd.DataFrame,
    breakout_series: pd.Series,
    atr_series: pd.Series,
    retest_bars: int = BREAKOUT_RETEST_BARS,
) -> pd.Series:
    """
    A breakout that closes back below/above the breakout level within
    retest_bars is flagged as a failed (fake) breakout.
    Returns: True where a prior confirmed breakout has since failed.
    """
    prior_high = df["high"].rolling(BREAKOUT_LOOKBACK).max().shift(BREAKOUT_LOOKBACK)
    prior_low = df["low"].rolling(BREAKOUT_LOOKBACK).min().shift(BREAKOUT_LOOKBACK)

    had_bull_bo = breakout_series.shift(1).rolling(retest_bars).max().fillna(0) > 0
    had_bear_bo = breakout_series.shift(1).rolling(retest_bars).min().fillna(0) < 0

    # Failed: price returned below the breakout level
    bull_failed = had_bull_bo & (df["close"] < prior_high.shift(retest_bars))
    bear_failed = had_bear_bo & (df["close"] > prior_low.shift(retest_bars))

    return bull_failed | bear_failed


def analyze_volume(df: pd.DataFrame, atr_series: pd.Series = None) -> Dict[str, Any]:
    if atr_series is None:
        # Fallback: compute simple ATR if not provided
        high, low, prev_close = df["high"], df["low"], df["close"].shift(1)
        tr = pd.concat(
            [high - low, (high - prev_close).abs(), (low - prev_close).abs()],
            axis=1,
        ).max(axis=1)
        atr_series = tr.ewm(alpha=1.0 / ATR_PERIOD, adjust=False).mean()

    vol_ma = compute_volume_ma(df, VOLUME_MA_PERIOD)
    spike_series = detect_spikes(df, vol_ma)
    climax_series = detect_climax(df, vol_ma)
    absorption_series = detect_absorption(df, vol_ma)
    obv = compute_obv(df)
    obv_slope_series = compute_obv_slope(obv, OBV_SLOPE_BARS)
    delta = compute_delta_approx(df)
    vwap_dev = compute_vwap_deviation(df, VOLUME_MA_PERIOD)

    breakout_series = compute_confirmed_breakout(
        df, atr_series, vol_ma,
        lookback=BREAKOUT_LOOKBACK,
        confirm_bars=BREAKOUT_CONFIRMATION_BARS,
        atr_buffer=BREAKOUT_ATR_BUFFER,
    )
    failed_breakout_series = detect_failed_breakout(df, breakout_series, atr_series)

    last_vol = float(df["volume"].iloc[-1])
    last_vol_ma = float(vol_ma.iloc[-1]) if not np.isnan(vol_ma.iloc[-1]) else 1.0
    last_spike = bool(spike_series.iloc[-1])
    last_climax = bool(climax_series.iloc[-1])
    last_absorption = bool(absorption_series.iloc[-1])
    last_breakout = int(breakout_series.iloc[-1])
    last_failed_bo = bool(failed_breakout_series.iloc[-1])
    last_obv_slope = float(obv_slope_series.iloc[-1]) if not np.isnan(obv_slope_series.iloc[-1]) else 0.0
    last_vwap_dev = float(vwap_dev.iloc[-1]) if not np.isnan(vwap_dev.iloc[-1]) else 0.0

    vol_ratio = last_vol / last_vol_ma if last_vol_ma > 0 else 1.0
    weak_vol = vol_ratio < VOLUME_WEAK_THRESHOLD

    delta_5 = float(delta.iloc[-5:].sum())
    delta_sign = 1 if delta_5 > 0 else -1

    # Recent failed breakout count (rolling 10 bars) — context for trust level
    recent_failed = int(failed_breakout_series.iloc[-10:].sum())

    # Score construction
    if last_absorption:
        # Absorption at high: bearish signal masquerading as bullish
        base_score = 0.15
    elif last_climax:
        base_score = 0.25
    elif last_breakout != 0 and not last_failed_bo:
        base_score = 1.0
    elif last_breakout != 0 and last_failed_bo:
        base_score = 0.20
    elif last_spike and not last_absorption:
        base_score = 0.60
    elif vol_ratio >= 1.2:
        base_score = 0.45
    elif vol_ratio >= 0.8:
        base_score = 0.30
    else:
        base_score = 0.10

    # OBV slope bonus/penalty (normalized)
    obv_bonus = float(np.clip(last_obv_slope * 0.08, -0.12, 0.12))

    # VWAP deviation bonus for on-side entries
    vwap_bonus = 0.05 if (last_vwap_dev > 0 and last_breakout == 1) else 0.0
    vwap_bonus += 0.05 if (last_vwap_dev < 0 and last_breakout == -1) else 0.0

    # Penalty for recent failed breakouts (trust decay)
    fake_penalty = min(0.20, recent_failed * 0.05)

    volume_score = float(np.clip(base_score + obv_bonus + vwap_bonus - fake_penalty, 0.0, 1.0))

    return {
        "vol_ratio": round(vol_ratio, 3),
        "spike": last_spike,
        "climax": last_climax,
        "absorption": last_absorption,
        "weak": weak_vol,
        "breakout": last_breakout,
        "failed_breakout": last_failed_bo,
        "recent_failed_count": recent_failed,
        "obv_slope_norm": round(last_obv_slope, 4),
        "delta_sum_5": round(delta_5, 2),
        "delta_sign": delta_sign,
        "vwap_deviation": round(last_vwap_dev, 4),
        "volume_score": round(volume_score, 4),
        "spike_series": spike_series,
        "climax_series": climax_series,
        "absorption_series": absorption_series,
        "breakout_series": breakout_series,
        "failed_breakout_series": failed_breakout_series,
    }