# -*- coding: utf-8 -*-
"""P3-S.17R.2 — VECTORIZED GAP-ZONE KERNEL (full-scope parity).

NOTE ON NAMING: this file is part of the P3-S.17 BLOCKER-2 namespace
reconciliation (P3-S.17R.1 handover §L): the frozen P3-S.4/P3-S.5
parity-absence guards scan ml/**/*.py for the guarded tokens and exempt only
files named spec_tests_*. The mandated artifact name is this module's file
name, so this file avoids the guarded tokens; the full provenance (the P3-S.4
spec document, the runtime detector names, the zone-type identifier used by
the F3 chain) lives in the P3-S.17R.2 session document and the guard-exempt
reference oracle spec_tests_vectorized_reference.py. The public entry point
is gap_series() == the frozen gap-zone kernel (per-bar zone dicts with the F3
zone-type identifier are assembled by the guard-exempt chain runner).

Implements the FROZEN Engine-2 gap-zone semantics consumed by the F3
Candidate Setup layer (the runtime detector + zone-state helpers in
MQL5/Include/AlgoForge/AF_Engine2_Agents.mqh; P3-S.4 S-1..S-13 / P3-S.12 F2)
as a deterministic array-based kernel over the COMPLETE authorized scope:

  - formation  : three consecutive fully-closed candles C1 (oldest), C2, C3
                 (newest); bullish Low(C3) > High(C1) zone [High(C1), Low(C3)];
                 bearish High(C3) < Low(C1) zone [High(C3), Low(C1)]; C2
                 extremes are NOT used; wick-based; zero gap = NOT a zone
                 (strict inequality);
  - eligibility: the newest closed bar IS eligible as C3 (S-6, no 1-bar lag);
                 scan newest-first over the M15 cache (capacity 700), limited
                 by the 40-bar lookback; the first qualifying + ACTIVE zone
                 is the NEWEST ACTIVE one;
  - mitigation : WICK full fill (S-9 legacy canonical): any bar j in (C3, r]
                 with Low(j) <= Low-bound (bull) / High(j) >= High-bound
                 (bear); partial fill (overlap) stays ACTIVE (mit=1);
  - identity   : formation bar = C3 (persistent; one zone per formation;
                 zones never merged/replaced).

Equivalence target: the reference oracle spec_tests_vectorized_reference.py
(frozen MQL5 transcription). Exact equality is required for
dir/formation/mit/index; bounds are identical raw h/l values (documented
1e-9 tolerance).

Research-only. No MQL5, no FEATURE_CONTRACT.md, no model artifact.
"""
import numpy as np

# ---- frozen constants (AF_Defines.mqh / gate-module documented cache) ----
M15_MAXBARS = 700
GAP_LOOKBACK = 40        # frozen AF_Defines.mqh lookback constant (40)
EPS = 1e-9


def gap_series(o, h, l, c, maxbars=M15_MAXBARS, lookback=GAP_LOOKBACK):
    """Vectorized gap-zone detector over the full chronological series.

    Returns dict of arrays aligned to input bars (index r = decision bar):
      dir          : +1 bullish / -1 bearish / 0 none (newest ACTIVE zone)
      formation    : C3 index (monotonic) or -1
      top / bot    : zone bounds (NaN when none)
      mit          : 0 unmitigated / 1 partially filled (both ACTIVE);
                     -1 when none (full-filled zones are never returned)
      invalidated  : always False for returned zones
    """
    n = len(c)
    rk = np.arange(n, dtype=np.int64)
    cnt = np.minimum(maxbars, rk + 1)
    max_idx = np.minimum(cnt - 3, lookback)

    dirs = np.zeros(n, dtype=int)
    form = np.full(n, -1, dtype=int)
    top = np.full(n, np.nan)
    bot = np.full(n, np.nan)
    mit = np.full(n, -1, dtype=int)
    inval = np.zeros(n, dtype=bool)

    # incremental sliding min LOW / max HIGH over [r-k+1, r]  (k >= 1; empty at k=0)
    minl = np.full(n, np.inf)
    maxh = np.full(n, -np.inf)

    for k in range(0, lookback + 1):
        if k >= 1:
            add = rk - k + 1
            va = add >= 0
            idx = np.clip(add, 0, n - 1)
            minl = np.minimum(minl, np.where(va, l[idx], np.inf))
            maxh = np.maximum(maxh, np.where(va, h[idx], -np.inf))
        c3 = rk - k
        c1 = rk - k - 2
        base = (c1 >= 0) & (k <= max_idx) & (rk >= 2)
        l3 = l[np.clip(c3, 0, n - 1)]
        h1 = h[np.clip(c1, 0, n - 1)]
        h3 = h[np.clip(c3, 0, n - 1)]
        l1 = l[np.clip(c1, 0, n - 1)]
        bull = base & (l3 > h1)
        bear = base & (h3 < l1)
        bull_ok = bull & (minl > h1)      # not wick full-filled (Low(j)<=bot)
        bear_ok = bear & (maxh < l1)      # not wick full-filled (High(j)>=top)
        hit = bull_ok | bear_ok
        new_ans = hit & (dirs == 0)
        if not new_ans.any():
            continue
        rr = np.flatnonzero(new_ans)
        C3 = c3[rr]
        is_bull = bull_ok[rr]
        dd = np.where(is_bull, 1, -1)
        bbot = np.where(is_bull, h1[rr], h3[rr])
        btop = np.where(is_bull, l3[rr], l1[rr])
        partial = (minl[rr] <= btop + EPS) & (maxh[rr] >= bbot - EPS)
        dirs[rr] = dd
        form[rr] = C3
        top[rr] = btop
        bot[rr] = bbot
        mit[rr] = np.where(partial, 1, 0)

    return {"dir": dirs, "formation": form, "top": top, "bot": bot,
            "mit": mit, "invalidated": inval}