#!/usr/bin/env node
'use strict';

/**
 * skill-v1-stagea — DOES THE WINDSHIELD BEAT THE REAR-VIEW MIRROR?
 *
 * Stage A's only question: on settled HITS props, does an archetype-selected,
 * skill-based forward projection call the LISTED LINE better than the frequency
 * counter that is the reigning champion? If it does not, it is not real yet and
 * it does not get promoted. That is the whole test.
 *
 * ── WHY THIS IS GENUINELY OUT-OF-SAMPLE ──────────────────────────────────
 * `statcast_aggregates` was last refreshed 2026-07-21 (the nightly job was
 * unreachable code until this session — see snapshotScheduler). Settled hits
 * rows run 2026-07-23 onward. So the skill profiles this model reads were
 * frozen BEFORE every game it is asked to predict. The staleness that was a bug
 * for production is, for this one measurement, a clean point-in-time snapshot.
 * Rows on or before the freeze date are EXCLUDED so no profile can contain the
 * game it is predicting.
 *
 * The opposing starter comes from the statsapi schedule for that date, and the
 * pitcher's skill profile from the same frozen aggregate table.
 *
 * ── THE BAR (identical to the one that refuted hits-v1) ──────────────────
 *   - hits rows only, direction-aligned to the graded side
 *   - matched rows only: champion and challenger scored on the SAME props
 *   - paired bootstrap, deterministic seed, CI on the DIFFERENCE
 *   - PROMOTE only if the CI excludes zero on the good side
 *
 * ── DISCIPLINE 4, MEASURED, NOT ASSUMED ──────────────────────────────────
 * Selectivity is reported, not claimed: accuracy is broken out by how confident
 * the model is, so "right 57% on the 8 you're sure of" is a number rather than a
 * slogan. LIFT over the naive base rate is reported beside it, because being
 * right about obvious chalk is not signal.
 *
 *   SUPABASE_URL=... node scripts/skill-v1-stagea.js
 */

require('dotenv').config();
const { createClient } = require('@supabase/supabase-js');
const sk = require('../src/services/model/skillProjection');
const reg = require('../src/services/model/featureRegistry');
const mlb = require('../src/services/adapters/mlbStatsAdapter');
const { nameKey } = require('../src/utils/playerName');
const { knownRate } = require('../src/utils/known');

/** Team games played by the 2026-07-21 profile freeze — turns season PA into PA/game. */
const GAMES_SO_FAR = Number(process.env.STAGEA_GAMES_SO_FAR || 103);

const SB_URL = process.env.SUPABASE_URL;
const SB_KEY = process.env.SUPABASE_SERVICE_ROLE_KEY || process.env.SUPABASE_SERVICE_KEY;
const PAGE = 1000;

function corr(xs, ys) {
  const n = xs.length;
  if (n < 3) return null;
  const mx = xs.reduce((a, b) => a + b, 0) / n;
  const my = ys.reduce((a, b) => a + b, 0) / n;
  let sxy = 0; let sxx = 0; let syy = 0;
  for (let i = 0; i < n; i += 1) {
    const dx = xs[i] - mx; const dy = ys[i] - my;
    sxy += dx * dy; sxx += dx * dx; syy += dy * dy;
  }
  if (sxx <= 0 || syy <= 0) return null;
  return sxy / Math.sqrt(sxx * syy);
}
const r4 = (v) => (v == null || !Number.isFinite(v) ? null : Math.round(v * 10000) / 10000);
const mean = (a) => (a.length ? a.reduce((x, y) => x + y, 0) / a.length : null);
const brier = (ps, ys) => (ps.length ? ps.reduce((s, p, i) => s + (p - ys[i]) ** 2, 0) / ps.length : null);

function makeRnd(seed) {
  let s = seed >>> 0;
  return () => { s ^= s << 13; s >>>= 0; s ^= s >>> 17; s ^= s << 5; s >>>= 0; return s / 4294967296; };
}

function bootstrapDiff(rows, keyA, keyB, iters = 4000, seed = 20260803) {
  if (rows.length < 30) return null;
  const rnd = makeRnd(seed);
  const n = rows.length;
  const diffs = [];
  for (let it = 0; it < iters; it += 1) {
    const ys = []; const a = []; const b = [];
    for (let i = 0; i < n; i += 1) {
      const r = rows[Math.floor(rnd() * n)];
      ys.push(r.won); a.push(r[keyA]); b.push(r[keyB]);
    }
    const ca = corr(a, ys); const cb = corr(b, ys);
    if (ca == null || cb == null) continue;
    diffs.push(ca - cb);
  }
  if (diffs.length < 100) return null;
  diffs.sort((x, y) => x - y);
  const q = (p) => r4(diffs[Math.floor(p * (diffs.length - 1))]);
  const ci = [q(0.025), q(0.975)];
  return {
    point: r4(corr(rows.map((r) => r[keyA]), rows.map((r) => r.won))
      - corr(rows.map((r) => r[keyB]), rows.map((r) => r.won))),
    ci95: ci,
    ci_excludes_zero: ci[0] > 0 || ci[1] < 0,
  };
}

async function page(sb, table, select, apply) {
  const out = [];
  for (let from = 0; ; from += PAGE) {
    const { data, error } = await apply(sb.from(table).select(select)).range(from, from + PAGE - 1);
    if (error) throw error;
    if (!data || data.length === 0) break;
    out.push(...data);
    if (data.length < PAGE) break;
  }
  return out;
}

/**
 * `date|team` → the starter that team FACED.
 *
 * Built from the statsapi schedule: a team faces the OTHER side's probable.
 */
async function opposingStarters(dates) {
  const byDateTeam = new Map();
  for (const d of dates) {
    let games = [];
    try { games = await mlb.getScheduleWithPitchers(d); } catch { games = []; }
    for (const g of games) {
      if (!g.home || !g.away) continue;
      if (g.away.probablePitcher) byDateTeam.set(`${d}|${g.home.team}`, g.away.probablePitcher.id);
      if (g.home.probablePitcher) byDateTeam.set(`${d}|${g.away.team}`, g.home.probablePitcher.id);
      // Also key by the PITCHING team, so "who did team X send out" is directly
      // answerable from the opponent name a game log gives us.
      if (g.home.probablePitcher) byDateTeam.set(`${d}|OPP:${g.home.team}`, g.home.probablePitcher.id);
      if (g.away.probablePitcher) byDateTeam.set(`${d}|OPP:${g.away.team}`, g.away.probablePitcher.id);
    }
  }
  return byDateTeam;
}

/**
 * `playerKey|date` → the OPPONENT team that player faced.
 *
 * THE LEDGER CANNOT ANSWER THIS: `team`/`opponent` are NULL on 575 of 576 rows
 * in this window, which is why the first run resolved a pitcher for exactly ONE
 * row and silently measured a batter-profile-only model instead of the matchup
 * model it claimed to test. The player's own statsapi game log names the
 * opponent for the exact date, so it is both authoritative and point-in-time
 * safe (a completed game's opponent is not a forecast).
 */
async function opponentByPlayerDate(players) {
  const map = new Map();
  for (const [key, name] of players) {
    try {
      const found = await mlb.searchPlayer(name);
      if (!found || !found.id) continue;
      const log = await mlb.getPlayerGameLog(found.id);
      for (const g of log || []) {
        if (g && g.date && g.opponent) map.set(`${key}|${String(g.date).slice(0, 10)}`, g.opponent);
      }
    } catch { /* a missing log just means no pitcher for those rows */ }
  }
  return map;
}

async function main() {
  if (!SB_URL || !SB_KEY) throw new Error('SUPABASE_URL / service key required');
  const sb = createClient(SB_URL, SB_KEY, { auth: { persistSession: false } });

  // Frozen skill profiles — by name (batters) and by source_id (pitchers).
  const statcast = await page(sb, 'statcast_aggregates', '*', (q) => q.eq('sport', 'mlb'));
  const freeze = statcast.reduce((mx, r) => (String(r.updated_at) > mx ? String(r.updated_at) : mx), '');
  const freezeDate = freeze.slice(0, 10);
  const batters = new Map();
  const pitchersById = new Map();
  for (const r of statcast) {
    // UNITS: statcast_aggregates stores percentages (0-100). Convert ONCE, here.
    if (r.role === 'pitcher' && r.source_id != null) pitchersById.set(Number(r.source_id), sk.fromStatcastRow(r));
    if (r.player_key && r.role === 'batter') {
      const prev = batters.get(r.player_key);
      const size = Number(r.sample_pa || 0);
      if (!prev || size > Number(prev.rawPa || 0)) {
        batters.set(r.player_key, Object.assign(sk.fromStatcastRow(r), { rawPa: size, archetype: null }));
      }
    }
  }

  const led = await page(sb, 'ledger_entries',
    'player_key, player_name, stat, line, side, outcome, game_date, p_win, team, opponent, quarantine_reason',
    (q) => q.eq('sport', 'mlb').is('user_id', null).eq('stat', 'hits')
      .in('outcome', ['hit', 'miss']).not('p_win', 'is', null));

  const clean = led.filter((r) => !(r.quarantine_reason || '').startsWith('nontakeable_book')
    // STRICTLY AFTER the profile freeze — no game may be inside its own inputs.
    && String(r.game_date) > freezeDate);

  const dates = [...new Set(clean.map((r) => r.game_date))].sort();
  const starters = await opposingStarters(dates);
  const players = new Map();
  for (const r of clean) if (!players.has(r.player_key)) players.set(r.player_key, r.player_name);
  const oppByPlayerDate = await opponentByPlayerDate(players);

  const allowed = reg.candidateFeatures('mlb'); // challenger-first: candidates measured, never served
  const rows = [];
  const drops = {};
  const drop = (k) => { drops[k] = (drops[k] || 0) + 1; };
  let withPitcher = 0;

  for (const r of clean) {
    const bat = batters.get(r.player_key);
    if (!bat) { drop('no_batter_profile'); continue; }
    // The team he FACED that day, from his own game log. `starters` is keyed by
    // the team doing the facing, so look up his own team — which is the
    // opponent's opponent. Resolve via the game log's opponent name and take the
    // schedule entry for the OTHER side.
    const facedTeam = oppByPlayerDate.get(`${r.player_key}|${r.game_date}`) || null;
    const starterId = facedTeam ? starters.get(`${r.game_date}|OPP:${facedTeam}`) : null;
    const pit = starterId != null ? pitchersById.get(Number(starterId)) : null;
    if (pit) withPitcher += 1;

    // Opportunity: the batter's own season PA per game, from the frozen profile.
    // Opportunity: season PA spread over the games played so far this season.
    // GAMES_SO_FAR is the frozen-profile era's team game count, so PA/game is a
    // real per-game rate rather than an arbitrary divisor.
    const pa = knownRate(bat.rawPa);
    const expectedPa = pa && pa > 0 ? Math.min(5.2, Math.max(2.0, pa / GAMES_SO_FAR)) : null;

    const out = sk.projectSkill({
      batter: bat, pitcher: pit, park: 1,
      archetype: bat.archetype || null,
      statType: 'hits', line: Number(r.line),
      expectedPa, allowed,
    });
    if (!out) { drop('projection_refused'); continue; }

    const under = String(r.side).toLowerCase() === 'under';
    rows.push({
      won: r.outcome === 'hit' ? 1 : 0,
      champ: Number(r.p_win),
      skill: under ? 1 - out.p_over_line : out.p_over_line,
      line: Number(r.line),
      had_pitcher: !!pit,
    });
  }

  const ys = rows.map((r) => r.won);
  const base = mean(ys);
  const bs = bootstrapDiff(rows, 'skill', 'champ');

  // DISCIPLINE 4 — selectivity, measured. Sorted by confidence in the graded
  // side; report accuracy and LIFT over the naive base rate at each depth.
  const byConf = [...rows].sort((a, b) => b.skill - a.skill);
  const depths = [8, 15, 25, 50, 100].filter((d) => d <= byConf.length);
  const selectivity = depths.map((d) => {
    const top = byConf.slice(0, d);
    const hit = mean(top.map((r) => r.won));
    return { top_n: d, hit_rate: r4(hit), lift_over_base: r4(hit - base) };
  });

  console.log(JSON.stringify({
    measurement: 'STAGE A — skill-v1 vs the frequency counter, out-of-sample on listed-line accuracy',
    out_of_sample_guarantee: `skill profiles frozen ${freezeDate}; only rows with game_date > ${freezeDate} scored`,
    registry: reg.summary('mlb'),
    matched_rows: rows.length,
    rows_with_opposing_pitcher: withPitcher,
    pitcher_coverage_pct: rows.length ? r4(withPitcher / rows.length) : null,
    dropped: drops,
    base_rate: r4(base),
    resolution: { skill_v1: r4(corr(rows.map((r) => r.skill), ys)), champion: r4(corr(rows.map((r) => r.champ), ys)) },
    brier: { skill_v1: r4(brier(rows.map((r) => r.skill), ys)), champion: r4(brier(rows.map((r) => r.champ), ys)) },
    mean_forecast: { skill_v1: r4(mean(rows.map((r) => r.skill))), champion: r4(mean(rows.map((r) => r.champ))) },
    delta_vs_champion: bs,
    verdict: !bs ? 'N-BLOCKED'
      : (bs.ci_excludes_zero && bs.point > 0) ? 'BEATS THE COUNTER — promotable'
        : (bs.ci_excludes_zero && bs.point < 0) ? 'LOSES to the counter — iterate, do not promote'
          : 'INCONCLUSIVE — not proven, do not promote',
    selectivity_discipline_4: selectivity,
  }, null, 2));
  process.exit(0);
}

main().catch((e) => { console.error(e); process.exit(1); });