'use strict';

/**
 * intradayRefreshService — Phase 2.5 (Session 60, night2/D).
 *
 * A lightweight ODDS-ONLY refresh during slate hours (~noon–midnight ET).
 * No full re-grade run: it re-reads the market, computes the signed delta
 * per graded prop RELATIVE TO THE GRADED SIDE, and acts on DIRECTION:
 *
 *   moved WITH the grade  (market chasing our number)   → STEAM ▲ +N badge.
 *     Good for the record; entry edge compressed. NO re-grade.
 *   moved AGAINST ≥ 1.0                                  → re-grade THAT
 *     PROP ONLY at the current line:
 *       grade holds → VALUE ▲ (better number, same read)
 *       grade drops → PUBLIC revision: grade updates with
 *         revised_from_grade set (original preserved, struck through in
 *         the UI + ledger). Never a silent regrade — Ledger ethos.
 *
 * Every displayed line stays a REAL book value from this refresh — the
 * refresh CAPTURES market numbers, never computes them. Each run also
 * re-captures closing_line/odds (ledgerService.captureClosing): the last
 * pre-game write IS the close, now at refresh fidelity.
 *
 * QUOTA MATH (zero out-of-pocket): one getOdds call per sport per run.
 * 20-min cadence × 12 slate hours = 36 runs/day/sport × 4 sports =
 * ≤144 PropLine requests/day — against 9,000/day free capacity (3 keys ×
 * 3,000). Re-grades are internal feature computation (free) and bounded
 * to props that moved against ≥ 1.0.
 *
 * Everything injectable → unit-tested with zero network.
 */

const { nameKey } = require('../utils/playerName');

const STEAM_NOISE = 0.5;     // ignore movement below this (both directions)
const REGRADE_TRIGGER = 1.0; // moved-against threshold that triggers a re-grade
const SNAP_TTL = 24 * 3600;  // keep in sync with snapshotService
const TICKER_MOVE_CAP = 6;
const HISTORY_CAP = 24;      // {t, line} points per grade (S6 sparklines)

const GRADE_RANK = { 'A+': 0, A: 1, 'A-': 2, 'B+': 3, B: 4, 'B-': 5, 'C+': 6, C: 7, 'C-': 8, D: 9, F: 10 };
const rank = (g) => (g && GRADE_RANK[g] !== undefined ? GRADE_RANK[g] : 99);

const sideOver = (dir) => String(dir || 'over').toLowerCase() !== 'under';

function indexOddsProps(props) {
  const map = {};
  for (const p of props || []) {
    if (!p || !p.player || !p.stat_type) continue;
    const k = `${nameKey(p.player)}|${String(p.stat_type).toLowerCase()}`;
    if (!map[k]) map[k] = p;
  }
  return map;
}

/**
 * S6 (A1 board) — line-history capture for the row sparklines. Appends the
 * CURRENT real feed line as a {t, line} point on the grade's movement
 * tracking, persisted in the snapshot this refresh already writes back
 * (zero new keys). Rules:
 *   - real points only: an unparseable current line appends nothing;
 *   - seed: an empty history first records the LOCKED line at its own
 *     graded timestamp (a real captured value);
 *   - dedupe: consecutive identical lines don't append — a point means the
 *     line MOVED, so ≥3 points = a real movement story, not a flat pulse;
 *   - cap: last HISTORY_CAP (24) points.
 */
function trackHistory(g, currentLine, ts) {
  const prev = Array.isArray(g.history) ? g.history : [];
  // Strict: Number(null) is 0 — a fabricated line (Data Semantics Rule).
  const current = currentLine == null ? NaN : Number(currentLine);
  if (!Number.isFinite(current)) return prev.length > 0 ? prev : undefined;
  let hist = prev;
  if (hist.length === 0) {
    const locked = g.gradedAt && g.gradedAt.line != null ? g.gradedAt.line : g.line;
    const lockedNum = Number(locked);
    if (locked != null && Number.isFinite(lockedNum)) {
      hist = [{ t: (g.gradedAt && g.gradedAt.timestamp) || ts, line: lockedNum }];
    }
  }
  const last = hist[hist.length - 1];
  if (!last || last.line !== current) hist = [...hist, { t: ts, line: current }];
  return hist.slice(-HISTORY_CAP);
}

/** Signed movement RELATIVE TO THE GRADED SIDE: positive = toward (with).
 *  Strict null-safe parse — Number(null) is 0, a fabricated line. */
function signedDelta(side, lockedLine, currentLine) {
  if (lockedLine == null || currentLine == null) return null;
  const locked = Number(lockedLine);
  const current = Number(currentLine);
  if (!Number.isFinite(locked) || !Number.isFinite(current)) return null;
  const raw = current - locked;
  return Math.round((sideOver(side) ? raw : -raw) * 100) / 100;
}

/**
 * Run one intraday refresh for a sport. Returns
 * { sport, status, checked, steam, value, revised } — never throws.
 */
async function runIntradayRefresh(sport, opts = {}) {
  const sp = String(sport || '').toLowerCase();
  const deps = {
    getOdds: opts.getOdds || require('./oddsService').getOdds,
    analyze: opts.analyze || require('./intelligence/analyzeViaEngine1').analyzeViaEngine1,
    cacheGet: opts.cacheGet || require('../utils/redis').cacheGet,
    cacheSet: opts.cacheSet || require('../utils/redis').cacheSet,
    ledger: opts.ledger || require('./ledgerService'),
    pushTickerItems: opts.pushTickerItems || require('./snapshotService').pushTickerItems,
    now: opts.now || (() => new Date().toISOString()),
  };
  const ts = deps.now();

  const snap = await deps.cacheGet(`snapshot:${sp}:latest`);
  if (!snap || !Array.isArray(snap.grades) || snap.grades.length === 0) {
    return { sport: sp, status: 'skipped', reason: 'no snapshot', checked: 0, steam: 0, value: 0, revised: 0 };
  }

  let odds;
  try {
    odds = await deps.getOdds(sp);
  } catch (e) {
    return { sport: sp, status: 'error', reason: e.message, checked: 0, steam: 0, value: 0, revised: 0 };
  }
  const props = odds && Array.isArray(odds.props) ? odds.props : [];
  if (props.length === 0) {
    return { sport: sp, status: 'skipped', reason: 'no odds', checked: 0, steam: 0, value: 0, revised: 0 };
  }
  const byKey = indexOddsProps(props);

  let steam = 0; let value = 0; let revised = 0; let checked = 0;
  const moveEvents = [];
  const grades = [];

  for (const g of snap.grades) {
    const player = g.player || g.player_name;
    const stat = String(g.stat_type || g.stat || '').toLowerCase();
    const locked = g.gradedAt && g.gradedAt.line != null ? g.gradedAt.line : g.line;
    const prop = byKey[`${nameKey(player)}|${stat}`];
    // Prop gone from the feed (game started / market pulled) → frozen as-is.
    if (!prop || prop.line == null || locked == null) { grades.push(g); continue; }
    checked += 1;

    // S6 — capture the real current line into the grade's {t, line} history
    // (sparkline fuel). Rides inside the snapshot write below — no new keys.
    const history = trackHistory(g, prop.line, ts);
    const withHist = (obj) => (history ? { ...obj, history } : obj);

    const delta = signedDelta(g.direction, locked, prop.line);
    if (delta == null || Math.abs(delta) < STEAM_NOISE) {
      grades.push(withHist({ ...g, movement: null }));
      continue;
    }

    const current = Number(prop.line);
    if (delta > 0) {
      // Moved WITH the grade — the market is chasing our number.
      steam += 1;
      grades.push(withHist({ ...g, movement: { kind: 'steam', delta, currentLine: current, at: ts } }));
      if (Math.abs(delta) >= REGRADE_TRIGGER) {
        moveEvents.push(moveEvent(sp, g, locked, current, ts));
      }
      continue;
    }

    // Moved AGAINST the grade.
    if (Math.abs(delta) < REGRADE_TRIGGER) {
      grades.push(withHist({ ...g, movement: { kind: 'against', delta, currentLine: current, at: ts } }));
      continue;
    }

    // ≥ 1.0 against → re-grade THIS PROP ONLY at the current (real) line.
    let res = null;
    try {
      res = await deps.analyze({
        player, stat_type: stat, line: current,
        direction: g.direction || 'over', sport: sp, book: prop.book,
      });
    } catch { /* re-grade unavailable → treated as hold below */ }
    moveEvents.push(moveEvent(sp, g, locked, current, ts));

    if (!res || !res.grade || res.insufficient_data || rank(res.grade) <= rank(g.grade)) {
      // Grade holds (or the model refuses to re-read) → better entry, same read.
      value += 1;
      grades.push(withHist({ ...g, movement: { kind: 'value', delta, currentLine: current, at: ts } }));
      continue;
    }

    // Grade DROPS → public revision. Original grade preserved once, forever.
    revised += 1;
    const fromGrade = g.revised_from_grade || g.grade;
    grades.push(withHist({
      ...g,
      grade: res.grade,
      revised_from_grade: fromGrade,
      movement: { kind: 'revised', delta, currentLine: current, at: ts },
    }));
    try {
      await deps.ledger.applyRevision(sp, {
        playerKey: nameKey(player), stat, line: Number(locked),
        side: sideOver(g.direction) ? 'over' : 'under',
        newGrade: res.grade, fromGrade,
      });
    } catch (e) {
      console.warn(`[intraday] ledger revision failed for ${player}:`, e.message);
    }
  }

  // Write back: refreshed movement state + the higher-fidelity close.
  const updated = { ...snap, grades, refreshed_at: ts };
  await deps.cacheSet(`snapshot:${sp}:latest`, updated, SNAP_TTL);
  await deps.cacheSet(`grades:${sp}`, { grades, updated_at: snap.updated_at, refreshed_at: ts, source: snap.source || 'refresh' }, SNAP_TTL);
  try { await deps.ledger.captureClosing(sp, props); } catch { /* best-effort */ }
  if (moveEvents.length > 0) {
    await deps.pushTickerItems(moveEvents.slice(0, TICKER_MOVE_CAP), deps);
  }

  return { sport: sp, status: 'ok', checked, steam, value, revised };
}

function moveEvent(sport, g, locked, current, ts) {
  const s = sideOver(g.direction) ? 'o' : 'u';
  const arrow = current > locked ? '▲' : '▼';
  const diff = Math.round((current - locked) * 100) / 100;
  const last = String(g.player || g.player_name || '').trim().split(/\s+/).pop() || '';
  return {
    tag: 'MOVE', color: 'var(--amber)', ts, sport,
    text: `${last} ${s}${locked} → ${s}${current} ${arrow}${diff > 0 ? '+' : ''}${diff}`,
  };
}

/** Slate hours: noon–midnight ET. */
function inSlateHours(date = new Date()) {
  const h = Number(new Intl.DateTimeFormat('en-US', { timeZone: 'America/New_York', hour: 'numeric', hour12: false }).format(date));
  return h >= 12 && h <= 23;
}

async function runAllIntradayRefreshes(opts = {}) {
  const sports = opts.sports || require('./snapshotService').ACTIVE_SPORTS;
  const results = [];
  for (const sp of sports) {
    try { results.push(await runIntradayRefresh(sp, opts)); }
    catch (e) { results.push({ sport: sp, status: 'error', reason: e.message }); }
  }
  return results;
}

module.exports = {
  runIntradayRefresh,
  runAllIntradayRefreshes,
  inSlateHours,
  __internals: { signedDelta, indexOddsProps, moveEvent, rank, trackHistory, STEAM_NOISE, REGRADE_TRIGGER, HISTORY_CAP },
};