vyndr/src/services/lineupService.js

'use strict';

/**
 * lineupService — MLB lineup confirmation (Session 64 / A1-S5).
 *
 * FREE statsapi `schedule?hydrate=lineups`: once a team posts its lineup the
 * feed carries homePlayers/awayPlayers in batting order. From that, per
 * player (nameKey):
 *   CONFIRMED (with batting slot) — the player is in a posted lineup.
 *   NOT_IN  — his team's lineup IS posted and he isn't in it. This visibly
 *             kills the grade on the slate (struck through + chip). The
 *             locked ledger read is untouched — honesty means SHOWING the
 *             read is dead, not deleting it.
 *   (absent) — his team hasn't posted yet → the UI renders PROJECTED.
 *
 * Cache 10 min (lineups post in waves pre-game). Pure parser + injectable
 * fetch → unit-tested on the real feed shape with zero network.
 */

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

const TTL = 600; // 10 min
const BASE = 'https://statsapi.mlb.com/api/v1';
const HTTP_TIMEOUT_MS = 10_000;

/**
 * Pure: statsapi schedule JSON → {
 *   byPlayer: { nameKey: { status:'confirmed', slot, team } },
 *   postedTeams: [team names whose lineup is up],
 * }
 * Players NOT in byPlayer whose team IS in postedTeams are NOT_IN —
 * resolved by statusFor().
 */
function parseLineups(scheduleJson) {
  const byPlayer = {};
  const postedTeams = [];
  const games = ((scheduleJson || {}).dates || [])[0]?.games || [];
  for (const g of games) {
    const lu = g.lineups || {};
    for (const side of ['home', 'away']) {
      const players = lu[`${side}Players`];
      if (!Array.isArray(players) || players.length === 0) continue;
      const team = g.teams?.[side]?.team?.name || null;
      if (team) postedTeams.push(team);
      players.forEach((p, i) => {
        if (!p || !p.fullName) return;
        byPlayer[nameKey(p.fullName)] = { status: 'confirmed', slot: i + 1, team };
      });
    }
  }
  return { byPlayer, postedTeams };
}

/** Resolve one player's viability given parsed lineups + his team. */
function statusFor(player, team, parsed) {
  if (!parsed) return { status: 'projected' };
  const hit = parsed.byPlayer[nameKey(player)];
  if (hit) return hit;
  const token = (n) => String(n || '').toLowerCase().split(/\s+/).pop();
  const posted = team && parsed.postedTeams.some((t) => t === team || token(t) === token(team));
  return posted ? { status: 'not_in', team } : { status: 'projected' };
}

async function fetchLineups(date, opts = {}) {
  const cacheGet = opts.cacheGet || require('../utils/redis').cacheGet;
  const cacheSet = opts.cacheSet || require('../utils/redis').cacheSet;
  const key = `lineups:mlb:${date}`;
  const cached = await cacheGet(key);
  if (cached) return cached;
  const axios = opts.axios || require('axios');
  try {
    const res = await axios.get(`${BASE}/schedule?sportId=1&date=${date}&hydrate=lineups`, { timeout: HTTP_TIMEOUT_MS });
    const parsed = parseLineups(res.data);
    await cacheSet(key, parsed, TTL);
    return parsed;
  } catch (e) {
    console.warn('[lineups] fetch failed:', e.message);
    return { byPlayer: {}, postedTeams: [] };
  }
}

module.exports = { fetchLineups, parseLineups, statusFor, __internals: { TTL, BASE } };