/**
 * College Football Data (CFBD) — advanced college analytics.
 *
 * 100% free API key. Covers historical betting lines, player usage, team
 * talent composites, advanced efficiency (PPA), recruiting. nba_api
 * doesn't cover college; CFBD fills the gap for NCAAB and NCAAFB props.
 *
 * Note: CFBD's primary product is college football. College *basketball*
 * coverage is via the /cbb endpoints. We expose both via the sport-aware
 * functions below.
 */

const axios = require('axios');
const { createLimiter, createCircuitBreaker } = require('../../utils/rateLimiter');
const { cacheGet, cacheSet } = require('../../utils/redis');

const SOURCE = 'cfbd';
const HTTP_TIMEOUT_MS = 10_000;
const CACHE_TTL_SECONDS = 6 * 60 * 60;  // 6h — most CFBD data is daily-fresh

const BASE_URL = process.env.CFBD_BASE_URL || 'https://api.collegefootballdata.com';

// Generous free tier — 10 req/min keeps us well under documented limits.
const limiter = createLimiter({ tokensPerInterval: 10, interval: 60_000 });
const breaker = createCircuitBreaker({ failureThreshold: 3, resetTimeout: 60_000 });

function configured() {
  return !!process.env.CFBD_KEY;
}

async function fetchWithGuards(url, params, cacheKey) {
  if (!configured()) return null;
  const cached = await cacheGet(cacheKey);
  if (cached) return cached;

  await limiter.waitForToken();
  try {
    const data = await breaker.call(async () => {
      const res = await axios.get(url, {
        params,
        headers: { Authorization: `Bearer ${process.env.CFBD_KEY}` },
        timeout: HTTP_TIMEOUT_MS,
        validateStatus: (s) => (s >= 200 && s < 300) || s === 429,
      });
      if (res.status === 429) {
        const err = new Error('cfbd rate limited');
        err.code = 'CFBD_429';
        throw err;
      }
      return res.data;
    });
    await cacheSet(cacheKey, data, CACHE_TTL_SECONDS);
    return data;
  } catch (err) {
    if (err?.code === 'CIRCUIT_OPEN') return null;
    console.warn(`[${SOURCE}] fetch failed for ${cacheKey}:`, err?.message);
    return null;
  }
}

async function getTeamStats(team, year) {
  const cacheKey = `cfbd:teamstats:${team}:${year}`;
  const data = await fetchWithGuards(`${BASE_URL}/stats/season`, { year, team }, cacheKey);
  return Array.isArray(data) ? data : [];
}

async function getPlayerUsage(player, team, year) {
  const cacheKey = `cfbd:usage:${player}:${team}:${year}`;
  const data = await fetchWithGuards(
    `${BASE_URL}/player/usage`,
    { year, team, player },
    cacheKey
  );
  return Array.isArray(data) ? data : [];
}

async function getTalentComposite(team, year) {
  const cacheKey = `cfbd:talent:${team}:${year}`;
  const data = await fetchWithGuards(`${BASE_URL}/talent`, { year }, cacheKey);
  if (!Array.isArray(data)) return null;
  return data.find((row) => (row.school || row.team) === team) || null;
}

async function getHistoricalLines(team, year) {
  const cacheKey = `cfbd:lines:${team}:${year}`;
  const data = await fetchWithGuards(`${BASE_URL}/lines`, { year, team }, cacheKey);
  return Array.isArray(data) ? data : [];
}

module.exports = {
  configured,
  getTeamStats,
  getPlayerUsage,
  getTalentComposite,
  getHistoricalLines,
  __internals: { limiter, breaker, BASE_URL },
};