import { Router } from 'express';
import db from '../db/index.js';
import { requireAuth } from '../auth/middleware.js';
import { getGame } from '../games/registry.js';

const router = Router();

const RESULTS = new Set(['win', 'loss', 'draw']);

// POST /api/history/single-player
// Body: { slug, score, opponentScores: number[], result }
// Records a finished single-player vs-AI match for the signed-in user.
// AI opponents do not get match_players rows (user_id is a FK to users).
router.post('/single-player', requireAuth, (req, res) => {
  const { slug, score, opponentScores, result } = req.body ?? {};

  if (typeof slug !== 'string' || !slug) {
    return res.status(400).json({ error: 'Missing slug.' });
  }
  const def = getGame(slug);
  if (!def) {
    return res.status(400).json({ error: 'Unknown game slug.' });
  }
  if (!Number.isFinite(score) || score < 0 || score > 100000) {
    return res.status(400).json({ error: 'Invalid score.' });
  }
  if (!Array.isArray(opponentScores) || !opponentScores.every((n) => Number.isFinite(n))) {
    return res.status(400).json({ error: 'Invalid opponentScores.' });
  }
  if (!RESULTS.has(result)) {
    return res.status(400).json({ error: 'Invalid result.' });
  }

  const tx = db.transaction(() => {
    db.prepare(
      `INSERT INTO games (slug, name, category, max_players, supports_multiplayer)
       VALUES (?, ?, ?, ?, 0)
       ON CONFLICT(slug) DO NOTHING`,
    ).run(def.slug, def.name, def.category, def.maxPlayers);

    const gameRow = db.prepare('SELECT id FROM games WHERE slug = ?').get(def.slug);

    const matchRes = db.prepare(
      `INSERT INTO matches (game_id, ended_at, status)
       VALUES (?, datetime('now'), 'completed')`,
    ).run(gameRow.id);
    const matchId = matchRes.lastInsertRowid;

    db.prepare(
      `INSERT INTO match_players (match_id, user_id, seat, result, score)
       VALUES (?, ?, 0, ?, ?)`,
    ).run(matchId, req.user.id, result, Math.round(score));

    return matchId;
  });

  try {
    const matchId = tx();
    res.json({ matchId });
  } catch (err) {
    console.error('[history/single-player]', err);
    res.status(500).json({ error: 'Failed to record match.' });
  }
});

export default router;