/* ============================================================
   routes/bazaar.route.js
============================================================ */

const express = require("express");
const router = express.Router();
const db = require("../database/database");
const { getMaxRarity } = require("../utils/rarity");

function requireLogin(req, res, next) {
  if (!req.session?.user)
    return res.status(401).json({ error: "Nicht eingeloggt" });
  next();
}

/* ════════════════════════════════════════════
   GET /api/bazaar/cards?page=1&limit=18
════════════════════════════════════════════ */
router.get("/bazaar/cards", requireLogin, async (req, res) => {
  const userId = req.session.user.id;
  const page = parseInt(req.query.page) || 1;
  const limit = parseInt(req.query.limit) || 18;
  const offset = (page - 1) * limit;

  try {
    const [[account]] = await db.query(
      "SELECT level FROM accounts WHERE id = ?",
      [userId],
    );
    const maxRarity = getMaxRarity(account?.level ?? 1);

    const [cards] = await db.query(
      `SELECT
         c.id, c.name, c.image, c.rarity,
         c.attack, c.defends, c.cooldown, c.\`range\`, c.\`race\`,
         COALESCE(p.price_wood, 0) AS price_wood,
         COALESCE(p.price_iron, 0) AS price_iron,
         COALESCE(p.price_gold, 0) AS price_gold,
         COALESCE(p.price_gems, 0) AS price_gems
       FROM cards c
       LEFT JOIN card_shop_prices p ON p.rarity = c.rarity
       WHERE c.rarity <= ?
       ORDER BY c.rarity ASC, c.name ASC
       LIMIT ? OFFSET ?`,
      [maxRarity, limit, offset],
    );

    const [[{ total }]] = await db.query(
      "SELECT COUNT(*) AS total FROM cards WHERE rarity <= ?",
      [maxRarity],
    );

    const [[currency]] = await db.query(
      "SELECT wood, iron, gold, gems FROM account_currency WHERE account_id = ?",
      [userId],
    );

    res.json({
      cards,
      total,
      page,
      totalPages: Math.ceil(total / limit),
      wood: currency?.wood || 0,
      iron: currency?.iron || 0,
      gold: currency?.gold || 0,
      gems: currency?.gems || 0,
    });
  } catch (err) {
    console.error("[bazaar/cards]", err);
    res.status(500).json({ error: "DB Fehler" });
  }
});

/* ════════════════════════════════════════════
   POST /api/bazaar/buy  { card_id }
════════════════════════════════════════════ */
router.post("/bazaar/buy", requireLogin, async (req, res) => {
  const userId = req.session.user.id;
  const { card_id, quantity } = req.body;
  if (!card_id) return res.status(400).json({ error: "card_id fehlt." });
  const qty = Math.max(1, Math.min(99, parseInt(quantity) || 1));

  try {
    const [[card]] = await db.query(
      `SELECT c.id, c.name, c.rarity,
              COALESCE(p.price_wood, 0) AS price_wood,
              COALESCE(p.price_iron, 0) AS price_iron,
              COALESCE(p.price_gold, 0) AS price_gold,
              COALESCE(p.price_gems, 0) AS price_gems
       FROM cards c
       LEFT JOIN card_shop_prices p ON p.rarity = c.rarity
       WHERE c.id = ?`,
      [card_id],
    );
    if (!card) return res.status(404).json({ error: "Karte nicht gefunden." });

    const [[account]] = await db.query(
      "SELECT level FROM accounts WHERE id = ?",
      [userId],
    );
    if (parseInt(card.rarity) > getMaxRarity(account?.level ?? 1)) {
      return res
        .status(403)
        .json({ error: "Dein Level reicht für diese Karte nicht aus." });
    }

    const [[currency]] = await db.query(
      "SELECT wood, iron, gold, gems FROM account_currency WHERE account_id = ?",
      [userId],
    );
    if (!currency)
      return res.status(400).json({ error: "Keine Währungsdaten gefunden." });

    const checks = [
      { key: "wood", label: "Holz" },
      { key: "iron", label: "Eisen" },
      { key: "gold", label: "Gold" },
      { key: "gems", label: "Gems" },
    ];
    for (const { key, label } of checks) {
      const need = card[`price_${key}`] * qty;
      if (need > 0 && (currency[key] || 0) < need) {
        return res.status(400).json({
          error: `Nicht genug ${label}. Benötigt: ${need} (${qty}×), Vorhanden: ${currency[key] || 0}`,
        });
      }
    }

    await db.query(
      `UPDATE account_currency
       SET wood = wood - ?,
           iron = iron - ?,
           gold = gold - ?,
           gems = gems - ?
       WHERE account_id = ?`,
      [
        card.price_wood * qty,
        card.price_iron * qty,
        card.price_gold * qty,
        card.price_gems * qty,
        userId,
      ],
    );

    await db.query(
      `INSERT INTO user_cards (user_id, card_id, amount) VALUES (?, ?, ?)
       ON DUPLICATE KEY UPDATE amount = amount + ?`,
      [userId, card_id, qty, qty],
    );

    const [[updated]] = await db.query(
      "SELECT wood, iron, gold, gems FROM account_currency WHERE account_id = ?",
      [userId],
    );

    res.json({
      success: true,
      card: { id: card.id, name: card.name },
      wood: updated?.wood || 0,
      iron: updated?.iron || 0,
      gold: updated?.gold || 0,
      gems: updated?.gems || 0,
    });
  } catch (err) {
    console.error("[bazaar/buy]", err);
    res.status(500).json({ error: "DB Fehler" });
  }
});

module.exports = router;