step 6.1: wip (not ticked)

2026-10-21 00:42:56 +11:00
parent ae8ee02721
commit ffee0efc47
6 changed files with 810 additions and 15 deletions
@@ -0,0 +1,337 @@
+// Shop service: buy and sell items.
+// Sell value = 40% of buy_price (materials with buy_price=0 use rarity default).
+const { getDb } = require('../db');
+const { AppError } = require('../utils/errors');
+
+// Rarity defaults for materials (buy_price = 0).
+const MATERIAL_SELL_DEFAULTS = { common: 2, uncommon: 4, rare: 8, epic: 16, legendary: 32 };
+
+// Prepared statements cached per DB handle (WeakMap).
+const stmtCache = new WeakMap();
+
+function getStmts(db) {
+  let s = stmtCache.get(db);
+  if (!s) {
+    s = {
+      // Get purchasable items (buy_price > 0) where character level >= min_level.
+      stock: db.prepare(
+        `SELECT it.*,
+                CASE WHEN ? >= it.min_level THEN 1 ELSE 0 END AS levelOk
+         FROM items it
+         WHERE it.buy_price > 0 AND ? >= it.min_level
+         ORDER BY it.type, it.rarity, it.id`
+      ),
+
+      // Get all items where character level >= min_level (for stock display).
+      allStock: db.prepare(
+        `SELECT it.*,
+                CASE WHEN ? >= it.min_level THEN 1 ELSE 0 END AS levelOk
+         FROM items it
+         WHERE ? >= it.min_level
+         ORDER BY it.type, it.rarity, it.id`
+      ),
+
+      // Get item details by id.
+      itemById: db.prepare(
+        'SELECT * FROM items WHERE id = ?'
+      ),
+
+      // Get character profile.
+      character: db.prepare(
+        'SELECT * FROM characters WHERE id = ?'
+      ),
+
+      // Get inventory rows for a character + item (for selling).
+      inventoryRows: db.prepare(
+        'SELECT * FROM inventory WHERE character_id = ? AND item_id = ? AND quantity >= ?'
+      ),
+
+      // Update character gold.
+      updateGold: db.prepare(
+        'UPDATE characters SET gold = ? WHERE id = ?'
+      ),
+
+      // Add item to inventory (or increment quantity if stackable).
+      addToInventory: db.prepare(
+        'INSERT INTO inventory (character_id, item_id, quantity, equipped_slot, acquired_at) VALUES (?, ?, ?, NULL, ?)'
+      ),
+
+      // Increment quantity for stackable items.
+      incrementQty: db.prepare(
+        'UPDATE inventory SET quantity = quantity + ? WHERE character_id = ? AND item_id = ?'
+      ),
+
+      // Decrement inventory quantity.
+      decrementQty: db.prepare(
+        'UPDATE inventory SET quantity = quantity - ? WHERE id = ? AND quantity >= ?'
+      ),
+
+      // Delete inventory row when quantity reaches 0.
+      deleteRow: db.prepare(
+        'DELETE FROM inventory WHERE id = ? AND quantity = ?'
+      ),
+
+      // List all inventory items for a character.
+      listInventory: db.prepare(
+        `SELECT i.id AS inventory_id, i.item_id, i.quantity, i.equipped_slot, it.slug, it.name, it.type, it.rarity,
+                it.min_level, it.stackable,
+                it.bonus_str, it.bonus_agi, it.bonus_int, it.bonus_vit,
+                it.bonus_attack, it.bonus_defense, it.effect
+         FROM inventory i
+         JOIN items it ON it.id = i.item_id
+         WHERE i.character_id = ?
+         ORDER BY CASE i.equipped_slot WHEN 'weapon' THEN 0 WHEN 'armor' THEN 1 WHEN 'trinket' THEN 2 ELSE 3 END,
+                  CASE it.type WHEN 'weapon' THEN 0 WHEN 'armor' THEN 1 WHEN 'trinket' THEN 2 WHEN 'consumable' THEN 3 WHEN 'material' THEN 4 ELSE 5 END`
+      ),
+    };
+    stmtCache.set(db, s);
+  }
+  return s;
+}
+
+/**
+ * Get shop stock: items the character can buy + materials they can sell.
+ * @param {number} characterId
+ * @returns {object} { stock: [...], character: {...} }
+ */
+function getStock(characterId) {
+  const db = getDb();
+  const s = getStmts(db);
+
+  const ch = s.character.get(characterId);
+  if (!ch) throw new AppError('NOT_FOUND', 'Character not found.', 404);
+
+  const rows = s.allStock.all(ch.level, ch.level);
+
+  const stock = rows.map((row) => ({
+    itemId: row.id,
+    slug: row.slug,
+    name: row.name,
+    type: row.type,
+    rarity: row.rarity,
+    buyPrice: row.buy_price,
+    levelReq: row.min_level,
+    levelOk: row.levelOk === 1,
+    canAfford: ch.gold >= row.buy_price,
+    // For materials: calculate sell price.
+    sellPrice: row.buy_price > 0
+      ? Math.floor(row.buy_price * 0.4)
+      : Math.max(1, Math.floor((MATERIAL_SELL_DEFAULTS[row.rarity] || 2) * ch.level / row.min_level)),
+  }));
+
+  return {
+    stock,
+    character: {
+      id: ch.id,
+      name: ch.name,
+      class: ch.class,
+      level: ch.level,
+      gold: ch.gold,
+    },
+  };
+}
+
+/**
+ * Sell an inventory item back to the shop.
+ * @param {number} characterId
+ * @param {number} itemId
+ * @param {number} quantity
+ * @returns {object} { gold, inventory }
+ */
+function sellItem(characterId, itemId, quantity) {
+  const db = getDb();
+  const s = getStmts(db);
+
+  const ch = s.character.get(characterId);
+  if (!ch) throw new AppError('NOT_FOUND', 'Character not found.', 404);
+
+  const item = s.itemById.get(itemId);
+  if (!item) throw new AppError('NOT_FOUND', 'Item not found.', 404);
+
+  if (item.type !== 'material') {
+    throw new AppError('VALIDATION_ERROR', 'Only materials can be sold.', 400);
+  }
+
+  // Calculate sell price for this material.
+  let sellPrice;
+  if (item.buy_price > 0) {
+    sellPrice = Math.floor(item.buy_price * 0.4);
+  } else {
+    const defaultRate = MATERIAL_SELL_DEFAULTS[item.rarity] || 2;
+    sellPrice = Math.max(1, Math.floor(defaultRate * ch.level / item.min_level));
+  }
+
+  // Find inventory rows for this (character, item).
+  const rows = s.inventoryRows.all(characterId, itemId, 1);
+  if (rows.length === 0) {
+    throw new AppError('NOT_FOUND', 'Item not in inventory.', 404);
+  }
+
+  // Calculate how many we can actually sell from available rows.
+  let remaining = quantity;
+  const sales = []; // { rowId, qty, sellPrice }
+  for (const row of rows) {
+    if (remaining <= 0) break;
+    const qty = Math.min(remaining, row.quantity);
+    sales.push({ rowId: row.id, qty, sellPrice });
+    remaining -= qty;
+  }
+
+  if (remaining > 0) {
+    throw new AppError('VALIDATION_ERROR', `Only ${quantity - remaining} in inventory.`, 400);
+  }
+
+  const totalGold = sales.reduce((sum, sale) => sum + sale.sellPrice * sale.qty, 0);
+  const newGold = ch.gold + totalGold;
+
+  // Execute the sale inside a transaction.
+  const doSell = db.transaction((salesArr, newGoldVal, cid) => {
+    for (const sale of salesArr) {
+      if (sale.qty === 1) {
+        s.deleteRow.run(sale.rowId, 1);
+      } else {
+        s.decrementQty.run(sale.qty, sale.rowId, sale.qty);
+      }
+    }
+    s.updateGold.run(newGoldVal, cid);
+  });
+
+  doSell(sales, newGold, characterId);
+
+  // Return updated inventory listing.
+  return listInventory(characterId);
+}
+
+/**
+ * Buy an item from the shop.
+ * @param {number} characterId
+ * @param {number} itemId
+ * @param {number} quantity
+ * @returns {object} { gold, inventory }
+ */
+function buyItem(characterId, itemId, quantity) {
+  const db = getDb();
+  const s = getStmts(db);
+
+  const ch = s.character.get(characterId);
+  if (!ch) throw new AppError('NOT_FOUND', 'Character not found.', 404);
+
+  const item = s.itemById.get(itemId);
+  if (!item) throw new AppError('NOT_FOUND', 'Item not found.', 404);
+
+  if (item.buy_price <= 0) {
+    throw new AppError('VALIDATION_ERROR', 'This item cannot be bought.', 400);
+  }
+
+  if (ch.level < item.min_level) {
+    throw new AppError('LEVEL_TOO_LOW', `${item.name} requires level ${item.min_level}.`, 422);
+  }
+
+  const totalCost = item.buy_price * quantity;
+  if (ch.gold < totalCost) {
+    throw new AppError('INSUFFICIENT_GOLD', `Not enough gold. Need ${totalCost}, have ${ch.gold}.`, 422);
+  }
+
+  const newGold = ch.gold - totalCost;
+  const now = require('../utils/time').now();
+
+  // Execute the purchase inside a transaction.
+  const doBuy = db.transaction((cost, ng, cid, iid, qty, acquiredAt) => {
+    // Deduct gold.
+    s.updateGold.run(ng, cid);
+
+    // If stackable and already owned, increment quantity.
+    const existing = s.inventoryRows.get(cid, iid, 1);
+    if (existing && item.stackable) {
+      s.incrementQty.run(qty, cid, iid);
+    } else {
+      // New inventory entry.
+      s.addToInventory.run(cid, iid, qty, acquiredAt);
+    }
+  });
+
+  doBuy(totalCost, newGold, characterId, itemId, quantity, now);
+
+  // Return updated inventory listing.
+  return listInventory(characterId);
+}
+
+/**
+ * List all inventory items for a character (used after buy/sell).
+ * @param {number} characterId
+ * @returns {object} { items, character, derived }
+ */
+function listInventory(characterId) {
+  const db = getDb();
+  const s = getStmts(db);
+
+  const ch = s.character.get(characterId);
+  if (!ch) throw new AppError('NOT_FOUND', 'Character not found.', 404);
+
+  const rows = s.listInventory.all(characterId);
+
+  // Calculate current derived stats including equipment bonuses.
+  const equipBonuses = {
+    bonus_str: 0, bonus_agi: 0, bonus_int: 0, bonus_vit: 0,
+    bonus_attack: 0, bonus_defense: 0,
+  };
+  for (const row of rows) {
+    if (row.equipped_slot) {
+      equipBonuses.bonus_str += row.bonus_str || 0;
+      equipBonuses.bonus_agi += row.bonus_agi || 0;
+      equipBonuses.bonus_int += row.bonus_int || 0;
+      equipBonuses.bonus_vit += row.bonus_vit || 0;
+      equipBonuses.bonus_attack += row.bonus_attack || 0;
+      equipBonuses.bonus_defense += row.bonus_defense || 0;
+    }
+  }
+
+  const { calcDerived } = require('../game/stats');
+  const derived = calcDerived(
+    { str: ch.str, agi: ch.agi, int: ch.int, vit: ch.vit },
+    ch.level,
+    ch.class,
+    equipBonuses
+  );
+
+  const items = rows.map((row) => ({
+    itemId: row.item_id,
+    inventoryId: row.inventory_id,
+    slug: row.slug,
+    name: row.name,
+    type: row.type,
+    rarity: row.rarity,
+    quantity: row.quantity,
+    equipped: row.equipped_slot !== null,
+    equipped_slot: row.equipped_slot || null,
+    bonuses: {
+      bonus_str: row.bonus_str || 0,
+      bonus_agi: row.bonus_agi || 0,
+      bonus_int: row.bonus_int || 0,
+      bonus_vit: row.bonus_vit || 0,
+      bonus_attack: row.bonus_attack || 0,
+      bonus_defense: row.bonus_defense || 0,
+    },
+  }));
+
+  return {
+    character: {
+      id: ch.id,
+      name: ch.name,
+      class: ch.class,
+      level: ch.level,
+      gold: ch.gold,
+    },
+    items,
+    derived: {
+      maxHp: derived.maxHp,
+      attack: derived.attack,
+      defense: derived.defense,
+      speed: derived.speed,
+      critChance: derived.critChance,
+      critMult: derived.critMult,
+    },
+  };
+}
+
+module.exports = { getStock, buyItem, sellItem };