Add Shop system with ShopManager, ShopUI, and ShopSlotUI; implement item purchasing and shop UI functionality

Assets/Scripts/Shop/ShopManager.cs

@@ -0,0 +1,96 @@
+using System;
+using System.Collections.Generic;
+using Inventory;
+using Sirenix.Serialization;
+using Systems;
+using UnityEngine;
+using Random = UnityEngine.Random;
+
+namespace Shop
+{
+    public class ShopManager : MonoBehaviour
+    {
+        private List<StatModifierItem> currentItemChoices = new();
+        private List<WeaponItem> currentWeaponChoices = new();
+        
+        [SerializeField] private ShopUI shopUI;
+        [SerializeField] private InventoryManager inventoryManager;
+
+        [SerializeField] private int itemsPerShop = 4;
+        [OdinSerialize, SerializeField] private List<StatModifierItem> possibleItems = new();
+        [OdinSerialize, SerializeField] private List<WeaponItem> possibleWeapons = new();
+
+        private void OnEnable()
+        {
+            // GameManager.Instance.OnRoundEnd += OpenShop;
+            GameManager.Instance.OnStoreOpen += OpenShop;
+        }
+
+        private void OnDisable()
+        {
+            // GameManager.Instance.OnRoundEnd -= OpenShop;
+            GameManager.Instance.OnStoreOpen -= OpenShop;
+        }
+
+        public void CloseShop()
+        {
+            shopUI.Hide();
+            Time.timeScale = 1f;
+        }
+
+        public void BuyItem(StatModifierItem item, int price)
+        {
+            if (GameManager.Instance.Coins < price) return;
+            
+            GameManager.Instance.SpendCoins(price);
+            inventoryManager.EquipItem(item);
+            shopUI.MarkAsPurchased(item);
+        }
+        
+        public void BuyWeapon(WeaponItem weapon, int price)
+        {
+            if (GameManager.Instance.Coins < price) return;
+            
+            GameManager.Instance.SpendCoins(price);
+            inventoryManager.EquipWeapon(weapon);
+            shopUI.MarkAsPurchased(weapon);
+        }
+        
+        public void RerollShop()
+        {
+            currentItemChoices = DrawRandomItems(possibleItems, itemsPerShop);
+            currentWeaponChoices = DrawRandomItems(possibleWeapons, itemsPerShop);
+            
+            shopUI.Show(currentItemChoices, currentWeaponChoices, this);
+        }
+        
+        private void OpenShop()
+        {
+            OpenShop(GameManager.Instance.CurrentRound);
+        }
+
+        private void OpenShop(int round)
+        {
+            currentItemChoices = DrawRandomItems(possibleItems, itemsPerShop);
+            currentWeaponChoices = DrawRandomItems(possibleWeapons, itemsPerShop);
+            
+            shopUI.Show(currentItemChoices, currentWeaponChoices, this);
+            Time.timeScale = 0f;
+        }
+
+        private List<T> DrawRandomItems<T>(List<T> pool, int count)
+        {
+            var result = new List<T>();
+            var poolCopy = new List<T>(pool);
+
+            for (var i = 0; i < count && poolCopy.Count > 0; i++)
+            {
+                var idx = Random.Range(0, poolCopy.Count);
+                result.Add(poolCopy[idx]);
+                poolCopy.RemoveAt(idx);
+            }
+            
+            return result;
+        }
+    }
+}