feat: item

- Add function for finding a random item spawn position

src/item.py

@@ -5,6 +5,35 @@ from src.settings import (
     COLOR_HP_BAR_YELLOW, COLOR_HP_BAR_BG
 )
 
+
+# try 50 times to find a free position to spawn item
+def _random_position(room_rect, blocked_rects):
+    attempts = 0
+    max_attempts = 50
+
+    while attempts < max_attempts:
+        # generate random x/y coordinates with room boundaries
+        # * 2 to have a margin to walls
+        x = random.randint(room_rect.left + ITEM_SIZE, room_rect.right - ITEM_SIZE * 2)
+        y = random.randint(room_rect.top + ITEM_SIZE, room_rect.bottom - ITEM_SIZE * 2)
+
+        # create a rect at this position for testing collision
+        test_rect = pygame.Rect(x, y, ITEM_SIZE, ITEM_SIZE)
+        blocked = False
+        for b in blocked_rects:
+            if test_rect.colliderect(b):
+                blocked = True
+                break
+
+        # if position is not blocked, return the position
+        if not blocked:
+            return x, y
+
+        attempts += 1
+        
+        # no spot after 50 attempts -> return
+    return None
+
 # remove expired items
 def update(self, room_rect, blocked_rects):
     now = pygame.time.get_ticks()