add saveState management

main.py

@@ -10,6 +10,7 @@
 # =============================================================================
 
 from cmu_graphics import *
+import json
 
 
 # =============================================================================
@@ -44,19 +45,31 @@ def loadCreatures(path="creatures.tsv"):
     return creatures
 
 
-def loadSave(path):
+def loadSave(path="save.json"):
     # Load save.json and return the player's saved state (money, owned baits,
     # owned upgrades, current bait, caught log, etc.). If the file is missing
     # or unreadable, return a fresh default-state dict so a first-time player
     # starts cleanly. This is the only place that reads the save file.
-    pass
+    defaultState = {
+        "cash": 0,
+        "owned_baits": [],
+        "owned_upgrades": [],
+        "current_bait": "worm",
+        "catch_log": []
+    }
+    try:
+        with open(path, "r") as f:
+            return json.load(f)
+    except (FileNotFoundError, IOError):
+        return defaultState
 
 
-def writeSave(path, saveState):
+def writeSave(saveState, path="save.json"):
     # Serialize the current player state to save.json. Call this at key moments
     # (after a sale, after a purchase, on quit) so progress persists between
     # sessions. Keep the written structure identical to what loadSave expects.
-    pass
+    with open(path, "w") as f: #overwrite existing
+        f.write(json.dumps(saveState))
 
 
 # =============================================================================