Merge pull request #135 from udaykiran243/feat/issue-37-ai-caching

Implement AI response caching with SQLite backend

Author: chilkotiKartik

app.py

@@ -7,7 +7,7 @@
 import os
 from datetime import datetime
 from ai_service import generate_book_note, get_ai_recommendations, get_book_mood_tags_safe, generate_chat_response, llm_service
-from models import db, User, Book, ShelfItem, register_user, login_user
+from models import db, User, Book, ShelfItem, BookNote, register_user, login_user
 from collections import defaultdict, deque
 from math import ceil
 from time import time
@@ -260,7 +260,24 @@ def handle_generate_note():
         title = data.get('title', '')
         author = data.get('author', '')
 
+        # Check cache
+        cached_note = BookNote.query.filter_by(book_title=title, book_author=author).first()
+        if cached_note:
+            print(f"Cache hit for {title} by {author}")
+            return jsonify({"vibe": cached_note.content})
+        
         vibe = generate_book_note(description, title, author)
+        
+        # Save to cache
+        try:
+            if vibe and title and author: # Ensure we have valid data to cache
+                new_note = BookNote(book_title=title, book_author=author, content=vibe)
+                db.session.add(new_note)
+                db.session.commit()
+        except Exception as e:
+            print(f"Failed to cache note: {e}")
+            db.session.rollback()
+
         return jsonify({"vibe": vibe})
 
     except Exception as e:

models.py

@@ -68,6 +68,17 @@ def to_dict(self):
             "created_at": self.created_at.isoformat()
         }
 
+class BookNote(db.Model):
+    id = db.Column(db.Integer, primary_key=True)
+    book_title = db.Column(db.String(255), nullable=False)
+    book_author = db.Column(db.String(255), nullable=False)
+    content = db.Column(db.Text, nullable=False)
+    created_at = db.Column(db.DateTime, default=datetime.utcnow)
+
+    __table_args__ = (
+        db.Index('idx_book_note_title_author', 'book_title', 'book_author'),
+    )
+
 def register_user(username, email, password):
     user = User(username=username, email=email)
     user.set_password(password)