Update app.py

app.py

@@ -766,49 +766,75 @@ def handle_get_speaking_sentence(data):
     Frame 5: Return a sentence for the user to repeat aloud.
     The reference_text field is ready to pass directly to assess_pronunciation.
 
-    Emit:     { "grammar_rule": "copula", "difficulty": 1, "exclude_ids": ["0"] }
+    Emit:     { "grammar_rule": "copula", "exclude_ids": ["0", "2"] }
     Response: { "grammar_rule", "sentence": {korean, english, difficulty},
                 "sentence_index", "total_sentences",
                 "instruction", "reference_text" }
+
+    NOTE: difficulty is intentionally NOT used as a filter here.
+    All sentences for the rule are pooled and sorted by difficulty ascending,
+    so easier sentences come first naturally. Filtering by difficulty caused
+    the pool to collapse to 1-2 sentences, making repeats unavoidable.
+    Use exclude_ids to track which sentences have been shown this session.
+    The server cycles back to the full pool once all sentences are excluded.
     """
     grammar_rule = (data or {}).get("grammar_rule", "")
-    difficulty   = (data or {}).get("difficulty", None)
+    # difficulty param accepted but NOT used as a hard filter — see docstring
     exclude_ids  = set(str(i) for i in (data or {}).get("exclude_ids", []))
+
     if not grammar_rule:
         emit('speaking_sentence', {"error": "grammar_rule is required"})
         return
 
-    logger.info(f"🗣️  Speaking sentence: rule={grammar_rule} diff={difficulty}")
-    sentences = get_speaking_sentences(grammar_rule, difficulty=difficulty)
+    logger.info(f"🗣️  Speaking sentence: rule={grammar_rule} exclude={sorted(exclude_ids)}")
+
+    # Always fetch full pool — sorted by difficulty so easier sentences come first
+    sentences = get_speaking_sentences(grammar_rule, difficulty=None)
+    sentences = sorted(sentences, key=lambda s: s.get("difficulty", 1))
 
     if not sentences:
+        # Last-resort fallback: use example sentences
         examples = get_example_sentences(grammar_rule)
         if examples:
-            first = examples[0]["positive"]
+            # Cycle through examples using exclude_ids too
+            available_ex = [(i, ex) for i, ex in enumerate(examples)
+                            if f"ex_{i}" not in exclude_ids]
+            if not available_ex:
+                available_ex = list(enumerate(examples))
+            import random
+            ex_idx, ex = random.choice(available_ex)
+            first = ex["positive"]
+            logger.warning(f"⚠️  No speaking sentences for {grammar_rule} — using example fallback ex_{ex_idx}")
             emit('speaking_sentence', {
-                "grammar_rule": grammar_rule,
-                "sentence": {"korean": first["korean"], "english": first["english"], "difficulty": 1},
-                "sentence_index": "ex_0", "total_sentences": len(examples),
-                "instruction": "듣고 따라 말해 보세요! Listen and repeat.",
-                "reference_text": first["korean"],
+                "grammar_rule":    grammar_rule,
+                "sentence":        {"korean": first["korean"], "english": first["english"], "difficulty": 1},
+                "sentence_index":  f"ex_{ex_idx}",
+                "total_sentences": len(examples),
+                "instruction":     "듣고 따라 말해 보세요! Listen and repeat.",
+                "reference_text":  first["korean"],
             })
             return
         emit('speaking_sentence', {"error": f"No speaking sentences for rule: {grammar_rule}"})
         return
 
-    import random
+    # Select next unshown sentence; wrap around once all are exhausted
     available = [(i, s) for i, s in enumerate(sentences) if str(i) not in exclude_ids]
     if not available:
+        logger.info(f"🗣️  All {len(sentences)} sentences shown — cycling back to start")
         available = list(enumerate(sentences))
+
+    import random
     idx, sentence = random.choice(available)
+    logger.info(f"🗣️  Serving sentence_index={idx} '{sentence['korean'][:20]}...' "
+                f"(pool={len(sentences)}, available={len(available)})")
 
     emit('speaking_sentence', {
-        "grammar_rule": grammar_rule,
-        "sentence": sentence,
-        "sentence_index": str(idx),
+        "grammar_rule":    grammar_rule,
+        "sentence":        sentence,
+        "sentence_index":  str(idx),
         "total_sentences": len(sentences),
-        "instruction": "듣고 따라 말해 보세요! Listen and repeat.",
-        "reference_text": sentence["korean"],
+        "instruction":     "듣고 따라 말해 보세요! Listen and repeat.",
+        "reference_text":  sentence["korean"],
     })