feat: add conversational RollCalc assistant

tests/test_conversation_api.py

@@ -0,0 +1,112 @@
+import base64
+import os
+import tempfile
+import unittest
+
+import app as rollcalc_app
+from conversation_service import ConversationService, InMemoryConversationStore
+from ollama_nlu import NLUResponse, OllamaUnavailableError, validate_nlu_payload
+
+
+class StaticNLUClient:
+    def __init__(self, payload):
+        self.payload = payload
+
+    def interpret(
+        self,
+        message,
+        *,
+        has_state=False,
+        expected_fields=(),
+        current_state=None,
+    ):
+        if isinstance(self.payload, Exception):
+            raise self.payload
+        return NLUResponse(
+            interpretation=validate_nlu_payload(self.payload),
+            raw_model_json="raw-json",
+            latency_ms=1.0,
+            model="test-model",
+        )
+
+
+class ConversationApiTests(unittest.TestCase):
+    def setUp(self):
+        self.temp_dir = tempfile.TemporaryDirectory()
+        self.original_log_file = rollcalc_app.LOG_FILE
+        self.original_service = rollcalc_app.CONVERSATION_SERVICE
+        rollcalc_app.LOG_FILE = os.path.join(self.temp_dir.name, "access.json")
+        rollcalc_app.app.config.update(TESTING=True)
+        self.client = rollcalc_app.app.test_client()
+        credentials = base64.b64encode(b"mtazl:rollcalc").decode("ascii")
+        self.headers = {"Authorization": f"Basic {credentials}"}
+
+    def tearDown(self):
+        rollcalc_app.LOG_FILE = self.original_log_file
+        rollcalc_app.CONVERSATION_SERVICE = self.original_service
+        self.temp_dir.cleanup()
+
+    def configure(self, payload):
+        rollcalc_app.CONVERSATION_SERVICE = ConversationService(
+            StaticNLUClient(payload),
+            store=InMemoryConversationStore(),
+            build_info=rollcalc_app.BUILD_INFO,
+        )
+
+    def create_conversation(self):
+        response = self.client.post("/api/conversations", headers=self.headers)
+        self.assertEqual(response.status_code, 201)
+        return response.get_json()["conversation_id"]
+
+    def test_conversation_success_exposes_authoritative_pdf(self):
+        self.configure({
+            "intent": "new_calculation",
+            "article_number": "180205",
+            "article_name_hint": "Bentofix NSP 4900",
+            "roll_length_m": 65.0,
+            "width_m": None,
+            "core_type": "150mm PVC",
+            "core_diameter_mm": None,
+            "include_roll_weight": False,
+        })
+        conversation_id = self.create_conversation()
+        response = self.client.post(
+            f"/api/conversations/{conversation_id}/messages",
+            json={"message": "Berechnen"},
+            headers=self.headers,
+        )
+        payload = response.get_json()
+
+        self.assertEqual(response.status_code, 200)
+        self.assertEqual(payload["status"], "success")
+        self.assertEqual(
+            payload["result"]["provenance"]["calculator"],
+            "roll_calculation.calculate_roll",
+        )
+
+        pdf = self.client.get(payload["pdf"]["url"], headers=self.headers)
+        self.assertEqual(pdf.status_code, 200)
+        self.assertEqual(pdf.mimetype, "application/pdf")
+        self.assertEqual(pdf.data.count(b"/Type /Page "), 1)
+        calculation = payload["result"]["calculation"]
+        self.assertIn(
+            f"{calculation['average_diameter_mm']:.1f} mm".encode("ascii"),
+            pdf.data,
+        )
+
+    def test_ollama_unavailable_returns_controlled_http_error(self):
+        self.configure(OllamaUnavailableError("offline"))
+        conversation_id = self.create_conversation()
+
+        response = self.client.post(
+            f"/api/conversations/{conversation_id}/messages",
+            json={"message": "Berechnen"},
+            headers=self.headers,
+        )
+
+        self.assertEqual(response.status_code, 503)
+        self.assertEqual(response.get_json()["status"], "nlu_error")
+
+
+if __name__ == "__main__":
+    unittest.main()