feat: implementa webapp FastAPI con API swagger e test

tests/test_api.py

@@ -0,0 +1,79 @@
+import tempfile
+import time
+from pathlib import Path
+
+from fastapi.testclient import TestClient
+
+from app import Settings, create_app
+
+
+def build_settings(db_path: str) -> Settings:
+    return Settings(
+        db_host="localhost",
+        db_port=5432,
+        db_name="postgres",
+        db_user="user",
+        db_password="password",
+        ping_query="SELECT 1;",
+        ping_interval_minutes=30,
+        web_host="0.0.0.0",
+        web_port=8080,
+        rrd_db_path=db_path,
+        rrd_retention_hours=48,
+    )
+
+
+def test_swagger_and_openapi_available():
+    with tempfile.TemporaryDirectory() as tmp:
+        db_path = str(Path(tmp) / "rrd.sqlite3")
+        app = create_app(config_override=build_settings(db_path), start_collector=False)
+
+        with TestClient(app) as client:
+            docs = client.get("/docs")
+            assert docs.status_code == 200
+            assert "Swagger UI" in docs.text
+
+            openapi = client.get("/openapi.json")
+            assert openapi.status_code == 200
+            payload = openapi.json()
+            assert "/api/history" in payload["paths"]
+            assert "/api/status" in payload["paths"]
+
+
+def test_history_api_window_and_ring_buffer():
+    with tempfile.TemporaryDirectory() as tmp:
+        db_path = str(Path(tmp) / "rrd.sqlite3")
+        settings = build_settings(db_path)
+        app = create_app(config_override=settings, start_collector=False)
+
+        with TestClient(app) as client:
+            store = app.state.store
+            now_ts = int(time.time())
+            for idx in range(settings.max_samples + 5):
+                store.add_sample(
+                    ts=now_ts - (settings.max_samples + 5) + idx,
+                    success=(idx % 2 == 0),
+                    latency_ms=float(idx),
+                    error_message=None if idx % 2 == 0 else "error",
+                )
+
+            history = client.get("/api/history", params={"hours": 48})
+            assert history.status_code == 200
+            payload = history.json()
+            assert payload["count"] == settings.max_samples
+
+            invalid = client.get("/api/history", params={"hours": 49})
+            assert invalid.status_code == 422
+
+
+def test_status_api_when_no_samples():
+    with tempfile.TemporaryDirectory() as tmp:
+        db_path = str(Path(tmp) / "rrd.sqlite3")
+        app = create_app(config_override=build_settings(db_path), start_collector=False)
+
+        with TestClient(app) as client:
+            status = client.get("/api/status")
+            assert status.status_code == 200
+            payload = status.json()
+            assert payload["success"] is None
+            assert payload["timestamp"] is None