def test_list_topics_empty(client):
    resp = client.get("/api/topics")
    assert resp.status_code == 200
    assert resp.json()["topics"] == []


def test_create_topic(client):
    resp = client.post("/api/topics", json={"name": "Finance", "description": "Financial docs", "color": "#ff0000"})
    assert resp.status_code == 200
    data = resp.json()
    assert data["name"] == "Finance"
    assert data["color"] == "#ff0000"
    assert "id" in data


def test_create_topic_deduplication(client):
    client.post("/api/topics", json={"name": "Finance"})
    resp = client.post("/api/topics", json={"name": "finance"})  # case-insensitive
    assert resp.status_code == 200
    topics = client.get("/api/topics").json()["topics"]
    assert len(topics) == 1


def test_update_topic(client):
    create = client.post("/api/topics", json={"name": "Old Name"}).json()
    resp = client.patch(f"/api/topics/{create['id']}", json={"name": "New Name"})
    assert resp.status_code == 200
    assert resp.json()["name"] == "New Name"


def test_update_topic_not_found(client):
    resp = client.patch("/api/topics/nonexistent", json={"name": "X"})
    assert resp.status_code == 404


def test_delete_topic(client):
    create = client.post("/api/topics", json={"name": "ToDelete"}).json()
    resp = client.delete(f"/api/topics/{create['id']}")
    assert resp.status_code == 200
    assert resp.json()["success"] is True

    topics = client.get("/api/topics").json()["topics"]
    assert not any(t["name"] == "ToDelete" for t in topics)


def test_delete_topic_cascades_to_documents(client, sample_txt):
    # Create a topic
    topic = client.post("/api/topics", json={"name": "Legal"}).json()

    # Upload doc (no auto classify to control topics manually)
    with open(sample_txt, "rb") as f:
        upload = client.post(
            "/api/documents/upload",
            files={"file": ("sample.txt", f, "text/plain")},
            data={"auto_classify": "false"},
        ).json()

    # Manually set topic on the document via classify endpoint
    import services.storage as st
    st.update_document_topics(upload["id"], ["Legal"])

    # Delete topic
    client.delete(f"/api/topics/{topic['id']}")

    # Verify document no longer has the topic
    doc = client.get(f"/api/documents/{upload['id']}").json()
    assert "Legal" not in doc["topics"]


def test_delete_topic_not_found(client):
    resp = client.delete("/api/topics/nonexistent")
    assert resp.status_code == 404