def _make_set_with_subclass(client, name="Enemy", sub_name="Bat"):
    set_id = client.post("/sets", json={"name": name}).json()["id"]
    main_class_id = client.post(f"/sets/{set_id}/main-classes", json={"name": name}).json()["id"]
    sub_class_id = client.post(f"/main-classes/{main_class_id}/sub-classes", json={"name": sub_name}).json()["id"]
    return set_id, sub_class_id


def _make_frame(client, session_name="run01", frame_index=0):
    payload = {"session_name": session_name, "frame_index": frame_index, "image_path": "x.png", "width": 1280, "height": 720}
    return client.post("/frames", json=payload).json()["id"]


def _make_reviewed_frame_with_label(client, set_id, sub_class_id, frame_index):
    frame_id = _make_frame(client, frame_index=frame_index)
    client.post(
        f"/frames/{frame_id}/sets/{set_id}/labels",
        json={"sub_class_id": sub_class_id, "x": 1, "y": 2, "width": 3, "height": 4},
    )
    client.put(f"/frames/{frame_id}/sets/{set_id}/status", json={"status": "reviewed"})
    return frame_id


def test_promote_defaults_to_reviewed_frames(client):
    set_id, sub_class_id = _make_set_with_subclass(client)
    reviewed_frame = _make_reviewed_frame_with_label(client, set_id, sub_class_id, frame_index=0)
    _make_frame(client, frame_index=1)  # stays unlabeled, should not be promoted

    resp = client.post(f"/sets/{set_id}/dataset-versions", json={"name": "v1"})
    assert resp.status_code == 201
    assert resp.json()["frame_count"] == 1

    detail = client.get(f"/dataset-versions/{resp.json()['id']}").json()
    assert [f["frame"]["id"] for f in detail["frames"]] == [reviewed_frame]
    assert detail["frames"][0]["labels"][0]["sub_class_id"] == sub_class_id


def test_promote_rejects_duplicate_name(client):
    set_id, sub_class_id = _make_set_with_subclass(client)
    _make_reviewed_frame_with_label(client, set_id, sub_class_id, frame_index=0)

    client.post(f"/sets/{set_id}/dataset-versions", json={"name": "v1"})
    resp = client.post(f"/sets/{set_id}/dataset-versions", json={"name": "v1"})
    assert resp.status_code == 409


def test_promote_rejects_empty_selection(client):
    set_id, _ = _make_set_with_subclass(client)
    resp = client.post(f"/sets/{set_id}/dataset-versions", json={"name": "v1"})
    assert resp.status_code == 422


def test_promote_with_explicit_frame_ids(client):
    set_id, sub_class_id = _make_set_with_subclass(client)
    frame_id = _make_frame(client, frame_index=0)  # not reviewed, but explicitly selected
    client.post(
        f"/frames/{frame_id}/sets/{set_id}/labels",
        json={"sub_class_id": sub_class_id, "x": 0, "y": 0, "width": 1, "height": 1},
    )

    resp = client.post(f"/sets/{set_id}/dataset-versions", json={"name": "v1", "frame_ids": [frame_id]})
    assert resp.status_code == 201
    assert resp.json()["frame_count"] == 1


def test_promote_rejects_unknown_frame_ids(client):
    set_id, _ = _make_set_with_subclass(client)
    resp = client.post(f"/sets/{set_id}/dataset-versions", json={"name": "v1", "frame_ids": [999]})
    assert resp.status_code == 422


def test_promote_requires_existing_set(client):
    resp = client.post("/sets/999/dataset-versions", json={"name": "v1"})
    assert resp.status_code == 404


def test_dataset_version_is_frozen_after_label_edits(client):
    set_id, sub_class_id = _make_set_with_subclass(client)
    frame_id = _make_reviewed_frame_with_label(client, set_id, sub_class_id, frame_index=0)

    version_id = client.post(f"/sets/{set_id}/dataset-versions", json={"name": "v1"}).json()["id"]
    original_labels = client.get(f"/dataset-versions/{version_id}").json()["frames"][0]["labels"]
    assert original_labels[0]["x"] == 1

    # edit the live label after promotion
    label_id = client.get(f"/frames/{frame_id}/sets/{set_id}/labels").json()[0]["id"]
    client.patch(f"/labels/{label_id}", json={"x": 999})

    # the promoted snapshot must be unaffected
    frozen_labels = client.get(f"/dataset-versions/{version_id}").json()["frames"][0]["labels"]
    assert frozen_labels[0]["x"] == 1

    # deleting the live label must not touch the snapshot either
    client.delete(f"/labels/{label_id}")
    frozen_labels_after_delete = client.get(f"/dataset-versions/{version_id}").json()["frames"][0]["labels"]
    assert len(frozen_labels_after_delete) == 1


def test_list_dataset_versions(client):
    set_id, sub_class_id = _make_set_with_subclass(client)
    _make_reviewed_frame_with_label(client, set_id, sub_class_id, frame_index=0)
    client.post(f"/sets/{set_id}/dataset-versions", json={"name": "v1"})

    resp = client.get(f"/sets/{set_id}/dataset-versions")
    assert resp.status_code == 200
    assert [v["name"] for v in resp.json()] == ["v1"]
    assert resp.json()[0]["frame_count"] == 1


def test_get_missing_dataset_version(client):
    resp = client.get("/dataset-versions/999")
    assert resp.status_code == 404