"""What each node has emitted, kept so a reconnecting client is not reset.

The brain graph pulses a neuron per emission and tallies them in the browser.
Moving between the shell and the canvas tears the websocket down, and the bus
has no replay — so the count is kept here and handed back in the snapshot.
"""

from pathlib import Path

import pytest

from fluksio.api.routes.flows import snapshot_payload
from fluksio.flow.controller import FlowController
from fluksio.flow.events import EventBus, event_bus
from fluksio.flow.messages import DType, MessageSpec
from fluksio.flow.nodes import Node
from fluksio.flow.pipeline import Pipeline
from fluksio.flow.store import FlowStore


def make_node(node_id: str, f, provides=()) -> Node:
    node = Node(f=f, provides=list(provides), name=node_id)
    node.assign_flow("house", node_id)
    return node


def test_a_node_that_publishes_advances_its_own_count():
    bus = EventBus()
    node = make_node(
        "sensor",
        lambda params: {"temp": 21.0},
        provides=[MessageSpec(name="temp", dtype=DType.FLOAT)],
    )
    pipeline = Pipeline(nodes=[node], events=bus)

    pipeline.run()
    pipeline.run()

    # Keyed the way `brain_graph` names its members, which is what the graph
    # looks a count up by.
    assert bus.emits == {"house.sensor": 2}


def test_a_node_that_publishes_nothing_is_not_counted():
    """Ran, but emitted nothing — the same thing the canvas declines to pulse."""
    bus = EventBus()
    pipeline = Pipeline(nodes=[make_node("quiet", lambda params: None)], events=bus)

    pipeline.run()

    assert bus.emits == {}


def test_the_snapshot_carries_what_every_node_has_emitted(
    tmp_path: Path, monkeypatch: pytest.MonkeyPatch
):
    monkeypatch.setattr(event_bus, "emits", {"house.sensor": 3})
    controller = FlowController(FlowStore(tmp_path / "flows"))

    assert snapshot_payload(controller)["emits"] == {"house.sensor": 3}