"""Message history: the series a node panel draws as a sparkline."""

from fluksio.flow.messages import MessageSpec
from fluksio.flow.nodes import Node
from fluksio.flow.pipeline import Pipeline
from fluksio.flow.state import HISTORY_LIMIT, MemoryState


def emitter(values) -> Node:
    """A node publishing the given values, one per execution."""
    remaining = list(values)

    def process(params):
        return {"out": remaining.pop(0)}

    node = Node(f=process, requires=[], provides=[MessageSpec(name="out")], name="src")
    node.assign_flow("f", "src")
    return node


def test_the_series_follows_the_order_values_were_published():
    node = emitter([1.0, 2.0, 3.0])
    pipeline = Pipeline(nodes=[node])

    # An injecting node publishes directly, an executed one goes through the
    # executor; both paths land in the same series.
    node.inject()
    pipeline.run()
    pipeline.run()

    points = pipeline.state.history("f.out")
    assert [value for _, value in points] == [1.0, 2.0, 3.0]
    assert [ts for ts, _ in points] == sorted(ts for ts, _ in points)


def test_the_series_is_capped():
    state = MemoryState()
    for i in range(HISTORY_LIMIT + 20):
        state.append_history({"f.out": float(i)}, ts=float(i))

    points = state.history("f.out")
    assert len(points) == HISTORY_LIMIT
    # The oldest twenty fell off the end.
    assert points[0] == (20.0, 20.0)
    assert points[-1] == (139.0, 139.0)


def test_only_numbers_are_recorded():
    state = MemoryState()
    state.append_history({"f.text": "warm", "f.flag": True, "f.temp": 21}, ts=1.0)

    assert state.history("f.text") == []
    assert state.history("f.flag") == []
    assert state.history("f.temp") == [(1.0, 21.0)]


def test_a_message_without_history_comes_back_empty():
    assert MemoryState().history("f.never") == []