"""
tests/unit/test_bottleneck.py

Unit tests for the BottleneckAlert dataclass.

TDD: Red phase — tests written before implementation.
"""
import pytest

from core.device.bottleneck import BottleneckAlert


class TestBottleneckAlert:
    def test_fields_accessible(self):
        alert = BottleneckAlert(
            stage_id="stage-1",
            queue_fill_rate=0.85,
            suggested_action="Add more Dongles to this stage",
            severity="warning",
        )
        assert alert.stage_id == "stage-1"
        assert alert.queue_fill_rate == 0.85
        assert alert.suggested_action == "Add more Dongles to this stage"
        assert alert.severity == "warning"

    def test_severity_critical(self):
        alert = BottleneckAlert(
            stage_id="stage-2",
            queue_fill_rate=0.95,
            suggested_action="Urgent: add Dongles",
            severity="critical",
        )
        assert alert.severity == "critical"

    def test_dataclass_equality(self):
        a = BottleneckAlert("s1", 0.9, "action", "warning")
        b = BottleneckAlert("s1", 0.9, "action", "warning")
        assert a == b

    def test_dataclass_inequality(self):
        a = BottleneckAlert("s1", 0.9, "action", "warning")
        b = BottleneckAlert("s1", 0.5, "action", "warning")
        assert a != b