"""Unit tests for the passive circuit breaker (circuit_breaker.py).

Offline, no network. Drive the pure get/record/clear logic directly. time.time
is monkeypatched so cooldown expiry is deterministic (no wall-clock dependence).
"""

from __future__ import annotations

import pytest

import circuit_breaker
from verification import verify_response


@pytest.fixture(autouse=True)
def _clean_circuit():
    circuit_breaker.clear()
    yield
    circuit_breaker.clear()


def _freeze(monkeypatch, t: float):
    monkeypatch.setattr(circuit_breaker.time, "time", lambda: t)


def test_is_down_miss_returns_false():
    assert circuit_breaker.is_down("m1", "p1", now=1000.0) is False


def test_first_failure_sets_initial_cooldown(monkeypatch):
    _freeze(monkeypatch, 1000.0)
    circuit_breaker.record_failure("m1", "p1", 30.0, 600.0, 2.0)
    # Within the cooldown window it's down.
    assert circuit_breaker.is_down("m1", "p1", now=1000.0) is True
    # Just past the window it is not down (passive recovery probe).
    assert circuit_breaker.is_down("m1", "p1", now=1000.0 + 30.0) is False


def test_second_consecutive_failure_doubles_cooldown(monkeypatch):
    _freeze(monkeypatch, 1000.0)
    circuit_breaker.record_failure("m1", "p1", 30.0, 600.0, 2.0)
    _freeze(monkeypatch, 1000.0 + 100.0)
    circuit_breaker.record_failure("m1", "p1", 30.0, 600.0, 2.0)
    # Second failure at t=1100: cooldown doubled to 60, down_until = 1160.
    assert circuit_breaker.is_down("m1", "p1", now=1159.0) is True
    assert circuit_breaker.is_down("m1", "p1", now=1160.0) is False


def test_cooldown_never_exceeds_max(monkeypatch):
    _freeze(monkeypatch, 1000.0)
    circuit_breaker.record_failure("m1", "p1", 10.0, 25.0, 2.0)  # -> 10
    _freeze(monkeypatch, 2000.0)
    circuit_breaker.record_failure("m1", "p1", 10.0, 25.0, 2.0)  # -> 20
    _freeze(monkeypatch, 3000.0)
    circuit_breaker.record_failure("m1", "p1", 10.0, 25.0, 2.0)  # -> capped 25
    _freeze(monkeypatch, 4000.0)
    circuit_breaker.record_failure("m1", "p1", 10.0, 25.0, 2.0)  # -> capped 25
    assert circuit_breaker.is_down("m1", "p1", now=4024.0) is True
    assert circuit_breaker.is_down("m1", "p1", now=4025.0) is False


def test_success_clears_and_next_failure_restarts_at_initial(monkeypatch):
    _freeze(monkeypatch, 1000.0)
    circuit_breaker.record_failure("m1", "p1", 30.0, 600.0, 2.0)
    _freeze(monkeypatch, 2000.0)
    circuit_breaker.record_failure("m1", "p1", 30.0, 600.0, 2.0)  # -> 60
    circuit_breaker.record_success("m1", "p1")
    assert circuit_breaker.is_down("m1", "p1", now=2000.0) is False
    _freeze(monkeypatch, 3000.0)
    circuit_breaker.record_failure("m1", "p1", 30.0, 600.0, 2.0)
    # Restarts at the INITIAL cooldown, not wherever backoff had climbed.
    assert circuit_breaker.is_down("m1", "p1", now=3029.0) is True
    assert circuit_breaker.is_down("m1", "p1", now=3030.0) is False


def test_state_is_keyed_by_model_and_provider(monkeypatch):
    _freeze(monkeypatch, 1000.0)
    circuit_breaker.record_failure("m1", "p1", 30.0, 600.0, 2.0)
    # Same model, different provider is unaffected.
    assert circuit_breaker.is_down("m1", "p2", now=1000.0) is False
    assert circuit_breaker.is_down("m1", "p1", now=1000.0) is True


def test_malformed_verdict_trips_breaker(monkeypatch):
    result = verify_response("", None, has_tool_calls=False)
    assert result.verdict == "malformed"
    _freeze(monkeypatch, 1000.0)
    circuit_breaker.record_failure("m1", "p1", 30.0, 600.0, 2.0)
    assert circuit_breaker.is_down("m1", "p1", now=1000.0) is True


def test_tool_call_empty_content_does_not_trip_breaker():
    result = verify_response("", None, has_tool_calls=True)
    assert result.verdict == "unverifiable"
    assert result.verdict != "malformed"


def test_ok_verdict_does_not_trip_breaker():
    result = verify_response(
        "```python\nprint('hello')\n```", None, has_tool_calls=False
    )
    assert result.verdict == "ok"
    assert result.verdict != "malformed"


def test_truncated_verdict_does_not_trip_breaker():
    result = verify_response("some text", "length", has_tool_calls=False)
    assert result.verdict == "truncated"
    assert result.verdict != "malformed"


def test_stream_cancelled_does_not_trip_breaker():
    """A client disconnect (GeneratorExit) must NOT record_failure.

    The streaming generator's finally block runs on disconnect. An interrupted
    stream verifies as 'malformed' (empty content), but that is a pipeline
    event, not a model fault. The stream_completed flag gates the breaker call.
    """
    # Simulate: verify_response on empty content returns malformed
    result = verify_response("", None, has_tool_calls=False)
    assert result.verdict == "malformed"

    # But stream_completed=False means the breaker should NOT be touched
    stream_completed = False
    if stream_completed:
        circuit_breaker.record_failure("m1", "p1", 30.0, 600.0, 2.0)
    assert circuit_breaker.is_down("m1", "p1", now=0.0) is False