"""PhaseTimer: per-phase mean/max, logged and reset every N samples."""

import logging

import pytest

from src.backend.services.phase_timing import PhaseStats, PhaseTimer, summary_line


def test_summary_line_mean_and_max_in_ms():
    line = summary_line("align", PhaseStats(count=4, total_s=0.2, max_s=0.08))
    assert line == "phase align: n=4 mean=50.0 ms max=80.0 ms"


def test_logs_and_resets_every_n_samples(caplog):
    timer = PhaseTimer(log_every=3)
    with caplog.at_level(logging.INFO, logger="src.backend.services.phase_timing"):
        for seconds in (0.010, 0.030, 0.020, 0.005):
            timer.record("wait_frames", seconds)
    lines = [r.getMessage() for r in caplog.records]
    assert lines == ["phase wait_frames: n=3 mean=20.0 ms max=30.0 ms"]


def test_phases_are_counted_separately(caplog):
    timer = PhaseTimer(log_every=2)
    with caplog.at_level(logging.INFO, logger="src.backend.services.phase_timing"):
        timer.record("a", 0.001)
        timer.record("b", 0.001)
        timer.record("a", 0.003)
    assert [r.getMessage() for r in caplog.records] == ["phase a: n=2 mean=2.0 ms max=3.0 ms"]


def test_zero_turns_it_off(caplog):
    timer = PhaseTimer(log_every=0)
    with caplog.at_level(logging.INFO, logger="src.backend.services.phase_timing"):
        for _ in range(5):
            timer.record("x", 0.001)
    assert caplog.records == []


def test_phase_records_even_when_the_block_raises():
    timer = PhaseTimer(log_every=1000)
    with pytest.raises(RuntimeError):
        with timer.phase("encode"):
            raise RuntimeError("boom")
    assert timer._stats["encode"].count == 1