from __future__ import annotations

import io
import json
from pathlib import Path

from cosma_log_analyzer.bus import StdoutPublisher
from cosma_log_analyzer.main import analyze_mcap, emit


EXPECTED_RULES = {
    "imu_outliers",
    "watchdog_imu",
    "usbl_snr_low",
    "usbl_distance_spike",
    "battery_low",
}


def test_analyze_fake_mcap_produces_all_rule_types(fake_mcap: Path) -> None:
    anomalies = analyze_mcap(fake_mcap, subject="AUV206")
    fired = {a.rule for a in anomalies}
    assert EXPECTED_RULES <= fired, f"missing rules: {EXPECTED_RULES - fired}"


def test_analyze_fake_mcap_subject_propagated(fake_mcap: Path) -> None:
    anomalies = analyze_mcap(fake_mcap, subject="AUV206")
    assert anomalies
    assert all(a.subject == "AUV206" for a in anomalies)


def test_watchdog_detects_the_gap(fake_mcap: Path) -> None:
    anomalies = analyze_mcap(fake_mcap, subject="AUV206")
    watchdog = [a for a in anomalies if a.rule == "watchdog_imu"]
    # The fixture inserts exactly one 3s gap.
    assert len(watchdog) == 1
    assert watchdog[0].context["gap_s"] > 2.9


def test_battery_low_fires_once(fake_mcap: Path) -> None:
    anomalies = analyze_mcap(fake_mcap, subject="AUV206")
    bat = [a for a in anomalies if a.rule == "battery_low"]
    assert len(bat) == 1
    assert bat[0].severity == "critical"
    assert bat[0].value < 13.5


def test_usbl_distance_spike_fires_once(fake_mcap: Path) -> None:
    anomalies = analyze_mcap(fake_mcap, subject="AUV206")
    spikes = [a for a in anomalies if a.rule == "usbl_distance_spike"]
    assert len(spikes) == 1
    assert spikes[0].context["delta_m"] > 50.0


def test_usbl_snr_low_fires(fake_mcap: Path) -> None:
    anomalies = analyze_mcap(fake_mcap, subject="AUV206")
    snr = [a for a in anomalies if a.rule == "usbl_snr_low"]
    assert len(snr) >= 1
    assert all(a.value < 5.0 for a in snr)


def test_stdout_publisher_emits_json_lines(fake_mcap: Path) -> None:
    anomalies = analyze_mcap(fake_mcap, subject="AUV206")
    buf = io.StringIO()
    publisher = StdoutPublisher(stream=buf)
    n = emit(anomalies, publisher)
    publisher.close()
    lines = [ln for ln in buf.getvalue().splitlines() if ln]
    assert n == len(lines) == len(anomalies)
    for line in lines:
        obj = json.loads(line)
        assert obj["subject"] == "AUV206"
        assert obj["rule"] in EXPECTED_RULES