"""Tests for Prometheus metrics utilities."""
import pytest
from prometheus_client import CollectorRegistry


def make_metrics(service_name="test-service", registry=None):
    from shared.metrics import ServiceMetrics
    return ServiceMetrics(service_name, registry=registry)


def test_metrics_creates_with_prefix():
    """ServiceMetrics stores sanitized service name prefix."""
    registry = CollectorRegistry()
    m = make_metrics("my-service", registry=registry)
    assert m.service_name == "my_service"


def test_errors_total_increment():
    """errors_total counter can be incremented with labels."""
    registry = CollectorRegistry()
    m = make_metrics("test-svc", registry=registry)
    m.errors_total.labels(service="test_svc", error_type="timeout").inc()
    assert m.errors_total.labels(service="test_svc", error_type="timeout")._value.get() == 1.0


def test_events_processed_increment():
    """events_processed counter can be incremented with labels."""
    registry = CollectorRegistry()
    m = make_metrics("test-svc", registry=registry)
    m.events_processed.labels(service="test_svc", event_type="candle").inc(5)
    assert m.events_processed.labels(service="test_svc", event_type="candle")._value.get() == 5.0


def test_processing_seconds_observe():
    """processing_seconds histogram can observe values."""
    registry = CollectorRegistry()
    m = make_metrics("test-svc", registry=registry)
    m.processing_seconds.labels(service="test_svc").observe(0.5)
    m.processing_seconds.labels(service="test_svc").observe(1.5)
    # Sum should be 2.0
    assert m.processing_seconds.labels(service="test_svc")._sum.get() == 2.0


def test_service_up_gauge():
    """service_up gauge can be set."""
    registry = CollectorRegistry()
    m = make_metrics("test-svc", registry=registry)
    m.service_up.labels(service="test_svc").set(1)
    assert m.service_up.labels(service="test_svc")._value.get() == 1.0
    m.service_up.labels(service="test_svc").set(0)
    assert m.service_up.labels(service="test_svc")._value.get() == 0.0