from datetime import datetime, timezone
from ipaddress import IPv4Address
from uuid import uuid4

from fastapi.testclient import TestClient
from prometheus_client import CONTENT_TYPE_LATEST

from core.domain.models import NormalizedCDR
from core.worker.observability.metrics import WorkerMetrics
from core.worker.observability.server import create_worker_observability_app
from core.worker.observability.stats import WorkerRuntimeStats


def create_sample_cdr() -> NormalizedCDR:
    now = datetime.now(timezone.utc)
    return NormalizedCDR(
        cdr_id=uuid4(),
        raw_id="raw-obs-1",
        msisdn="+19875551234",
        imsi="310410998877665",
        service_type="4G_DATA",
        radio_access_type="LTE_4G",
        cell_id="4021_8812",
        bytes_uploaded=100,
        bytes_downloaded=200,
        total_bytes=300,
        duration_seconds=300,
        session_start_time=now,
        session_end_time=now,
        source_ip=IPv4Address("10.240.12.1"),
    )


def test_worker_observability_health_endpoint() -> None:
    metrics = WorkerMetrics()
    stats = WorkerRuntimeStats()
    app = create_worker_observability_app(metrics=metrics, stats=stats)
    client = TestClient(app)

    response = client.get("/health")
    assert response.status_code == 200
    assert response.json() == {"status": "ok"}


def test_worker_observability_metrics_endpoint() -> None:
    metrics = WorkerMetrics()
    stats = WorkerRuntimeStats()
    app = create_worker_observability_app(metrics=metrics, stats=stats)
    client = TestClient(app)

    response = client.get("/metrics")
    assert response.status_code == 200
    assert CONTENT_TYPE_LATEST in response.headers["content-type"]
    assert "cdr_processed_total" in response.text
    assert "cdr_dlq_total" in response.text


def test_worker_observability_internal_stats_endpoint() -> None:
    metrics = WorkerMetrics()
    stats = WorkerRuntimeStats()
    app = create_worker_observability_app(metrics=metrics, stats=stats)
    client = TestClient(app)

    response = client.get("/internal/stats")
    assert response.status_code == 200
    body = response.json()
    assert "pipeline" in body
    assert "breakdown" in body
    assert body["pipeline"]["total_processed"] == 0
    assert body["pipeline"]["total_dlq"] == 0


def test_shared_instance_behavior_between_processing_and_observability() -> None:
    # Processing and observability must share the identical metrics and stats instances
    metrics = WorkerMetrics()
    stats = WorkerRuntimeStats()
    app = create_worker_observability_app(metrics=metrics, stats=stats)
    client = TestClient(app)

    # Simulate worker processing activity updating the instances
    cdr = create_sample_cdr()
    metrics.record_processed(cdr)
    stats.record_processed(cdr)

    metrics.record_dlq("invalid_rat_value")
    stats.record_dlq("invalid_rat_value")

    metrics.set_buffer_size(5)
    stats.set_buffer_size(5)

    # Verify that the observability server sees the exact same updates
    stats_response = client.get("/internal/stats")
    assert stats_response.status_code == 200
    stats_body = stats_response.json()

    assert stats_body["pipeline"]["total_processed"] == 1
    assert stats_body["pipeline"]["total_dlq"] == 1
    assert stats_body["pipeline"]["in_flight_buffer"] == 5
    assert stats_body["breakdown"]["by_service_type"]["4G_DATA"] == 1
    assert stats_body["breakdown"]["by_radio_access_type"]["LTE_4G"] == 1
    assert stats_body["breakdown"]["dlq_by_reason"]["invalid_rat_value"] == 1

    # Verify metrics endpoint output contains the recorded metrics
    metrics_response = client.get("/metrics")
    assert metrics_response.status_code == 200
    assert 'cdr_processed_total{radio_access_type="LTE_4G",service_type="4G_DATA"} 1.0' in metrics_response.text
    assert 'cdr_dlq_total{reason="invalid_rat_value"} 1.0' in metrics_response.text
    assert 'cdr_in_flight_buffer_size 5.0' in metrics_response.text