"""
Настройка телеметрии OpenTelemetry.

Автор: Сергей Антропов
Сайт: https://devops.org.ru
"""
import logging
from opentelemetry import trace
from opentelemetry.sdk.resources import Resource, SERVICE_NAME
from opentelemetry.exporter.otlp.proto.http.trace_exporter import OTLPSpanExporter
from opentelemetry.sdk.trace import TracerProvider
from opentelemetry.sdk.trace.sampling import TraceIdRatioBased
from opentelemetry.sdk.trace.export import SimpleSpanProcessor
from opentelemetry.instrumentation.fastapi import FastAPIInstrumentor

logger = logging.getLogger(__name__)


def setup_telemetry():
    """
    Настройка провайдера телеметрии OpenTelemetry.
    
    Returns:
        TracerProvider: Провайдер трейсинга.
    """
    from app.core.config import settings
    
    resource = Resource(attributes={SERVICE_NAME: settings.otel_service_name})
    sampler = TraceIdRatioBased(1.0)  # 100% семплирование
    
    # Настройка экспортера OTLP
    exporter_config = {}
    if settings.otel_exporter_otlp_endpoint:
        exporter_config['endpoint'] = settings.otel_exporter_otlp_endpoint
    exporter_config['insecure'] = settings.otel_exporter_otlp_insecure
    
    exporter = OTLPSpanExporter(**exporter_config)
    
    provider = TracerProvider(sampler=sampler, resource=resource)
    processor = SimpleSpanProcessor(exporter)
    provider.add_span_processor(processor)
    trace.set_tracer_provider(provider)
    
    logger.info(f"Telemetry настроен для сервиса: {settings.otel_service_name}")
    return provider


def add(app):
    """
    Добавить инструментацию OpenTelemetry к приложению FastAPI.
    
    Args:
        app: Экземпляр приложения FastAPI.
    """
    from app.core.config import settings
    
    if settings.otel_enabled:
        try:
            tracer_provider = setup_telemetry()
            FastAPIInstrumentor.instrument_app(
                app,
                tracer_provider=tracer_provider,
                excluded_urls="/openapi.json,/docs,/redoc"
            )
            logger.info("OpenTelemetry инструментация добавлена")
        except Exception as e:
            logger.error(f"Ошибка настройки OpenTelemetry: {e}")
    else:
        logger.info("OpenTelemetry отключен")