import logging
from jaeger_client import Config
from grpc_opentracing.grpcext import intercept_server
from grpc_opentracing import open_tracing_server_interceptor

from tracing import (Tracer,
        empty_server_interceptor_decorator)

logger = logging.getLogger(__name__)


class TracerFactory:
    @classmethod
    def new_tracer(cls, tracer_type, tracer_config, span_decorator=None, **kwargs):
        if not tracer_type:
            return Tracer()

        if tracer_type.lower() == 'jaeger':
            config = Config(config=tracer_config.TRACING_CONFIG,
                    service_name=tracer_config.TRACING_SERVICE_NAME,
                    validate=tracer_config.TRACING_VALIDATE
            )

            tracer = config.initialize_tracer()
            tracer_interceptor = open_tracing_server_interceptor(tracer,
                    log_payloads=tracer_config.TRACING_LOG_PAYLOAD,
                    span_decorator=span_decorator)

            return Tracer(tracer, tracer_interceptor, intercept_server)

        assert False, 'Unsupported tracer type: {}'.format(tracer_type)