/*
 * Copyright (c) 2019 Oracle and/or its affiliates. All rights reserved.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package io.helidon.tracing;

import java.util.Iterator;
import java.util.ServiceLoader;

import io.helidon.common.serviceloader.HelidonServiceLoader;
import io.helidon.tracing.spi.TracerProvider;

/**
 * Tracer provider helper to find implementation to use.
 */
final class TracerProviderHelper {
    private static final ServiceLoader<TracerProvider> SYSTEM_LOADER = ServiceLoader.load(TracerProvider.class);
    private static final HelidonServiceLoader<TracerProvider> SERVICE_LOADER = HelidonServiceLoader.create(SYSTEM_LOADER);

    private TracerProviderHelper() {
    }

    static TracerBuilder<?> findTracerBuilder() {
        Iterator<TracerProvider> iterator = SERVICE_LOADER.iterator();

        if (iterator.hasNext()) {
            return iterator.next().createBuilder();
        } else {
            return NoOpBuilder.create();
        }
    }
}
