/*
 * Copyright The OpenTelemetry Authors
 *
 * 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
 *
 *      https://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.
 */

import { SpanProcessor } from './SpanProcessor';
import { ReadableSpan } from './export/ReadableSpan';

/**
 * Implementation of the {@link SpanProcessor} that simply forwards all
 * received events to a list of {@link SpanProcessor}s.
 */
export class MultiSpanProcessor implements SpanProcessor {
  constructor(private readonly _spanProcessors: SpanProcessor[]) {}

  forceFlush(cb: () => void = () => {}): void {
    let finished = 0;
    const total = this._spanProcessors.length;
    for (const spanProcessor of this._spanProcessors) {
      spanProcessor.forceFlush(() => {
        if (++finished === total) {
          cb();
        }
      });
    }
  }

  onStart(span: ReadableSpan): void {
    for (const spanProcessor of this._spanProcessors) {
      spanProcessor.onStart(span);
    }
  }

  onEnd(span: ReadableSpan): void {
    for (const spanProcessor of this._spanProcessors) {
      spanProcessor.onEnd(span);
    }
  }

  shutdown(cb: () => void = () => {}): void {
    let finished = 0;
    const total = this._spanProcessors.length;
    for (const spanProcessor of this._spanProcessors) {
      spanProcessor.shutdown(() => {
        if (++finished === total) {
          cb();
        }
      });
    }
  }
}
