/*
 * Copyright 2017-2020 original 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.
 */
package io.micronaut.reactive.rxjava2;

import io.micronaut.core.annotation.Internal;
import io.micronaut.scheduling.instrument.Instrumentation;
import io.micronaut.scheduling.instrument.InvocationInstrumenter;
import io.reactivex.parallel.ParallelFlowable;
import org.reactivestreams.Subscriber;

Inspired by code in Brave. Provides general instrumentation abstraction for RxJava2.
See https://github.com/openzipkin/brave/tree/master/context/rxjava2/src/main/java/brave/context/rxjava2/internal.
Author:
graemerocher
Type parameters:
<T> – The type
Since:
1.1/**
 * Inspired by code in Brave. Provides general instrumentation abstraction for RxJava2.
 * See https://github.com/openzipkin/brave/tree/master/context/rxjava2/src/main/java/brave/context/rxjava2/internal.
 *
 * @param <T> The type
 * @author graemerocher
 * @since 1.1
 */
@Internal
final class RxInstrumentedParallelFlowable<T> extends ParallelFlowable<T> implements RxInstrumentedComponent {
    protected final ParallelFlowable<T> source;
    private final RxInstrumenterFactory instrumenterFactory;
    private final InvocationInstrumenter instrumenter;

    
Default constructor.
Params:
source –              The source
instrumenterFactory – The instrumenterFactory/**
     * Default constructor.
     *
     * @param source              The source
     * @param instrumenterFactory The instrumenterFactory
     */
    RxInstrumentedParallelFlowable(ParallelFlowable<T> source, RxInstrumenterFactory instrumenterFactory) {
        this.source = source;
        this.instrumenterFactory = instrumenterFactory;
        this.instrumenter = instrumenterFactory.create();
    }

    @Override
    public int parallelism() {
        return source.parallelism();
    }

    @Override
    public void subscribe(Subscriber<? super T>[] s) {
        if (!validate(s)) {
            return;
        }
        InvocationInstrumenter instrumenter = this.instrumenter;
        if (instrumenter == null) {
            source.subscribe(s);
            return;
        }
        int n = s.length;
        @SuppressWarnings("unchecked")
        Subscriber<? super T>[] parents = new Subscriber[n];
        for (int i = 0; i < n; i++) {
            Subscriber<? super T> z = s[i];
            parents[i] = RxInstrumentedWrappers.wrap(z, instrumenterFactory);
        }
        try (Instrumentation ignored = instrumenter.newInstrumentation()) {
            source.subscribe(parents);
        }
    }
}