// Licensed to the Apache Software Foundation (ASF) under one
// or more contributor license agreements.  See the NOTICE file
// distributed with this work for additional information
// regarding copyright ownership.  The ASF licenses this file
// to you 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 utils

import "sync"

type ParallelExecutor struct {
	wg sync.WaitGroup

	errorsLock sync.Mutex
	errors     []error
}

func (exec *ParallelExecutor) Add(handler func()) {
	exec.wg.Add(1)
	go func() {
		defer exec.wg.Done()
		handler()
	}()
}

func (exec *ParallelExecutor) AddE(handler func() error) {
	exec.wg.Add(1)
	go func() {
		defer exec.wg.Done()
		err := handler()
		if err != nil {
			exec.errorsLock.Lock()
			defer exec.errorsLock.Unlock()
			exec.errors = append(exec.errors, err)
		}
	}()
}

func (exec *ParallelExecutor) Wait() {
	exec.wg.Wait()
}

func (exec *ParallelExecutor) Errors() []error {
	return exec.errors
}
