/*
 * Copyright 2021 CloudWeGo 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
 *
 *     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"
	"sync/atomic"
	"testing"

	"github.com/cloudwego/kitex/internal/test"
)

func TestMaxCounter_Inc(t *testing.T) {
	var wg sync.WaitGroup
	var cnt int64

	// max > 0
	counter := NewMaxCounter(10)
	for i := 0; i < 100; i++ {
		wg.Add(1)
		go func() {
			defer wg.Done()
			if counter.Inc() {
				atomic.AddInt64(&cnt, 1)
			}
		}()
	}
	wg.Wait()
	test.Assert(t, cnt == 10)

	// max == 0
	cnt = 0
	counter = NewMaxCounter(0)
	for i := 0; i < 100; i++ {
		wg.Add(1)
		go func() {
			defer wg.Done()
			if counter.Inc() {
				atomic.AddInt64(&cnt, 1)
			}
		}()
	}
	wg.Wait()
	test.Assert(t, cnt == 0)

	// max < 0
	cnt = 0
	counter = NewMaxCounter(-1)
	for i := 0; i < 100; i++ {
		wg.Add(1)
		go func() {
			defer wg.Done()
			if counter.Inc() {
				atomic.AddInt64(&cnt, 1)
			}
		}()
	}
	wg.Wait()
	test.Assert(t, cnt == 0)
}

func TestMaxCounter_Dec(t *testing.T) {
	var wg sync.WaitGroup

	counter := NewMaxCounter(10)
	for i := 0; i < 100; i++ {
		wg.Add(1)
		go func() {
			defer wg.Done()
			counter.Dec()
		}()
	}
	wg.Wait()
	test.Assert(t, atomic.LoadInt64(&counter.now) == -100)
}
