/*
 * 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 connpool

import "time"

// IdleConfig contains idle configuration for long-connection pool.
type IdleConfig struct {
	MinIdlePerAddress int
	MaxIdlePerAddress int
	MaxIdleGlobal     int
	MaxIdleTimeout    time.Duration
}

const (
	defaultMaxIdleTimeout = 30 * time.Second
	minMaxIdleTimeout     = 2 * time.Second
	maxMinIdlePerAddress  = 5
	defaultMaxIdleGlobal  = 1 << 20 // no limit
)

// CheckPoolConfig to check invalid param.
// default MaxIdleTimeout = 30s, min value is 2s
func CheckPoolConfig(config IdleConfig) *IdleConfig {
	// idle timeout
	if config.MaxIdleTimeout == 0 {
		config.MaxIdleTimeout = defaultMaxIdleTimeout
	} else if config.MaxIdleTimeout < minMaxIdleTimeout {
		config.MaxIdleTimeout = minMaxIdleTimeout
	}

	// idlePerAddress
	if config.MinIdlePerAddress < 0 {
		config.MinIdlePerAddress = 0
	}
	if config.MinIdlePerAddress > maxMinIdlePerAddress {
		config.MinIdlePerAddress = maxMinIdlePerAddress
	}
	if config.MaxIdlePerAddress <= 0 {
		config.MaxIdlePerAddress = 1
	}
	if config.MaxIdlePerAddress < config.MinIdlePerAddress {
		config.MaxIdlePerAddress = config.MinIdlePerAddress
	}

	// globalIdle
	if config.MaxIdleGlobal <= 0 {
		config.MaxIdleGlobal = defaultMaxIdleGlobal
	} else if config.MaxIdleGlobal < config.MaxIdlePerAddress {
		config.MaxIdleGlobal = config.MaxIdlePerAddress
	}
	return &config
}
