package util

import (
	"sync"
)

type Channel struct {
	m      sync.Mutex
	closed bool
	C      chan interface{}
}

func NewChannel() *Channel {
	return &Channel{
		C:      nil,
		closed: true,
	}
}

func (c *Channel) Open() {
	c.m.Lock()
	defer c.m.Unlock()
	if c.isClosed() {
		c.C = make(chan interface{})
		c.closed = false
	}
}

func (c *Channel) Close() {
	c.m.Lock()
	defer c.m.Unlock()
	if !c.isClosed() {
		close(c.C)
		c.C = nil
		c.closed = true
	}
}

func (c *Channel) IsClosed() bool {
	c.m.Lock()
	defer c.m.Unlock()
	return c.isClosed()
}

func (c *Channel) isClosed() bool {
	return c.C == nil && c.closed
}