package broker

import (
	"context"
	"sync"

	"git.asio.asia/nixevol/NixMsg/internal/app/port"
)

type uplinkItem struct {
	conn    port.ConnInfo
	payload []byte
}

// uplinkQueue 每端串行队列，长度 256，满了堵住 OnPublish（背压）。
type uplinkQueue struct {
	b          *Broker
	endpointID string
	ch         chan uplinkItem
	once       sync.Once
}

func newUplinkQueue(b *Broker, endpointID string) *uplinkQueue {
	q := &uplinkQueue{
		b:          b,
		endpointID: endpointID,
		ch:         make(chan uplinkItem, uplinkQueueSize),
	}
	go q.loop()
	return q
}

func (q *uplinkQueue) push(item uplinkItem) {
	q.ch <- item // 满则阻塞读循环，形成背压
}

func (q *uplinkQueue) close() {
	q.once.Do(func() { close(q.ch) })
}

func (q *uplinkQueue) loop() {
	for item := range q.ch {
		_ = q.b.uplink.HandleUplink(context.Background(), item.conn, item.payload)
	}
}