package publish

import (
	"fmt"
	"sync"
)

type Topic string

const (
	Topic_Quote   = "quote"   // 实时行情
	Topic_Trading = "trading" // 交易服务通知
)

type Publisher struct {
	subscribers map[Topic][]chan interface{}
	mu          sync.RWMutex
}

func NewPublisher() *Publisher {
	return &Publisher{
		subscribers: make(map[Topic][]chan interface{}),
	}
}

func (p *Publisher) Subscribe(topic Topic) chan interface{} {
	p.mu.Lock()
	defer p.mu.Unlock()

	ch := make(chan interface{}, 100)
	p.subscribers[topic] = append(p.subscribers[topic], ch)
	return ch
}

func (p *Publisher) Unsubscribe(topic Topic, ch chan interface{}) {
	p.mu.Lock()
	defer p.mu.Unlock()

	subs := p.subscribers[topic]
	for i := range subs {
		if subs[i] == ch {
			p.subscribers[topic] = append(subs[:i], subs[i+1:]...)
			break
		}
	}
	close(ch)
}

func (p *Publisher) Publish(topic Topic, data interface{}) {
	p.mu.RLock()
	defer p.mu.RUnlock()

	if subs, ok := p.subscribers[topic]; ok {
		if topic == Topic_Trading {
			fmt.Printf("Publish-Topic_Trading 获取sub, topic: %v sub: %v \n", topic, subs)
		}
		for _, ch := range subs {
			select {
			case ch <- data:
			default:
				// 如果消息管道已满，直接跳过，不阻塞订阅者
			}
		}
	} else {
		fmt.Printf("Publish 获取订阅目标失败, topic: %v \n", topic)
	}
}