package main

import (
	"sync"
)

type SSEEvent struct {
	Type string `json:"type"`
	ID   string `json:"id"`
	Path string `json:"path,omitempty"`
}

type SSEHub struct {
	mu      sync.RWMutex
	clients map[chan SSEEvent]struct{}
}

func newSSEHub() *SSEHub {
	return &SSEHub{clients: map[chan SSEEvent]struct{}{}}
}

func (h *SSEHub) subscribe() chan SSEEvent {
	ch := make(chan SSEEvent, 16)
	h.mu.Lock()
	h.clients[ch] = struct{}{}
	h.mu.Unlock()
	return ch
}

func (h *SSEHub) unsubscribe(ch chan SSEEvent) {
	h.mu.Lock()
	delete(h.clients, ch)
	h.mu.Unlock()
	close(ch)
}

func (h *SSEHub) broadcast(ev SSEEvent) {
	h.mu.RLock()
	defer h.mu.RUnlock()
	for ch := range h.clients {
		select {
		case ch <- ev:
		default:
		}
	}
}