From 3175c5c23abcc523cec80c700642b86510c99a62 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Pedro=20P=C3=A9rez?= <hola@pedroperez.dev>
Date: Tue, 22 Jul 2025 00:11:49 +0200
Subject: [PATCH] add sse handle with std lib

---
 broker.go | 172 +++++++++++++++++++++++++++++++++++-------------------
 1 file changed, 113 insertions(+), 59 deletions(-)

diff --git a/broker.go b/broker.go
index c8593e8..25bf63f 100644
--- a/broker.go
+++ b/broker.go
@@ -6,6 +6,7 @@ import (
 	"fmt"
 	"html/template"
 	"log/slog"
+	"net/http"
 	"strings"
 	"sync"
 	"time"
@@ -120,8 +121,98 @@ func (b *SSEBroker) Broadcast(event string, data ...any) {
 	b.broadcast <- Message{Event: event, Data: payload}
 }
 
-func (b *SSEBroker) HandleFiberCtxSSE(c *fiber.Ctx) error {
+// Interface para abstraer las diferencias entre Fiber y HTTP estándar
+type SSEWriter interface {
+	Write(data []byte) (int, error)
+	Flush() error
+}
 
+// Wrapper para http.ResponseWriter
+type httpSSEWriter struct {
+	w http.ResponseWriter
+}
+
+func (h *httpSSEWriter) Write(data []byte) (int, error) {
+	return h.w.Write(data)
+}
+
+func (h *httpSSEWriter) Flush() error {
+	if flusher, ok := h.w.(http.Flusher); ok {
+		flusher.Flush()
+	}
+	return nil
+}
+
+// Wrapper para bufio.Writer
+type fiberSSEWriter struct {
+	w *bufio.Writer
+}
+
+func (f *fiberSSEWriter) Write(data []byte) (int, error) {
+	return f.w.Write(data)
+}
+
+func (f *fiberSSEWriter) Flush() error {
+	return f.w.Flush()
+}
+
+func (b *SSEBroker) handleSSEConnection(clientID string, client *Client, writer SSEWriter) {
+	slog.Info("SSE connection established", "client_id", clientID)
+
+	defer func() {
+		b.UnregisterClient(clientID)
+		slog.Info("SSE connection closed", "client_id", clientID)
+	}()
+
+	fmt.Fprintf(writer, "event: client_id\n")
+	fmt.Fprintf(writer, "data: %s\n\n", clientID)
+	writer.Flush()
+
+	ticker := time.NewTicker(time.Minute)
+	defer ticker.Stop()
+
+	for {
+		select {
+		case message := <-client.Send:
+			var data string
+			switch v := message.Data.(type) {
+			case string:
+				data = v
+			case template.HTML:
+				data = string(v)
+			default:
+				jsonData, err := json.Marshal(v)
+				if err != nil {
+					slog.Error("error marshaling message", "error", err)
+					continue
+				}
+				data = string(jsonData)
+			}
+
+			fmt.Fprintf(writer, "event: %s\n", message.Event)
+			scanner := bufio.NewScanner(strings.NewReader(data))
+			for scanner.Scan() {
+				fmt.Fprintf(writer, "data: %s\n", scanner.Text())
+			}
+			fmt.Fprint(writer, "\n")
+
+			if err := writer.Flush(); err != nil {
+				slog.Warn("flush error, closing client", "client_id", clientID)
+				return
+			}
+
+		case <-ticker.C:
+			fmt.Fprintf(writer, "event: ping\n")
+			fmt.Fprintf(writer, "data: %s\n\n", "ping")
+			writer.Flush()
+
+		case <-client.Close:
+			return
+		}
+	}
+}
+
+func (b *SSEBroker) HandleFiberCtxSSE(c *fiber.Ctx) error {
 	c.Set("Content-Type", "text/event-stream")
 	c.Set("Cache-Control", "no-cache")
 	c.Set("Connection", "keep-alive")
@@ -131,69 +222,32 @@ func (b *SSEBroker) HandleFiberCtxSSE(c *fiber.Ctx) error {
 	client := b.RegisterClient(clientID)
 
 	c.Status(fiber.StatusOK).Context().SetBodyStreamWriter(fasthttp.StreamWriter(func(w *bufio.Writer) {
-		slog.Info("SSE connection established", "client_id", clientID)
-
-		defer func() {
-			b.UnregisterClient(clientID)
-			slog.Info("SSE connection closed", "client_id", clientID)
-		}()
-
-		fmt.Fprintf(w, "event: client_id\n")
-		fmt.Fprintf(w, "data: %s\n\n", clientID)
-		w.Flush()
-
-		ticker := time.NewTicker(time.Minute)
-		defer ticker.Stop()
-
-		for {
-			select {
-			case message := <-client.Send:
-				var data string
-				switch v := message.Data.(type) {
-				case string:
-					data = v
-				case template.HTML:
-					data = string(v)
-				default:
-					jsonData, err := json.Marshal(v)
-					if err != nil {
-						slog.Error("error marshaling message", "error", err)
-						continue
-					}
-					data = string(jsonData)
-				}
-
-				fmt.Fprintf(w, "event: %s\n", message.Event)
-				scanner := bufio.NewScanner(strings.NewReader(data))
-				for scanner.Scan() {
-					fmt.Fprintf(w, "data: %s\n", scanner.Text())
-				}
-				fmt.Fprint(w, "\n")
-
-				if err := w.Flush(); err != nil {
-					slog.Warn("flush error, closing client", "client_id", clientID)
-					return
-				}
-			case <-ticker.C:
-				fmt.Fprintf(w, "event: ping\n")
-				fmt.Fprintf(w, "data: %s\n\n", "ping")
-
-			case <-client.Close:
-				return
-
-			default:
-				err := w.Flush()
-				if err != nil {
-					slog.Warn("error while flushing", "error", err)
-					return
-				}
-			}
-		}
+		writer := &fiberSSEWriter{w: w}
+		b.handleSSEConnection(clientID, client, writer)
 	}))
 
 	return nil
 }
 
+func (b *SSEBroker) HandleHTTPSSE(w http.ResponseWriter, r *http.Request) {
+	w.Header().Set("Content-Type", "text/event-stream")
+	w.Header().Set("Cache-Control", "no-cache")
+	w.Header().Set("Connection", "keep-alive")
+	w.Header().Set("Transfer-Encoding", "chunked")
+
+	clientID := uuid.New().String()
+	client := b.RegisterClient(clientID)
+
+	writer := &httpSSEWriter{w: w}
+
+	go func() {
+		b.handleSSEConnection(clientID, client, writer)
+	}()
+
+	<-r.Context().Done()
+	slog.Info("client disconnected", "client_id", clientID)
+}
+
 func (b *SSEBroker) Shutdown() {
 	close(b.done)
 }