From 497abfe83fe25ff052aff184cc4afd9a2f5bb775 Mon Sep 17 00:00:00 2001
From: Atridad Lahiji <me@atri.dad>
Date: Mon, 24 Mar 2025 01:22:20 -0600
Subject: [PATCH] ????

---
 api/sse.go                         | 58 +++++++++++++++++++-----------
 pages/templates/tools.ssedemo.html | 28 +++++++++++++--
 2 files changed, 62 insertions(+), 24 deletions(-)

diff --git a/api/sse.go b/api/sse.go
index dbb2d20..1cd49ff 100644
--- a/api/sse.go
+++ b/api/sse.go
@@ -2,6 +2,7 @@ package api
 
 import (
 	"fmt"
+	"net/http"
 	"time"
 
 	"atri.dad/lib"
@@ -26,51 +27,66 @@ func SSE(c echo.Context) error {
 	// Use the request context, which is cancelled when the client disconnects
 	ctx := c.Request().Context()
 
-	c.Response().Header().Set(echo.HeaderContentType, "text/event-stream")
-	c.Response().Header().Set(echo.HeaderConnection, "keep-alive")
-	c.Response().Header().Set(echo.HeaderCacheControl, "no-cache")
+	// Set headers for SSE
+	c.Response().Header().Set("Content-Type", "text/event-stream")
+	c.Response().Header().Set("Cache-Control", "no-cache, no-store, must-revalidate")
+	c.Response().Header().Set("Connection", "keep-alive")
+	c.Response().Header().Set("Pragma", "no-cache")
+	c.Response().Header().Set("Expires", "0")
+	c.Response().Header().Set("X-Accel-Buffering", "no")
 
-	// Get origin from request
-	origin := c.Request().Header.Get(echo.HeaderOrigin)
-	// Only allow specific origins
+	// Set CORS headers
+	origin := c.Request().Header.Get("Origin")
 	if origin == "https://atri.dad" || origin == "http://localhost:3000" {
-		c.Response().Header().Set(echo.HeaderAccessControlAllowOrigin, origin)
-		c.Response().Header().Set(echo.HeaderAccessControlAllowCredentials, "true")
+		c.Response().Header().Set("Access-Control-Allow-Origin", origin)
+		c.Response().Header().Set("Access-Control-Allow-Credentials", "true")
+	} else {
+		// Allow any origin as fallback for testing
+		c.Response().Header().Set("Access-Control-Allow-Origin", "*")
 	}
 
-	// Create a channel to receive messages from the lib.SSEServer
+	// Set response status
+	c.Response().WriteHeader(http.StatusOK)
+	c.Response().Flush()
+
+	// Create a channel to receive messages
 	clientChan := make(chan string)
 
-	// Add the client to the lib.SSEServer
+	// Add the client to the SSEServer
 	lib.SSEServer.AddClient(channel, clientChan)
 
-	defer func() {
-		// Remove the client from the lib.SSEServer when the connection is closed
-		lib.SSEServer.RemoveClient(channel, clientChan)
-	}()
+	// Clean up when the connection is closed
+	defer lib.SSEServer.RemoveClient(channel, clientChan)
 
-	// Create a ticker that fires every 15 seconds
-	ticker := time.NewTicker(30 * time.Second)
+	// Write the initial message
+	initialMsg := ": connected\n\n"
+	if _, err := c.Response().Write([]byte(initialMsg)); err != nil {
+		return err
+	}
+	c.Response().Flush()
+
+	// Create a ticker for keep-alive messages
+	ticker := time.NewTicker(15 * time.Second)
 	defer ticker.Stop()
 
+	// Event loop
 	for {
 		select {
 		case <-ctx.Done():
-			// If the client has disconnected, stop the loop
+			// Client disconnected
 			return nil
 		case <-ticker.C:
-			// Every 30 seconds, send a comment to keep the connection alive
-			if _, err := c.Response().Write([]byte(": keep-alive\n\n")); err != nil {
+			// Send keep-alive comment
+			if _, err := c.Response().Write([]byte(": ping\n\n")); err != nil {
 				return err
 			}
 			c.Response().Flush()
 		case msg := <-clientChan:
-			// Handle incoming messages from the lib.SSEServer
+			// Format the SSE message
 			data := fmt.Sprintf("data: %s\n\n", msg)
 			if _, err := c.Response().Write([]byte(data)); err != nil {
 				return err
 			}
-
 			c.Response().Flush()
 		}
 	}
diff --git a/pages/templates/tools.ssedemo.html b/pages/templates/tools.ssedemo.html
index 5473bfc..12db32f 100644
--- a/pages/templates/tools.ssedemo.html
+++ b/pages/templates/tools.ssedemo.html
@@ -7,7 +7,7 @@ Atridad Lahiji // Tools // SSE Demo
 {{end}}
 
 {{define "description"}}
-A demo of my SSE implimentation.
+A demo of my SSE implementation.
 {{end}}
 
 {{define "head"}}
@@ -17,9 +17,9 @@ A demo of my SSE implimentation.
 <h2 class="text-2xl font-extrabold tracking-tight text-white sm:text-[2rem]">Server Sent Events Demo</h2>
 
 <p class="text-lg">This page demonstrates the use of the <a href="https://htmx.org/extensions/sse/">HTMX SSE
-    Extention</a> to receive Server Sent Events on the "default" channel.</p>
+    Extension</a> to receive Server Sent Events on the "default" channel.</p>
 <p class="text-lg">Any events received on the "default" channel will appear below:</p>
-<div hx-ext="sse" sse-connect="/api/sse" sse-swap="message">
+<div id="sse-target" hx-ext="sse" sse-connect="/api/sse" sse-swap="message">
   Waiting for SSE Message...
 </div>
 
@@ -37,4 +37,26 @@ A demo of my SSE implimentation.
 
 {{define "foot"}}
 <script src="/public/js/htmx.sse.js"></script>
+<script>
+  // Custom EventSource factory with better retry handling
+  htmx.createEventSource = function(url) {
+    console.log("Creating EventSource for:", url);
+    
+    // Create EventSource with credentials
+    const source = new EventSource(url, { withCredentials: true });
+    
+    // Log connection state changes
+    source.onopen = function() {
+      console.log("SSE connection opened successfully");
+      document.getElementById('sse-target').innerHTML = "Connected to SSE. Waiting for messages...";
+    };
+    
+    source.onerror = function(err) {
+      console.error("SSE connection error:", err);
+      document.getElementById('sse-target').innerHTML = "Connection error. Retrying...";
+    };
+    
+    return source;
+  };
+</script>
 {{end}}