From 7c5eaa74d92ab6be2db7ea83ec6dd48145587539 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Magnus=20=C3=85hall?= <magnus.ahall@gibon.se>
Date: Sun, 7 Jan 2024 16:18:49 +0100
Subject: [PATCH] Added a webservice static JS library

---
 js_library.go           | 17 +++++++--
 pkg.go                  |  2 +-
 static/js/websocket.js  | 22 ------------
 static/js/websocket.mjs | 77 +++++++++++++++++++++++++++++++++++++++++
 4 files changed, 93 insertions(+), 25 deletions(-)
 delete mode 100644 static/js/websocket.js
 create mode 100644 static/js/websocket.mjs

diff --git a/js_library.go b/js_library.go
index a02bda2..a0cfd46 100644
--- a/js_library.go
+++ b/js_library.go
@@ -5,15 +5,28 @@ import (
 	"embed"
 	"fmt"
 	"net/http"
+	"regexp"
 )
 
 var (
 	//go:embed static/js
 	embedded embed.FS
+	pathMatcher *regexp.Regexp = regexp.MustCompile("^/_js/v[0-9]+/(.*)$")
 )
 
-func staticJSWebsocket(w http.ResponseWriter, r *http.Request) {
-	contents, err := embedded.ReadFile("static/js/websocket.js")
+func (service *Service) staticJSHandler(w http.ResponseWriter, r *http.Request) {
+	var path string
+	if comp := pathMatcher.FindStringSubmatch(r.URL.Path); comp != nil {
+		path = fmt.Sprintf("static/js/%s", comp[1])
+	} else {
+		service.logger.Debug("webservice", "request", r.URL.Path)
+		return
+	}
+
+	service.logger.Debug("webservice", "request", r.URL.Path, "path", path)
+	w.Header().Add("Content-Type", "text/javascript")
+
+	contents, err := embedded.ReadFile(path)
 	if err != nil {
 		fmt.Println(err)
 		return
diff --git a/pkg.go b/pkg.go
index d87d33f..71ffd91 100644
--- a/pkg.go
+++ b/pkg.go
@@ -106,7 +106,7 @@ func New(configFilename, version string, logger *slog.Logger) (service *Service,
 	http.HandleFunc("/_ws", service.websocketHandler)
 	http.HandleFunc("/_ws/css_update", service.cssUpdateHandler)
 
-	http.HandleFunc("/_js/websocket.js", staticJSWebsocket)
+	http.HandleFunc("/_js/", service.staticJSHandler)
 
 	return
 } // }}}
diff --git a/static/js/websocket.js b/static/js/websocket.js
deleted file mode 100644
index b3e92d7..0000000
--- a/static/js/websocket.js
+++ /dev/null
@@ -1,22 +0,0 @@
-package webservice
-
-import (
-	// Standard
-	"embed"
-	"fmt"
-	"net/http"
-)
-
-var (
-	//go:embed foo.txt
-	embedded embed.FS
-)
-
-func staticJSWebsocket(w http.ResponseWriter, r *http.Request) {
-	contents, err := embedded.ReadFile("foo.txt")
-	if err != nil {
-		fmt.Println(err)
-		return
-	}
-	w.Write(contents)
-}
diff --git a/static/js/websocket.mjs b/static/js/websocket.mjs
new file mode 100644
index 0000000..459bae1
--- /dev/null
+++ b/static/js/websocket.mjs
@@ -0,0 +1,77 @@
+export class Websocket {
+	constructor() {//{{{
+		this.websocket = null
+		this.websocket_int_ping = null
+		this.websocket_int_reconnect = null
+		this.hooks = {
+			open: [],
+			message: [],
+			error: [],
+			close: [],
+		}
+	}//}}}
+
+	register(event, fn) {//{{{
+		this.hooks[event].push(fn)
+	}//}}}
+
+	start() {//{{{
+		this.connect()
+		//this.loop()
+	}//}}}
+	loop() {//{{{
+		setInterval(() => {
+			if (this.websocket === null) {
+				console.log("websocket loop connect")
+				this.connect()
+			}
+		}, 1000)
+	}//}}}
+
+	connect() {//{{{
+		const protocol = location.protocol;
+		const domain = location.hostname;
+		const port = location.port;
+
+		let wsProtocol = 'wss'
+		if (protocol == 'http:')
+			wsProtocol = 'ws'
+		const websocketURI = `${wsProtocol}://${domain}:${port}/_ws`
+
+		this.websocket = new WebSocket(websocketURI)
+		this.websocket.onopen = (evt) => this.open(evt)
+		this.websocket.onmessage = (evt) => this.message(evt)
+		this.websocket.onerror = (evt) => this.error(evt)
+		this.websocket.onclose = (evt) => this.close(evt)
+	}//}}}
+	open() {//{{{
+		this.hooks.open.forEach(fn=>fn())
+		// A ping interval to implement a rudimentary keep-alive.
+	}//}}}
+	close() {//{{{
+		this.websocket = null
+		this.hooks.close.forEach(fn=>fn())
+	}//}}}
+	error(evt) {//{{{
+		this.websocket = null;
+		this.hooks.error.forEach(fn=>fn(evt))
+	}//}}}
+	message(evt) {//{{{
+		const msg = JSON.parse(evt.data)
+		if (msg.ID == '' && msg.Op == 'css_reload')
+				this.refreshCSS()
+
+		this.hooks.message.forEach(fn=>fn(evt.data))
+		return
+	}//}}}
+
+	refreshCSS() {//{{{
+		let links = document.getElementsByTagName('link')
+		Array.from(links).forEach(l=>{
+			if (l.rel == 'stylesheet' && !l.hasAttribute('x-no-reload')) {
+				l.href = l.href.replace(/\?.*/, '') + `?cache=${Date.now()}`
+				console.log(l.href)
+			}
+		})
+	}//}}}
+}