From 12307b7ae65fd4288c8390dd985906782e17ecaa Mon Sep 17 00:00:00 2001
From: "D. Berge" <dberge@aaltronav.eu>
Date: Sat, 4 Nov 2023 10:40:05 +0100
Subject: [PATCH] Refactor ETag watcher to use path-to-regexp.

Simplifies the code and makes it easier to look at.
---
 lib/www/server/api/middleware/etag/watch.js | 46 ++++++++-------------
 1 file changed, 17 insertions(+), 29 deletions(-)

diff --git a/lib/www/server/api/middleware/etag/watch.js b/lib/www/server/api/middleware/etag/watch.js
index 09914f7..d76cc11 100644
--- a/lib/www/server/api/middleware/etag/watch.js
+++ b/lib/www/server/api/middleware/etag/watch.js
@@ -1,3 +1,4 @@
+const pathToRegExp = require("path-to-regexp");
 const { getCache } = require('./cache');
 const { listen } = require('../../../lib/db/notify');
 const channels = require('../../../lib/db/channels');
@@ -9,38 +10,27 @@ const rels = [
 	},
 	{
 		channels: [ "event" ],
-		urls: [ /^\/project\/([^\/]+)\/event/ ],
-		matches: [ "project" ]
+		urls: [ "/project/:project/event" ],
 	},
 	{
 		channels: [ "project" ],
-		urls: [ /^\/project\/([^\/]+)\// ],
-		matches: [ "project" ]
+		urls: [ "/project/:project" ]
 	},
 	{
 		channels: [ "preplot_lines", "preplot_points" ],
-		urls: [ /^\/project\/([^\/]+)\/line[\/?]?/ ],
-		matches: [ "project" ]
+		urls: [ "/project/:project/line" ]
 	},
 	{
 		channels: [ "planned_lines" ],
-		urls: [ /^\/project\/([^\/]+)\/plan[\/?]?/ ],
-		matches: [ "project" ]
+		urls: [ "/project/:project/plan" ]
 	},
 	{
-		channels: [ "raw_lines", "raw_shots" ],
-		urls: [ /^\/project\/([^\/]+)\/sequence[\/?]?/ ],
-		matches: [ "project" ]
-	},
-	{
-		channels: [ "final_lines", "final_shots" ],
-		urls: [ /^\/project\/([^\/]+)\/sequence[\/?]?/ ],
-		matches: [ "project" ]
+		channels: [ "raw_lines", "raw_shots", "final_lines", "final_shots" ],
+		urls: [ "/project/:project/sequence" ]
 	},
 	{
 		channels: [ "info" ],
 		urls: [ ],
-		matches: [ ],
 		callback (url, data) {
 			if (data.payload?.table == "info") {
 				const pid = data.payload?.pid;
@@ -84,19 +74,17 @@ function invalidateCache (data, cache) {
 		for (let rel of rels) {
 			if (rel.channels.includes(channel)) {
 				for (let url of rel.urls) {
+
+					const matches = typeof url === "function"
+						? url
+						: pathToRegExp.match(url, {decode: decodeURIComponent, end: false});
+
 					for (let [key, data] of Object.entries(cache)) {
-						const match = key.match(url)?.slice(1);
-						if (match) {
-							if (rel.matches) {
-								if (rel.matches.every( (field, idx) => match[idx] == fields[field] )) {
-									console.log("DELETE ENTRY (MATCHES)", key);
-									delete cache[key];
-								}
-							} else {
-								// Delete unconditionally
-								console.log("DELETE ENTRY (UNCONDITIONAL)", key);
-								delete cache[key];
-							}
+
+						const { params } = matches(key);
+
+						if (params && Object.entries(params).every(i => fields[i[0]] == i[1])) {
+							delete cache[key];
 						}
 
 					}