From 6302565942646495dcee7543e9592637116b40ea Mon Sep 17 00:00:00 2001
From: Cory McWilliams <cory@unprompted.com>
Date: Wed, 4 Oct 2023 22:57:39 +0000
Subject: [PATCH] Store app blob history.

git-svn-id: https://www.unprompted.com/svn/projects/tildefriends/trunk@4484 ed5197a5-7fde-0310-b194-c3ffbd925b24
---
 core/core.js | 25 +++++++++++++++++++++----
 1 file changed, 21 insertions(+), 4 deletions(-)

diff --git a/core/core.js b/core/core.js
index 47543c5a..2c4e5e02 100644
--- a/core/core.js
+++ b/core/core.js
@@ -735,7 +735,6 @@ async function blobHandler(request, response, blobId, uri) {
 	} else if (uri == "/save") {
 		let match;
 		if (match = /^\/\~(\w+)\/(\w+)$/.exec(blobId)) {
-			let newBlobId = await ssb.blobStore(request.body);
 			let user = match[1];
 			let appName = match[2];
 			let credentials = auth.query(request.headers);
@@ -743,6 +742,25 @@ async function blobHandler(request, response, blobId, uri) {
 				(credentials.session.name == user ||
 				(credentials.permissions.administration && user == 'core'))) {
 				let database = new Database(user);
+
+				let app_object = JSON.parse(utf8Decode(request.body));
+				let previous_id = database.get('path:' + appName);
+				if (previous_id) {
+					try {
+						let previous_object = JSON.parse(utf8Decode(await ssb.blobGet(previous_id)));
+						delete previous_object.previous;
+						delete app_object.previous;
+						if (JSON.stringify(previous_object) == JSON.stringify(app_object)) {
+							response.writeHead(200, {"Content-Type": "text/plain; charset=utf-8"});
+							response.end("/" + previous_id);
+							return;
+						}
+					} catch {
+					}
+				}
+				app_object.previous = previous_id;
+				let newBlobId = await ssb.blobStore(JSON.stringify(app_object));
+
 				let apps = new Set();
 				let apps_original = database.get('apps');
 				try {
@@ -757,14 +775,13 @@ async function blobHandler(request, response, blobId, uri) {
 					database.set('apps', apps);
 				}
 				database.set('path:' + appName, newBlobId);
+				response.writeHead(200, {"Content-Type": "text/plain; charset=utf-8"});
+				response.end("/" + newBlobId);
 			} else {
 				response.writeHead(401, {"Content-Type": "text/plain; charset=utf-8"});
 				response.end("401 Unauthorized");
 				return;
 			}
-
-			response.writeHead(200, {"Content-Type": "text/plain; charset=utf-8"});
-			response.end("/" + newBlobId);
 		} else if (blobId === '') {
 			let newBlobId = await ssb.blobStore(request.body);
 			response.writeHead(200, {"Content-Type": "text/plain; charset=utf-8"});