Reopen the last DM that was open when navigating back to chat (#81)

#60

Co-authored-by: mplorentz <mplorentz@users.noreply.github.com>
Reviewed-on: #81
Co-authored-by: Matt Lorentz <mplorentz@noreply.coracle.social>
Co-committed-by: Matt Lorentz <mplorentz@noreply.coracle.social>

src/app/util/history.ts

@@ -1,10 +1,14 @@
 import {page} from "$app/stores"
 
 export const lastPageBySpaceUrl = new Map<string, string>()
+export let lastChatUrl: string | undefined = undefined
 
 export const setupHistory = () =>
   page.subscribe($page => {
     if ($page.params.relay) {
       lastPageBySpaceUrl.set($page.params.relay, $page.url.pathname)
     }
+    if ($page.params.chat) {
+      lastChatUrl = $page.url.pathname
+    }
   })

src/app/util/routes.ts

@@ -27,7 +27,7 @@ import {
   DM_KINDS,
   ROOM,
 } from "@app/core/state"
-import {lastPageBySpaceUrl} from "@app/util/history"
+import {lastPageBySpaceUrl, lastChatUrl} from "@app/util/history"
 
 export const makeSpacePath = (url: string, ...extra: (string | undefined)[]) => {
   let path = `/spaces/${encodeRelay(url)}`
@@ -56,6 +56,10 @@ export const goToSpace = async (url: string) => {
   }
 }
 
+export const goToLastChat = () => {
+  goto(lastChatUrl ?? "/chat")
+}
+
 export const makeChatPath = (pubkeys: string[]) => `/chat/${makeChatId(pubkeys)}`
 
 export const makeRoomPath = (url: string, h: string) => `/spaces/${encodeRelay(url)}/${h}`