refactor(ui): isolate session components (#33670)

packages/session-ui/src/components/markdown-worker-protocol.ts

@@ -0,0 +1,48 @@
+import type { ThemeRegistrationResolved } from "shiki"
+
+export type MarkdownToken = [content: string, style: string]
+
+export type MarkdownWorkerRequest =
+  | { type: "init"; theme: ThemeRegistrationResolved }
+  | { type: "highlight"; id: number; key: string; text: string; language: string; complete?: boolean }
+  | { type: "dispose"; key: string }
+
+export type MarkdownWorkerResponse =
+  | {
+      type: "highlight"
+      id: number
+      key: string
+      reset: boolean
+      stable: MarkdownToken[]
+      unstable: MarkdownToken[]
+    }
+  | { type: "error"; id: number; key: string; message: string }
+  | { type: "superseded"; id: number; key: string }
+
+export type MarkdownWorkerState = {
+  id: number
+  generation: number
+  stable: MarkdownToken[]
+  unstable: MarkdownToken[]
+}
+
+export function shouldReleaseMarkdownWorkerState(complete: boolean, latestID: number | undefined, responseID: number) {
+  return complete && latestID === responseID
+}
+
+export function markdownBlockKey(owner: string, cacheKey: string | undefined, index: number, mode: string) {
+  return `${owner}:${cacheKey ? `${cacheKey}:${index}:${mode}` : `block:${index}`}`
+}
+
+export function applyMarkdownWorkerResponse(
+  state: MarkdownWorkerState | undefined,
+  response: Extract<MarkdownWorkerResponse, { type: "highlight" }>,
+) {
+  if (state && response.id <= state.id) return state
+  return {
+    id: response.id,
+    generation: (state?.generation ?? 0) + (response.reset ? 1 : 0),
+    stable: response.reset ? response.stable : [...(state?.stable ?? []), ...response.stable],
+    unstable: response.unstable,
+  }
+}