refactor(iframe): [PKG-IFRAME-03] scope requests to active documents

packages/artplayer-tool-iframe/src/protocol.ts

@@ -1,5 +1,27 @@
 import type { Packet } from './requests'
 
+export const sessionType = 'artplayer-tool-iframe:session'
+export type SessionPhase = 'inject' | 'message' | 'ack' | 'leave' | 'resume' | 'fragment'
+export interface SessionMetadata {
+  version: 1
+  document: string
+  phase: SessionPhase
+}
+
+interface SessionPacket extends Packet {
+  __artplayerIframe: SessionMetadata
+}
+
+export function sessionMetadata(packet: Packet): SessionMetadata | undefined {
+  const value = (packet as Partial<SessionPacket>).__artplayerIframe
+  if (value?.version === 1 && typeof value.document === 'string' && value.document && ['inject', 'message', 'ack', 'leave', 'resume', 'fragment'].includes(value.phase))
+    return value
+}
+
+export function withSession(packet: Packet, documentId: string, phase: SessionPhase): SessionPacket {
+  return { ...packet, __artplayerIframe: { version: 1, document: documentId, phase } }
+}
+
 export function acceptsMessage(event: MessageEvent<unknown>, peer: Window | null): event is MessageEvent<Packet> {
   if (event.source !== undefined && event.source !== null && event.source !== peer)
     return false