refactor(voice-call): split manager

extensions/voice-call/src/manager/state.ts

@@ -0,0 +1,51 @@
+import { TerminalStates, type CallRecord, type CallState, type TranscriptEntry } from "../types.js";
+
+const ConversationStates = new Set<CallState>(["speaking", "listening"]);
+
+const StateOrder: readonly CallState[] = [
+  "initiated",
+  "ringing",
+  "answered",
+  "active",
+  "speaking",
+  "listening",
+];
+
+export function transitionState(call: CallRecord, newState: CallState): void {
+  // No-op for same state or already terminal.
+  if (call.state === newState || TerminalStates.has(call.state)) return;
+
+  // Terminal states can always be reached from non-terminal.
+  if (TerminalStates.has(newState)) {
+    call.state = newState;
+    return;
+  }
+
+  // Allow cycling between speaking and listening (multi-turn conversations).
+  if (ConversationStates.has(call.state) && ConversationStates.has(newState)) {
+    call.state = newState;
+    return;
+  }
+
+  // Only allow forward transitions in state order.
+  const currentIndex = StateOrder.indexOf(call.state);
+  const newIndex = StateOrder.indexOf(newState);
+  if (newIndex > currentIndex) {
+    call.state = newState;
+  }
+}
+
+export function addTranscriptEntry(
+  call: CallRecord,
+  speaker: "bot" | "user",
+  text: string,
+): void {
+  const entry: TranscriptEntry = {
+    timestamp: Date.now(),
+    speaker,
+    text,
+    isFinal: true,
+  };
+  call.transcript.push(entry);
+}
+