0.2.0: refactor into domain modules

lib/model-switch.ts

@@ -0,0 +1,62 @@
+/**
+ * In-flight Telegram model-switch helpers
+ * Encodes the safe restart and continuation rules for switching models during active Telegram-owned runs
+ */
+
+import type { Model } from "@mariozechner/pi-ai";
+
+import type { TelegramInFlightModelSwitchState } from "./queue.ts";
+
+export type TelegramThinkingLevel =
+  | "off"
+  | "minimal"
+  | "low"
+  | "medium"
+  | "high"
+  | "xhigh";
+
+export function canRestartTelegramTurnForModelSwitch(
+  state: TelegramInFlightModelSwitchState,
+): boolean {
+  return !state.isIdle && state.hasActiveTelegramTurn && state.hasAbortHandler;
+}
+
+export function shouldTriggerPendingTelegramModelSwitchAbort(state: {
+  hasPendingModelSwitch: boolean;
+  hasActiveTelegramTurn: boolean;
+  hasAbortHandler: boolean;
+  activeToolExecutions: number;
+}): boolean {
+  return (
+    state.hasPendingModelSwitch &&
+    state.hasActiveTelegramTurn &&
+    state.hasAbortHandler &&
+    state.activeToolExecutions === 0
+  );
+}
+
+export function restartTelegramModelSwitchContinuation<TTurn, TSelection>(state: {
+  activeTurn: TTurn | undefined;
+  abort: (() => void) | undefined;
+  selection: TSelection;
+  queueContinuation: (turn: TTurn, selection: TSelection) => void;
+}): boolean {
+  if (!state.activeTurn || !state.abort) return false;
+  state.queueContinuation(state.activeTurn, state.selection);
+  state.abort();
+  return true;
+}
+
+export function buildTelegramModelSwitchContinuationText<
+  TModel extends Pick<Model<any>, "provider" | "id">,
+>(
+  telegramPrefix: string,
+  model: TModel,
+  thinkingLevel?: TelegramThinkingLevel,
+): string {
+  const modelLabel = `${model.provider}/${model.id}`;
+  const thinkingSuffix = thinkingLevel
+    ? ` Keep the selected thinking level (${thinkingLevel}) if it still applies.`
+    : "";
+  return `${telegramPrefix} Continue the interrupted previous Telegram request using the newly selected model (${modelLabel}). Resume from the last unfinished step instead of restarting from scratch unless necessary.${thinkingSuffix}`;
+}