// Pure settle decision for the goal loop — extracted so the abort/error/cap
// paths (AC4, AC5) are hermetically testable without a live agent run.

import { checkLimitReached, type GoalState } from "./state.ts";

export type SettleDecision = { action: "inject" } | { action: "wait" } | { action: "pause"; reason: string };

/** An untimed wait never spends model tokens on automatic reconciliation. */
export function hasUnresolvedWait(state: GoalState): boolean {
  return !!state.activeWait && (!state.waitTimeoutSeconds || !state.activeWait.wakeSent);
}

/**
 * Decide what the loop does when the agent settles while a goal is active.
 * stopReason comes from the last assistant message ("stop", "toolUse",
 * "aborted", "error", ...).
 */
export function decideSettle(state: GoalState, stopReason: string | undefined): SettleDecision {
  if (stopReason === "aborted") {
    return { action: "pause", reason: "paused: run aborted (Esc)" };
  }
  if (stopReason === "error") {
    return { action: "pause", reason: "paused: run error" };
  }
  if (hasUnresolvedWait(state)) {
    return { action: "wait" };
  }
  if (checkLimitReached(state)) {
    return {
      action: "pause",
      reason: `paused: cap of ${state.maxChecks} checks reached without a report`,
    };
  }
  return { action: "inject" };
}