export type DispatchPlanUiTarget = {
  projectId: string;
  threadDisplayName: string;
};

export type DispatchPlanUiPayload = {
  planId: string;
  status?: string;
  summary?: string;
  targets?: DispatchPlanUiTarget[];
};

export function latestPendingDispatchPlan(plans: DispatchPlanUiPayload[] | null | undefined) {
  return (plans ?? []).find((plan) => plan.status === "pending_user_confirmation") ?? null;
}

export function latestRejectedDispatchPlan(plans: DispatchPlanUiPayload[] | null | undefined) {
  return (plans ?? []).find((plan) => plan.status === "rejected") ?? null;
}

export type DispatchPlanComposerState = {
  pendingDispatchPlan: DispatchPlanUiPayload | null;
  rejectedDispatchPlan: DispatchPlanUiPayload | null;
  recoveryHint: string | null;
  recoveryActionLabel: string | null;
};

export function resolveDispatchPlanComposerState(
  plans: DispatchPlanUiPayload[] | null | undefined,
): DispatchPlanComposerState {
  const pendingDispatchPlan = latestPendingDispatchPlan(plans);
  const rejectedDispatchPlan = pendingDispatchPlan ? null : latestRejectedDispatchPlan(plans);

  if (rejectedDispatchPlan) {
    return {
      pendingDispatchPlan,
      rejectedDispatchPlan,
      recoveryHint: "上次推荐已拒绝。直接点击“重新生成新的推荐”即可继续协作，不用重新发送整条消息。",
      recoveryActionLabel: "重新生成新的推荐",
    };
  }

  if (pendingDispatchPlan) {
    return {
      pendingDispatchPlan,
      rejectedDispatchPlan: null,
      recoveryHint: "当前有待确认推荐，已折叠旧的拒绝状态。",
      recoveryActionLabel: null,
    };
  }

  return {
    pendingDispatchPlan: null,
    rejectedDispatchPlan: null,
    recoveryHint: null,
    recoveryActionLabel: null,
  };
}

export function summarizeDispatchPlan(plan: DispatchPlanUiPayload | null | undefined) {
  if (!plan) {
    return "主 Agent 暂未生成推荐线程。";
  }
  const summary = plan.summary?.trim() || "主 Agent 已生成推荐线程。";
  const titles = (plan.targets ?? [])
    .map((target) => target.threadDisplayName?.trim() || "")
    .filter(Boolean);
  if (!titles.length) {
    return summary;
  }
  return `${summary}\n推荐线程：${titles.join("、")}`;
}

export function summarizeDispatchPlanCompact(plan: DispatchPlanUiPayload | null | undefined) {
  if (!plan) {
    return "主 Agent 暂未生成推荐线程。";
  }
  const summary = plan.summary?.trim() || "主 Agent 已生成推荐线程。";
  const titles = (plan.targets ?? [])
    .map((target) => target.threadDisplayName?.trim() || "")
    .filter(Boolean);
  if (!titles.length) {
    return truncateDispatchSummary(summary);
  }
  return `推荐给：${titles.join("、")}\n${truncateDispatchSummary(summary)}`;
}

export function summarizeDispatchPlanLightTitle(plan: DispatchPlanUiPayload | null | undefined) {
  const count = (plan?.targets ?? []).length;
  return count > 0 ? `主 Agent 已推荐 ${count} 个线程` : "主 Agent 已推荐线程";
}

function truncateDispatchSummary(summary: string) {
  return summary.length > 32 ? `${summary.slice(0, 32)}…` : summary;
}

export function extractApprovedTargetProjectIds(plan: DispatchPlanUiPayload | null | undefined) {
  return (plan?.targets ?? [])
    .map((target) => target.projectId?.trim() || "")
    .filter(Boolean);
}