/**
 * 验证「会话卫生」所依赖的机制是否真的有效 —— 不需要模型、不需要显卡。
 *
 * 背景：熔断中止后，我用 `agent.state.messages = [...]` 把被污染的尾巴换成一句干净的说明。
 * 但实测里下一轮仍在复读旧对话，我当时记为"卫生没生效"。这里直接验证机制本身：
 *   1) `agent.state.messages` 赋值是否被采纳？
 *   2) 赋值是否复制数组（Pi 的注释声称会复制）？
 *   3) 赋值后 `get messages` 读回来的是不是新内容？
 */

import { Agent } from "@earendil-works/pi-agent-core";

const agent = new Agent({
  initialState: {
    systemPrompt: "test",
    model: {} as never,
    tools: [],
    messages: [],
    thinkingLevel: "off",
  },
  streamFn: (() => {
    throw new Error("not used");
  }) as never,
  sessionId: "hygiene-check",
});

const before = agent.state.messages.length;
console.log(`初始 messages 长度 = ${before}`);

const replacement = [
  { role: "user", content: [{ type: "text", text: "原始问题" }] },
  { role: "assistant", content: [{ type: "text", text: "(本轮中止说明)" }] },
];

agent.state.messages = replacement as never;
const after = agent.state.messages;
console.log(`赋值后 messages 长度 = ${after.length}`);
console.log(`内容与预期一致 = ${JSON.stringify(after) === JSON.stringify(replacement)}`);

// 复制语义：改原数组不应影响内部状态
replacement.push({ role: "user", content: [{ type: "text", text: "事后追加" }] } as never);
console.log(`改动源数组后内部长度 = ${agent.state.messages.length}（若仍为 2，说明是复制）`);

// 读回来的对象是不是同一引用（对象字面量 getter 每次返回同一个数组）
const first = agent.state.messages;
const second = agent.state.messages;
console.log(`两次读取是同一引用 = ${first === second}`);

console.log(
  after.length === 2 && agent.state.messages.length === 2
    ? "结论：赋值机制有效 —— 会话卫生的失败不能归因于此"
    : "结论：赋值机制无效 —— 这就是会话卫生失败的原因",
);